A PEDO-ECOLOGICAL STUDY OF SOIL GENESIS IN THE TROPICS ... · of soil genesis in the tropics from sea level to eternal snow star mountains, central new guinea proefschrift ter verkrijging

A PEDO-ECOLOGICAL STUDYOF SOIL GENESIS IN THETROPICS FROM SEA LEVEL

TO ETERNAL SNOWSTAR MOUNTAINS, CENTRAL NEW GUINEA

JJ.REIJNDERS

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A PEDO-ECOLOGICAL STUDY OF SOIL GENESISIN THE TROPICS FROM

SEA LEVEL TO ETERNAL SNOW

2523

A PEDO-ECOLOGICAL STUDYOF SOIL GENESIS IN THETROPICS FROM SEA LEVEL

TO ETERNAL SNOW

STAR MOUNTAINS, CENTRAL NEW GUINEA

PROEFSCHRIFT

TER VERKRIJGING VAN DE GRAAD VAN DOCTOR INDE WISKUNDE EN NATUURWETENSCHAPPEN AANDE RIJKSUNIVERSITEIT TE UTRECHT OP GEZAG VANDE RECTOR MAGNIFICUS PROF. MR. L. J. HIJMANS VANDEN BERGH, VOLGENS BESLUIT VAN DE SENAAT DERUNIVERSITEIT IN HET OPENBAAR TE VERDEDIGENOP MAANDAG 12 OKTOBER 1964, DES NAMIDDAGS

VIER UUR PRECIES

DOOR

JOHAN JACOB REIJNDERSGEBOREN 2 MAART IQ2Ó TE OOSTBURG ( Z L )

LEIDENE. J. BRILL

1964

PROMOTOR:

PROF. DR. IR. F. A. VAN BAREN

Dit proefschrift verschijnt in NOVA GUINEA, Geology, Number 6, 1964

LUCTOR ET EMERGO

ERRATA

A PEDO-ECOLOGICAL STUDY OF SOIL GENESIS IN THE TROPICSFROM SEA LEVEL TO ETERNAL SNOW.

J. J. REIJNDERS. 1964.

page 18, line 9 from bottom:read: rivers instead of: ivers

page 40, line 16 from bottom:read: LOVERING instead of: LOVERINK

page 53, line 13 from top:read: BELLIS instead of: BELIUS

page 60, read: Mabilabol instead of: Mabolabolpage 63, line 15 from top: delete;

add: originate from igneous complexes in Eastern New Guinea,page 130, line 19 from top:

read: limestone instead of: limesonepage 136, table VIII :

read: A1 instead of: A2

page 137, lines 2 and 9 from top:read: Ax instead of: A2

page 140, line. 16 from bottom:read: communication instead of: comminucation

'I

Stelling VII, lees:

De verklaringen voor het voorkomen van de kleimineralen in de terrasgrondenvan het Sterrengebergte gegeven door VERSTAPPEN zijn grotendeels onjuist.

Nova Guinea. Geology. Nr. 5. 1964. pp. 101.

CONTENTS

Chapter " page

I . I n t r o d u c t i o n . . . . . . . . . . . i

G e n e r a l . . . . . . . . . - I

S u m m a r y of c o n t e n t s . . . . . . . . - • I

I I . C l i m a t e 4

G e n e r a l . 4

E f f e c t i v e d r a i n a g e 8

P a l e o - c l i m a t e . . . - 9

I I I . G e o l o g y . . . . . . . . . . . . g

T h e a l l u v i a l p l a i n . . . . . . . . . . 1 0

T h e f o o t h i l l b e l t . . . 1 0

T h e m o u n t a i n a r e a . . . . . . . . . . n

T h e i n t r u s i v e r o c k s . . . . . . . . • 1 1

R e c e n t r i v e r d e p o s i t s . . . . . . . . . 1 1

I V . V e g e t a t i o n 1 1

V . M i s c e l l a n e o u s . . - 1 4

M a n . . . . . . . . . . . . 1 4

F a u n a 1 5

V I . A e r i a l P h o t o I n t e r p r e t a t i o n . - 1 5

I n t r o d u c t i o n . . . . . . . .• . • . 1 5

P h o t o g r a p h i c e l e m e n t s . . . . . . . . . 1 7

V I I . L a n d s c a p e a n a l y s i s . . ' . . . . . . . . 2 1

T h e S o u t h e r n l o w l a n d s a n d u p l a n d s . . . . •. . 2 1

T h e M u y u a n d M a n d o b o l a n d s c a p e . . . . . . . 2 1

T h e O k I w u r l a n d s c a p e 2 6

T h e D i g u l M t s . l a n d s c a p e 2 9

T h e S i b i l r e g i o n 3 2

T h e U p p e r D i g u l o r O k T s o p l a n d s c a p e . . . . . 3 4

T h e O k B o n l a n d s c a p e . . . . . . . . . 3 7

T h e J u l i a n a M t s . l a n d s c a p e 30,

VIII CONTENTS

V I I I . W e a t h e r i n g a n d s o i l f o r m a t i o n 4 0

I n t r o d u c t i o n . . . . . . . . . . . 4 0

O r g a n i c m a t t e r . . . . . . . . . . 4 0

C l a y t r a n s p o r t . . . . . . . . . . 4 4

D e s t r u c t i o n o f c l a y m i n e r a l s . . . . . . . . 4 6

• L e a c h i n g a n d m o b i l i t y o f s i l i c i u m , a l u m i n i u m a n d i r o n . . . 4 6

T i t a n i u m 5 0

F o r m a t i o n o f c l a y m i n e r a l s 5 1

I X . S o i l t y p e s o f o t h e r M o u n t a i n r e g i o n s 5 2

X . M i n e r a l o g i c a l a n a l y s i s o f t h e s a n d f r a c t i o n 5 6

H e a v y m i n e r a l s 5 6

M i n e r a l o g i c a l a s s o c i a t i o n s 5 6

S o m e c o m p l e m e n t a r y n o t e s o n t h e t o t a l s a n d f r a c t i o n . . - 6 3

S o m e r e m a r k s o n t h e m a g n e t i c s a n d f r a c t i o n . . . . 6 5

X L D e s c r i p t i o n a n d A n a l y s e s o f t h e s o i l p r o f i l e . . . . . 6 6

T h e t o p o s e q u e n c e W e s t o f t h e D i g u l ( l o w l a n d i n c l u d e d ) . . 6 8

T h e p r o f i l e s E a s t o f t h e D i g u l . . . . . . . 0 , 8

X I I . D i s c u s s i o n o f t h e s o i l s . . . . . . . . • 1 1 8

T h e s o i l s o f t h e l o w l a n d . . . . . . . . 1 1 8

T h e s o i l s o f t h e l i m e s t o n e a r e a . . . . . . . 1 2 2

T h e s o i l s o f t h e K a t e m a r e a . . . . . . . . 1 2 9

T h e s o i l s o f t h e G r o t e B e e r M t s 1 3 2

T h e s o i l s o f t h e A n t a r e s m a s s i f . . . . . . . 1 3 3

M o u n t a i n s e d i m e n t s . . . . . . . . . 1 3 7

T h e s o i l s o f t h e S i b i l v a l l e y . . . . . . . 1 3 7

A l l u v i a l s o i l s o f t h e O k I w u r r e g i o n . . . . . 1 4 1

X I I I . T h e s o i l m a p . . . . . . . . . . . 1 4 4

X I V . C o n c l u s i o n s 1 4 g

S a m e n v a t t i n g j ^

L i t e r a t u r e . . . . . . . . . . . . 1 5 4

E n c l o s u r e : Soi l m a p , scale 1 : 2 5 0 0 0 0 . . a t t he e n d of t h e book

STELLINGEN

Om tot een juiste vergelijking tussen bodemtypen met een gelijke morfologischeopbouw uit verschillende delen der wereld te komen, is een analytisch onderzoekvolgens bepaalde standaardmethoden door één laboratorium noodzakelijk.

II

Bij de studie van de genese van bodemtypen dient men er rekening mee te houdendat vele bodems karakteristieken bezitten, die niet het gevolg zijn van recent bodem-vormende factoren, doch zijn toe te schrijven aan een voorgaande ontwikkeling.

III

Gedurende seizoensveranderingen kunnen humustypen worden gevormd, die hetdominerende genetische proces in de bodem tijdelijk een ander karakter geven.

IV

Een juiste interpretatie van de chemische cijfers van diverse horizonten van eenbepaald bodemprofiel vereist een onderzoek naar de onderlinge samenhang vande betrokken horizonten door middel van een analyse van de zware mineralen.

V

De toename van het titaangehalte in de kleifractie in de bodem van de bovensteten opzichte van dieper gelegen horizonten, staat in verhouding tot de mate vanverwering van de kleimineralen in deze horizonten.

VI

De verklaring gegeven door MOSES en MICHELL betreffende de „two-step origine"van de bauxietvoorkomens in Brits Guiana en Suriname blijkt niet volledig uithun gegevens.

Economic Geology. Vol. 58. Nr. 2. 1963. pp. 250.

VII

De verklaringen voor het voorkomen van kleimineralen in de terrasgronden vanhet Sterrengebergte gegeven door VERSTAPPEN is grotendeels onjuist.

Nova Guinea. Geology. Nr. 5. 1964. pp. 101.

VIII

De rendzina's in het bergland in de tropen, gelegen onder de boomgrens, zijn over-wegend een gevolg van antropogene invloeden.

IX

De termen „ultimate stages of weathering" en „final products of weathering"die BAKKER gebruikt bij de correlatie tussen de voorkomende kleimineralen ingronden in bepaalde gebieden op aarde en de daar heersende klimaattypen haddenbeter vervangen kunnen worden door „dominant products of weathering".

Zeitschrift für Geomorphologie. Suppl. Band I. i960. pp. 69.

XDe verschuiving van de kleurintensiteit in een brown podzolic soil die optreedt bijde beoordeling tussen de kleuren van de A2-horizont in vochtige en in drogetoestand, is groter dan of gelijk aan die van de Ai-horizont, doch altijd groterdan die van dieper gelegen horizonten.

XI

Voor de beoordeling van de bodemvruchtbaarheid van een ladanggebied onderbloekar dient men de rotatieperiode in dat gebied te kennen.

XII

De studie van de morfologie van het landschap vormt, een onmisbare basis bij debodemkunde.

XIII

Het gebruik van ansjovispastei bij het tourneren in de tropen verdient sterkeaanbeveling.

H. J. Kesler. H. P. B. Mindiptana. 1959.

12 oktober 1964 J. J. REIJNDERS

VOORWOORD

De kennis, die de achtergrond van dit proefschrift vormt, werd vergaard insamenwerking met en door onderricht van anderen onder zich steeds wijzigendeomstandigheden. Bij het beëindigen van dit proefschrift wil ik dan ook gaarne allenmijn dank betuigen.

U, Hoogleraren, Oud-Hoogleraren en Docenten van de Landbouwhogeschool teWageningen hebt mij landbouwkundige en bodemkundige kennis bijgebracht. Debrede opzet, waarop de studie gebaseerd is, heb ik later onder zeer primitieveomstandigheden bijzonder leren waarderen. U hebt de grondslag voor dit proef-schrift gelegd. Ik ben U hiervoor veel dank verschuldigd.

Hooggeleerde Van Baren, Hooggeachte Promotor, ik acht het een bijzonder voor-recht onder Uw leiding te mogen werken. Uw stimulerende invloed, alsmede Uwgrote belangstelling zijn van grote betekenis geweest bij het tot stand komen vandit proefschrift. In het Sterrengebergte reeds liet U mij het terreinwerk naar eigeninzicht uitvoeren; in Utrecht liet U de analyse methoden en de indeling van mijndissertatie geheel aan mij over. De discussies met U heb ik bijzonder gewaardeerdte meer daar wij onze meningen tegen over elkaar stelden en de oplossingen uitde „chocs des opinions" geboren werden. Ik ben U zeer erkentelijk voor hetvertrouwen dat U in mij stelde.

Hooggeleerde Doeglas, Hooggeleerde Edelman (f) en Hooggeleerde Schuffelen,Uw colleges en practica en het werken in Uw laboratoria hebben mijn belang-stelling voor de bodem richting gegeven en mij in staat gesteld de biologische, zowelals de physische en chemische problemen waarvoor ik geplaatst werd, te lerenbegrijpen of te onderkennen.

Voor de vele prettige contacten en hulp ondervonden bij de Dienst van Econo-mische zaken en in het bijzonder bij het Agrarisch Proefstation, gedurendede jaren dat ik op Nieuw Guinea werkte, wil ik allen, doch in het bijzonder U,Hoogedelgestrenge Van Loenen, hartelijk danken. De jaren die ik op NieuwGuinea heb doorgebracht, vaak werkende onder de meest primitieve omstandig-heden, zijn van grote waarde voor mijn verdere leven.

U, Hooggeleerde Brongersma, en alle leden van de Sterrengebergte Expeditiedank ik voor de kameraadschap en steun gedurende de zes maanden in het hoog-gebergte ondervonden.

Het veldwerk op Nieuw Guinea ware welhaast onmogelijk geweest zonder dehulp van vele Papoea's die mij op mijn tournée's begeleiden. De wijze waarop zijmijn pad baanden door de onvergetelijke schone woestheid van hun land zal iknooit vergeten.

X VOORWOORD

U, Hoogleraren en Stafleden van het Geologisch Instituut ben ik erkentelijkvoor de wijze waarop U mij na mijn benoeming in Utrecht bent tegemoet getreden.

U, Hooggeleerde Dijkstra en Hooggeleerde Smittenberg dank ik voor de grotegastvrijheid die ik steeds in Uw laboratorium heb ondervonden. Nooit deed iktevergeefs een beroep op U, en ik kreeg steeds de assistentie en technische hulpdie ik behoefde.

Dear Mr. Cady and Mr. Vanden Heuvel, I am very grateful to you for theopportunity given, during my stay at Beltsville (Maryland), to study the X-rayfluorescence analysis, and no less for the personal contact outside the purelyscientific field.

U, Zeergeleerde Tolk, Zeergeleerde De Widt en Geleerde Bent, wil ik mijn dankbetuigen voor de opbouwende gesprekken en de sfeer, waarin wij in de problematiekvan de röntgenfluorescentie mochten samenwerken.

Zeergeleerde Van Moort, U dank ik voor het determineren van mij onbekendemineralen en het vaak eentonige opnemen van de diffractie beelden van een aantalkleimineralen.

Waarde Mouthaan, grote dank ben ik je verschuldigd voor de nooit aflatendehulp bij het samenstellen van dit proefschrift. Wij hebben elkaar leren kennen bijtemperaturen waarin werken bijna onmogelijk was, bij angstaanjagende gadzi-feesten in de jungle, of terwijl wij tot onze nek in het moeras ploeterden. Steedsging het voorwaarts en altijd was je een prettige collega.

Mevrouw Van Putten-Van Baren, U wil ik bijzonder danken voor de buiten-gewone accurate en vlotte wijze waarop U het manuscript voor mij hebt getypt.Vaak heb ik een beroep op U moeten doen, doch nimmer tevergeefs.

U, Waarde Van der Kruk, treft mijn erkentelijkheid voor het corrigeren van deengelse tekst.

De Topografische Dienst te Delft vervaardigde de bodemkaart. De StichtingFilm en Wetenschap UNFI maakte een aantal afdrukken van diffractie beeldenvan kleimineralen. De tekenkamer van het Geologisch Instituut maakte een aantaltekeningen. Allen mijn dank hiervoor.

De Stichting Sterrengebergte Expeditie heeft door financiële steun de publikatievan dit onderzoek mogelijk gemaakt. Het Bestuur van de Stichting ben ik grotedank verschuldigd.

A PEDO-ECOLOGICAL STUDY OF SOIL GENESISIN THE TROPICS FROM SEA LEVEL TO ETERNAL SNOW

STAR MOUNTAINS, CENTRAL NEW GUINEA

CHAPTER I

INTRODUCTION

GeneralThe Star Mountains Expedition, organized by the "Koninklijk Nederlands

Aardrijkskundig Genootschap", had to explore the Central part of the mountainrange of New Guinea during the period from April up to and including September1959. The object was to study this region — still untouched by modern civilizationand not yet entered by former expeditions — scientifically as intensively as possible(Fig. 1 and Fig. 2).

The field party was composed of a large group of scientists dealing with differentsubjects, namely various aspects of anthropology, zoology, botany, geology andgeodesy. The author was responsable for the pedological investigations. Ourstudy was concerned with the genesis of the high altitude soils in the tropics onvarious parent materials and to compile a provisional soil map. Moreover, a generalstock-taking was made of the agricultural methods and products of the indigenouspopulation. The outcome of this latter study has been published (REYNDERS, 1962).

Summary of contentsThe results of the pedological investigations are presented in this volume along

the following lines.The physical factors of importance for soil formation are dealt with in chapters

II on Climate, III on Geology, IV on Vegetation and V on Miscellaneous. Thechapters VI and VII on Aerial Photo Interpretation and the resulting LandscapeAnalysis give a fairly detailed information on the topography. Combiningthe soil forming factors soil landscape units have been conceived, which form thebasis for the soil map.

SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

Fig. i. Map of West Irian or Western New Guinea.

In chapter VIII on Weathering and Soil formation special consideration is givento the importance of organic matter, the transport of clay and clay formation anddestruction, and to the mobility of the most important elements, in order to under-stand the genetic processes. In chapter IX a review of soil types of other moun-tainous regions is given.

The analysis of the sand fraction is discussed in chapter X. Chapters XI andXII jointly discuss the soils encountered, the analytical data and the morphologicalobservations so as to get a deeper insight into the genetic characteristics as a basisfor their classification.

A special chapter (XIII) is devoted to the soil map, constructed on the basisof the landscape analysis and the soil classification data. In the final chapter generalconclusions are presented.

The matter was studied in the field as well as in the laboratory. It wasimpossible to analyse the more than 400 soil and rock samples collected duringthe expedition period, divided over 70 odd profiles. To these a number of topsoilsamples were added. A closer study leads to rejection of a number of profiles.

The total area surveyed amounts 9 500 km2.

Fig. 2. Topographical map of the Star Mountains area and the southern lowland.

4 SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

CHAPTER II

CLIMATE

General

In the territory concerned there are very great differences in height withinshort distances, and climate as well as vegetation are strongly related to thetopography. Of this a brief discussion is given.

10; _

AVERAGE ANNUAL RAINFALLin mm

I I I I I 1000 - 2 0 0 0II I I II 2 0 0 0 - 3 0 0 0

II I I I II 3 0 0 0 - 4 0 0 0

I l l l l l l l l 4000 - 5000minimi 5000 - 6000

Over 6000

STATIONS

B

S

T

N

M

TM

Saliern

Sibil

TelefominNinati

Mindiptana

Tanah Merah

Fig. 3. Average annual rainfall distribution of Central New Guinea.

CLIMATE 5

From the central part of New Guinea only a few meteorological data are known.For this reason no more than a rough description of the climate can be given whilelocal observations, however, will contribute to the understanding of some edapho-logical phenomena in more detail.

In the large low-lying plain of Southern New Guinea the precipitation graduallyincreases in a northern direction from the yearly average of 1524 mm nearMerauke to 6272 mm near Ninati. So the rainfall in the Muyu and Mandobo isextremely high and no month has a mean value below 200 mm; it is usually evenmore than 300 mm. In the northern direction over the Central Divide this amountdecreases to about 3000 mm in the large Lake Plain (Fig. 3).

Although the mean monthly precipitation is very high, occasionally dry interludesoccur, e.g. in five months in 1941 at Tanah Merah — June/October — the totalrainfall was 132 mm.

The following table gives a review of the montly distribution of rainfall of thenearest stations to the Star Mountains. (Reports Meteorological and GeophysicalBureau).

TABLE I

Mean monthly precipitation in mm.

T F M A M T J A S O N D Y e a rTanah • Merah21 years

Mindiptana8 years

Ninati9 years

Sibil 1958

1959i9601961

4 years

Telefomin10 years

Baliem3 years

369

317

534

325279300

467

343253

286

401

371

392

354352486291

371

304

382

442

299

437

434342277355

352

277

166

440

285

565

307422

330411

392

294

213

394

278

633

329280

219

293

280

297

in

303

367

545

159308288325

270

268

121

291

362

616

352344330398

356268

105

308

442

580

346161

359438

324

314

187

373

374

683

307382

319153

290

329

195

334

256

391

231

131178275

204

265

212

365

239

426

322

131

235159

212

237

163

404

354

474

475274295272

329212

92

4425

3942

6272

39413406

3616

3839

3700

3318

2233

In other valleys in mountainous regions of New Guinea, like the Baliem valley,the Wissel Lakes and the Kebar plain, where rainfall is registered the precipitationin these valleys is less than in the surrounding high land. Because of this "lens-effect" one may assume that the rainfall in the Star Mountains is yearly about4000 mm or perhaps a little more.

In the Sibil valley, elevation 1260 m, the average number of rainy days per monthis 23. The mean daily duration of sunshine in hours was 3.7 during 1958. Thevariation between the monthly values was very small. This already small numberof hours of sunshine will be less in other valleys in the Star Mountains as these

Ö SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

are mostly steeper sloped and flanked by higher mountains. The daily fluctuationof the temperature at Tanah Merah shows little variation during the year. Themean yearly values are at 06.30, 12.30 and 18.30 hours, 23°o, 29°4 and 25°8 Celsiusrespectively. In the Sibil valley these values have not been registered. In the tropicsmean temperatures of the relative moisty air decreasing with 0.4-0.70 C per 100 melevation are as follows (see MOHR and VAN BAREN, 1959) :

o- 200 m 25-270 C,200-1000 m 18-240 C,

iooo-i8oom 13-180 C,2000-3000 m about io° C (mossy forest; see LANE-POOL

in RICHARDS, 1952).These figures are also correct for the low land of New Guinea and agree with

the data obtained in higher belts.A rough estimation based on a few determinations in the Sibil valley is as follows :

clear weather: daily 200 to 250 C;nightly io° to 150 C;

cloudy weather: daily 180 to 200 C;nightly 150 to i8ü C.

One may assume that the average yearly temperature at a certain elevation(h in hectometers) may be indicated by the formula t = 27°5 C — 0.6 h. Underthese topographical conditions, however, there can locally be great variations intemperature.

On several trips through the valley in the mountains the following types ofweather were observed:

a. Bright weather during the whole day. Only in the early morning there is mistin the lower parts of the valleys, which is dissolved by the sun between sevenand eight o'clock. This type of weather does not often occur.

b. The day begins as mentioned under a, but half an hour after the lift of the fogclouds are formed along the slopes of the mountains.Because of the warming of the surface of the earth, air streams rise and cloudsare formed if a condensation level is reached. In the tropics the fluctuationof temperature and humidity does not greatly vary in one place. The condensationlevel will therefore be fairly constant. However, upstream in the valley thetemperature will be lower and, owing to a lower vapour capacity of the air,the condensation level will be reached sooner. The elevation of the bottom of agreat number of valleys in the Star Mountains is about 1000 m. The cloudsare formed on the slopes at about 1700 m. At higher sites, for instance in theUpper Ok Tsop valley, at an elevation of 1800 m, the condensation level is foundat about 2100 m.

c. The valley is covered by clouds wrapping the mountain chains and peaks. Onlylower down small clouds and fog will lift in the morning.

CLIMATE 7

d. The whole valley is wrapped in clouds as under c, but during the whole day thereis a thick fog. It is the most depressing weather one can imagine, during whichit is impossible to leave the bivouac.

The types of weather described under b and c are very frequent. The zone ofcloud formation on the slopes is highly influencing the vegetation as in thiszone the rainfall is high and the humidity almost always ioo %. This is the reasonwhy in the Star Mountains the mossy forest belt is found at these altitudes. Thetemperature is cool.

Higher up, above the tree limit — on the Antares Massif at 3000 m — thetemperature will, at an estimate, be about 50 to 120 C. Occasionally, in brightsunshine, it is much warmer. On the Juliana Peak the tree limit is found at about3700 m. Eternal snow was observed at an altitude of about 4500 in. After hailand snow storms near the top, upwards of 4000 m the mountain was covered bysnow. (This was observed from the top of the Antares).

In several places it was noticed that at the end of the afternoon airstreams andlong channels of clouds penetrated the valleys through small -gorges. This willaccount for the light variation of mossy forest found at lower altitudes in thesegorges. The mossy forest was also met with south of the Ok Iwur at an altitudeof about 900 m. The high rainfall and the high humidity in this region favoursthe conditions for this type of vegetation.

The weather types mentioned are related to the cloud formation, temperatureand sunshine in the lower parts of the air. The higher types of clouds were nottaken into account. Above the mountains often very high cumuli are formed bythe lift of air streams. This can very often be perceived from planes flying overthe Central Range. Apart from passing weather fronts in the higher air strata theStar Mountains are frequently covered by these cumuli.

Although the above are but very superficial data on the metereological conditionsof the Star Mountains an effort was made to come to a rough classification of theclimate according to KOPPEN.

Af From sea level to 1000 m, in the northern and southern lowland. Atropical rainforest climate with a high precipitation during the whole year.

CGf 1000 m to 1700 m. A mountain climate, rich in rain and with a temperaturecooler than the Af-type;

CGfn 1700 m to 3000 m. A weather type like CGf, but still cooler and with muchfog;

EFH 3000 m to 4000 m. A high mountain steppe climate;ETH 4000 m and higher. A high mountain snow climate.

All types have a mean yearly temperature with very small fluctuations. Theclassification is very approximate and it does not claim that the units heredistinguished can be sketched along contourlines.

As already remarked by BOERMAN (1949), New Guinea has all types ofmonsoon climates from Af to Aw. Parts of the Central Mountain Range, including


the Star Mountains, form islands of C-climates, and in these very small points ofE-climates are found.

Effective drainage.

The leaching in the soil is a function of the precipitation and the evapotranspira-tion, being the water needed for evaporation and transpiration of a vegetation-covered surface. The difference between these two values is the amount of wateravailable for drainage. In the tropical regions it may occur that an annual rainfallof e.g. iooo mm is equal to the evapotranspiration. According to the values givenby PAPADAKIS (1961) for rain recording stations of Eastern New Guinea (seealso: Resources of Territory of Papua and New Guinea, 1951), the annual evapo-transpiration is between 800 mm and 1000 mm. Comparable data of the mountain-ous regions are not given, but according to equal climatological conditions and tothe figures found in Scandinavia during the summer months, the evapotranspirationwas estimated at 40O mm to 500 mm in the mountains of central New Guinea.Using the calculation formula given by TUKC (1954, 1955)

PE =

p2O.9 + L(t)2

in which P is precipitation in mm and t is temperature in °C and L = 300 +25t + 0.05t3 and E the evaporation in mm/year, the values for the region con-cerned will be:

Locality Temperature Precipitation EvaporationNinati 27°5 C 6272 mm I939 m m

Sibil 190 C 3700 mm 1075 mm

In the calculation used it is assumed that: the annual evaporation from lakes isof the order indicated by the formula, it will be possible within a half or a thirdof the total time of the radiation, and shows a parallel with variations in tempe-rature. The last two considerations will not tally with the facts in the center ofNew Guinea and consequently the figure calculated will be too high. The extremelyhigh rainfall throughout the year will greatly reduce the evaporation. Moreover,in the field it was observed that many rainshowers fall just after midday, and sono evaporation could take place.

The water surplus, which is the difference between precipitation and evapo-transpiration, and which is the total amount of the water that runs off the surfaceand the water that percolates through the soil, in the Star Mountains and thesouthern lowlands, will be of the following order (according to the values given byPAPADAKIS) :

Tanah Merah (elevation 20 m): 4400-1000 = 3400 mm;Ninati (elevation 120 m) : 6300-1000 = 5300 mm;Sibil (elevation 1260 m) : 2700- 500 = 3200 mm.

CLIMATE 9

In conclusion it may be said that, besides localities of extremely high rainfall(e.g. Ninati), the effective drainage in the greater part of the area, lowland andthe mountains to a height of 1700 m, will be of the order of about 3000 mm peryear. This value is extremely high and though on slopes the majority of the waterwill run over the surface, still a large quantity of water will percolate the soil andcause a leaching process. It will further be clear that when a leaching limit has beenreached excess of precipitation will have no further influence. Higher up into themountains in the moss-forest belt the influence of the precipitation on the soil willbe greater. The evaporation will be strongly reduced.

Paleo-climate.

Of the paleo-climates of New Guinea not much is known. DICKERSON (1925)reports that since the Tertiary until recent times little change has occurred in thetropical climate of these regions south of the Philippines.

Admittedly the influence of the Pleistocene glaciation has been felt in this region(see also KOPPEN and WEGENER, 1924).

Locally (e.g. in Australia) the snow and ice limits lay 900 m to 1500 m lowerthan at the present time. In these periods the trade wind belt was narrower thanit is nowadays. Also the lower level of the sea (150 m) may have been of influenceon the climate. A relatively drier climate owing to a smaller surface of the seabetween New Guinea and the Australian continent may have existed.

CHAPTER III

GEOLOGY

The geological investigations of the Star Mountains area as well as those of theadjoining regions to the north and to the south have been reported by BÄR et al.(1961). Some general remarks are given by VISSER et al. (1962). As the rockforms the parent material of the soils, (with the other factors of soil formationacting on it), a short review is given of the lithology of the formations croppingout. The distribution of the rock over the area is not the only matter of importance,there is also the lithological succession. In some cases soils will not be derived fromthe underlying rock as it is found today, but are the result of the weathering ofthe originally overlying, different kind of rock.

Morphologically the mapped area can be distinguished into three large units(see also the description of the various landscapes, chapter VII).

1. An alluvial plain in the south, stretching from the shore up to the Muyu-Mandobo region over a distance of about 400 km. In this plain many relics ofterraces divided by wide marshy river channels are found. This very extensiveand flat plain changes irregularly into:

2. A foothill belt that is situated between an elevation of about 50 m and 500 m.This zone is generally sharply bounded from the mountainous area by greatdifferences in height caused by faults or flexure zones.

IO SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

3. The mountain area is very rugged. Many deeply incised river valleys alternatewith high and sharp mountain ridges. This region elevates from about 1000 mup to 5000 m, including the Juliana peak.

As far as it will be of importance for the pedological data these three regionsare geologically divided into sedimentary rocks from the Mesozoic, Tertiary andQuarternary periods.

In the Tertiary period three cycli of rock formation can be distinguished, namely:1. The New Guinea limestone group (Oligo-Miocene), and the overlying terrige-

nous deposits of the Iwur formation (Miocene).2. The Kau limestone formation (Miocene-Plio-Pleistocene), also covered by ter-

rigenous sediments (Buru formation, early Plio-Pleistocene).3. The Birim formation (Plio-Pleistocene).

The three terrigenous deposits (Iwur, Buru and Birim) are the result oferosional forces caused by the uplift of the Central Range in the periods given.

The rocks will be discussed from the south to the north, that is from theyounger to the older sediments.

The alluvial plain.

The alluvial plain consists mainly of Quarternary fan sediments, which arefinely clastic in the greater part of southern New Guinea, and which are moreor less conglomeratic near the foothill belt.

The foothill belt.

To the north, the Quarternary deposits wedge out against the Birim formation.The latter forms the hilly and mostly intersected parts of the Muyu region anda small ribbon in the northern part of the Mandobo district. In general the stratigra-phy of the Birim formation indicates a decrease of grain size in upward direction.The lower parts consist of coarse conglomerates in which all components of therocks of the uplifting Central Mountain Range are present. In the higher layerssiltstones and sandy claystones occur, while in the uppermost beds exclusively clay-stones are found. Volcanic activity during the process of sedimentation is clearlyestablished. Throughout the whole formation lignite bands are encountered. Thesedimentation took place in marine environment. The Birim formation lies on theBuru formation which outcrops north of the former.

The Buru formation consists of hard and soft sandy marls, shales, siltstonesand calcareous sandstone. It is not found in the eastern part of the area (Muyudistrict). It has a gradual transition to the underlying Kau limestones. The volcanicinfluence is less than in the Birim formation.

The Kau limestone is composed of limestone in which sand is increasing inupward direction and in the transition in the Buru formation. The northernedge of these limestones forms the escarpment along the East Digul and east of

GEOLOGY I I

the settlement Katem. The Iwur formation crops out mainly in the region ofKatem (Ok Iwur, Ok Irin, Ok Kair)*. It is composed of blue-gray siltstones,shales and sandy, marly limestone. This formation was also found on the northernslopes of the Juliana Mountains and is perhaps older, as indicated by the com-position of its micro-fauna. They are marine deposits, of which the upper bedshave a coarser texture than the lower ones.

The mountain area.

The greater part of the mountainous region consists of the New Guinea limestoneformation, which forms extensive outcrops in the Central Mountain Rangeof New Guinea. The formation, about 800 m to iooo m thick, is built up of thin,dark, gray, marly limestone beds, lying on more or less coral limestone, whichrests upon the lower parts of dolomitic limestones. The uppermost part is gradinginto the Iwur sediments.

The older, Mesozoic, deposits of importance in this investigation, are representedby the Kembelangan formation. This group is mainly composed of glauconiticsandstones, slates and shales. They are found in the Upper Ok Tsop region (OkMimka) and at the western part of the Antares area (e.g. Grote Beer Mts.).Locally siltstones occur which are very strongly eroded.

The intrusive rocks.

The most important intrusion in the Star Mountains is the Antares Massif,which consists of granodiorite. The intrusion is supposed to be of Neogene Age.The small volcanoes, lying in the foothill belt (e.g. Koreon, Arem, Isil) arecomposed of andesites and intruded during the late Plio-Pleistocene.

Recent river deposits.

The most recent deposits along the rivers, and also on recent accumulation ter-races, in the foothill zone as well as in the lowland, consist of sandy to clayeysediments, strongly influenced by the erosion products derived from the intrusions.

CHAPTER IV

VEGETATION

The various vegetation belts, as far as they are known in the literature and asthey are found in the terrain, are discussed briefly, and in addition somespecific species which are typical of certain soil factors or which correspond withcertain soil types, are recorded.

It is obvious that in the area studied an altitudinal zonality will be found. Adescription of the zoning of the vegetation on the high ranges of New Guinea isgiven by RICHARDS (1952), drawing on the publications of GIBB (1917), LAM(1945), VAN STEENIS (1937) and LANE-POOL (1925). The mountains of New

* Ok means : river or water.


Guinea are the most favourable region in the eastern tropics for studying thiszoning of vegetation. They reach from sea level up to the eternal snow; they arenon-volcanic, so that the development of the vegetation is not disturbed by erup-tions; and because of the very thin population they are not affected by man.

LANE-POOL distinguishes the following zones, which are similar to those of theother authors mentioned:

1. Lowland forest: 0-300 m. This is the characteristic tropical rain forest.2. Foothill forest: 300-1650 m. Generally the trees are not as high as in the

lowland rain forest. Characteristic for this zone is the oak (Quercus sp.); theAlbizzia also occurs.

3. Mid-mountain forest: 1650-2250 m. The forest consists of an oak-coniferassociation. Quercus sp. and Araucaria cunninghamii grow in this zone. Otherconifers are represented by species of Podocarpus and Phyllocladus.

4. Mossy forest: 2250-3000 m. This is the mountain rain forest, in which thetrunks and branches of the trees are covered and papered with a thick layer ofmosses. The Podocarpus sp. are characteristic; bamboos are present. The averagetemperature in this zone is about io° C, but the most dominant climatologicalfactor is the continual dampness and persistent mist.

5. High mountain forest: 3000-3600 m. This type of forest is taller than the mossyforest. The majority of the trees consists of conifers. This forest is rarely foundas a continuous belt, but it is sometimes interrupted by grassland or shrubs.It lies above the mist belt.

6. Alpine grassland: above 3600 m. In this zone the vegetation is formed bygrassland, bogs and shrub on rocky patches.

The height of these zonal sections changes from place to place and it is impossibleto draw a sharp boundary between two of them. The exposure of the mountainsto the prevailing winds or sunshine, or the difference in precipitation between twoneighbouring regions can have an important effect. On small isolated peaks andridges the altitude of the vegetation belts is lower than on extensive mountainranges; they also tend to be less elevated on coastal mountains than on thosefarther from the sea. The last phenomenon is the so-called "Massenerhebung"effect (RICHARDS). This effect will be of less importance in the Star Mountainsarea. The results of the geographical position and possibly the kind of parentmaterial will cause the main differences.

The Upland forest zone or the foothill forest belt is very difficult to determineon the fringe of the Star Mountains. This zone does either not exist or it is verynarrow due to the very steep mountain slopes on the western side of the 2000 m-3000 m Digul Mountain range; on the other hand, the region of the rivers OkIwur and Ok Irin, east of Katem, is partly fenced by higher mountains or it issurrounded by ridges, so that the exposure, or the coulisse effect, plays an im-portant part. VAN STEENIS (quoted by RICHARDS) divides the tropical rain forestinto the lowland sub-zone 0-500 m and the colline sub-zone 500-1000 m. Perhaps

VEGETATION 13

one had better group the vegetation zone in the Star Mountains region accordingto this sub-classification, though a real representation of the colline zone does notexist.

The zones given below are based on the personal communication of KALKMAN

and on the author's observations.In the Star Mountains Area and in the Mandobo and Muyu districts to the south

the following zones can be distinguished:1. Lowland forest: 0-500 m. Besides this tropical rain forest which, in general,

is not so very rich in species as might be expected, regions with swamps occur.In these swamps sago (Metroxylon sp.) is characteristic. Swamps withfluctuating watertables may vary between forest swamps, and swamps witha low shrub or grass vegetation.

2. Upland forest: 500-1000 m.3. Mid-mountain forest: 1000-1700 m.

This sub-division into Upland and Mid-mountain forest is less satisfactory.Agathis was found in several places between 200 and 900 m, but always on acid,quartz containing, podzolized soils. Metroxylon penetrates into the Digul valleyto a level of 700 m, and Artocarpus altilis occurs up to 400 m. Albizzia sp. weremet with in both zones, but Quercus sp. only in the Mid-mountain forest zone(with acorns with a diameter of about 5 cm). The Araucaria occurs only in thebelt between iooo en 1700 m on parts of terraces which are not waterlogged.Climbing bamboo (ChLoothamnus) is also present in the Mid-mountain forestzone, but it has better (thicker) development in the mossy forest zone.In the Upper Ok Tsop valley the Mid-mountain forest zone will be broader,as the lower limit of the mossy forest is found at about 2100-2200 m elevation.

4. Mossy forest: 1700-3000 m. This forest type was encountered on the slopesof the Antares Massif at the height given. Although the observations were madeonly on mountain chains and in the neighbourhood, two or three sub-zonesshould be recorded, viz. the zone at about 1700-2000 m, in which the trees aremuch taller than those at higher altitude, the zone between about 2000-2500 m,in which the climbing bamboo is very abundant, and the zone above 2500 m,where the trees are very crooked, gnarled and not so high. It should beremarked here, however, that in many other places in the Star Mountains (e.g.on the high and flat top of the Grote Beer Mountains (1700 m), in equal flatsites on the ridges of the Orion Mountains (2000 m) and on the Mimi-Sini Mountain-chain (3000 m)) the same less developed vegetation was observed.In these spots soils with highly gleyed profiles are found, which probablycause the poor growth of the trees.The soil in the mossy forest is covered with a thick — sometimes several meters —layer of peat, on which mosses and several kinds of orchids grow. Asalready mentioned the mossy forest on the slopes of the Juliana Mountains inthe Upper Ok Tsop valley lies at a higher altitude; south of the Star Mountains,near Almun-Wending, about 12 km east of Katem, the mossy forest is found


at a height of about 800-900 m. This is possibly due to the relatively highrainfall south of the Star Mountains (compare the precipitation of Ninati intable I). In the mossy forest of the Antares Massif grow the conifèresPodocarpus sp., Phyllocladus hypophyllus, several Myrtaceae, Mearnsia sp.and Rhododendron species as undergrowth.

5. Alpine meadow: 3000-4000 m. On the Antares at a height of 3000-3500 ma kind of alpine grassland occurs, in which many orchids, Ranunculus sp.,Euphrasia, Gentiana lorentzii were found between grasses and heathy vegeta-tion, among which some low trees, the Papuacedrus with candelabrum shapedcrowns were observed.On the Juliana Peak, this belt lies between 3700 and 4000 m. On the EastPeak of the Antares no vegetation is seen (VERSTAPPEN, i960).

6. The zone of ice and snow without vegetation was found on the Juliana Peakabove 4000 m.KALKMAN (1963) published in a recent paper a rather complete survey of

the species of vegetation sampled in the Star Mountains region.

The absence of the high mountain forest, as mentioned by LANE-POOL, isinteresting. This can perhaps be explained by the snowline, which during thepleistocene period, was about iooo m lower than at present (see Paleo-climate,page 9, VERSTAPPEN, i960 and VISSER et al. 1962).

CHAPTER V

MISCELLANEOUS

In this chapter the influence of man and some animals on the soil formationwill be dealt with.

Man.

Man as an anthropogenic factor can greatly influence soil formation. It wasthought to be of interest to give attention to this factor in ,this very primitive andisolated, and very thinly populated area. In developed regions man has devisedmany agrotechnical methods to preserve the fertility of the arable land or toimprove it, and as such fulfils a soilpreserving task on a long term basis.

In very primitive areas, such as the Star Mountains, however, the exploitationof land is first of all directed to the production of food for the next day or, at theutmost, for the very near future. The local vegetation is destroyed partly orcompletely if a plot is used for gardening. During the growth period of the cropthe soil is completely exhausted, and when harvesting is no more possible thespot is abandoned and the process is repeated at another place, often bordering onthe first site (REYNDERS, 1962). Most gardens are laid out on the slopes so thatthe erosion in the abandoned field will be severe. Also paths initiate erosion. Oftenthey form gullies, by which the unity of the rootmat is broken and land slides,

MISCELLANEOUS 15

carrying parts of the forest away, are the result. Thus the extent of eroded soilsis gradually enlarged.

It may, in general, be said that the majority of the shallow soils and lithosolsis due to the destructive interference of man. It is finally to be expected that theintroduction of the iron axe will result in a more complete cutting of stems oftrees, and consequently more erosion and more shallow soils.

In the more elevated regions fire does not play a part. The litter and under-growth are too moisty so that the fire cannot spread. However, in the lowland itcauses large deforestation and deterioration, the more so as fields and hills are seton fire by the population so as to be able to hunt small animals (e.g. Sentanilake district and Merauke area).

Fauna.

Large animals play a very minor part in the soil formation of the StarMountains region. There are pigs as well as boars, but their effect on soil erosion,caused by routing, is very small.

Nearly always their activity is bound to gardens if any, and as such linked tothe enterprise of man.

Rats, snakes and other small animals are hardly of importance. The influenceof earthworms is less conspicuous than in temperate regions. The number of wormsis relatively high in young alluvial soils, which are found on small spots alongthe rivers (Ok Sibil, Ok Tsop), and which are not frequently inundated. Inone slab of earth about ten small individuals were found. In the older riveiterraces, however, the number is very small, e.g. one or two per square meter.Generally a very acid anaerobic soil is met with on these terraces. Also on soil?with a top layer of about ten centimeters of organic matter in the forests on slopesthe earthworms were scarce; under thick peaty layers, e.g. under the mossy forest,they were absent. However, above the moss forest belt on the top of the Antaresearthworms were found.

In shallow soils, very rich in organic matter, developed on limestone (blackrendzinas) the number was equal to that in the alluvial deposits.

These observations agree with the general rules (RUSSELL, 1950) that earth-worms are found in soils which are reasonably aerated and not in very wet soils,that they need a continous supply of calcium, and that the acidity should notdecrease below a pH of 4.5. Except for the cases mentioned above these conditionsdo not occur in the soils in the Star Mountains area.

CHAPTER VI

AERIAL PHOTO INTERPRETATION

Introduction.

The aerial photo interpretation of the Star Mountains Area has been based on thestudy of several aerial photo runs, being verticals with their high obliques. They

i6 SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

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were flown in east-west or reverse direction in 1948. The scale of the photographsis about 1 : 33 000, but great deviations occur, which were caused not only bydifferences in elevation of the terrain alone. The distances between the flyingcourses vary: between some runs the distance is about 50 km, others intersect eachother. The areas covered by vertical photographs are given in Fig. 4. The qualityof most of the obliques is far from favourable, owing to the climatological condi-tions during flight and other factors. Moreover, the terrain concerned is veryaccidented, so that when obliques are used, coulisse effects very often occur,[n spite of these imperfections, however, the study and the interpretation of thelandscape could be made with this photographic material.

The topographical and pedological elements analysed from these aerial photo-graphs are shown on the available sheets of the topographical map of NewGuinea 1 : 100 000 (Topografische Dienst, Delft) as the basis. Lacking sheetsor parts were constructed by means of Canadian grids from obliques, but withoutground controls. The sheets 18 Y, 19 Y and Z, 20 Y and Z, 21 Y, 22 Y and Z and23 Y and Z were available, while parts of 20 Y and Z and 21 Z were constructed.The area concerned, east of the Digul and between 50 15' and 50 30' SouthernLatitude, is therefore rather schematic.

AERIAL PHOTO INTERPRETATION 17

The procedure of the soil survey was as follows:Observations in the field were made, using topographical maps or terrainsketches of varying accuracy and in some places aerial photographs for orienta-tion. After the author's return to the Netherlands this could be followed by amore systematic stereoscopic analysis of the aerial photographs available at theTopographic Service.

The units distinguished on the map are largely based on photo interpretation,and partly on terrain study and laboratory analysis. In connection with the largesurface interpreted the survey in the terrain was relatively extensive, consequentlyextrapolation had to be applied. This procedure, a preliminary overall terrain studyand detailed investigations in some small areas, resulted in a small scale recon-naissance map.

Photographic elements.The stereo-images of aerial photographs gave surface pictures of the terrain,

resulting in certain patterns, elements and derived factors. However, the surfaceof the soil is, not always detectable, whereas a soil profile is never visible. As thesoil is the ultimate object of our interest the relation of these patterns and elementsand the soil must be accounted for. In this connection reference should be madeto the fact that a soil profile is partly the result of physical and partly of chemicalprocesses, which are the reflection of the external soil-forming factors: climate (C),vegetation (V), parent material (P), topography (relief) (T), hydrology (H),influence of man (m) and time (t). This may be expressed in one of the manysoil (S) formulas, as found in the literature (e.g. DUKUCHAEV, ROBINSON, etc.):

S = f (C, V, P, T, H, m, t).

Some of the factors given above can be seen on the aerial photograph e.g. thevegetation, whereas others can be deduced from the shape in which the imagesappear, as is the case with e.g. the parent material. In this way a number ofelements can be analysed from the aerial photograph, which separately or in combi-nation can point to certain external soil characteristics and which can causedifferent soil processes, possibly indicating the presence of different soil units.

In order to arrive at a logical construction of the aerial photo interpretation,ZONNEVELD (i960) distinguished elements of different orders, viz.: first orderelements, being objects that are directly observable; second order elements, leadingto a picture that can be arrived at by the arrangement of the first order elements;and the third order elements, which can be deduced from the presence, arrangementand knowledge of the first and second elements.

The images, or elements of the first order in the sense used above, which can bedistinguished on aerial photographs by stereoscopic view are divided into five kindsof patterns.

l 8 SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

They are: i. relief patterns,2. vegetation patterns,3. drainage patterns,4. cultural patterns,5. tone patterns.

On aerial photographs macro, meso and micro forms of these patterns can beanalysed.

A short survey of the five elementary patterns, which are not wholly independentof one another, is given below. This part of the chapter deals with the factorsof soil formation that connect these five patterns and the type of analyticalelements in which they result. For completeness sake it should be noted that thereare many more analytical elements which are left out' of discussion here. Forthem the reader may be referred to the Manual of Photo Interpretation, Chapters5 and 11.

1. R e l i e f p a t t e r n s . The relief gives the three dimensional differences inthe shape of the surface of the earth. The patterns which may be distinguishedare the result of geological processes such as: tectogenesis, weathering, andsedimentation. The patterns reflecting these processes are primarily dependenton parent material. In the second place they are the result of climate, vegetationand drainage conditions. Many typical relief patterns can be mentioned: e.g.erosion patterns (closely related to drainage patters), watershed patterns, strati-graphic patterns, slope patterns, land form patterns (a unit with the same kindof slope patterns) and a land type pattern (a complex of different land formsbelonging to one another because of a given landscape factor).

2. V e g e t a t i o n p a t t e r n s . The vegetation is the natural covering of thesurface of the earth. In a negative sense the lack of vegetation, e.g. in thedesert, is an image belonging to this category. Also crops cultivated by mancan appear in certain patterns, but this kind of vegetation, either crop or forest,will mostly be classified as to belong to the cultural patterns. The vegetationpatterns reflect the soil, the climate and the drainage conditions. The featuresthat can be observed are specific single trees or areas or ribbons with the samekind of vegetation, while also the associations are important.

3. D r a i n a g e p a t t e r n s . The hydrology of a region bears among other thingson external drainage of water. This may occur along the surface and the watercollected into torrents, ivers, creeks, etc. and transported to lower parts. Asmentioned already, for the internal drainage conditions of the soil vegetationoften gives useful information. The drainage patterns are the result ofrelief and parent material, also of climate and vegetation. In most cases differentkinds or shapes of these patterns indicate different parent material or soils.Several systems that can be analysed are those of rivers, streams, gullies, lakes,swamps, etc.

4. C u l t u r a l p a t t e r n s . Cultural elements indicate the influence of man. Therural as well as the urban pictures visible on the aerial photographs supply

AERIAL PHOTO INTERPRETATION 19

information about the soil conditions as do the agricultural or forest patterns.The lower the stage of development the more the agricultural patterns will givea pure reflection of the soils concerned. In the regions of the Star Mountainsthe shifting cultivation systems as an agricultural pattern will produce a welldetermined image. The cultural patterns are due to soil conditions, parentmaterial, climate and local traditions. In a number of cases these patternshave been of useful diagnostic value for the kind of parent material. Ofcourse the influence of man may be recognized in the pictures of relief anddrainage too.

5. T o n e p a t t e r n s . The tone patterns are the representation of the colourpatterns. They generally do not reflect specific elements like the other patterns.On the contrary, they give shades and can only be seen in connection withexisting patterns. Tone differences are variations in an element due to a certaineffect, e.g. light, temperature, moisture, direction of wind, and texture. They arespecifically of importance for the analysis of the micro patterns.The elements complemental in constructing the pattern are subject to variations.

These can be listed as follows according to BURINGH (i960) :a. grade or density,b. type or shape,c. size,d. regularity or structure,e. site or geographical position.

When describing a unit, resulting from aerial photo analysis it is necessary torecord all the relevant, or at least the most important and most distinct, elements. Inthis way the unit is characterized and a correct picture of the landscape and anunderstanding of the soil conditions is obtained. In many cases of reconnaissancesoil surveys, certainly in forest areas, the pictures derived from aerial photos willbe more complete than those of the field control; on the other hand, the mutualobservations are a necessary complement.

The various elements, analysable in the aerial photograph, are either thereflection of the properties or conditions of the soil, or they are soil-formingfactors. For a number of elements this will be always true; in other cases afield control is necessary. The boundaries of the units derived from aerial photodetermination will appear to shift from those found on the terrain. Generallythis will play no part in small scale mapping. If a factor has a very strongdominant influence on another factor, e.g. the moisture on the vegetation, it mayoccur that within this area no soil differences are found at all. This will usuallyonly be the case on very flat terrain under swampy conditions. To ascertain theexact nature of the soil, which belong to a unit analysed by the aerial photo method,field investigations have always to be made.

The analytical elements and patterns do not have the same weight in a recon-naissance mapping. The r e l i e f is the most important element.

If there i s a p r o n o u n c e d r e l i e f , like that in the greater part of the Star

2O SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

Mountains region, most soil units are determined according to relief patterns visibleon the photographs. These units are consequently mostly based on topography onthe one hand, and on geological patterns etc. on the other (compare Manual ofPhoto Interpretation, Chapter 6, Tab. i, p. 417). The geological map of BÄR et al.(1961) forms a good basis for establishing units of soils developed on differentparent material. Though the pedological interpretation is carried out apart from thegeological one, many boundaries of soil units coincide with those of the -geologicalformations. Small deviations in position and shape occur owing to dispositionaldifferences in soil cover.

As far as the topography is concerned, it should be remarked that the geogra-phical position and the altitude play a decisive part in the subdivision of the reliefpattern based on parent material, or in other words in the distinguishing of soilunits.

If the r e l i e f is l e s s p r o n o u n c e d , like some parts of the southern low-lying land, the patterns of vegetation are the dominant indicators. Where the landis generally rather thinly populated there is mostly the natural vegetation thatproves to be very useful for aerial analysis. The drainage conditions and themoisture of the soil are very well reflected in the structure of the upper stratum,the form of the crowns in the canopy layer and the variation in height of the visibletrees (see LINDEMAN, 1953)- The forest in marshland has an irregularlybroken canopy layer with considerable variations in crown diameter and tree height.

In ordinary marshes or swamps the terrains are permanently inundated or atleast so during the greater part of the year. The soils always remain wet or moist(see also VAN DER EIJK, 1957). In swamps with a fluctuating water table themoisture content of the soil is subject to sharp fluctuations. In the rainy seasonthe soil is waterlogged, for a short period even inundated. In the dry season thesoil can be completely desiccated to a considerable depth. In ordinary marshes thetrees are mostly uniformly low, whereas in marshes with fluctuating water tablesthe variations in height in the vegetation are generally conspicuous.

Water or low herbaceous vegetation can be detected in open swamps. Atrelatively small and flat places on mountain tops in the zone of the mossy forestin the Star Mountains a lower vegetation is found (see page 13). Theseare terrains in which the soil is permanently wet so that we have a kind of smallordinary swamp. It is comprehensible that in the area with high rainfall, highhumidity and a flat relief this conditions may prevail. In dryer land of the tropicalrainforest the higher stages of the canopy are more regular and closed on thephotographic picture.

Two other factors can cause an irregular broken canopy layer, in which variationsin tree height occur. They are a shallow soil cover and/or a karst landscape withridges or pinnacles and sinkholes.

The following chapter contains an enumeration of the analytical elements and thepatterns of the photographic representation of the soil units distinguished in theStar Mountains area and in the lowland south of them.

CHAPTER VII

LANDSCAPE ANALYSIS.

The map, obtained by aerial photo interpretation, of the Star Mountains andthe adjacent southern-lying lowland is composed of a number of landscapes. Eachlandscape is composed of a number of regions. In the description of the landscapesand regions special attention is given to the factors of soil formation.

The whole area analysed can be divided into the main landscapes :The Southern Lowlands and Uplands, viz:

the Muyu and Mandobo Landscape andthe Ok Iwur Landscape.

The Digul Mountain Landscape,including the Sibil region.

The Upper Digul or Ok Tsop Landscape.The Ok Bon Landscape.

Some remarks on the Juliana Mountains Landscape are added.

The Southern Lowlands and Uplands.The lowlands and uplands south of the Star Mountains region can be divided

into two parts.1. The landscape south of the mountainous terrain at the upper courses of the

Blue and Red Digul in the west, the Digul and Arim Mountains in the middleand the escarpment, stretching from Katem to the Mount Arem crossing theboundary of the Territory of Papua and New Guinea. Roughly taken thislandscape lies south of the 50 05' S.L. It will be called the Muyu and Mandobolandscape. It comprises part of the alluvial plain and part of the foothill belt(see Chapter on Geology).

2. The uplands lie north of the area mentioned above and east of the East Digul,and south of the mountain complexes of the Jukmondi and Antares Mountains.It stretches eastward up to the boundary. The landscape forms another part ofthe foothill belt. It will be called the Ok Iwur region.The area interpreted with the aid of the aerial photographs is restricted toabout 1400 50' Latitude.

The Muyu and Mandobo Landscape.This landscape is characterized by:

a very gradually rising landscape from nearly sea level in the south-westerncorner to an elevation of 500 m at the scarp of Katem in the north. In the south-western part swampy areas are a general occurrence; in the north-eastern cornerthe terrain is a rather rough, sloping and hilly landscape.

The Digul and the Kau are the two main rivers flowing through the country.The easternmost site belongs to the water catchment area of the Fly river. The

2 2 SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

watersheds between these great streams are predominantly orientated to the east,so that the catchment areas on either sides of these rivers are divided asymetrically.For example: the western site of the Kau valley forms the highest ridge of thelandscape lying west of it. This feature is well indicated by the large numberof parallel courses, being tributaries of the rivers Digul and Kau, which findtheir sources close to the Kau river and the Ok Mat and Ok Birim respectively,both confluents of the Fly. The fall of the rivers in this region is generallysmall. The greater differences are found in the northern zone.

The Muyu and Mandobo Landscape (L) is subdivided into:L i. South-western swampy region,L 2. The Tanah Merah region,L 3. The Mindiptana region,L 4. The Woropko-Ninati region,L 5. The Northern Muyu region,L 6. The Umkubun region,L 7. The Welkozigibi region,L 8. The Red Digul region,L 9. The Koreon,

R The River zones: R 1. The river plain zones along the Digul,R 2. The river zones along the Kau and Muyu,R 3. The river zones along the Mandobo,R 4. Other river plains and/or terraces.

L 1. T h e S o u t h - w e s t e r n s w a m p y r e g i o n .

West of the Digul swampy areas are present over vast extensive terrains, whichare given as a small zone on the map. The height of the vegetation is irregularover great distances. Large surfaces have low bush, grass plains, reed or openswamps. From field observations (see also BEVERSLUIS, 1927, and VAN SOELEN,1956) it is known that this region is inundated during a greater part of the year.In the southern parts, near the confluence of the rivers Kau and Digul, large sagoswamps are observed. On other sites these are found scattered in smaller units.In the terrain creeks and small, strongly winding rivers flow, without depositingany sediment along their borders.

Scattered along the Digul we find some mounds, mostly with a village or ahamlet on top. The activity of man is practically nihil in these swamps. Morewestward, in the Mappi region, the mounds, relics of an old terrace or table land-scape, form vaster plateaux (outside the area visited).

These types of landscape are also met with in the lowlands of Sumatra andBorneo (WHITE, 1928). They are formed by the action of rivers in an old landsurface. Because of the mounting of the erosion level in a latter stage the verybroad valleys were filled up with new sediments. The surface of these new de-posits is rising towards the river, so that at a distance of the stream swamps

LANDSCAPE ANALYSIS 2ß

occur. Locally swamps are bordered by the old terrace slopes, making the shapeof the swamp resemble the projection of a lobster shell.

L 2. T h e T a n a h M e r a h r e g i o n .

This region comprises the southern part of the area between the Digul andthe Kau. The macro relief of the terrain is flat; the meso relief is softly undulating,by which the differences in height increase in eastern direction. The averageelevation of the region is between sea level and some tens of meters.

In the vegetation visible on the aerial photographs we recognize a kind ofmozaic, caused by small variations in the canopy, which is the result of the topo-graphy and the related hydrological conditions. Generally the soils are wet witha fluctuating ground water table close to the top soil. Some low ridges whichare spurs of higher ones in northern regions, cross the area in south-westerndirection. The „main" paths lie on these ridges, and locally some human occupationis observed on or near to them.

There are some real swamps in the area with sago as the most dominant vege-tation; a large part of the sago used in the neighbourhood of Mindiptanahoriginates from such a region in the south near Amburan.

The rivers in this country all flow parallel in south-western direction. Theyare meandering in the flatter parts, representing most recent swampy deposits ofthose rivers. These last mentioned phenomena i.e. fluviatile sediments alongtributaries, visible on aerial photographs, were used as an analytical element forthis landscape unit.

L 3. T h e M i n d i p t a n a r e g i o n .The region is formed by a zone of about 20 km width, which stretches from

north-west to south-east. The area had to be taken as a transition between theformer and the next area discussed in more than one respect namely concerningthe accidentation, the moisture conditions of the terrain, the number of settle-ments and the regeneration patterns in the vegetation.

The same parallel rivers as in the southern area flow through this country; buton aerial photographs no flat deposits can be detected along the winding courses.Only at the borders of the greater rivers, the Digul, Kau and Muyu, do the recentdeposits continue in the landscape. More to the north these riverine ribbons occuronly along the Digul.

L 4 . T h e W o r o p k o - N i n a t i r e g i o n .This region includes a small zone on either bank of the West and East Digul,

and a greater part west and east of the Kau river. The terrain is even moreelevated than the former landscapes, while the accidentation increases in north-eastern direction too. The elevation is about between 50 m and 300 m above sealevel. In this rugged area a number of higher hills or low mountain ridges is seenbetween the parallel formed by the rivers flowing to the Kau. The vegetation con-


sists of a high forest with a rather coarse canopy. The villages situated on thehigher parts of the ridges are well-populated. There are many paths and somejeep tracks. Owing to the bad quality of the aerial photographs the northernboundary in the Muyu district had to be drawn schematically.

L 5. T h e N o r t h e r n M u y u r e g i o n .

The Northern Muyu region comprises the country north of the former unit,south of the Katem scarp and about east of the Kau river. It is the most intersectedpart of the landscape which rises gradually from southern direction. The terrainlies at an elevation between about 300 m and 500 m.

The vegetation and agricultural patterns are similar to the former region.According to New Guinea standards the valleys and its surroundings found inthe eastern part of the area are rather thickly populated.

L 6. T h e U m k u b u n r e g i o n .

This region lies north of the cuesta bordering the Woropko region at thewestern side of the river Kau. The landscape is rather strongly eroded, with theresult that the area is relatively low. The broad valleys visible on the areal photo-graphs are partly in swampy condition. The rivers in these valleys flow towardsthe Digul. Generally the vegetation consists of medium high forest, in whichlocally swamp associations are found. Here sago complexes grow.

In this area the Buru formation crops out. The macro relief is sloping whilea hilly meso relief occurs.

In comparison to adjoining areas the density of population is very low. Thelocal people live isolated in the jungle. As a result the small gardens are widelyseparated and on the aerial photographs no occupation patterns are visible.

L 7. T h e W e l k o z i g i b i r e g i o n .

This region lies north of the former and south of the elongated Katem scarpsouth of the East Digul. The elevation is between 300 m and 500 m. The dif-ferences with the northern Muyu area are the softer relief and the smootherand finer fabric of the canopy of the vegetation. Also occupation patterns aremore frequent than those in the north-western corner of the northern Muyuregion. The rock in this area consists of limestone.

L 8. T h e R e d D i g u l r e g i o n .

The Red Digul region is found north-west of the former landscape and southof the hogback, which forms the transition to the mountainous landscape westof the Digul Mountains scarp.

The predominant feature in this landscape, visible on the aerial photographs,are the braided river systems. This characteristic occurs frequently in the rivercourses westward of the Star Mountains at the southern foothill belt of the

LANDSCAPE ANALYSIS 2 5

Central Mountain Range. Another typical morphological element is the topo-graphy.

In the strongly accidented region a number of erosion terraces (at least three)are recognizable. Probably the uplift of the land took place in three stages. Ata rough estimation the elevation of the area is between 300 m and 500 m. Therocks consist of silt- and claystones of the Iwur formation. The region carriesa rather tall type of forest. Agricultural occupations were detected in a fewplaces only.

R. T h e R i v e r z o n e s .

In some cases the zones along the rivers can be separated from the enclosinglandscapes. They can be divided into the following categories: «

R. 1. T h e r i v e r p l a i n z o n e s a l o n g t h e D i g u 1.

The principal characteristic of the zones along the Digul is the pronouncedmeander pattern, which consists of a linked up series of countless large river bends.Between them and many old river channels and oxbows an anastomotic patternis visible.

The vegetation is very irregular due to the meandering of the river and locallyswampy terrain conditions. Sites with low swamp vegetation are interchanged byhigher forest zones or complexes. Along older river channels small ribbons withstill taller trees are present on levees.

Traces of human activity are very scarce. Locally in the southern parts we findsmall settlements on the border of the river. In northern direction a single hut on aclearing or in the crown of a tree in the neighbourhood of a side creek is all we cansee. There are but very few paths or none at all. Travelling or transport of thelocal people usualy takes place with proas.

The relief is flat. The drainage conditions are very bad, the greater part of theterrain being swampy with a fluctuating water table.

R. 2. T h e r i v e r z o n e s a l o n g t h e K a u a n d M u y u .

Generally these river zones comprise older river deposits than the formercategory. The zones consist mostly of accumulation terraces, a number of which areinundated only at higher levels of the river water. The vegetation is mostlyformed by fairly high forest. In the vicinity of the villages the soils are usedfor gardening. The relief of the terraces itself is flat, but in most cases owingto a higher position above the river there is good drainage.

R 3. T h e r i v e r z o n e s a l o n g t h e M a n d o b o .

The zone along the Mandobo river deviates from the former zones. Thevegetation is fairly low, which points to swampy terrain conditions. Recent riverdeposits are not frequently found.


R 4. O t h e r r i v e r p l a i n s a n d / o r t e r r a c e s , occurring along tribu-taries of the greater rivers in the regions: Northern Muyu, Welkozigibi and Um-kubun. The observations on the aerial photographs of these landscapes had to bedone from obliques and at great distance from the flying line. The plains are foundin rather broad valleys. These valleys show a flat to gentle undulating relief,which forms a contrast to the strongly intersected and surrounding land. Inthe Northern Muyu region the density of the population is high. This is the resultof higher fertility of the sediments being erosion products of the small recentvolcanoes north of the region (Mt. Isil and Mt. Arem). These valleys resemblesmooth and lightgreenish lenses in the darker coloured and very rough landscape.

Also the valleys in the Welkozigibi region must be rather thickly populated, asconcluded from the low and irregular pattern of the vegetation.

The valleys in the Umkubun landscape as well as the valley or the depressionin which the Mandobo river flows are swampy, and therefore sparcely or evennot at all populated. The last zone is inundated during some months with high andcontinuous rainfall.

The Ok Iwur Landscape.

This part of the uplands south of the Star Mountains lies between 200 m and800 m above sea level.

The area is characterized by very strongly intersected uplands. Flying in ahelicopter through the Digul valley from Songgam to Katem, one gets the impres-sion that, south of the high uprising mountainous Antares-Yukmondi region, thelandscape is formed by a number of mountain spurs coming from the north, whichare the remnants of an eroded peneplain. This plain is sloping gradually to the southbetween an elevation of about 800 m to 400 m. In this area all tops of mountains andsmall, flat surfaces are visible. A number of broader accumulation terraces liein the valleys between the mountain spurs. Two levels can still be recognized inthese terraces (see VERSTAPPEN, i960). In the lower terraces flow the rivers EastDigul or Ok Tsop, Ok Bouw, Ok Iwur, Ok Irin, Ok Denom and Ok Walimkan.Along the Ok Iwur and East Digul in the high Katem scarp two half-circular edgesof erosion are frequently visible.

The region is subdivided into:U 1. The Iwur terrace region.U 2. The Tarup terrace region.U 3. The Digul accumulation terrace region.U 4. The Digul erosion terrace region.U 5. The Irin terrace region.U 6. The Ok Irin upland region.U 7. The Ok Bouw region.U 8. Steeply rising slopes.

LANDSCAPE ANALYSIS 2"]

U i. T h e I w u r t e r r a c e r e g i o n .

North of the escarpment of Katem a zone of about 3 km stretches from west toeast over a distance of about 20 km. In this zone several terraces are found betweenthe Ok Irin and Ok Iwur, south of the great bending in the Ok Iwur in themiddle of the zone and along the Ok Tarup and along, the banks of the Ok Iwurin northern direction towards the Antares. This area can be divided into two partseach with its own characteristics.

Roughly a western part, consisting of a flat, gradually sloping terrace fromabout 200 m near Katem to about 700 m near Almun-Wending, and another zonestarting north of the last settlement near the great Ok Iwur bending and extendingeastward along the banks of the Tarup river. The former region has been calledthe Iwur terrace zone, the latter the Tarup terrace zone.

At the edges the Iwur terraces are eroded by the Ok Irin and Ok Iwur, by whicha small lower terrace of about 80 m to 100 m is formed. At the eastern higher endthe terrace is incised by the Iwur river. Near the settlement Kenengbetip, in thehigh terrace a nearly 25 m high raise in the terrain occurs, where limestone isexposed, which should also be present in the subsoil of the terrace deposits.

The vegetation consists mainly of a forest type of irregular height. This pointsto wet soil conditions. A great number of high Agathis grows on this terrace.In the terrain several swampy spots were encountered.

Agricultural patterns are not found, except near Kenengbetip, mentioned above.The terraces are built up of alluvial deposits, containing many cobble stones. The

size of the rounded stones and rocks varies between very small to some cubic metersin the west, to some tens of cubic meters in the eastern part.

The Iwur terraces continue to the north along the Ok Iwur. These terracescorrespond with the lower parts mentioned above.

U 2. T h e T a r u p t e r r a c e r e g i o n .

In contrast to the former and flat unit the Tarup terrace region is stronglyincised by small tributaries of the Tarup.

The vegetation is irregular too, however; this is due to the great number ofgardens and regeneration patterns. The area has a good drainage and the soilconditions are less wet then in the Iwur terrace zone.

The sediments are the same as from the former region. VERSTAPPEN (i960)deals more extensively with the morphology of both regions.

U 3. T h e D i g u l a c c u m u l a t i o n t e r r a c e r e g i o n .

In the broad Digul valley between Katem and Songgam accumulation terracesexist. The region is rising gradually from 200 m to 400 m over a distance of about10 km. Northward of Songgam the Digul flows from a narrow gorge; the samehappens south-west of Katem. Generally two levels are detectable in the terraces.Locally remnants of the hard rock crop out. The height of the vegetation is


less irregular than that of the Iwur terraces. Scattered over the area some gardenscan be observed.

In the terrain it was observed that the deposits of the terraces consist of sandyto loamy material and cobble stones. These coarse textured soils generally weremoist to wet.

U 4. T h e D i g u l e r o s i o n t e r r a c e r eg ion .

South of Katem at the left bank of the Digul, there are two large erosion areas,lying below each other. Over greater distance in south-western direction repeatedthey give the impression of edges milled like coins. The upper one shows anothersubterrace at the brim. The terraces and the steep parts above them together formthe Katem scarp. The latter continues east of this settlement. The relief is verysteep. The differences in height are 200 m to 300 m within a short distanceof 1 or 2 km. On the steep, nearly perpendicular, limestone walls no vegetation isseen. On the terraces the forest shows an irregular picture. This is due to theshallow soils and to the regeneration patterns .

U 5. T h e I r i n t e r r a c e r e g i o n .

On the mountain spurs, which have general very sharp watersheds, somesmall and flat sites can be noticed. They are found between the Ok Katem and theOk Irin and also observed in the field between the Ok Irin and the Ok Iwurnear Debroka. The latter is very small. They form the remnants of a stronglyeroded peneplain, mentioned in the introduction to the Ok Iwur region. Theyare found on an elevation of about 400 m, 600 m and 800 m. The vegetationon this terraces consists of medium high forest. There is no agricultural activity.In the field A gat his trees were observed.

In this terrain one is struck by the fact that these high terraces show greatresemblance to the lower parts of the moss forest. This is mostly clearly expressedin the highest terrace near Almun-Wending (about 800 m) and is the resultof the high precipitation in this area.

Many times it was noticed that there are great differences in the degree ofcloudiness, e.g. the higher terraces were warped in the clouds, while the sun wasshining over the valleys.

U 6. Th e Ok I r i n u p l a n d r e g i o n .

This region is strongly intersected by rivers. Moreover, there is a large fault inthis area as well as synclines and anticlines. The macro structures can be studiedon the aerial photographs. The sloping and folded rocks consist of silt- and clay-stones (Iwur formation)., and it is partly draped like a cloak against the risingmountains in the north. The slopes dip generally into south-eastern direction. Thelandscape lies between 200 m near Katem and 800 m at the northern side.

An interesting fact is that the Ok Irin (confluent) and the Ok Iwur (main

LANDSCAPE ANALYSIS 2Ç

river) flow in the neighbourhood of Debroka at an elevation of ca 600 m and 700 mrespectively. More northward we can observe that the upperstream of the OkBouw is incised deeper into the terrain than the Ok Iwur is. The resistance of thegranodiorite sediments (very coarse) is probably greater than that of the claystones.The vegetation in this region is rather irregular, owing to the erosion (shallow soils)and the shifting cultivation.

Many agricultural patterns are visible in this area. As a result of the slopingrelief the soil conditions are not wet but moist.

U 7. T h e Ok B o u w r e g i o n .

This region, situated in the north and partly spanned by the Ok Irin uplandregion, has a rather small area. It deviates strongly from the surrounding area.The tributaries of the Ok Bouw flow through the landscape. It has an undulatingand sloping relief. The vegetation is very irregular and largely low, it is the resultof the great number of gardens found in this triangle.

The rock is formed by limestone.

U 8. S t e e p l y r i s i n g s l o p e s .

The very steeply rising slopes, occuring at the Katemscarp are apartly indicatedin the map. They do not carry vegetation.

The Digul Mountain Landscape.

The Digul Mountain landscape forms the western part of the Star Mountains.It is composed by two, about equal, enormous limestone cliffs, sticking out insouth-western direction, with a funnel-shaped lower part between. The westernand northern sites at the very steep scarp of the Digul Mountains rise up to anelevation of about 3000 m, while the eastern part, bordering on the Digul valleydescends to a height of 1000 m. In the north we find the Sibil valley at an elevationof about 1250 m.

The type of weathering of the northern limestone area is different from that ofthe southern one. In the northern part an irregular network of pinnacles andsinkholes can be observed. This is characterized as labyrinth karst by VERSTAPPEN

( i960). In the southern area there is a more regular picture of tower karst, ridgesof pinnacles, dolines or uvalas in diaclases. The labyrinth karst is a result ofthe weathering of porous coral limestones in the upper beds of the New Guinealimestone formation. The underlying beds are more massive and harder.

The vegetation of the limestone areas largely consists.of a moderately thickforest, of which the medium high canopy of the trees reflects the form of the karstfeatures. Generally there are no traces of occupation. On the aerial photographsagricultural patterns are only visible in some diaclases, in dry valleys or at thelower edges of the regions. Because of the rough topography and the lack ofwater it is impossible to travel through this area.


The landscape is divided into:D i. The Southern Digul Mountain region.D 2. The Arim Mountain region.D 3. The Ok Kair region.D 4. The Upper Ok Kair region.D 5. The Northern Digul Mountain region.D 6. The Songgam region.D 7. The Awitagoh region.S. The Sibil region: a. the upper Sibil region

b. the Sibil terraces region.Narrow valleys.

D 1. T h e S o u t h e r n D i g u l M o u n t a i n r e g i o n .

Again this limestone region is composed of a northern and a southernpart. The latter is the highest and follows the steep scarp along the DigulMountains. A number of meandering, dry valleys, having the slopes reverse tothe course of the rivers formerly flowing in the valleys. The fossil river valleysindicate that in an earlier period rivers ran in southern direction. In that periodthe landscape was lower and flat, while the groundwater table was higher than atpresent (VERSTAPPEN, i960).

In the northern and lower part of this region another fossil river system can beobserved. However, in this case the river was flowing in eastern direction.

D 2. T h e A r i m M o u n t a i n r e g i o n .

The Arim Mountain region forms the highest part of the southern limestoneformation. The elevation of this mountain range is between 1500 m and 2500 m.The vegetation is composed of an irregular, medium high (on the aerial photos),dark-tinted type of forest. This had to be interpreted as a kind of mossy forest.

No traces of population could be detected.

D 3. T h e Ok K a i r r e g i o n .

This region shows more or less the form of a triangle. It is bounded to the northby the high and steep mountain slopes of the northern part of the Digul Mountains.To the west, to an elevation of iooo m, it is narrowed and it transforms into anoblong zone, (the Upper Ok Kair region) mentioned below. To the east the areais getting broader and descends to the Digul valley at the height of about 500 m.The gradually sloping landscape is hilly, though some steeper mountain ridgesoccur. The region is less accidented than the corresponding Ok Irin upland regionat the other side of the Digul.

In contrast with the limestone regions, we find active rivers. The area is namedafter the Ok Kair, which has a number of confluents. Everywhere occupationsare found scattered over the region. Owing to the numberless regeneration

LANDSCAPE ANALYSIS 31

patterns the vegetation has an irregular picture. The crowns of the trees togethergive a coarser fabric on the aerial photo than those of the limestone regions.

D 4 . T h e U p p e r Ok K a i r r e g i o n .

In the eastern end of the Ok Kair region a narrow zone exists. Here wesee some parallel flowing upper courses of the Ok Kair. Near the very steepnorthern and western slopes they are fed by several torrents. The lithologyof the westernmost part is not quite clear. According to the pictures on the aerialphotographs also sandstones of the Kembelangan formation crop out.

The aerial photographs give the impression that the erosion is very considerable.Lithosols, bare rocks and coarse material will dominate.

D 5. T h e N o r t h e r n D i g u l M o u n t a i n reg ion .

This area comprises the limestone landscape south of the Sibil valley, fromthe Aidum Mountains in the east to the Awitagoh region in the west. The averageelevation is about 1500 m. The upper limit in the west reaches as high as 2500 m,while the eastern edge rises about iooo m.

The large valleys, sketched on the map, mostly form deep grooves or gorgesof 200 m to 300 m in depth. However, in spite of this morphology and the highprecipitation no rivers were observed. In the Arimkop valley a little well wasdetected, but the water disappeared within a dozen meters between the limestone.VERSTAPPEN discovered the vaucluse spring of the Sibil river in the Digul at somedistance north of the settlement Songgam.

D 6. T h e S o n g g a m r e g i o n .

In the south-eastern angle a number of valleys exist between some spurs ofthe Northern Digul Mountains region. These parts as well as the sloping fringeof the area in the Digul valley lie between iooo m and 500 m elevation. Manyagricultural patterns are met with. As a result the vegetation is more irregular andgenerally lower than that of the former region. It is sketched on the map as aseparate region because of its lower elevation, agricultural use and differentvegetation. In the field it appears that this distinction is justified by the presenceof a different soil type.

D 7. T h e A w i t a g o h r e g i o n .

The more than 3000 m high brim and peak of the most western high side of thenorthern limestone cliff, shows a typical structure. The highest edge of this flatsurface which is sloping in eastern direction is completely bare. One of thesesky-piercing peaks is the Awitagoh (or the "Leeuw") after which the region hasbeen named. Below this bare surface there is an area carrying midget vegetation,and still lower a zone with a higher vegetation cover. The lower boundary is formedby a kind of bank, starting with labyrinth karst stretching eastward. The differences


in vegetation and the lack of it are caused by various strata of the New Guinealimestone, and the considerable erosion in the lower beds (here the higher sites).The lower boundary mentioned is found at 2500 m. In those places where forest isdeveloped because of good drainage conditions, there is no pronounced mossyforest.

There are no marks of human activity.The weakly sloping and triangle-shaped area, extending east of the Awitagoh

region towards the Sibil valley also belongs to the Northern Digul Mountain region,though there are small deviations. Apart from dolines and uvalas also karrenfieldsare present.

S. The Sibil region.

The Sibil region lies in a fault zone between the limestone formations of theDigul Mountains region and those of the Orion Mountains. In this zone we finda depression between the mountainous landscape, in which a rather broad valley,the Sibil valley, can be observed. In contrast with nearly all the other valleys inthe Star Mountains, sedimentation took place which resulted in two terraces abovethe actual river plain. The rock beneath these accumulation terraces consists oflimestone, in which many dolines and chains of dolines occur, so that the levelsof these terraces are frequently interrupted. Moreover, owing to the fault mentionedabove, the terraces on the southern slopes are very strongly disturbed. Forexample: the village Tulo is situated on a terrace remnant which is on a higherposition than the highest terrace recognized at the northern side of the valley.

On account of karst phenomena the Sibil river ends in a ponore in the easternpart of the valley. The tributaries the Ok Atem and the Ok Aisjek dissapearin the rock and reach the Sibil by a vauclusion spring. These rivers rise on theOrion Mountains and in their upper courses, being mountain torrents, they cutinto the glauconitic sandstones and shales of the Kembelangan formation. Thehigher and adjacent slopes and crests of the Orion Mountains consist of lime-stone. The geological maps do not give indications about the rocks of the westernvalley, where the upper courses of the Sibil flow. Terraces are not seen here and theKembelangan formation need not be exposed at all.

The terraces of the Sibil are partly swämpy. Low bushes and grasses grow onit. At the edges of the terraces and round the dolines only Araucaria trees arefound. On the terraces themselves gardens do not occur. They are but laid out onthe slopes within the dolines or on the river plain in the most recent soils. Hereinundation is possible in periods of high precipitation. The mountain slopes of thevalley, the northern as well as the southern sides, are very intensively cultivated(REYNDERS, 1962). As a result of these occupations and the regeneration followingthem, the forest is of a pronounced secondary nature.

The Sibil region is subdivided into:S 1. The upper Sibil region, and


The Sibil terraces region consisting of: S 2. an upper terraceS 3. a medium terraceS 4. the actual riverplain.

A part of the Sibil valley on a greater scale than the reconnaisance map is givenin Fig. 10 on page 138 (See also: VAN BAREN, i960 and REYNDERS, 1962).

S 1. T h e u p p e r S i b i l r e g i o n .

This country consists of a narrow, east-west stretching, zone at the foot of theOrion Mountains. The area descends from an elevation of about 1800 rri to theSibil terraces at 1300 m. A number of rivers flow parallel and form the uppercourses of the Sibil. The erosion is severe and probably recent deposits cannot beexpected. The larger part of the surface will be occupied by karrenfields. Thevegetation consists of a rather high forest type. The crowns show a rather coarsefabric.

On the aerial photographs agricultural patterns are not visible.

T h e Sibil t e r r a c e s region.

The Sibil terraces are found at an elevation between 1200 m and 1300 m. Theyare flat and they slope very gradually in eastern direction. The difference in heightbetween them is 10 m to 15 m. As already mentioned, the dominant vegetation ofthe two higer terraces consists of grasses and low bushes.

S 2. On the highest terrace small villages have been built. On the aerialphoto paths can be seen as a network of thin white lines.

S. 3. The greater part of the northern valley is occupied by the mediumterrace. At the southern side the terraces are disturbed, as has been remarkedalready. Only in the south-eastern corner does a flat terrace correspond to thenorthern medium one. The drainage conditions in this medium terrace are very bad.The groundwater is stagnant. In the north-eastern corner a long ribbon of thisterrace extends towards the Utek Mountains and can be followed as far as somecaves in a local limestone barrier. The several levels of the terraces alsocorrespond with the lower places in the limestone gorge in the direction ofArimkop (VERSTAPPEN, 1964, will deal more extensively with this in a consecutivepublication).

S. 4. The actual riverplain, however, has a vegetation which is very irregularowing to the regeneration patterns, plates of cobble stones, galleries of trees(Albizzia) along the river or along old channels. The Sibil river is stronglymeandering.

N a r r o w V a l l e y s

As has been pointed out, in the limestone landscape many valleys or uvalas canbe distinguished. Only the broader ones like those of the Sibil valley and the UpperKair valley, are described as separate units. The fossil,'dry valleys in the southern


parts of the Digul Mountains region and a great number in other units are dis-cussed in the section on the units treated below. It is impossible to indicate allthese smaller valleys on the map. Only the larger ones are sketched in. Mentionis made of the Arimkop valley. It is situated in the Sibil fault. It has very steepslopes and it is very deeply incised. In the field, just near the hamlet Arimkop,a flat part with white sandy sediment was found. Generally the valley is slopingirregularly towards the Digul.

The Upper Digul or Ok Tsop Landscape.

This landscape consists of a number of valleys extending more or less innorthwest-southeastern direction, which are deeply incised and lie between steeplyrising mountain chains. This landscape comprises the land between the confluenceof the Ok Bon and Ok Tsop or the point where the Tsop bends in northwesterndirection, and the place where the Digul Mts. and the Orion Mts. and the JulianaMts. come together. The Juliana Peak itself is not included in the Star Mts. area.However, some remarks on the landscape around this peak are given at the end ofthis chapter.

The mountain chains of the Ok Tsop valley comprise the Orion Mts. in thesouth and the chain north of the river, beginning with the Aburop Peak, continuingwith the Mol Mts., Bini Mts. and Wa Mts. ending with the Yagum Mts. The nextnorthern chain, consisting of the Yong Mts. and Bee Mts., situated between theOk Silaga and the Ok Tse, is also considered to belong to the region. The river bedof the Ok Tsop itself descends in this area over a distance of about 30 km fromabout 2000 m to 900 m. The mountain chains mentioned rise in the south to anelevation of 2000 m to 2500 m, and in the north to over 3000 m. In the north-south cross-section the very great variations in elevation are very pronounced.These differences have been caused by faults and by erosion.

Since the northern sides of the Tsop valley are extremely steep, the valley is

4 km

Mo/M/s3O0Om

250Om

ZOOOm

Fig. 5. Cross-section Upper Tsop valley. 1 : river bed ; 2 : terrace ; 3 : talus cone, a : top zone ;b : moss forest zone ; c-d : mid-mountain — shifting cultivation zone ; e : very steep slope.


more or less asymetrical (see Fig. 5). In the lower part of the valley in manyplaces a strongly eroded and interrupted terrace occurs, on which locally a recentsediment (S 5) has been noted. The river itself is mostly flanked by high andsteep borders. In some places colluvial fans are found along the river. They willbe washed away in the next period of high rainfall when the river is in spate.Other fans are found on the erosion terraces, mentioned above, and at the bottomof the steep northern sides or walls.

The Ok Siliga valley shows a more symmetrical shape because it lies in a greatfold of a syncline. Over a short distance a small recent sedimentary ribbon (S 6)is found in the Silaga valley. In this deposit the river is meandering.

The topographical differences over short distances cause also a number of smallzones, in which the factors for soil formation vary. The higher parts of the moun-tains consist of limestone, while in the lower eastern parts sandstones and shalesof the Kembelangan formation are exposed. Especially the steeply sloping areanear the confluence of the Ok Siliga, Ok Tse and Ok Mimka with the Ok Tsopwhich is composed of these parent materials, is very strongly eroded. Here themajority of the (steep) surface does not have soils, but regolithic material. Inthe region of the Ok Mimka river on the sloping terrain no forest was observed.Although erosion is active the whole Mimka valley is occupied by garden complexes.On the top of the erosion terraces found north of the Ok Tsop, locally a sediment(S 5) occurs which corresponds with the Sibil deposits. Sandy gley soils are formedon them. At the southern banks of the Ok Tsop river very shallow limestone soilswere encountered. On the geological map the Kembelangan formation is indicated,but it was not observed by the author. In the higher parts of the Ok Tsop valley,in the neighbourhood of the Juliana Top, there is the Iwur formation.

The variation in vegetation (climate and landuse) was the following. On thelimestone mountains the lower boundary of the moss forest occurred at an elevationof about 2000 m, although this type of forest was less developed than on the slopesof the Antares. Locally the upper limit of the shifting cultivation systems reachesup to this'moss forest boundary.

At the top of the mountain chains, particularly on the Orion Mountains, aerialphotographs showed here and there a lower forest type. The experience in otherplaces of the Star Mountains taught us that in those places soils with stronglyimpeded drainage or gley soils will occur. The zonality present in the vegetationis emphasized by the activity of man. The zone of about 200 m above the river baseis in use for shifting cultivation. Since the slopes are very steep this use of landhas a destroying effect on the soil and on the regeneration of the vegetation. Deepto medium deep forest soils erode to lithosols.

As a result of the strongly intersected landscape the tops of the formerlimestone mountain chains are fairly small, or in other words, they have not veryextensive flat surfaces, which show karst phenomena. The Yagum Mountains, risingup to over 3000 m have a flat surface. The meso relief is accidentated by manysinkholes, and labyrinth karst as is found in the northern Digul Mountain region


and the Yukmondi Mountains region. The south-western side is formed by avery steep precipice. Agricultural patterns are not present on the Yagum Mountains.The vegetation assumedly consists of moss forest.

South of the Yagum Mountains three other areas on different levels with variousparent material were met with. Round the southern flanks of the Yagum Mountainsthe topography is very steep. The parent material is formed by the Kembelanganformation which continues further in eastern direction in the Ok Bon valley. In theregion concerned wet and weak, locally coalcontaining shales, alternating withsteeper sites with harder shales are exposed. Shifting cultivation systems arepresent. The vegetation shows an irregular pattern due to this type of landuse. Thisarea will be dealt with in the section on the Ok Bon Landscape.

Still more southward, in the angle formed by the Ok Tsop and the Ok Bon,the topography is a little less rough. We found a small area with a surface gentlysloping in south-eastern direction. The vegetation is formed by a medium highforest, which is fairly irregular in height, because of the impeded drainageconditions. Here Agathis trees grow. Gardens are not seen. The soils arecomparable with those found on the leached Sibil terrace. There is probablya small sedimentation area (S 5) of weathering products of the southern flanksof the Yagum Mountains.

South of this area, in the utmost corner between the two rivers mentionedabove, a cultivated limestone area was noted, which continues in southern directionalong the left bank of the Digul. This triangle may be compared with the shiftingcultivation zone mentioned above, which will be discussed again in the section onthe Ok Bon landscape.

Summarizing in the Upper Tsop landscape the following units can bedistinguished (compare Fig. 5).

On limestone:T 1. On the top of the mountain chains, locally low moss forest.T 2. On sloping terrain near the mountain tops a moss forest zone.

On the Yagum Mountains this vegetation type is found on a fairly flat areawith karst phenomena.

T 3. The mid-mountain forest zone.T 4. Deeper in the valleys a zone in which shifting cultivation patterns were

observed, and where erosion is severe.T 5. Very steeply rising mountain slopes, without soil or vegetation, mostly

occurring at the northern sides.On sandstones and shales:

T 6. Along the Ok Mimka an area in which shallow soils exist, which are in usefor agriculture, the Ok Mimka region.

T 7. Near the confluence of the rivers Tse, Silaga and Tsop a very stronglyeroded area in which hardly any vegetation or soil occur', the Ok Tse region.


On sediments:S 5. On disturbed terraces along the Tsop river and south of the Yagum

Mountains.S 6. Locally along the banks of the Ok Silaga.

Separate landscape units, which could be called soil region, could not bedistinguished, as the result of the long-drawn and narrow zones, being parts of thesame mountain range.

The Ok Bon Landscape.

The mountainous Ok Bon Landscape is situated north of the Ok Iwur uplandregion, and it comprises the Yukmondi Mountains, the Grote Beer (Bi) Mountains,the Antares Mountains and the Sini-Mimi Mountain range. As in the Upper OkTsop region the topography is very rough, the landscape is strongly intersected,resulting in great differences in elevation within short distances. The river basesin the area lie on an elevation of about 900 m to 1200 m, while the mountain topsand chains rise up to an elevation varying between 1700 m and 3600 m.

B 1, B 2. T h e Y u k m o n d i M o u n t a i n s r e g i o n .

The Yukmondi Mountains can be divided into two parts, namely one at anelevation of about 1000 m (B 2) and a higher part rising up to a height of about2000 m (B 1). Both consist of limestone. Apart from the steep surroundingslopes, the macro relief of the surfaces of the tops is fairly flat. However, the mesorelief is strongly disturbed and is very accidented due to karstphenomena. Agricul-tural patterns are not present. The two parts are covered with forest, showing anirregular picture because of the rough meso relief. The higher part seems to belifted up by the intrusion of the Antares zone, and will have a moss forestvegetation. The top of this area is the Andromeda Peak which rises to an elevationof about 2500 m.

This Yukmondi region corresponds with the Northern Digul Mountains region.

B 3, B 4. T h e G r o t e B e e r M o u n t a i n s r e g i o n .

This region lies fairly low among the surrounding mountains. The areaconsists of shales of the Kembelangan formation, which is slightly sloping to thesouth. The region is divided into a lower and smaller part between the Imur andKatmo rivers and a higher part between the Ok Imur and the Ok Bon. This areais surrounded by fairly steep slopes, while the upper side is nearly flat andsloping to the south. The uppermost ridge lies at an elevation of 1700 m. Here thelower level of the moss forest occurs. However, on this ribbon the forest isdwarfish, because of the impeded drainage conditions (B 4).

Locally the lower parts of the mountain crest and the slopes are in use forshifting cultivation. The greater part of the surface, in which the erosion is severe,is overgrown with medium high and medium to finely structured forest.


T h e A n t a r e s r e g i o n .

The Antares region rises to 3600 m, and consists of the Antares itself and themountain spurs, lying between the rivers rising from the mountain. These spursare mainly composed of sandstones, slates and siltstones of the Bon formation,which greatly resembles the Kembelangan formation. The Antares cone itselfconsists of granodiorite rocks that are surrounded by augite containing quartz-diorite, and a metamorphic marble and limestone (New Guinea limestone forma-tion) zone (BÄR et al., 1961). The mountain spur between the Ok Minam and theOk Bon is composed of different rocks, which may cause the soil units to becomevery complicated.

However, the dominating factors in the soil formation of the Antares regionare topography, climate and vegetation, while the parent material plays an inferiorpart or has no importance at all.

The Antares region can be divided into three belts, namely:B 5. The footbelt, which rises from 1200 m to an elevation of 1700 m. This belt

is very steep, so that erosion is very severe. The vegetation being a mid-mountain forest type, consists of medium high trees, which are very irregu-larly distributed, because of the erosion. The result is that the soils areshallow.

B 6. The moss forest belt, which lies between 1700 m and 3000 m, where the treelimit is found. In this belt the humidity is nearly a hundred percent, sothat the trees and the soil are covered with thick moss layers. As a resulta mineral soil is hard to discover and the majority of the rock coverconsists of organic material or peat.

B 7. The zone above 3000 m, which is only observed at the Antares massifitself, reaches above the tree limit. Here an alpine meadow vegetation occurs(see KALKMAN, 1963), while the highest parts, namely the East Peak(3600 m) and its surroundings above 3500 m, have bare rocks or are coveredwith a thin layer of moss only. This area of alpine meadows and bare rockforms a small mountain ridge of some tens of meters width and somekilometers length.

B 8. T h e S i n i - M i m i M o u n t a i n r a n g e .

The Sini and the Mimi Mountains form a part of the 3000 m steeply risingmountain chain found north of the Ok Bon and the Grote Beer Mountains and theAntares Mountains.

The slopes are very steep and the erosion is severe, so that the soils observedin the Bon valley are stoney and shallow. The parent material consists of the slatesand siltstones of the Bon formation, which corresponds to the Kembalanganformation. At the lower parts of the slopes that are not too steep (about 300 to45°) gardens of the local population are seen. The forest vegetation is irregular andis due to erosion and regeneration patterns.


B 4. On the top ridge of the mountain chain the aerial photos revealed a dwarfforest type, similar to forest type on other tops, caused by soils with impededdrainage conditions (see page 37).

T h e r i v e r b a n k s .

S 7. The Ok Bon has the character of a mountain torrent. The banks arecomposed of very coarse material of stones, large, rounded blocks of rocks, andin between sandy and loamy material. Locally, and particularly close to theconfluence with the Ok Tsop, irregular terraces can be observed. The parentmaterial of this river bank soils consists of a mixture of granodiorite, sandstone,shales and limestone material. The vegetation is dominantly formed by grassesand some scrubs. Locally some Albizzia grows. Gardens are found onlyon small pieces where rock fragments are lacking.

T 4. As already mentioned, under the Upper Ok Tsop region, the river banksand lower mountain parts along the Ok Tsop consist of limestone. They are eroded,yet there is a shallow soil with many gardens, as well as regeneration patternsof the vegetation.

J. The Juliana Mountains Landscape.

At the end of this chapter some remarks may be made on the Juliana Mountains.Although this region was not visited, the mountain was passed several times byaeroplane and very clear aerial photographs were available, which made it possibleto establish the following features.

To the south an enormous precipice of several kilometers exists which joinsthe steep sides of the Digul Mountains. The top of this mountain range is coveredwith eternal ice and snow. This snow landscape is found between about 4500 mand 4700 m. Below this zone a belt consisting of bare, limestone rocks wasobserved. Sometimes a snow cover is present here. (One morning, from the AntaresPeak, it was observed that the snow covered a zone of about 400 m under theaverage snow line. This snow disappeared again in the following days). In this belt,between 4000 m and about 4500 m, bare rocks and shallow soils with a kind ofalpine meadow vegetation were noted. In the zone between 3700 m and 4000 mthe alpine meadow landscape is better developed. Lower down the landscapechanges into the moss forest region mentioned already in the section on theUpper Ok Tsop region. However, the boundary is not so sharp as on theAntares Mountains because of peri-glacial phenomena, which are shown bymoraines, small lakes and long and fairly horizontal, tongue-shaped valleys.The vegetation in these valleys consists of low and medium high grasses, whichindicates a fairly wet soil. Similar pictures of valleys have been observed east ofthe Antares in the Hindenburg Mountain Range, at an elevation of about 3000 m.Summarizing the following zones are distinguished:

J 1. The top, covered with ice and snow (4500-4700 m),J 2. A bare rock zone (4000-4500 m),


J 3. An alpine meadow zone (3700-4000 m),J 4. The moss forest zone (2000-3700 m), andJ 5. Glacial valleys, not indicated on the soil map (3000-4000 m).

CHAPTER VIII

WEATHERING AND SOIL FORMATION

Introduction.

In the region investigated the precipitation is much higher than the evapo-transpiration (see chapter on Climate). Consequently we have only to deal withprocesses in which leaching plays a very important part. Secondly, the varioussoils are found in the tropical zone nearly under the equator (Lat. 6°oo to 4°45 S.)but rise from sea level up to eternal snow. This means that the temperaturechanges from warm to very cold, with as result different types of decompositionof the organic material produced by the vegetation. In warm and moist climatesorganic matter is mineralized quickly and in a cold climate the destruction is veryslow resulting in humification and accumulation. For a better understanding ofthe soil development under these various conditions the processes involved, arebriefly discussed.

Organic matter.

Organic matter can be broken down into several humus types, which are relatedto the activity of fungi and bacteria in the soil and to its content in bases. Thelatter does not only depend on the original parent material, e.g. basic, intermediateor acid, but also on the degree of leaching of the top horizons, and on the kindof vegetation (see BLOOMFIELD 1953, 1954; and LovERiNg; 1959).

Generally, it may be concluded that in fertile soils the bacteriological activity. will be high and the soil will be worked through by soil fauna. This means thatin base-saturated soils the possibility of a quick decomposition of the litter anda mixing of the humus formed with the mineral soil components will be evident.In leached soils the decomposition is much smaller owing to a weak activity ofbacteria and there will be hardly any mixing of organic matter and mineral parts.Consequently there will be an accumulation of organic material on the surface.In very poor soils there is no activity of bacteria and only fungi play a part inthe decomposition of the litter if the conditions are favourable, that is, the littermust be moist to wet.

Fresh organic matter derived from higher plants generally has C/N-ratios of50 to 60 as an average. In most cases fungi break the fresh material down intoorganic products with a C/N-ratio of about 30, after which bacteria, if present,decompose the organic substances further down to lower C/N-ratios. During thisfermentative decomposition process carbon dioxide is produced too. In very

WEATHERING AND SOIL FORMATION 4 1

favourable conditions, e.g. in warm and moist micro-climates on the soil surface,the mineralization will be about complete so that hardly any humus is formed.In cooler climates types of humus are found with C/N-ratios between 25 and 10,or sometimes still lower values. The composition of humus is very complex (seeSCHEFFER and SCHACHTSCHABEL, i960, and DUCHAUFOUR, i960). The mostimportant component parts are the fulvic acids and the humic acids, notions whichare at the same time collective nouns. Some analytical data given by ALEKSAN-

DROVA and PONOMAREVA (cited by VILENSKII, 1957) are the following:

TABLE II

E l e m e n t a r y c o m p o s i t i o n s of f u l v i c a c i d s a n d h u m i c a c i d s(in percentages)

Acid C H O Nhumicfulvic

52-6245-48

2.!

53-5-8-6

3 !-4-3943 -48.5

2.6-5.11-5-3

The humic acids are coloured brown to black. They have a low C/N-ratio (seeTable II) . Several kinds of humic acids are classified by TYURIN (cited byDUCHAUFOUR), according to the possibility to bind mono-, bi- and tri-valentcations, as Hj., H 2 and H 3 humic acids. The more polyvalent the cations the lesssoluble the organic compounds are.

The fulvic acids are mostly coloured yellow to yellowish brown. They have highC/N-ratios, are soluble in water, and are frequently formed under a-bacteriologicalconditions, that is in poor and acid soils under leaching circumstances. The fulvicacids bind the sesquioxides which can thus be removed by leaching, the iron com-pounds being more mobile than the aluminium ones. According to TYURIN thehumic acid/fulvic acid-ratio is about 1 in chernozems and chestnut soils and muchlower in podzols: 0.4, and in red earths or krasnozems: 0.3.

The types of humus are classified according to morphological characteristics(KUBIENA, 1950, JoNGERius, 1962 and i960). The most important types are:mull, moder and mor or raw humus. The mull is intensively mixed with themineral parts of the soil by the soil fauna. This humus is very stable and producesvery stable aggregates with clay. The moder is a humus form which is less mixedwith the mineral parts of the soil. It contains more water-soluble compounds thanthe mull, and the soil aggregates in which this kind of humus is found are ratherunstable. The moder can disperse clays, and it can form complexes with iron andaluminium hydroxide colloids, so that they can migrate. This activity is increasedby higher acidity and decreased by higher concentration of calcium ions. Themor is found in organic accumulations with small biological activity and thereis no mixing of the humus with the soil particles. This humus is nearly totallysoluble and it is formed in very acid environments. It greatly aids the mobilityof iron and aluminium and it decomposes clay minerals.

The following summarized table gives the range of values of the various humustypes (after DUCHAUFOUR, i960).


TABLE III

S o i l c h a r a c t e r i s t i c s as r e l a t e d to h u m u s t y p e s

Humus C/N-ratio pH-range Saturation perc.Calcium mull 10 7S-&-5 saturated"forest" mull 10-15 ( < 20) 5-0-6-5 20-60Moder 15-20 < 5.0 10-20Mor 30-45 ( > 20) 4.0-4.5 < 10Oligotrophe peat 30-40 3-5-4-O < 10

C/N-ratios of the humus of some soils are (VILENSKII, 1957; DUCHAUFOUR,1957, MOHR and VAN BAREN, 1959): chernozems: 10-12; red earths: 13-16;podzols: 20-30.

The values given above represent "normal" soils. However, also C/N-values areknown to occur, which are much lower than 9 or 10. These low ratios are found ine.g. more or less hydromorphic and often in peaty soils as they are also encounteredin the Star Mountains. Generally in the soils concerned a mor or moder-likehumus is present. These lower C/N-ratios are to be attributed to a very highammonia content, that can be present in e.g. peat (4%) and also in mountainmeadow soils (VILENSKII). Under very acid circumstances, which may be causedby low temperature and a very high moisture content, the decomposition of theorganic matter is mainly produced by fungi, the absence of certain bacteria pre-venting nitrification. The low C/N-value found by the sod-podzols, e.g. eight, mustbe based on the same phenomena. SCHACHTSCHABEL ( i960) explains that C/N-ratiosof swampy soils, which can be about 6, will be about 15 if ammoniacal nitrogenis ignored in the calculation of the ratio.

FINCK (1963) reports examples of very low C/N-ratios (e.g. one), whichoccurs in some heavy clays. These values have been explained by ammoniumfixation in the interlayers of 2 : 1 clay minerals. This ammonium is not exchange-able.

The nitrification of ammonium in the soil is affected by aerobic bacteria. Theiractivity is strongly reduced when the pore volume in the soil is filled for more than60 percent by water (VAN DIJK, 1951). These conditions are easily realised inthe Star Mountains because of the very high rainfall. Moreover, a study of thin-sections of soil aggregates and clods made clear that the structure of most soilsis very compact.

In the course of investigations on the fertility and the exhaustion of soils usedfor shifting cultivation in the Star Mountains, a number of analyses were carriedout to ascertain the content in available plantnutrients, using Morgan's extract(PEECH, et al. 1943, LUNT, et al. 1950, SCHUFFELEN, et al. 1961). The ammoniumvalues appeared to be extremely high, which correspond with the data mentionedabove.

After this review it is apt to discuss the change of the C and N values andthat of the C/N-ratio in the soils and in the soil profile in relation to the climato-


logical conditions, precipitation and temperature, which is also related to theelevation.

In a warm and wet climate the mineralization will be high. At higher elevationand at lower temperatures the mineralization will decrease and the humificationincreases, while at still greater elevations the accumulation of organic matterwill dominate over the decomposition. As a result the total amount of organicmatter will increase with increasing elevation.

Interesting investigations have been carried out by VAN SCHUYLENBORGH et al.(1957), and TAN et al. (1961), on the behaviour of organic matter in thetropical regions from sea level up to mountainous zones (about 3000 m). TANreports that in soils develloped from acid volcanic material, with a yearly rainfallof about 3000 mm, the carbon dioxide up to about 500 m elevation is nearly 2.5vol. percentages, the zone of about 600 m has 4.3 %, while measured at an altitudeof 1100 m the content decreases rapidly to 0.8%. The rapid mineralization oforganic material in the low land causes that the litter is very thin or absentand the carbon dioxide will partly volatilize.

It is surprising that TAN. does not report a strong increase of the organic matteror formation of peat at higher elevations. The reason probably is that reallycontinuously high precipitation is not considered in the investigations and that theparent material consists of fairly "young" volcanic material. Under humid tropicalconditions the elevations in which mineralization or humification is dominantdepends also on the kind of parent material. On basic parent material and on acidparent material the elevations in which mineralization is dominant are respectivelyin the zones of 0-600 m and 0-500 m at an average temperature of over 230;mineralization is equal to humification at respectively 600-1000 m and 500-1100 mat a temperature of 200 to 230 C; and humification is dominant at an altituderespectively over 1000 m and 1100 m.

In monsoon climates, thus with alternating drier and wetter interludes the zonein which the mineralization of organic matter prevails is much broader and risesup to about 1000 to 1400 m (compare table IV, page 52).

In the lowland of the surveyed area (Muyu and Mandobo districts) theprecipitation is extremely high and the parent material consists of very poor sandysediments. In relation to the investigations, mentioned above, it can be expectedthat the zone in which the mineralization is dominant will be fairly small and low,or, the influence of the humification of the organic matter on the soil is importantat still lower elevations than 500 m.

As a result of the extent of decomposition of the organic material at differentelevations the C/N-ratio in the topsoil will first decrease and afterwards it willincrease with height (HARDON, 1936, cited by MOHR and VAN BAREN, 1959).

If the mineralization in the soil is high, the C/N-ratio will not vary greatly withincreasing depth; in the case of strong humification the C/N-ratios will varywith depth.

As has been mentioned the decomposition of humus results in compounds


with lower C/N-ratios. In soils in which the leaching of the humus is fairly slow,the C/N-ratios will decrease with depth.

However, if the humification proceeds less rapidly than the percolation of thehumus through the soils, the C/N-ratios in the deeper horizons will be largelyinfluenced by the humus compounds which are more soluble and better transportable(compare differences between fulvic acid und humic acid, page 41). These com-pounds have higher C/N-ratios. In leached and coarse textured soils the C/N-ratio may increase with depth (e.g. podzols, see TAN et al., 1961). The accumula-tion of humus in podzols has been discussed by DEB (1950). Some authors supposethat this action is due to an increase in divalent cations or ferric ions. However,the investigations of DEB proved that this is not the case. He assumes that theprecipitation of iron and organic acids is a microbiological process. VILENSKII(1957) has dealt with the fact that in podzols, under anaerobic conditions, theleached crenic acids (fulvic acids) are reduced by bacteria to apocrenic acids. Theapocrenates of ferric iron, manganese and aluminium are insoluble in water.

The decomposition and/or mineralization of the organic matter and its influenceon the transport of silica, aluminium and iron under humid conditions can nowbe accounted for. A review on thé mobility of these elements as related to organicmatter is given on pages 48 and 49.

Clay transport.

The transport of clay occurs under the following conditions: (MÜCKENHAUSEN,1962):

1. T h e m e c h a n i c a l t r a n s p o r t . Clay transport by rainwater from thetop horizons into cracks of the sub-soil, whereby the sandy parts are left. Thisclay forms coatings round the soil aggregates. This transport is only possible aftera warm and dry period in which the soil dries up to a certain depth, by which thefissures are formed, that is of course if the soils are not too sandy. In sandysoils, or generally in coarse parent material clay, if present at all, will be washeddown, but it will accumulate only on impermeable layers or in hollow rock surfaces.On the other hand, if the soils are too heavy it is hardly possible to analyse anincrease of the clay fraction in a subsoil horizon.

2. T h e s a t u r a t i o n of t h e c o m p l e x . The adsorption complex shouldbe partly saturated. In saturated soils the macro and micro aggregates are too stableand no clay segregation occurs. In soils with highly unsaturated complexes andconsequently an acid reaction, the clay minerals are decomposed. Iron and alumi-nium ions are set free and these sesquioxides produce a stable iron and aluminiumflock, and again no clay transport will arise. These very stable soil aggregates arewell known in red tropical soils. DESHPANDE, et al. 1964, doubt of the im-portance of iron oxides for aggregation of soils. Several investigations confirmedthat aluminium oxide can cement soil particles. Only the less stable micro-flockof the partly saturated soil will disintegrate so that the clay can move downwardin the soil profile.

WEATHERING AND SOIL FORMATION 45

3. T h e p r e s e n c e of c h e l a t e s . Chelates are organic compounds whichmay "embrace" other compounds or electrically charged combinations, which thenare neutralized. This "embracing" can also occur with clay minerals. However,in connection with the size of clay minerals this mechanism should take place witha chain of chelates or they must act like a "Schutzkolloid".

4. "S c h u t z k o 11 o i d". KUBIENA (1948) reports that also silica can act as a"Schutzkolloid", making the clay transportable. This action can be inactivated bydesiccation.

DUCHAUFOUR (i960) stresses the importance of the kind of humus for the claytransport as the most significant factor after the transport by gravitation water.Organic matter can be broken down into:

1. unsoluble humic acids, which can be tied to clay particles, thus being structurebuilding.

2. soluble humic compounds, which may disperse the clay. They cause iron andaluminium oxides to solve and form complexes with them that may migrate. Thisaction is enhanced by higher acidity and it is lowered by a higher concentrationof calcium.

Although indeed each of these processes is instrumental in the transportof clay in the soil, they do not act separately. An unstable soil aggregate can beformed if the adsorption complex becomes partly unsaturated. In this fairly acidstate the humus compounds will be more soluble. A chelate will be more active inthis environment. The leaching will be quantitatively greater when there are manycracks in the soil than when the clay particles have to move through the soil pores.The clay will precipitate or remain behind at the horizon where the cracks end orthe pores are finer and the percolation of the suspension is very low. This, however,can also be caused by the presence of- a watertable and also if the chelating organiccompounds are destroyed or at horizons where the saturation of the adsorptioncomplex increases.

In cases of clay transport in the soil, the silica/aluminium oxide ratio will remainconstant throughout the profile.

As regards the soils in the Star Mountains region it may be stated that in mostcases the saturation of the adsorption complex is very low. The leaching due to theexcess of precipitation and the very acid humus forms in the generally poor soilsdo not make it probable that clay transport takes place through the solum. On theother hand, decomposition of the clay minerals will be the acting process in theupper horizons. From this decomposition a relative increase in the percentage ofclay with depth could be expected. Finally especially on terraces, horizons withhigher clay content are often present in the subsoil. This may be the result of theoriginal sedimentation or of the factor of decomposition just mentioned or of theformation of clay under the influence of impeded drainage.

Still in some places a kind of clay coating was discovered. These coatings arenot the wellknown thin brown humic-iron clay covers around soil aggregates with


generally lighter colours, but a kind of gelatinous clayey material transportedby rainwater into cracks and larger pores. They were visible only in a few placesin the soil profile. They are called semi-coatings. This is definitely a kind of claytransport but not the same as found by normal "lessivage". On flat sites as wellas on slopes it can be observed that on the surface of the ground a milky flow isformed owing to the destructional forces of the rain drops on very weakaggregates. The sand fraction is left and the suspension of partly decomposedclay and of the decomposition products is removed. This produces locally some sortof clay translocation. Generally it is one of the reasons why the top soils in such-like areas show a lighter texture than the subsoil.

Destruction of clay minerals.

Clay minerals are formed as soon as primary minerals weather. This occurs atthe boundary of the parent material. In stable condition and under the protectioncover of the vegetation a thick weathered layer will gradually be formed. However,if the destructive power of the percolating solution is very excessive even the clayminerals which are formed in the initial contact with the parent material aredestroyed and only the most resistant minerals are preserved.

The destruction of clay takes place if the complex is strongly unsaturated, theacidity is lower than the abrasion pH of the clay minerals present (see page 48)and there is an acid type of humus (C/N-ratio high). In the area surveyed theseconditions are mostly fulfilled because of the high precipitation, severely leaching,the acid soil reaction and the moder to mor humus.

Leaching and mobility of silicium, aluminium and iron.

Often the weathering is initiated by mechanical disintegration of the rockafter which the chemical weathering starts. However, this is not the generalrule. In many cases weathering begins with hydrolysis by rain water, possiblyenhanced by carbonic acid, which is dissolved in water and produced by e.g.bacteria and lichens and sometimes by higher plants. This hydrolysis may result indifferences in pressure in the parent material by which the mechanical destructionis increased. The surface which can be affected becomes enlarged; the chemicalweathering is still more intensified, etc.

Alkali and alkaline earth metals are removed first. They may cause a slightalkaline reaction, but as soon as there is sufficient soil material, this is not neces-sary. The majority of the minerals are silicates and the main constituents aresilicium, aluminium and iron. These elements play a dominant part in soil genesis.In the following special attention will be given to the conditions in which theyare mobile, whereas at the end of this chapter also titanium will be considered.

The classic conception that podzolization takes place under acid and laterizationunder alkaline conditions will be submitted to a closer examination. Most soilsin humid climates are acid, independent either they are podzolic or lateritic:besides, there are alkaline podzols as well as alkaline latosols. During the last


few decades several authors have not only given field descriptions and analyticaldata, but they have tried to explain how a certain soil is formed.

The weathering of the silicates is a very complicated affair and the behaviourof aluminium and silicium is not yet well known. The following concept isabstracted from the publications of BONIFAS (1959), Di GLERIA (1962),D'HOORE (1953, I954), CoRRENS ( I94O, I961, I962), MlLLOT (i960).

An endeavour is made to give a description in such a way that the lateritic andpodzolic weathering of the soil both under good and impeded drainage conditionscan be explained.

S i l i c i u m .Silicium can be soluble as mono silicic acid, H4SiO4, and as a polymer of this

acid, or as a colloidal solution of amorphic SiC>2. The solubility of mono silicic acidis much greater than those of the other silicium compounds.

The behaviour of silicium is discussed by MILLOT (i960). Under naturalconditions mono silicic acid was always found in free solution at a concentrationbelow 100-140 ppm at 250 C. Higher concentrations lead to polymerisation, bywhich colloidal solutions of amorphous silica are formed. In rivers, seas, and in thesoil the concentration of mono silicic acid is always lower than the value mentioned.Above a pH 9 to 10 mono silicic acid is dissociated and the solubility is highlyincreased (see Fig. 6). This alkalinity is very exceptional in soils so that silicatransportation is not exclusively governed by this condition. Normally the solubilityof silicium is not influenced by the presence of other cations or salts. Only A1+3-ions, already in small amounts, can reduce the solubility enormously (see page 49).Soluble silicic acid is converted into the sol phase if the solubility product is ex-ceeded. Silica gel is formed from this sol through loss of water, e.g. caused byevaporation.

The solubility of silica gel, which is of submicroscopic size, depends on the pH10

TiOz

\

Fe2°3 A,203

V

FeO SiO2

'

*'2°3

O I 2 3 4 5 6 r 8 9 10 II 12 13 pHFig. 6. Solubility in relation to the pH of silicium, iron, aluminium and titanium (afterCORRENS, 1940; VON ENGELHARDT, 1940; ALEXANDER et al., 1954; VINOGRADOV, 1959;

KRAUSKOPF, 19.SQ).


(CORRENS, 1940), whereas it is increased when alkali metals are present, anddecreased when alkaline earth metals are in the solution (SCHEFFER et al., i960).The colloidal silica gel is hydrophile, and the amorphic state is only very slowlyconverted into opal, chalcedone or cristobalite. In the presence of calcium thisreaction proceeds at an advanced rate.

The conclusion can be drawn that silicium is always soluble in small concentra-tions, a solubility that is only reduced by aluminium ions. The relatively degreeof leaching of silicium in relation to aluminium depends on the amounts and theconditions by which these elements are mobile.

A l u m i n i u m .

Aluminium may occur in ionic state below pH 4-5 and above pH 10, (see Fig.6). In the former case aluminium ions A1+3 are present: under the latter condi-tions we find AIO3"3. Although these values are mostly not encountered in soils,the very acid conditions will be taken into account. Highly alkaline soils are notbeing met with in very humic regions.

In normal soil conditions a sol of aluminium hydroxide can be present. Thissol may, subsequently, be transported if protected by humus, chelates and otherorganic compounds. BLOOMFIELD (1953 and 1954) proved that the transport ofaluminium in the soil was not bound necessarily to an acid reaction, but resultedfrom the action of organic extracts of leaves at various pH's.

Chelates are stable only in weak acid and weak alkaline state, so that in veryacid environments transport of aluminium is due to transport in combination withhumus.According to KUBIENA (1948) and SCHEFFER and SCHACHTSCHABEL (i960)aluminium is also transportable if silica acts as „Schutzkolloid". These compoundshave not yet been very well studied.

An interesting report about weathering is given by KELLER (1958). Consideringthat the decomposition of aluminium silicates depends on the effect of H-ionsand the metal-ions on the relatively less soluble aluminium and silicium and is ruledby the rate of rainfall, the permeability of the regolith, the living flora and the com-position of the parent material, he emphasizes primarily the influence of the pHon various minerals. Each mineral has its own abrasion pH, that is the acidityfound in the very thin layer of weathering surrounding the mineral grain. It canbe measured by making a paste of the pulverized mineral and water. Nearly allminerals have an alkaline abrasion pH; e.g. taken into groups: amphiboles andpyroxenes 10 to n , feldspars 8 to 9 (albite 9 to 10), micas 7 to 9, calcite 8,aluminium oxides 6 to 7, quartz 6 to 7 and clay minerals 5 to 7. As regards thesolubilities of aluminium and silicic acid (see Fig. 6) KELLER distinguishes threepH- ranges:

pH 10 and higher: aluminium and silicium soluble;pH 7 to 9.5: aluminium immobile, silicium mobile;pH 4.5 to 7: aluminium immobile and silicium mobility low.


In the first two ranges bauxite can be formed if silicium is leached. In the lastrange the circumstances are favourable to recombination of aluminium hydroxideand silicium acid to i : i clay minerals, (kandites),provided the Si/Al-ratio is low,and the concentration of H is high, and that of cations low. The 2 : i-layer clayminerals will be formed under conditions of a high Si/Al-ratio and high M/H-ratio1). However, the suitable conditions for clay mineral formation also dependon precipitation and drainage. With good drainage and high rainfall during thewhole year there will generally be no concentration of metal ions in the soil liquid,and the silica will be leached completely and no clay minerals will be found.However, if there are dry periods crystallization of clay minerals, kandites ormicas, may occur and in cases of very scarce rainfall, leading to saturatedconditions, even montmorillonite can be formed. This tallies with the observationsof Fox et al. (1962), that in Hawaii, in soils derived from basalts, the leachingof silica is proportional to the precipitation if the drainage is perfect, e.g.1500-2500 mm results in a residue of gibbsite and goethite, and 250-750 mm resultsin a residue of kaolinite.

The abrasion pH of clay minerals lies in the range between 5 and 7 and explainswhy under normal soil conditions they are mostly very stable. If the acidityis lower than pH 5 they are broken down and aluminium and silicium are set free.By further decreasing pH the mobility of Al exceeds that of Si and suppresses itssolubility as may be concluded from the experiments of MILLOT (i960). Thismeans than when the pH is lowered during the weathering process and organicmatter does not play a part (mineralization) the genetic process will change by apH of about five from laterization into podzolization.

It also explains why in some cases large amounts of aluminium as well as ofsilicium can be leached out. This is for instance the case in acid lateritic soils, inwhich the pH fluctuates round the value five. In the case, that in the lowlandin tropical regions under very wet circumstances in acid parent material (sandysediments) and under influence of humic acids, the pH is permanently lower thanfive bleached or podzolized soils are normal. These conditions are dominant inlarge areas of the lowlands of New Guinea.

I r o n .Iron can be present in ionic state as ferric ion below a pH = 2 and as ferrous

ion below a pH = 5.5 (D'HOORE 1954). The latter is oxidized very easily innormal aerated soils, so that under normal conditions in most soils iron does notoccur in the ionic state. In very anaerobic or reducing environments iron may betransported as ferrous compounds, for instance as ferrous hydrocarbonate.

Ironhydroxide complexes can be translocated in different ways. Ferric oxidesprotected by silica are transportable. However, KUBIENA mentions that the ratio ofiron to silica will be about 1 : 13. Iron can also be mobile as ferric oxide protectedby humus compounds, chelates or organic complexes. They are the most

(H = hydrogenium ions; M = metal ions).


important carriers of iron moving through the soil. Especially the transport ofiron runs parallel to that of aluminium. Podzolization under influence of organicextracts is possible with any soil pH in the range of 4 to 8.

In conclusion it may be said, that relative mobility of silicium, aluminium andiron depends on the nature of the decompositional products of the organic matter.

If there are enough organic acids in the soil profile, and these acids incombination with cations are soluble in the soil solution, the transport of iron andaluminium will be constant. As organic iron compounds are leached more thanthose of aluminium, the Al2O3/Fe2O3-ratio will decrease with depth.

If the mineralization is strong, the amount of humic acids in the soil will bevery small and the transport of silica will be greater than that of iron andaluminium. However, if the strong mineralization produces a high carbon dioxidecontent in the soil, so that the pH drops below five, the leaching of aluminium willbe more evident and in that case the Al2O3/Fe2O3-ratio increases with depth.Temporarily drier interludes or periods of higher temperature cause volatilizationof the carbon dioxide, resulting in a decrease of the possibility of the transportof aluminium and an increase of the leaching of silica.

In a zone of a certain elevation the influence of carbon dioxide and of humusacids in the soil will be equal. In such cases the leaching of aluminium and ironcombinations will not differ very much.

Titanium.

Titanium has been determined as an accessory element, as the possibility existedthat the percentage in which it occurred might be indicative for the variousprocesses of soil formation.

A further consideration has been that the behaviour of the element in soil genesisis not well known, as follows from an extensive discussion by VINOGRADOV

(1959), and that some interesting data might emerge.Titanium is mostly found in stable minerals, which are accumulated in the final

products of weathering in strongly leached horizons. In ionic state titanium issoluble only at an acidity lower than pH = 2. However, titanium is supposedto be mobile as a colloidal organic compound, thereby showing resemblance to thesesquioxides. One might therefore expect some concentration in the B horizonof podzols, an assumption, which was clearly confirmed.

It should be also a logical consequence if titanium was present in higherpercentages in tropical soils as in soils developed in temperated regions. In thetoposequence of the Star Mountain area this assumption concurs likewise withthe established facts.

In the Star Mountains region and the southern lying lowland the averagetitanium oxide content in the soils are higher (latosolic soils 1-2.5 % a nd podzolicsoils 0.4-1.3 %) than in many soil types in other countries (compare also KOVDA

et al., 1964).


Formation of clay minerals.

Some broad lines on the formation of clay minerals may be quoted fromJASMUND (1955) and JACKSON (1959). The state of weathering or the richnessin cations seems to be of the greatest importance. The concentration of cations inthe soil solution is reflected by the pH.

Higher pH-values lead to clay minerals with higher SiO2/Al2O3-ratios, togetherwith potassium and calcium ions illites will crystallize.

In recent and undeveloped soils, such as lithosols, regosols, alluvial soils, brownearths, etc. illite is the dominant clay mineral. Also in regions where the chemicalweathering is stopped during a longer period caused by frost, illite is present.The formation of this clay mineral can be the result of the weathering of feld-spar, augite and K-micas, but the presence of potassium is necessary. Higher con-centrations of magnesium and calcium lead to the formation of montmorillonites.The weathering of biotite, serpentine and olivine, by which potassium and mag-nesium are set free results in vermiculite. Variable concentrations of magnesium,aluminium and iron cause chlorite to be formed out of the weathering productsof olivine and augite. By fresh formation of chlorite in the soil mostly aluminium-iron chlorite is built up, while the primary weathering of rocks mostly results inmagnesium chlorite (SCHEFFER and SCHACHTSCHABEL, i960). Also BROWN(1955) reports chlorite varieties rich in iron.

The weathering of micas to montmorillonite may lead via illite. On the otherhand, illite can also be formed as a result of weathering of montmorillonite.

Lower pH-values lead to the formation of clay compounds with low SiC^/A^C^-ratios, whereby the kaolinitic clay minerals are formed. These circumstances arepresent in soils in humid tropical regions, in which the leaching of bases is severeand silica is stronger leached than aluminium as a result of the rapid mineralizationof humic compounds. As for the dominating process of soil formation in thetropics, the laterization, extensive data are to be found in LACROIX (1913),HARRISON (1934), D'HOORE (1953 and 1954), MOHR and VAN BAREN (1959)and LENEUF (1959). These authors distinguish between primary or crustweathering and kaolinite weathering. From the katamorphism of basic parentrock primary weathering may result: alkali and alkaline earth metals and silicaare leached and hydrargillite is left. This process takes place relatively quickly(ABBOTT, 1958). At a greater distance from the rock or in the weathering mantlealready formed, in other words, in higher horizons, resilification may occur. Fromthis process kaolinite arises. In acid parent material kaolinite is produced directly,without the intermediate phase of primary laterization. On intermediate parentmaterial lateritic profiles are found with variable percentages of gibbsite andkaolinite. Independent of parent material, if the drainage conditions are im-peded the silica is not leached completely and the remaining silica and liberatedaluminiumhydroxide form the kaolinite (RUSSELL, 1950; BALDWIN and THORP,1940). It should be stressed here that the drainage conditions are to a certainextent independent of the climatological conditions. A stagnant water level in the


soil profile may occur in a climate with a long dry interlude. On the other hand,if drainage conditions are very favourable there is a relationship between theamount of silica leached and the total precipitation (see page 49 and FOX et al.,1962). Also MOHR and VAN BAREN (1959) give a diagram in which the relationis sketched between precipitation and the kaolinite percentage present in the soilcolloids of a number of soils on Hawaii (after TANADA, 1944). The higher theprecipitation the lower the percentages of kaolinite.

In a recent publication VAN DER MERVVE and W E B E R (1963) report similarresults on soils in South Africa. Mixed layered illite-montmorillonites, illite, andkaolinite and gibbsite are successively dominant in the clay fraction of soils inregions with increasing rainfall from less than 400 mm up to over 900 mm.

KELLER (1958) reports that montmorillonite can be produced under conditionsof scanty rainfall through alkaline reaction. The concentration of aluminium, sili-cium and metal ions is increased by evaporation of the water. Under certainconditions also montmorillonite is present in lateritic soils derived from basalt(see e.g. BONIFAS, 1959).

It should be recorded that many rocks, and specially sedimentary, already con-tain various amounts of clay minerals (DUPLAIX et al., i960), e.g. montmorillo-nites in limestone deposits so that the clay mineralogy of related soils may showthe inheritage of earlier weathering cycles.

CHAPTER IX

SOIL TYPES OF OTHER MOUNTAIN REGIONS

In this chapter some mountainous soils and toposequences in other places inthe world will be dealt with. Moreover, some definitions and characteristics ofsoil types will be given or discussed. Although it is impossible to be complete inthis matter, it is thought to be useful to make some comparisons and give somecomments.

The investigations of TAN and VAN SCHUYLENBORGH (1961), carried out inIndonesia lead to the distinguishing of a number of soils as summarized intable IV.

TABLE IV

G r e a t S o i l G r o u p s f o r m e d on d i f f e r e n t p a r e n t m a t e r i a la n d c l i m a t e s u n d e r c o n d i t i o n s of p e r f e c t d r a i n a g e a s

o c c u r r i n g in I n d o n e s i a .Soil Group Parent

materialH u m i d c l i m a t e

Humic Gray Brown Podzolic soil Andesitic tuffTropical Gray Brown Podzolic soil ,, ,,Acid Brown Earth „ „Podzolic Latosol „ ,,

Altitudein meters

> 1300

1300-1000

1000- 600

600- 350

Temperaturei n ° C

> 18.518.5-20.520.5-22.5

22.5-24.0

SOIL TYPES OF OTHER MOUNTAIN REGIONS 53

Reddish Brown and Red Latosol Andesitic tuff 350- o 24.0-26.5Humus Iron Podzol Liparitic tuff 2000-1500 14.5-17.5Podzol-Brown Podzolic Intergrade „ „ 1500-1100 17.5-20.0Brown Podzolic soil „ „ 1100- 500 20.0-23.5Red and Yellow Podzolic soil „ „ 500- o 23.5-26.5

M o n s o o n c l i m a t e

Brown Podzolic soil Andesitic tuff 3400-2500 6.0-11.5Non Calcic Brown Forest soil „ ,, 2500-1400 11.5-18.0Latosolic Brown Forest soil „ „ 1400-1000 18.0-20.5Brown Latosol „ ,, 1000- 600 20.5-22.5Reddish Brown Latosol „ „ 600- 300 22.5-24.5

Another toposequence of mountain soils in the tropics is reported from theKenya highlands by THORP and BELIUS (i960). The acidity, the total carbon con-tent in the upper horizons and the thickness of these horizons increase with higherrainfall and lower temperature, which go parallel with increasing height. However,in this region a seasonal rainfall is found, that ranges between 500 mm and2000 mm yearly. Compared with the New Guinea circumstances these figures arerather low. At an elevation of about 3000 m moor soils are present. At lowerregions, owing to the relatively dry climatological conditions and high temperature,brown soils, chestnut soils, chernozems and red soils occur.

RODE (1962) has reported on the mountain soils of the Caucasus. Schematicallythe vertical zonality in the distribution of soil groups can be given as follows(according to ZAKHAROV):

TABLE V

S o i l z o n e s on n o r t h e r n a n d s o u t h eM a i n C a u c a s u s

NE-slopes:Elevation Elevation

in m. in m.4000-3000 perennial snow 4000-32003000-2200 bare rocks 3200-260022Ó0-1700 mountain meadow and 2600-2100

mountain tundra soils1700-1200 mountain forest podzolic 2100-1700

soils1200- 750 gray mountain forest soils 1700-1200750- 250 mountain steppe soils 1200- 500

250- o serozems 500- o

rn s l o p e s of t h e

SW-slopes:

perennial snowbare rocksmountain meadow andmountain tundra soilsmountain forest podzolicsoilsgray mountain forest soilsmountain forest brownsoils (burozems)red earth (krasnozems)and yellow earth (zhelto-zems)


'The northern foot of these mountains is situated in a steppe climate. Thesouthern foot has a sub-tropical semi-humid climate, with a temperature stronglyfluctuating during the year, averaging 150 C and a precipitation of 1500 mm to2500 mm.

However, the precipitation is generally less than the last value. The krasnozemsshow an acidity of about pH = 5, and a saturation of 4 to 6 percent throughoutthe profile, by which aluminium probably is not taken into account.

The most remarkable mountain soil type is the burozem. Characteristics are:a leaching of aluminium, by which silica is relatively accumulated in the top-horizons (Si02/Al2C>3-ratios: 6.8, 5.7 and 5.3 with increasing depth). Whereasalso the iron content in the horizons is high (12-14 %) showing no effect ofleaching (SiO2/Fe2C>3-ratios: 13.0, 13.2 and 11.3 with increasing depth, calculatedon the total soil). The saturation is between 81 and 90 percent. These figures,together with the lack of clear morphological horizons, indicate the difference withpodzolic soils whereby iron is leached. Although the soils are relatively high inhumus, which gradually decreases with depth (50 cm: 1.5 %) , the kind of humusmust be very stable and mineralization in warm summers must occur, so thataluminium is leached and iron does not. The burozems tend to chernozems.

Some data on the still drier and eastern part of the Caucasus is given by ALIEV(i960). Here the influence of a dry climate is even greater. At an elevation ofabout 2200 m mountain meadow soils, which are turfy or peaty are encountered,but at lower heights less leached soils and reddish earths occur, such as humus-carbonated soils ("rendzina-like"), chernozem-like soils, cinnamon mountain andsteppe soils. The lowest zone is occupied by salinized soils.

Some data on the soils in the mountains of South-America is given by SCHAU-FELBERGER (1952). Moor soils and humus- and ironortstein podzols occur at anelevation over 3000 m on granite parent material in the Central Andes Mountains.

STEPHENS (1961) has reported on moor peat and alpine humus soils, whichoccur above an elevation of 1000 m in the Australian mountains.

TAVERNIER and MÜCKENHAUSEN (i960) describe the mountain soils of WesternEurope. Generally the highest parts of the mountains are occupied by snow-covered areas, bare rocks and lithosols. The steeper and higher mountain slopescarry lithosols, rankers, rendzinas and podzolized soils. In the subdued mountainsin the northern and center parts we find also brown forest soils, acid brown forestsoils, gray brown podzolic soils, while in the southern subdued mountains in theMediterranean region we encounter red mediterranean soils, rubrozems, reddishbrown soils and red-yellow podzolic soils.

As the dominating genetic process in the mountainous region is podzolization,a number of podzolic soil types are enumerated. Descriptions of TAVERNIER andSMITH (1957), and those given in the Yearbook of the U.S. Dept. of Agr. 1938,Soils and Men, combined with our experiences, result in the following character-istics of some podzolic great soilgroups:

"So l b r u n a c i d e " or a c i d b r o w n e a r t h is a soil with a B-paren-

SOIL TYPES OF OTHER MOUNTAIN REGIONS 55

thesis, (B), of which the adsorption complex is unsaturated, the formation ofsilicate clays is slight, and in which the eluviation and illuviation of oxides or clayis very low. This type is formed on moderately acid parent material.

The moder humus is characteristic; the soil reaction is acid to strongly acid.

The g r a y b r o w n p o d z o l i c s o i l is a soil with an appreciable contentof adsorbed bases so that the degree of saturation is medium and there is a trans-port or lessivage of undecomposed clay, which causes a B-texture, (Bt).

The activity of micro-organisms in the top soil is high, leading to a fairly rapiddecomposition of the organic matter, resulting in a mull type of humus. Thesoil reaction is weakly acid to acid.

The b r o w n p o d z o l i c s o i l is a soil with a pronounced podzolic character,having a decomposition of clay and other minerals in the top horizons and aleaching of sesquioxides to lower strata. Only a shallow A2-horizon is present.The saturation of the adsorption complex is low; the soil reaction is very acid.

The p o d z o l s are mostly developed on mineral-poor and sandy material.There is a pronounced destruction of the clay minerals and other minerals inthe topsoil and eluviation and illuviation of sesquioxides. As a result of the ratherpoor mineral composition and the coarse texture we find a strongly bleachedA2-horizon. Whether a B-horizon will be found, and what its nature will be isparticularly caused by the drainage conditions in the profile.

The classification of derno-podzolic soils and podzols according to RODE (1962)reads as follows:

weakly derno-podzolic: having an A1 ; an intermitted, small and patchy, lightcoloured A2 , and a not very pronounced B;

medium derno-podzolic: having an A1( A2 well-marked but thinner as A1 ; amarked B;

strongly derno-podzolic:. having A1 ; A2 thicker than A1 ; well-developed B;podzols: A2 well-developed, a pronounced and sharp B (Ax is

missing).

The first three types can occur on any parent material, the proper podzols areonly found on coarsely textured material.

In the system of RODE the rate of podzolization is expressed in morphologicalterms. However, as this process is a result of chemical destruction, difficultieswill arise if the chemical leaching of weakly podzolized soils is found to be muchstronger than that of real podzols.

LYFORD (1946) gives a review on some brown podzolic soils in NorthernAmerica.

This soil type is situated in a large bend near the frontier of the United Statesand Canada, north of the Great Lakes, and from the east coast to the west coastfrom the State of Washington to the State of Massachusetts. North of this belt


the podzol soils occur, while south of it near the east coast the gray brown podzolicsoils are found.

The horizon sequence of the brown podzolic soils is: Ao (0-5 cm); A1

(5-12.5 cm) very dark-grayish brown sandy loam or loam; A2 (barely visible,but mostly absent); B2i (12.5-20 cm) yellowish-brown fine sandy loam to loam(B-hor. is heavier than the A-hor.); B22 (20-35 c m ) yellowish-brown fine sandyloam or loam; B23 (35-55 cm) yellowish-brown fine sandy loam or loam; B3

(55-75 cm) light yellowish-brown, with texture similar to the underlying horizon;C consists of material deposited by glacial till.

A point of interest is that the brown podzolics in the western states differ fromthose in the eastern states in that the former contain a large number of rounded,dark iron concretions or "shot" in the A-horizon and in the upper part of theB-horizon. This occurrence is not explained. However, the same differences arefound in the Star Mountains and the presence of iron concretions in podzolizedsoils in these instances is explained as a relic of a former soil genesis (seepage 128).

CHAPTER X

MINERALOGICAL ANALYSIS OF THE SAND FRACTION

The mineralogical composition is one of the characteristics of a soil. This isparticularly the case with regard to:

1. The source of the material, including its relationship to the underlying rock.2. The homogeneity of the soil profile (compare VAN BAREN and KIEL, 1956).3. The stage of weathering of the whole soil and its individual horizon.

Heavy minerals.

Since in most soils quartz and feldspars form the greater part of the sand-fraction and because those minerals are less specific, the heavy fraction has beenused as a diagnostic feature (EDELMAN, 1933; VAN BAREN, 1934), though alsosome attention has been paid to the sand fraction as a whole.

The results of the mineralogical analyses indicate great conformity with theunits of the aerial photo analysis and the formations on the geological map, asfollows from the mineral assemblages as listed below (see table VI).

Mineralogical associations.

The following mineralogical associations can be derived from the various dataon the heavy minerals of the profiles analysed.

M e r a u k e t r a n s g r e s s i o n f o r m a t i o n . 1305/11.Association: zircon, epidote; other minerals: tourmaline, garnet, hornblende, rutile,

anatase, brookite, titanite and andalusite. continued on page 61

MINERALOGICAL ANALYSIS OF THE SAND FRACTION

TABLE VI

57

Soa

epth

P

paqu

O

n3u

rm

H

rcon

Nar

net

O

0)

Nriaofei

0)

(Tl

esuv

i

>

util

e

K

0)

nata

s

<

rook

i

itani

l

H

.-S

;aur

o

(D

yani

l

M

!"'55

ndal

u +JO

•o'ftW

mT )Cl1)

ornb

i

•o

len

, Û

c

O

thug

iteyp

ers

DÖ

sn.

auco

O

îlor

it

O

]

13050 60 7

0 80 91 0

1 1

2450

5 152

53545556

1 9 1

9 2

9394 2)95 2)

2 0 4

°50 60 70 8

2 2 2

2 32 42 52 6

2 5 0

5 152

53 2)

VIerauke.0- 15

15- 4040- 95

95-115115-140140-180

over 180

Vlappi. 50- 25

25- 5050- 8080-110

110-150150-180

over 180

0 m.

75789776846779

Alluvium. 1)2 1

2 2

19

79

172 6

363 132

472 32 0

13

51 2

1 2

5586

m. Alluvium. 1)484732

34484845

Tanah Merah.0- 55- 18

18- 50

50-115115-13°

95959889

1 0 0

88744

18

82 0

91 2

142

1

647 0

7579726358m.696 1

5881

Alluvium——

i

i

—

Djononggo. 100 m. Alluvium.0- 5

5- 2525- 6060-120

120-150

Wampon.0- 10

10- 25

25- 6060- 80

80-140

South of0- 55- 4°

40- 90

over go

97969996

971 6 0

9998989797

1 0

5834

m.1 0

52

43

736557708 0

2

—

—

—

—

Alluvium.385362

6563

Umkubun.—8 0

9 29 2

—543

—2 2

339

—

—

—

i

1

1 2

146

15876

2 419161 62 1

172 2

2 0

2 42 3

1

—

31 1

1 1

181 2

1 2

15171616

32

2

442

4

2

2

2

1

32

1 1

390 m. Alluvium—

72

1 1

—

132 0

2

1

—

1

1

1

—

1

1

—

—

—

—

—

1

31

432

2

2

—

1

—

—

—

—

—

I

I

I

I

I

I

16

1719

73026

19

2

1

41 0

!7172 2

33

1

31

3

—

1

1

33

—

1

—

2

914

16

94

2 32 1

1 2

916

4 24 0

1442

1

3

81

6

—1

2

—

—

2

1

2

—

2

—

J) analysed by W. L. P. J. Mouthaan. Treated with ammonia.2) insufficient non-opaque minerals.

SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

Tip

le N

r.

pth

in c

m.

Qaq

ue

OH

O

urm

alin

e

nH

con

N

met

mO

nazi

te

O

äuvi

anit

e

>

tile

3

atas

e

r!

Dok

ite

ffl

anit

e

H

Lur

olit

ean

ite

dalu

site

idot

e

OiW

rnbl

ende

oM

y-ho

rnbl

end

XO

gite

pers

then

elu

coph

ane

O

orite

2 4 54 6

4748

9 0

9 19 2

9394

8586

878889

2 6 5

666768

1555657

1352535455 *)

4 1 01 1

1 2

Jmkubun0- 55- 20

20- 9090-120

'Vrnjol. 3300- 10

10- 2020- 5050-110

110-130

Amjol. 5500- 66- 25

25- 3030-110

110-120

4 4 0

—

999596

m.76——8 1

77

m.—7 1—

—

56

Songgam. 7100- 10

10- 2222- 4545- 80

95999698

Betabip (West0- 15

15- 3535- 7°

8 1

7485

Crest of Utek0- 55- 20

20- 4040- 60

Molbakon.0- 88- 12

12- 25

98999999

m. Limestone.

18 579 53

19 43

Limestone.29 29

37 3625 49

5——

1

2

Limestone.

20 42

18 42

—

2

—

—

3

m. Limestone

14 539 644 698 68

Sibil).21 22

14 159 7

1

436

1300 m.

7 513 —11 —

—

18

2 9

2 5

1 1

—

—

1716

—

17—

—

15

171516

13

—

2

1

—

Limestone.392

Mountains. 1400 m.

1 1 1 1

13 1518.454 14

1

1

6—

1820 m. Limestone—889 0

— —22 219 27

—61

1

493

—8

1 2

5 1 121 1 —

Limestone.1

1

62

3 3 —3 1 1

—

—

1

—

—

1

—

—

—

—

—

1

1

—

1

—

5 —6 1

1 12 —

7 14

4 46 2

11 6

11 3

11 2310 3115 45

3 44— 1 54

2 121 4

5 322 44

3l— I

5 —

2 14 27 1

15 126 5

— 1

insufficient non-opaque minerals.

MINERALOGICAL ANALYSIS OF THE SAND FRACTION 59im

pie

Nr.

m

epth

in

cm.

0

paqu

e

Oou

rmal

ine

Hrc

onN

arne

t

Ü

onaz

ite

+•>

13

>

util

e

nata

se

« <

rook

ite

M

Ltan

ite

H

:aur

olite

yani

te

M

ndal

usit

e

<

pido

te

W

ombl

ende

E

xy-h

ornb

len

O

ugit

e

yper

sthe

ne

< E

[auc

opha

ne

O

ilor

ite

O

Temnomabe sigin. 2060 m. Limestone.4°5060708

0-

5-10-

40-

510

4080

86888999

16 5119 4417 4520 38

1921

21

18

5 —3 14 13 -

Burning Mountains. 2100 m. Limestone.413

14151617 i)

15-0-

2-

25-

O

2

2595

95-II5

9997979999

— 617

13

6 —5 43 2

Mol Mountains. 2150 m. Limestone.422

232425

435363738

818283

29303132

34353637

9596

20-

0-

10-

15-

0

10

1560

—

979793

20 12

17 13II 14

13II

7

354650

Juliana Mountains. 2550 m. Limestone.0-

5-40-

70-

540

7080

94899391

9 —5 —5 —

— 8 2

141712

12

North of Katem. 240 m. Bluish-gray siltstone.0 - 5 9 2 28 —5- 30 15 2 10 1

30- 50 15 1 8 1Debroka. 640 m. Bluish-gray siltstone.

0- 88- 20

20- 5050-100

74—7788

9 10 7

11 13

8 6

Near Debroka. 730 m. Bluish-gray siltstone.28 12 11°- 3

3- 2020- 5050-80

73—7292

7 1946

West of Katem. 200 m. (Digul) Alluvium,o- 10

10- 30 1 17

3431

1

41

12

11

13

11

910

19

1

382

12

730

747481

78

505348

1

2

—

1

1

—

— 31 41 4

———1

—

1

1

51723

2— 7

20 2

8

63

6069

5077

8 44 6 171) insufficient non-opaque minerals.

6o SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

"ft

aiO)

e

3th

in c

Oaq

ue

On

O

a

urm

alin

oH

con

N

met

at

O

naz

ite

o

3uvi

ani1

tile

atas

e

3 e

Dok

ite

m

anit

e

H

turo

lite

•00

anit

e

«

'553

"cdT lG

<

idot

e

ftW

o

rnbl

enc

oE

blen

dy-

Hor

n

XO

oc

gite

pers

the

3 >.

< X

a

luco

pha

O

ori

te

O

Iwur terrace. 400 m. Alluvium.i 8

192 O

2 1

2 42 52 6

48495 05 152

1

2

3456

1342

434445

3 0 40 50 60 7

3 0 80 91 0

1 0 -

0 -

5-1 5 -

[wur

0 -

1 0 -

0

515

5 0

—72

857 0

—1779

terrace. 600

1 0

3 030-110

—

1 2

—3i

Almun Wending.2 0 -

0 -

1 0 -

1 8 -

5 0 -

0

1 0

18

5 08 0

Vlabolabo]1 0 -

0 -

8-1 8 -2 8 -4 0 -

0

8182 84 07 0

—

78—

89

—

7——

i

(West656 176

537456

2 318162 61 1

15

^Jimdol. 1300 m.0 -

1 0 -

3 0 -6 0 -

Srote5-0 -

5"2 5 -

1 0

3 06 07 0

97969898

132 8

2 52 9

—

34524 2

m.——

2

780

—

63—

5i

—67

1 2

—

597

Alluvium.—2 42 0

m.—

4—

2

!4

Sibil).53586 0

596 1

65

——

1

—

1

1

Shales.4 0J71 9

!4

Beer Mountain0

52 575

Fop Grote5-0 -

5-

0

575

—

937699

—1 1

161 1

—2 1

2 8

2 3

54

—1

—

Conglomerate.———

1

1

—15—

2

—

—

—

—

1

—

[260 m. Alluvium.

1 2

2 0

18

132 315

2 1

1 1

1513

2 —— —

— 3

8 1

9 —5 17 1

1320 m. Slates.

—1

—

—

—

482

——

1

4

Beer Mountain. 1730 m. Slates.

—8 1

83

—

334 1

—

4635

—

—

2

—

1916

——

2

—

—

57

—76

—

7—

1

3

1

—

—

—

i 9 —11 7 — i 19 8 3 1 1

4 505 54

1852 73

— 9— 4

1 4— 2

1 2

— 1

— 16

3 321 342 34

I 62

I 46

3 57

MINERALOGICAL ANALYSIS OF THE SAND FRACTION 6 lSa

mpl

e

cm

g

Dep

th

Opa

qua

ali

1 T

ourm

Zir

con

Gar

net

m-M

Mon

azit

e|

Ves

uvi

Rut

ile

„, CDcy j j

Ana

tas

Bro

oki

Tit

anit

.-£

Sta

uro

Kya

ni'

o>

| A

ndal

i

Epi

doi

T3

«3

SoX

pu

orO

xy-H

Aug

ite

ene

Hyp

ers

ane

"ex,

Gla

uco o

Chl

orit

Mountain spur Antares Massif. 2125 m. Bluish-gray clay- or siltstone.

12-o-

o3

3- 88- 18

7380

99

15 33 —29 38 —

1 1

3 —6

21

Top Antares Mountain. 3250 m. Granodiorite.

++0 -

2 -

2-5"

1552

2-515

2328

41515

Top Antares Mountain. 3290 m. Granodiorite0 -

1 0 -

1 8 -

35-

1 0

18

355 0

2 72 0

2 6

4 1

41

rite1

1

9598

1 0 0

1 0 0

1 0 0

1 96TOO

— 99— 98

365666768

33536373839

340414243x) insufficient non-opaque minerals.

A l l u v i a l P l a i n of S o u t h e r n N e w G u i n e a f o r m a t i o n .2450/56, i9!/95-Association: zircon; other minerals: rutile, tourmaline, hornblende, andalusite,

garnet, brookite and titanite.The amount of easy weatherable minerals (pyriboles) decrease in seawarddirection.

B i r i m f o r m a t i o n . 204/08, 222/26.Association: zircon-hornblende; other minerals: rutile, tourmaline, augite, epidote,

hypersthene, garnet and andalusite.There is an increase of volcanic influence in northern direction, which is in-dicated by coarse-sized pyriboles.

B u r u f o r m a t i o n . 250/53.Association: hornblende-zircon; other minerals: rutile, tourmaline, garnet, augite,

epidote, hypersthene.

K a u l i m e s t o n e f o r m a t i o n . 245/48, 90/94, 85/89.Association: zircon-tourmaline; other minerals: rutile, epidote, hornblende,

garnet, andalusite, staurolite, kyanite, augite, glaucophane.


N e w G u i n e a l i m e s t o n e f o r m a t i o n . 265/68, 155/57, (1352/55), 405/08,410/12, 413/17.

Association: zircon-tourmaline; other minerals: rutile, hornblende, garnet, ana-tase, epidote, brookite, augite, titanite, hypersthene, monazite.In this formation there is variation in the amount of igneous minerals.

T r a n s i t i o n : New Guinea limestone — Iwur formation. 423/25, 435/38.Association: titanite-hornblende; as a result of the transition zone the other

minerals are subject to a great variation, they are: tourmaline, zircon, garnet,rutile, epidote, augite.

I w u r f o r m a t i o n . 81/84, 34/37. 29/32-Association: chlorite; other minerals: hornblende, garnet, zircon, tourmaline,

epidote, augite, rutile, hypersthene, andalusite, oxy-hornblende, vesuvianite.Locally the amount of hornblende is high.

K e m b e l a n g a n f o r m a t i o n . 1342/45, 304/07, 308/10, 365/68.Association: tourmaline-zircon; other minerals: rutile, hornblende, epidote, ana-

tase, brookite, andalusite, garnet, chlorite.There is a great variation in the amounts of hornblende.

A n t a r e s f o r m a t i o n . 335/39, 340/43-Association: hornblende; other minerals: zircon, garnet, titanite, epidote in very

small amounts.

K a t e m f o r m a t i o n , (alluvial deposits east of Katem, and also north-westof it) 18/23, 24/26, 48/52, 95/96.

Association: hornblende, the amounts of this mineral depend strongly on the stateof weathering. Other minerals: zircon, garnet, rutile, tourmaline, epidote,augite, hypersthene, oxy-hornblende, chlorite, andalusite, titanite, vesuvianite.The minerals have mostly a coarse granular size.

S i b i l f o r m a t i o n , (alluvial deposits in the Sibil valley) 1/6.Association: zircon-tourmaline-rutile; other minerals: hornblende, epidote, augite,

hypersthene, brookite, anatase, garnet. These minerals have a small grain size.

The history of the orogenesis, as mentioned on page 10, is reflected by themineralogical composition of the soils, developed on the rocks formed in theperiods concerned. In the terrigenous deposits (Iwur, Buru and Birim), formedduring the uplifts of the Central Range, erosion products are found, which arerich in hornblendes. This influence is greater in the Buru formation than in theBirim formation, while in the Iwur formation a transition of the hornblendes intochlorites took place. The mineralogical composition of the Birim formation hasbeen affected by recent volcanic material (augite, hypersthene) from the Mt.Koreon, Mt. Isil and Mt. Arem.

The result of the several geological and pedological weathering cycli successivelythe Iwur, the Buru and the Birim formation, is reflected in increasing percentages of

MINERALOGICAL ANALYSIS OF THE SAND FRACTION 6 3

zircon and other stable minerals, finding its final stage in the most recent depositsof the Alluvial Plain of Southern New Guinea. In presence of lime the titaniumbearing chloritic minerals — originating from amphibole-rich parent material —may alter into titanite. These circumstances are favourable in the transition zoneof the Iwur and New Guinea limestone formations.

The limestone formations have been built up in the interludes between theuplifts of the Central range. In these periods deeper soils have been developed inwhich more stable minerals are left. They were supplied to the sedimentation areasby rivers after the soils had been attacked by weak erosion. The heavy mineralspresent in the soils developed on the limestone formations have a smaller granularcomposition than those found in the terrigenous deposits.

The Kembelangan formation belongs to a much older erosion cycle, in whichterrigenous sediments were deposited. The variation in the amounts of pyribolesis high. No correlation can be made with other formations. Possibly the sedimentsrounded by a zone of augite-quartz diorite. In the contact zone with the limestone

The mineralogical composition of the Antares formation, which consists ofgranodiorite, is very rich in hornblendes. This central intrusive cone is sur-rounded by a zone of augite-quartz diorite. In the contact zone with the limestonethe quartz diorite contains exogenetic enclosures of a calcite-garnet-vesuvianiterock (BÄR, et al. 1961). The Antares massif forms the main source for the horn-blendes found in the other formations.

The Katem formation reflects the mineralogical composition of the soilsdeveloped on the rocks of the hinterland, namely those found in the Antares-,Kembelangan-, New Guinea limestone-, and Iwur formations.

The Sibil formation is composed of minerals originating from the surroundingKembelangan- and New Guinea limestone formation. As a result of the severepedogenetic weathering the stable minerals are dominant.

Some complementary notes on the total sand fraction.

Apart from the heavy mineral associations, discussed above, some general remarkson the other components may be made.

Profile 191/95. The iron concretions are abundant in the three higher horizonsand fairly small in the lower ones, taken on the total amount of sand.

Profile 204/08. The quantity of iron concretions decreases with depth. Accordingto the shape and structure of the iron concretions one gets the impression thathornblendes have been weathered into iron concretions. Magnetite is present in thewhole profile in moderate amounts. Gibbsite is found in a very small numberwith a relative increase in the third and lower horizon. In these same horizonsseveral stages of weathering of biotite were observed, which form transitions tokaolinite (compare MOHR and VAN BAREN, 1959, pg. 245, Fig. 42).

Profile 222/26. Iron concretions are present throughout the profile. Especiallyfrom Nr. 224 on they decrease with depth. Light yellow aluminium concretionsincrease with depth, in the lower horizons greater particles of these concretions


are found. Chalcedone particles increase with depth. The samples show a numberof kaolinite grains.

Profile 245/48. The percentages of iron concretions are very low, with a slightincrease in Nr. 248. Whitish chalcedone particles are very regularly distributedover the profile.

Profile 90/94. In the profile only some iron concretions and some chalcedoneoccur, which increase with depth. In the lower horizon some feldspars are present.

Profile 85/89. Very few iron concretions occur in the sand fraction; also veryfew chalcedone particles; some micas were observed.

Profile 265/68. Very large and many iron concretions are detected in thetopmost horizons, the number of concretions decreases with depth. Chalcedone isfound in every sample in moderate quantities, with a slight increase in sampleNr. 266.

Profile 155/57. Very few iron concretions are present: some coarse, dark-browngrains in the topsoil and some yellowish-brown in the lower horizon. In theprofile chalcedone particles are found in small amounts, which decrease withdepth. Some Y-shaped and tubular phytolites are present.

Profile 1352/55. In the top horizon there are many iron concretions, the percen-tage is strongly decreasing with depth. The amount of chalcedone particles in-creases with depth.

Profile 410/12. In Nrs. 411 and 412 chalcedone particles are present. Very fewiron concretions were observed. Some gibbsite grains were perceived.

Profile 405/08. Hardly any iron concretions were found. Chalcedone particlesare observed in the whole profile, and the amount decreases with depth.

Profile 413/17. Very few iron concretions were noticed. Chalcedone was present,but distributed over the profile without a certain trend.

Profile 422/25. The percentage of iron concretions in the profile is very low.In Nr. 423 fairly great chalcedone particles are found, in the lower horizonsthe amounts decrease with depth. At the bottom some partly weathered feldsparsoccur.

Profile 435/38. In the profile iron concretions are seen in fair amounts. Alsochalcedone occurs throughout the whole profile.

Profile 81/83. The fine sand contains some orthoclase crystals and some chalce-done particles.

Profile 1342/45. Very few iron concretions occur in the whole profile with aslight accumulation in Nr. 1345. Chalcedone is found in the entire profile andshows a slight increase with depth. Some muscovite and chlorite were observed.

Profile 308/10. Very few iron concretions are present. Most of them are foundin the top sample. In connection with the lower horizons chalcedone shows a slightincrease in the top. At the bottom of the profile a single gibbsite grain wasnoticed.

MINERALOGICAL ANALYSIS OF THE SAND FRACTION 65

Profile 335/39. This profile is discussed in detail on page 136.Profile 340/43. Orthoclase is fairly abundant, also some intermediate plagio-

clase crystals occur. In Nr. 340 much lower amounts of dark minerals andfeldspars are observed than in the other horizons. The percentages of magnetiteincrease with depth. Biotite is found in the whole profile.

Some remarks on the magnetic sand fraction.

Soils formed on sediments, being weathering products of the Antares Massif(granodiorite), contain a relatively high percentage of heavy minerals. Theseminerals are predominately hornblende and opaque compounds. The latter aremainly magnetic ironoxides. This magnetic fraction was separated from severalsamples in order to get a better preparation for the counting. It was weighed andthe ratios of the magnetic fraction to the total heavy fraction were determined.The values are given in the following table. The first four profiles are situatedeast of Katem, while the other two are found in the lowland and on the top ofthe Antares respectively.

TABLE VII

Magnetic fraction (MF) in relation to the total heavy fraction (THF) and depth.

Sample Nr. Depth in cm MF in perc. Soil typesof THF

565758

2526

20

21

5152

204

05060708

340414243

52560

20

70

20

40

5080

3154090

5142540

10.2

24.7

12.3134

0.42.7

0.71.8

5352647985

24253560

sol brun acide, onrecent alluvium

sol brun acide,on lower terrace

strongly podzolizedsoil, on lower terrace

peaty podzol, on oldhigher terrace

podzolized latosolon old alluvium

sol brun acide on summitAntares


From these figures it follows that the magnetic/total-ratio is increasing withdepth and that the ratios in various profiles seem to reflect the extent of timeduring which weathering took place. Consequently, it may obviously be assumedthat the magnetic fraction has been attacked by humic and other acids in the soils,and especially in the higher horizons. The increase in podzolic soils is greaterthan that in (podzolized) latosols. This would mean that magnetite weathers underthe prevailing conditions more rapidly than do hornblendes and related minerals.This is also demonstrated in the mineral composition of profile Nr. 335/39 givenon page 137.

CHAPTER XI

DESCRIPTION AND ANALYSES OF THE SOIL PROFILE

The descriptions of the soil profiles have been kept as brief as possible andhave been given according to the standards used in the Soil Survey Manual (1951)and the 7th. Approximation of the Soil Survey Staff (i960). The soil sampleswere taken just in the middle of a horizon described.

The analyses were partly carried out in the laboratory of the Royal TropicalInstitute at Amsterdam, and partly in the laboratory of the Soils Departmentof the University of Utrecht, following standard procedures (see among ohers,JACKSON, i960).

The total analyses of the clay fraction as well as of the fine earth (total soilsmaller than 2 mm) were performed with Philips' X-ray fluorescence apparatus.

The samples were fused into a glass with lithium borate in a ratio of 1 : 5, inorder to eliminate disturbances. The percentages of the oxides given in the tableshave been corrected for absorption effects. The details of the procedure have beenpublished elsewhere (REYNDERS, 1964).

The mineralogical composition of the clay fraction of all samples was studiedby X-ray investigation with the aid of Debije-Scherrer powder cameras. A greatnumber of clays was selected for differential thermal analysis (d.t.a.). Theanalytical methods used are based on information derived from BRINDLEY(1951), GRIM (1953), JASMUND (1955), KUNZE (1955), MACKENZIE (1957)and BROWN (1961). A review of the shifting of the basal reflections (001) ofthe X-ray records of various clay minerals (and interstratified modifications) isgiven in figure 7, (revised and according to LUCAS, et al. 1959). Some typicalX-ray records are given in figures 8 and 9 (facing page 1241125).

The d.t.a. analyses of the most strongly weathered minerals of the Star Mountainssoils give rise to many indistinctnesses or apparent deviations as compared with theX-ray data. This is discussed in detail by ARENS (1951), VAN DER MAREL(1956) and KELLEY (1956). Interesting investigations in this domain and speciallyon the weathering of montmorillonite are reported by HIGASHI (1961) andHiGASHi and AOMINE (1962). The severe leaching of montmorillonite led to ad.t.a. curve of a beidellitic montmorillonite or even a halloysite curve. These pheno-mena were also observed in the analyses of the samples of the Star Mountains soils.

DESCRIPTION AND ANALYSES OF THE SOIL PROFILE 67

1

(

8A 1

G

SA

• * —

1

—I

—<

—«

4Â

•

»—

» —

?• —G

i?

1

- » • •

— • • >

2Â

H

1

G

SG

1

— h

r

(

oA

^

H

)

Ï--

7

i

A

Montmorillonite.,

VermlcuPte

C - V

Chlorite

M,2-V

I-M14

I - V

I - C

I M

llllt e

Halloyslte

i Kaolinite

GrGlycolated H = Heated h = heated and disappeared

Fig. 7. X-ray diffraction lines in A of clay minerals and interstratified clay minerals(modified after LUCAS, et al., 1959).

The X-ray diffraction analysis shows that the 001-reflections become weaker anddiffuse by weathering. The weathering disturbs primarily the surfaces of theintermolecular plates. Locally small lattices of other clay minerals can be formedin the original lattice.

The interpretation of the X-ray films met with some difficulties as in mostcases more than one mineral is present. A comparing and abstracting system asadopted by e.g. SACHEZ CALVO (1963) has been applied.

The clay minerals have been indicated in the analytical lists as follows: M =montmorillonite, iM = interstratified montmorillonite, I = illite, Ch — chlorite,K = kaolinite, dK = disordered kaolinite, G = gibbsite, Q = quartz, Cr =cristobalite, An = anatase, Go = goethite.

The amounts of clay minerals present in the clay fraction have been evaluated as:

continued on page 11S

A N A L Y T I C A L D A T A

Soil type-: Podzolized, gley l a t e r i t e

Sample Nrs. 191/95

Sample

number

Hori-

Depth

in

Partiole size distribution Isand ! silt I clay t

! 50,n- 20,u- ! !

J 2 0 3 < 2 M2 mm- 200/1200^1 50/1

pH

Organic

matter

Cations adsorption complexm. aeq. p. 100 gram

20M < KC1 C/N Ca Mg K Na TEB(S)

CEC(T)

Sat.(V)

O

MC/1

C/1

>

19119?193194195

IC2°

0- 55- 18

18- 5050-115115-130

169623

3937284127

4554665770

4.55.14.84.84.5

3.6'3.93.93.93.8

3.201.500.53O.670.20

O.28 11.430;l4 10.710.13 4.080.17 3.94O.O8 2.50

O.8OO.8Otrtr

O.62 O.26 O.370.48 0.46 0.57O.23 0.15 0.300.28 0.26 O.33

2.16 23.05 9.22.42 19.57 12.40.79 19.57 4.0I.05 22.18 4.7

Chemical and mineralogical analyses of the clay fraction ( ( 2 microns ).

III

O

zH>SinOMH

Sample

number

191192193194195

1 Si02

1

44.4442.7843.0648.0650.83

Al

2930323131

2U3i n

.71

.96

. 2 2

.38

.80

Fe2°3weight

7.718.497.394.714.41

TiO2 CaO

percentages

2.041.79I.291.291.29

0.180.I80.210.160.20

V

1.050.940.97I.943.05

1Total 1

1

85.1385.1485.1487.5491.95

SiO-d

A 12°3

2,542.352.272.602.72

SiO,c.

Fe20?

15.8813.4415.5427.2130.74

Al 0—t_lFe2°3

6.255.726.85

10.4711.30

1! Clay 01

!+

Ch'ChJ

I +

I +

liner«

dK+

v dK+

dK*dK+

ils:

h AnAn

y AnAnAn

C h e m i c a l

Sample

number

analyses1 SiO_1 A

1

of

W 2

to ta l soi l

°3 Fe2°3in weight

sample ( ( 2 nuTiO2 CaO

percentages

n.) .K20 1

!1

Total! Ignition!! loss 1I % 1

, S 1 0 2

A12O,

SiO2

Fe2°3

A l .

£

t

,0 111

191192193194195

60.5355.0051.1159.0852.22

14.2316.7427.2026,9530.13

13.7119.1712.274.876.40

1.441.431.351.281.26

0.110.100.100.090.09

0.420.480.841.661.70

9092929391

.44

.92

.87^.80

7.235.593.193.812.95

11.777.65

1 1 . 1 1

32.3521.76

1.631.373.488.497.38

25


Profile: 191/95.Location: Tanah Merah. Elevation: 20 m.Relief: flat terrain, gently undulating.Vegetation: high, tropical rain forest, hardly any scrubs.Parent material: alluvium.Soil conditions: moist to wet.Soil type: podzolized gley laterite (discussion page 119).

191 Ai 0-5 cm moist, reddish brown (5YR5/4), rooted, slightly humic, mediumcrumbly, silty clay, with scattered iron concretions ; merging into :

192 B21 5-18 cm moist, yellowish red (5YR5/6), poorly rooted, semi-coated, fine tomedium subangular blocky clay, with large, sometimes platy ironconcretions ; gradually merging into :

193 B22 18-50 cm moist to wet, red (2.5YR5/6) clay; coarsely subangular blocky tostructureless, with scattered iron concretions ; with greatly scatteredsmall white stains ; merging into :

194 CiG 50-115 cm wet, white clay with scattered reddish and purply reddish andyellowish mottles, very compact and structureless; merging graduallyinto :

195 C2G 115-139 cm wet, white clay, with greatly scattered purply reddish and yellowishmottles, very compact and structureless.

0

10

20

30.

Vo

•SO

60

70.

80

90

100.

110

120.

130

Clay S610 20 30 40 50 60 ?C

Carbon %1 2 3 h 5

Sat. %10 20 30

S a t À ,••

• /

1

|

•

i

/

I

a. \\

Clay v

(

/

\

P3

a* 5

s\i

1

1

1I

\

\\

Cl)

1

i1

iiii

1

1

\ i i

H,0

Si.0,/7.,0,, Al,0,/7e,0,0 10 20 30

11

t

11

sto,

A1.0,

y

i (\\

\

\11\

1 À1.0,

1 »«tO,1

1

1',

\\\\'\\

-

-

10,

10

20

30

1)0

50

60

70

So

90

100

no

120

ljo

depth depth


Soil type: Podzolized latoeol

Sample Nrs. 204/08

Sample

number

Horl-

Depth

in

zon

Particle size distribution Isand I silt I clay 1

1 1 12 mm- 200yU , 50/1- 2Qu- , .200/1 50yu , 20ji ifx , < Z/i [

Organic

matter

KC1 C/N

Cations adsorption complexm.-aeq. p. 100 gram

Ca Mg K TEB(s)

CEC(T)

Sat.(V) O

MZ204 IA 0 - 5 6 7 37 7 43 4.9 4.0 2.83 0.30 9.4

205 IIA^ 5-25 7 7 32 11 43 5.0 4.0 I.67 0.16 10.4206 IIB^ 25- 60 1 5 25 24 45 4.7 3.9 0.64 0.07 9.1207 IIC, 60-120 2 11 21 25 41 4.7 3.9 0.24 0.03 8.0208 liote 120-150 1 2 37 18 42 4.5 3.7 0.17 0.02 8.0

1.180.640.53

1.37 I.51 0.080.35 I.08 0.08tr O.65 0.10

0.40 tr O.55 0.14

4.14 22.832.15 18.291.28 18.24- 17.391.09 18.75

15.411.87.0

5.8

Chemical and mineralogical analyses of the clay fraction ( ( 2 microns ).

Sample I SiO2 ^2 03 Fe2°3 T i 02 C a 0 K2° ' '

number I in weight percentages

OczH

in

SO

SiO21 Total

3.ÛI.! Clay minerals:

204205206207208

•36.71

38.2944.6249.0551.90

28.6327.0635.6937.2437.65

99

11

76

.95

.35

.10

.26

.20

11111

.38

.48

.44

.35

.30

0.070.090.090.090.09

0.160.160.190.150.18

76.9076.4393.1395.1497.32

2.182.412.132.242.43

9.8410.9710.7417.9922.36

4.514.565.058.049.64

dK+

KdK+

dK+

CrCrCr

G+ CrG Cr

Chemical analyses of total soil sample ( i Z mm*)« _ _ M

Sample I SiO- A1.0, Fe,0, *i0, CaO K,0 MnO | llgnltionl SiO. SiO Al,0 I Î z z 3 d i * d I Total ! losB ! —^-2 ! O

number I in weight percentages I I % 1 A12°3

Fe2°3 Fe2°3 ' S» _ » _ „ — » „ _ _ _ — — „ _ « « _ — _ — _ _ — — » » _ _ — — — _ _ — — — - . _ _ _ - . — — — _ _ — — — ^ _ _ _ - . - - - _ - . _ _ — — _ - . — — — . — — _ — _ — — - . _ - _ - . — — _ _ _ — — — — _ — — — — — — — — — — ~ — — — — — — — — — — — — — — — — — — • - — — — — — — — — — — - • - • - - • — --- — — — ^

204 37.87 25.74 16.02 I.70 0.17 0.31 0.09 81.90 2.50 6.3O 2.52 5205 38.67 26.73 13.93 1.39 0.10 0.96 0.14 81.92 2.46 7.40 3.01206 37.33 24.75 14.68 1.67 0.13 0.19 0.16 78.91 2.54 6.78 2.67207 39.73 29.21 10.95 1.24 0.23 0.24 0.14 8-1.74 2.51 9.68 4.19208 43.73 .28.22 8.66 1.47 0.12 0.31 0.10 82.61 2.63 13.47 5.12


Profile: 204/08.Location: Djononggo. Elevation: 100 m.Relief: hilly terrain, close to top of a ridge.Vegetation: high, tropical rain forest with slight undergrowth, interrupted by

gardens.Parent material: alluvium.Soil conditions: moist; fairly good drainage; some erosion.Soil surface: some litter and some roots.Soil type: podzolized latosol (discussion page 120).

204 IA11 0-5 cm moist, dark brown (7.5YR4/2), medium rooted, slightly humic,silty clay, with scattered reddish yellow (7.5YR7/6) blocky orrounded concretions, crumbly to angular blocky structure ; merginginto:

205 IIA11 5-25 cm moist, brown (7.5YR5/4) silty clay; angular blocky structure,with some rounded iron concretions scattered, poorly rooted;merging into :

20,6 IIB2 25-60 cm moist, yellowish red (5YR5/6) clay; angular blocky structure,merging gradually into :

207 IICi 60-120 cm moist, reddish yellow (7.5YR6/6) silty clay; angular blockystructure, containing white to yellowish earthy aluminium con-cretions ; merging into :

208 IIC2g 120-150 cm moist to wet, strong brown (7.5YR5/6) silty clay, structureless;with small white mottles.

0

10

20

30 .

ko .

50

fio

70

80

90

100

110

l?0

130

11(0

1W

Clay *10 20 30 1(0 50

Carbon %1 2 3

Sat. %10 20

Sat. •'

; /

a'il;\c.

1 '

/11

11

i1

Clay

i

! Al,0,/r.,0,10 20

11,0,

41,0,

F.,0,

o,

0,

cUptb

. o

. 10

. 20

• 30

. <»o

. 50

- . 60

. 70

. 80

. 90

. 100

. 110

-120

-130

. 11(0

.150

cadipth


Soi l type: Deeply podaolised la toso l

Sample Nrs. 222/26

Sample

number

222223224225226

1I

1

Chemical

Sample

number

222223224225226

1

Hori-

zon.

Ar?A*

cd

Depth

in

cm.

0- 1010- 2525- 6060-100100-140

111. 2 mm-

200ii

335213

and mineralogical anales

SiO2

44.6244.0042.7246.2047.47

M2°3in

34.9034.9034.9038.4337.65

Fe2°3

Particlesand

es

T

200/150/1

4101135

of th

L02

size

1

1

3

C

weight percentages

12.1913.2714.409.739.37

11111

7775623733

00000

50 120,u

4738273011

;lay

1O

0909090909

distributionsilt 1

120^- ;

128131020

fraction

K2

0.0.0.0.0.

0

1111080620

Cli

< 2/

3441445551

( <

»y

2

1

1

11

1

pH

H O KC1

4.9 4.5.2 4.5.1 4.5.2 4.5.1 4.

microns )

93.6894.1293.8195.8896.II

12200

1

1

1

1

42100

Organic

matter

C N C/N

.12 0.40 10.3

.22 0.21 10.6

.43 0.12 11.9

.33 0.03 11.0

.28 0.02 14.0

.SiO2 SiO2 ;

A12O3 Fe2O2 I

2.17 9.762.14 8.842.08 7.912.04 12.662.14 13.51

Ca

0.400.260.130.400.26

a2°3

'e2°3

4.494.133.806.196.30

Cations adsorption complm. aeq.

Mg K

O.29 I.03tr 0.91tr 0.750.08 O.55tr O.60

1

p. 100

Na j

0.070.360.050.120.09

1

dK++

dK++

dK++

dK++ 0dK++ G

CrCrCr

+ Cr+ Cr

gram

TEB(S)

1.791.430.931.150.95

ix

CEC(T)

2116141414

5081483367

Sat.(V)

886106

45455

1

O(-<

OM•zra

mir>H

O

z

m

nra

>

Chemical analjrsas of t o t a l Boil_eample_(_<_2_Ea.). . M

Sample I S1CL A l , 0 , Fe.O, TiO, CaO K,0 I l lgni t ionl SiO, SiO, Al-O, 1 <, 2 2 3 2 3 2 Z , T o t a l , l o s a , é û _ ^ i 1 o

number I in weight percentages I I SS ! 'U-j0! F e 2°3 F e 2°3 ' 2_- — — . — 12;

222 41.60 21.05 18.12 2.00 0.12 0.15 83.04 3.35 6.12 1.83 5223 42.45 21.86 18.40 2.03 0.12 0.14 85.00 3.30 6.15 1.86224 41.31 23.08 19.39 2.08 0.11 0.13 86.10 3.04 5.68 1.87225 35.90 31.17 15.38 1.47 0.10 0.14 84.16 I.96 6.22 3.17226 43.59 27.53 14.63 1.57 0.10 0.24 87.66 2.69 7.95 2.96

Conor. 12.82 51.82 6.13 0.71 0.14 0.08 71.70 0.42 5.58 13.2?


222 A l l o-io cm

Profile: 222/26.Location: Wampon. Elevation: 160 m.Relief: hilly to steep, near top of a ridge.Vegetation: high, primary tropical rainforest, slight undergrowth. In the neigh-

bourhood some gardens. Litter occurs in a very thin layer.Parent material: alluvium.Soil conditions: moist, fairly good drainage, some erosion.Soil type: deeply podzolized latosol (discussion page 121).

moist, medium humic, medium rooted in surface layer, dark brown(10YR3/4) silty clay loam, crumbly structure; containing light reddishand light yellowish irregular rounded concretions ; merging into :moist, dark yellowish brown (10YR4/4) silty clay with scatteredlight yellowish concretions and dark-brown rounded iron concretions,subangular blocky to angular blocky structure, poorly rooted ; merginginto:moist, yellowish brown (10YR4/5) silty -clay, yellow and brownconcretions ; angular blocky structure ; merging into :

ucture ; merg-

white earthymerging into

223 A12 10-25 cm

224 A13 25-60 cm

225 B2

226 C

00-100 cm

100-140 cm

0

1 0 .

20 .

30 .

ifO

50

60

70

80.

9 0

1 0 0

110 .

1 2 0

1 3 0

cmdopt

moist, yellowish red (5YR5/6) clay,ing into :blocky to structurelessaluminium concretions ;reddish yellow (5YR6/6)

Clay *10 20 30 kO 5p 6.0

Carbon SI

ISat. *

10 ;

o a t

•

!

7

/

ƒ

1. •'1 :i ;

I ƒ

£pH

3 't

V •

', Clay

1|

11

V\

\\

\\

11

1

1

11

1

KC1

1 \

i

1i

i

i

angular blocky str

clods, with scattered somelower down very graduallystructureless clay.

SiO, /Al, 0,P I 2.SiO,/re, 0,

0

\ o

i

1

i1

1

s

1

1

11

\

\

1 0 ,

r

3

' l Q

|

1\

|

A l ,

F . ,

't 5

2P

n

\

\

\

0, SiO,

F.,0

. 10

. 20

5°

. to

. 50

60

70

80

. 90

1 0 0

. 110

1 2 0

. « 0

140

emdopth

. N A L Ï T I C A L D A T A

Soil type: Brown podzolio soil

Sample Nrs. 245/48

Sample

number

2 5246247248

1!1(1t

Hori-

zon.

Depth

in

cm.

!B22g

0- 55- 20

20- 9090-120

1Ij

1

(

2 mm-200/1

_

111

Particlesand

20qu50 u

_215

size distribution!j

1

.

8

50/1-20M

_363125

ilt20/1-

4"

262027

111

1

clay

< 2u

_354742

!I|[

| H2

4.5.5.

pH

0

702

KC1

.

3.83.93.9

!1i

JJ c

_1.0.0.

Organic

matter

N

_6 0.249 0.1405 0.05

C/N

661

740

!1

11j

000

Ca

.

.14

.27

.14

Cations adsorption complexm.

Mg

_0.030.050.03

aeq

K

_0.45

0.770.85

P. 100

Na I

_0.0.0.

I

081109

gram

TEB(S)_0.701.201.11

CEO(T)_

28.3329.64

33.63

Sat.(V)_

2.54.03.3

111t1

t/i

Of-l

C

zMu

; ST

A

Chemical and mineralogical analyses of the clay fraction ( < 2 microns ). S

Sample I SiO Al-0 Fe?0 TiO CaO K O ! I SiO. SiO A1.0, I gI * c y * > * * I Total ï £ - — " ! Clay minerals: 3

number I in weight percentages 1 I A1.0, Fe o0 Te-0 I J>

„__„„,. „_-„__„ _„_„___—_... „„„„„.. __.--. _-5 .„__5- -„5 __» „_- - ___-_ "-1

245 - - - - g246 53.48 24.31 10.08 1.75 0.09 1.54 91.25 3.74 14.15 3.78 iM+ Q Cr247 43.35 20.00 9.08 1.30 O.08 1.53 75.34 3.68 12.73 3.46 iM+ 0. Cr S248 42.72 23.92 9.29 1.14 0.10 1.22 78.39 3.04 12.26 '4.04 iM+ Q Cr Z

>

Chemical analyses of total soil sample ( < 2 mm«)* ^

Sample ! SiO Îp0^ Fep°i T i Op C a 0 Kp° ' llgnitionl SiO SiO *lp0^ ' <

I d > * i * d ! Total t loss I ' ! onumber I in weight percentages I X % \ *lpO^ ê2®1 ^"e2^^ ' ^

... _ . . : . . _ .. -. .. I246 65.03 12.55 10.62 I.23 0.11 O.69 80.21 8.81 16.39 1.86 >247 56.13 17.41 13.17 1.14 0.10 1.03 88.98 5.48 11.36 2.07248 53.28 18.22 12.17 O.92 0.09 0.84 85.52 4.97 II.67 2.35


Profile: 245/48.

Location: Umkubun. Elevation: 440 m.Relief: hilly terrain (samples taken on a long gentle slope).Vegetation: high, tropical rainforest, poor undergrowth. Surface some litter.Parent material: limestone.Soil conditions: moist to wet.Soil type: brown podzolic soil (discussion page 122).

245 Ai 0-5 cm wet, dark reddish brown (5YR3/3) loam; containing much humus andorganic matter ; crumbly ; well rooted ; merging into :

246 A2 5-20 cm wet, brownish yellow (10YR6/6) silty clay loam; very poorly rooted;angular blocky to structureless clods, with semi-coating in some holes ;very few stains ; merging gradually into :

247 B21 20-90 cm wet to moist, yellowish brown (10YR5/6) silty clay; angular blockyto structureless clods ; with semi-coatings in holes ; very few graystains and some rust-coloured stains ; merging gradually into :

248 B22g 90-120 cm moist, yellowish brown (10YR5/8) silty clay, with gray and somereddish yellow mottles; angular blocky.

10

20

30

"to

50

60

70

80

90

100

110

120cmdepth

Clay %10 20 30 ko 50

Carbon %1 2

Sat. *10 20

at. p

1

1

iii

ii

\

\

Clay

\

\

ii111

i

sio, Ai, o,0 1 2

pH

CCI, 11

iI

H,0

1

1

11

S10,/Fe,O,0, 10

FejCf

I Sir< 510, 10

20

30

50

60

70

80

90

• 100

. 110

. 120cmdepth


Soil type: Weakly gleyed, brown podzolio aoil

Sample Nrs. 85/89

Sample

number

Hori.

son,

in pH

Depth I Particle size distribution !1 sand 1 eilt I clay I[ 2 mo- 200/1 ! 50/1- 2Qu- ! ! ., 200/1 50/1 J 20M 3 " , < 2" ' H„0 KC1 ! CI !

Organic

matter

N C/N

Cations adsorption complexm. àeq. p. 100 gram

•Ca Mg K Na TEB(S)

CEO(T)

Sat.(V)

O

OM85 A, 0- 686 A; 6- 1587 si 15- 3088 B^g 30-11089 B^Cg 110-120

20 9

16 16 25

't.8 3.9 1.6 0.25 é.it 0.3 0.40 O.31 tr 1.01 10.80 $.k

4.8 4.0 0.3 0.04 7.5 tr 0.60 O.33 tr O.93 11.0 8.5

Chemical and mineralogical analyses of the clay fraction ( (, 2 microns ) • O

nM

>f

M

OG5M>

Sample I SiO2

number t

TiO2 CaO KgO

in weight percentages

I S10,1 Total I — ^1 I A1,O, Fe,O, Fe,O,

! Clay minerals:

_2_2 ..î.l „O.8586 3**. 19 18.59 7.05 0.91 0.11 0.7287

89 44.44 18.10 6.38 O.99 0.10 1.59

51.57 3.13 12.93 "f.13

71.60 4.17 18.57 4.46

Chemical

Sample

number

i

111

inal^ses

sio2

of total soil

AlgOj Fe2O3

in weight

samnle ( ( 2 mm

TiO2 CaO

percentages

. ) .

K2O 1! Total

1Ignition!! loss I

SiO2 sio2

Fe2O, F e 2 ° 2 '

8586 82.26 6.07 3.25 O.62 0.09 O.3487 - - - - - -88 - - - . _ .89 73.19 10.53 ^.96 2.23 0.08 0.68

92.63

91.85

23.04 67.50 2.93

11.82 39.35 3.33

DESCRIPTION AND ANALYSES OF THE SOIL PROFILE JJ

Profile: 85/89.

Location: Amjol, south of Katem. Elevation: 550 m.Relief: top of the scarp, which is very steep to the west (Digul valley) and

sloping to the east.Vegetation: medium high forest, some litter on the soil surface and lateral roots.Parent material: limestone.Soil conditions: drainage good, moist to wet.Soil type: weakly gleyed, brown podzolic soil (discussion page 130).

85 Ai 0-6 cm moist, well rooted, humic, dark gray brown (10YR4/2), crumbly,sandy loam ; merging into :

86 A2 6-15 cm moist, rooted, lightly humic; crumbly to subangular blocky; yellowishbrown (10YR5/4) sandy loam to loam; merging into:

87 B2 1S-30 cm moist, blocky, yellowish brown (10YR5/6) loam; poorly rooted;merging gradually into :

88 B2g 30-110 cm moist, blocky, yellow (10YR7/6) loam; with scattered light yellow,gray and brown stains ; merging into :

89 B2Cg 110-120 cm moist, angular blocky, yellow (10YR7/6) clay loam; with grayishyellow and brown yellow small mottles (resembles rotten rockmaterial).


Soil type:

Sample Nrs.

Brown podzolio soil (on fossile latosol)2 6 5 / 6 8 (polygenetio)

co

Sample . Hori-

number

Depth

in

I Particle size distribution !! sand ! silt ! clay !! a mm- 200/1 j 50M- 20,U- ! !, 200/1 50/1 , 20M 2u , < 2M j

pH

Organic

matter

C/N

Cations adsorption complexm. aeq. p. 1Ö0 gram

Ca Mg K Na TEB(S)

CEC(T)

Sat.(V)

mO

O

mm

mH

265266267268

$

&

0- 1010- 2222- 4545- 80

52442511

9 1612 1811 145 10

13131521

10133553

55.3 4.25.9 4.37.1 6.1

2.51.00.30.3

0.25 10.00.12 8.30.10 3.00.12 a.5

4.151.5010.0518.48

0.21 0.43 O.67tr 0.19 0.840.29 0.22 0.940.13 0.05 1.42

5.46 15.8a 34.52.55 9.86 25.811.50 27.75 41.420.00 45.24 44.2

Chemical and mineralogical analyses of the clay fraction ( ( 2 microns ) • _ _ _ _ _ _ _ ^

Sample I SiO Al 0 Fe O TiO CaO K O I ! SiO SiO Al,0 ! y! ^ -1 ^ I Total 1 •• •> ! Clay minerals: H

number I in weight percentages I I Al 0 Fe,0 Fe,0 ! jî..i i.i i.i 2;

265 38.31 11.03 4.63 3.74 0.44 0.47 58.62 5.90 22.06 3.74 iM+ q++ <"266 41.79 12.87 7.81 2.59 O.25 0.45 65.67 5.52 14.27 2.59 iM+ Q++ An n267 44.44 19.08 12.8a 2.33 0.18 O.92 79.77 3.96 9.24 2.33 iM+ Q+ An M268 45.58 19.57 13.72 2.24 O.15 1.04 81.30 3.96 8.86 2.24 iH+ Q+ An Z

>

rChemical analyses of total soil sample ( ( 2 mm.). _ M

Sample ! SiO, Al,0, Fe,0, TiO CaO K,0 I llgnitionl SiO, SiO A1.0, I "I 2 2 3 2 3 2 2 ! Total I loss I — 2 - J ! O

number 1 in weight percentages I I % I A^ 0? Fe2°3 Fea°? ' "

265 47.24 5.36 35.73 O.?8 0.28 0.06 89.05 14.98 3.53 0.24 S266 50.25 5.36 34.32 0.44 0.22 0.06 90.65 15.94 3.90 0.24267 60.55 10.71 18.78 0.70 0.50 O.36 91.60 9.61 8.6O O.89268 59.05 12.15 14.40 O.74 1.38 0.60 88.32 8.26 10.94 1.32


Profile: 265/68.

Location: Digul valley, Songgam. Elevation: 710 m.Relief: small flat site in generally sloping to steep terrain.Vegetation: primary rainforest with a soil cover of small herbs; many lateral

roots in the soil surface.Parent material: limestone.Soil moisture: moist to wet.Soil type: brown podzolic soil (on fossile latosol) (discussion page 122).

265 Ai 0-10 cm moist to wet, brown (7.5YR4/2) sandy loam; rooted; rich in organicmatter ; soft crumbly structure to granular structure ; iron concre-tions present ; merging into :

266 A2 10-22 cm moist to wet, light yellowish brown and brown mixed (10YR6/4-4/3)sandy loam; with a soft granular structure; medium rooted; con-taining iron concretions ; undulating merging into :

267 B21 22-45 cm moist to wet, brownish yellow (10YR6/6) clay loam; poorly rooted;semi-coated, soft, subangular blocky to structureless clods ; mediumand small iron concretions present ; gradually merging into :

268 B22g 4S-80 cm wet, yellowish brown (10YR5/6) clay; very soft, structureless;containing small iron concretions ; very poorly rooted ; with dispersedsome very small white mottles, lying irregular on limestone.

0

1 0

2 0

30.

'to.

50.

60

70

Rn

Clay %10 ?t> 3P ko 50 6p

Carbon %1 2 3

Sat. %10 20 30 kP 50

\

/

I

|

ijc.

y /

X '•-.v •.

' \\

Sat

\"A«. "\; -cia

•pH

L 6 7

/

:

1

i\

r 1

1

1

\

\

Cl\

\

\

.B

S1O,/A1,O,I ? 13 ». 5 6,

Si0 , /7 . ,0 , i Al.O./Te.O,0 10 2p

ƒ

1

! 1

IAI, o, 1re,0, 1

/

1 0 ,

•.o,

/

SiO,

A l ,

j

-

0

10

20

30

ItO

50

60

70

80

depth depth

8o SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

IS• CO

ISI E-i

H I — — —

3 C ^ l

m u

o o o o o

mr r rHC-IM41

K~ H

•O O l

f\J CO

IA H

• tTiO li•o ru ir\r

iH (\J K\-*- 1AMJ

•ó -o

O O H H i-t

H H O O O

HJ-O-*^

O O (M KN c\j


Profile: 127/31.

Location: Mabilabol, West Sibil. Elevation: 1240 m.Relief: flat, low terrace.Vegetation: tall grasses and some ferns.Parent material: alluvium.Soil conditions: wet; near the accumulation terrace a small peaty ribbon is

formed; close to the river the profile contains more cobble stones, while the peatlayer is absent. Throughout the profile of gray to bluish gray colour, brown mottlesand coatings on clods are found.

Soil type: peaty, alluvial gley soil (discussion page 139).127 A00G 35-0 cm wet, brown, rooted, loose peat}' layer, lies on:

128 AoG 0-5 cm wet, dark gray (10YR4/1) clayey and peaty layer, soft crumbly tosubangular block}', rooted ; merging into :

129 A11G 5-20 cm wet, dark gray (10YR4/1) clay, poorly rooted, with scatteredbrown mottles ; merging into :

130 A12G 20-45 cm wet, light gray (2.5YR6-7/0) clay to sandy clay, with dark brownzones along root channels, and mottles and brown coatings on clods,rooted : merging into :

131 CG 45-85 cm wet, greenish gray (5BG6/1) clayey sand with sand lenses,structureless.

(Chemical analyses p. 80)


Profile: 1/6.

Location: Mobilabol, West Sibil. Elevation: 1260 m.Relief: flat, accumulation (middle) terrace.Vegetation: low herbs (Melastoma, Nepenthes, club-moss, etc.), grasses and

some Araucaria trees. •Parent material: alluvium.Soil conditions: wet; soil cover consists of 5 cm to 15 cm partly decomposed

organic material and rootmat. The profile occurs on the fringe of the terraces,where the soil is poorly drained.

Soil type: shallow iron-humus podzol, (discussion page 140).1 Aoo 10-0 cm moist to wet, very dark brown (10YR2/2) peaty organic matter

layer, well-rooted, on :

2 Ai 0-8 cm moist to wet, gray (2.5Y5/1) sand, loose and structureless, verypoorly rooted ; merging into :

3 A2 8-18 cm wet, white (2.5Y8/2) sand, compact and hardened, intermitted withdark gray brown humic bands, always underlain by a small whitesandy zone ; merging quickly into :

4 B2 18-28 cm wet, yellow to yellowish brown (10YR7/6-5/6) mottled loamy sand,firm and compact to slightly blocky structure ; merging quickly into :

5 B2Cg 28-40 cm wet, olive gray (5Y5/2) sandy loam, with scattered small brownmottles ; merging gradually into :

6 Cg 40-70 cm wet, light gray (2.5Y6/2) sandy loam, with scattered vague, small,gray mottles. Deeper in the profile 90-110 cm a cobble layer occursbedded in loam, in which many yellowish brown mottles ; at a depthof about 2 m, and again at about 3 m small peat layers are found.

(Chemical analysis p. 80J


Profile: 104/08.

Location: Mabilabol, West Sibil. Elevation: 1260 m.Relief: flat, accumulation (middle) terrace.Vegetation: short grasses; normally inundated.Parent material: alluvium.Soil conditions: wet. Places in the middle of the terrace without drainage;

stagnant water.Soil type: shallow iron-humus podzol (discussion page 140).

104 Aoo 15-0 cm wet, dark brown (7.5YR3/2) layer of peaty organic matter porridge-like, medium rooted, with sharp boundary on :

105 Ao 0-14 cm wet, gray brown (10YR5/2) sandy loam, rich in organic matter,poorly rooted, structureless, on :

A2 14-15 cm wet, very thin, whitish sandy layer, a little hardened, irregular andintermittent on :

106 CiG 15-85 cm wet, plastic and very adhesive, structureless, white clay, containingsome dead, very thin roots, locally a cobble-stone, merginginto:

107 C2G 85-145 cm wet, greenish gray (5GY5/1) loamy clay, structureless, some vague'mottles, continued by:

108 C3G 145-? cm wet, greenish gray loam, with small sand lenses.

Profile: 117/22.

Location: Betabip, West Sibil. Elevation: 1280 m.Relief: flat, accumulation (high) terrace.Vegetation: low herbs (Melastoma, Nepenthes, Orchids, club-moss, etc.), grasses.Parent material: alluvium.Soil conditions: moist to wet. Generally better drained than profile nr 1/6 on

lower terrace.Soil type: podzol (discussion page 141).

5-0 cm moist, brown organic matter, poorly decomposed, and rootmat, lyingon:

0-4 cm moist, black (10YR2/1) loamy sand, rich in organic matter, crumblystructure, rooted, merging quickly into :

4-6 cm moist, light gray (10YR7/2-6/1) loamy sand, merging quickly into:6-40 cm moist, reddish yellow (7.5YR6/8) loam, poorly rooted, weak blocky

structure, merging gradually into :40-105 cm wet, white (2.5Y9/2) clay loam, with lightly yellow mottles, merging

gradually into :105-155 cm wet, pale yellow (2.5 Y9/4) loam, structureless, with reddish yellow

mottles.Owing to the longer drought of the weeks before sampling, the soilwas cracked to a depth of about 40 cm in irregular, prismatic columns.The surfaces of the cracks were coated black by the humus containingwater.

(Chemical analysis p. 80)

117

118

119120

121

1 2 2

Aoo

A i

A 2

B 2

Cig

C2K


Soi l type:

Sample Nrs.

Podzol

155/57

Sample

number

Hori-

Depth

in

Particle Bize distribution Isand I eilt I clay !

2 mm- 200/1 j 50/1- 20/1- .j j200/1 50/1 j 20^ 2/1 | < 2M J

pH

KOI

Organic

matter

H C/N


Ca Mg Na TEB(S)

CEC(T)

Sat.(V)

O

O

ww

155156157

0- 1515-3535- 70

423826

363814

121358

5.2 4.15.2 3.95.3 3.7

4.070.270.36

0.34 11.90.04 6.80.11 5.7

3.721.01

14.08

O.58 0.53 0.04tr 0.10 0.01

0.55 0.96 0.09

4.87 18.29 26.61.12 5.69 19.7

15.68 39.19 39.9

en

>

Chemical

Sample

number

155156157

Chemical

Sample

number

and mineralogical analyses of the clay

1 SiO2

1

36.3966.5043.67

A 1 2 0 J

in

I6.0814.5122.75

Fe20 Ti02 CaO

weight percentages

2.33 I.60 0.155.54 1.84 0.16II.67 1.24 0.16

analyses of total soil aamgle ( ( 2 on

1 SiO2

1

Al203

in

Fe2O T102 CaO

weight percentages

fraction ( <

K20

0.550.440.81

. ) .

K20

( 2

111

11

microns )

Total

57.1088.9980.30

Total

1!1

SiO2

A12O2

3-857.793.26

llgnitlonl1 loss 11 % 1

SiO2

41.6532.019.98

SiO2

A12O3

A12O

IO.834.113.O6

sio2

Fe2°3

1 Clay!

M+ ,H + + ,M++

minerals:

111

Cr AnCr AnCr An

s>

C

z

zwr1

z

G

155156157

85.90.61.

782394

3.3.

15.

246428

2.3-

12.

668360

0.0.0.

778898

000

.23

.19

.59

000

.14

.15

.43

929891

.82

.92

.92

45426

.00

.14

.85

856213

.99

.82

.11

111

.91

.49

.91

DESCRIPTION AND ANALYSES OF THE SOIL PROFILE «5

Profile: 155/57.

Location: Betabip, West Sibil. Elevation: 1300 m.Relief: sloping mountain side.Vegetation: medium high secondary forest.Parent material: limestone; locally cropping out.Soil conditions: wet. Soil surface consists of 2 cm to 10 cm organic material

and rootmat.Soil type: podzol (discussion page 123).

155 Ai 0-15 cm moist, dark gray brown (10YR4/2) silty loam; humic, crumbly tosubangular blocky structure ; containing some charcoal, and scatteredsome pieces of limestone; rooted; merging undulatingly and quicklyinto:

156 A2 15-35 cm wet, light gray (10YR7/2) silty loam; with scattered brown andyellow mottles, angular blocky to structureless; poorly rooted;merging widely undulating into :

157 B2 35-70 cm wet, dark brown (7.5YR5/6) silty clay; with small gray stains,.structureless to angular blocky, containing limestone pieces ; lies onlimestone, locally solid, locally stony.

0

10

20

30

ko

50

60

70

Clay %10 20 30 kO 5p

Carbon %1 2 3

Sat . %10 20 30 kO SO

pH't 5 6

Cla> , H,0

SiO,/Al,O,1 2 3.

SiO./Fa.O, ; AJ.O,/ t.,0,0. 10 20 2ß_ JtSL

/

1

>> i ' s io ,

), ' Fe, 0,

*

30

kO

50

60

70

depth depth

oo

A N A L 1

Sample

number

135213531354 ]1355 ]

I 1 I C A

1

Eorl-J1

zon..

IAIAJ(B)IA,IB2

L

De

D A

pth

in

c

0-5-

20-40-

m.

5204060

T

!!

.I

A

2 mm200^

242882

Particlesand

200u50/1

6731

size1

j

1

distributionsilt !

50^- 2Ciu- ;20,

36393943

1 ^ 1

22163419

clay

< 2»

12101635

!1•

1 H

5555

pH

2°.0.3.0.7

Soil type:

Sample Nrs.

1!

1

Kei ; c

4444

.1 2.

.4 0.

.0 0.

.7 0.

Acid brown

1352/55

Organic

matter

N

23 0.1773 0.0834 0.0581 0.11

C/N

13.9.6.7.

11

11

1184

1101

forest sc

Ca

.44• 33.32.05

>il/brown podzolic(polygenetic)

Cations Em

Mg

0.39O.6I0.20tr

aeq

K

0.37O.I30.16O.32

soil

idsorption complexp. 100 gram

Na j TEB

(s)0.10 2.300.05 2.120.04 O.720.02 1.39

CEC(T)

12.959.809.74

10.07

Sat.(V)

1721713

.8

.6

.4

.8

!1I1

cp0

zp:if.

>

Chemical and mineralogical analyses of_the clay fraction C ( 2 microns ) . O

Sampla 1 SiO, Al,0 Fe,0 TiO, CaO K O I I SiO SiO, Al,0 I 2;I c *• •> c > * 1 Total I —S-2 ! Clay minerals: H

number I in weight percentages I I Al-0 Fe_O- ê.,0, ! î-i i.Z S-J Z

1352 54.11 I6.O8 10.46 2.08 0.21 O.34 83.28 5.72 13.79 2.41 M + Q + + An ">1353 48.10 18.43 13.11 1.73 0.15 O.35 81.87 4.44 9.78 2.21 M + + Q+ An n.1354 5O.63 20.00 9.52 1.Ç2 0.15 0.47 82.58 4.3O 14.18 2.30 M + + Q + + An WI355 44.62 24.31 7.22 1.59 0.15 0.53 78.42 3.12 16.48 5.28 M + + Q + An ^

Chemical_analjBes_of_total_soil sample_^_<_2_mmi2i ___ _ _ 5

Sample ! SiO_ Al 0, Fo,O, TIO- CaO K O MnO I llgnitionl SiO, SiO, Al,0, I <

I d * i * i * d ! Total i loss I —^-* I anumber I in weight percentages I I 56 1 A1.0 Fe,0 Fe,0 I S. ..-«._ . . » . £-2 _«£ _»£ - 21352 61.93 4.46 27.75 0.68 0.19 0.05 0.14 95.20 23.60 5.95 0.25 m1353 60.21 5.45 29.80 0.69 0.14 0.08 0.15 96.52 18.78 5.39 0.29 >1354 67.34 5.45 16.25 O.78 0.17 0.07 0.06 99.12 28.81 12.54 0.441355 68.17 13.86 9.63 0.94 0.48 0.30 0.03 93.41 8.36 18.88 2.26


Profile: 1352/55.

Location: Crest on Utek Mountains. Elevation: 1400 m.Relief: small f late site on top of mountain ridge, with slopes steep on both sides.Vegetation: high forest, some climbing bambu and pandanus.Parent material: limestone.Soil conditions: wet. Soil surface consists of 10 to 15 cm organic material and

root mat.Soil type: acid brown forest soil/brown podzolic soil-podzol (polygenetic);

(discussion page 124).

1352 Ai O-5 cm moist, light yellowish brown and some brown (10YR6/4-5/3) siltyloam, rather poorly rooted, poorly humic, porously crumbly tosubangular blocky structure, containing small iron concretions,merging quickly into :

1353 Ai(B) 5"2O cm wet, very pale brown and light yellowish brown mottled(10YR8/3-6/4) silty loam, poorly rooted, subangular to angular blockystructure, containing iron concretions ; merging waving into :

1354 A2 20-40 cm wet, very pale brown (10YR8/3) and strongly yellow mottled(10YR7/8) silty loam, subangular blocky to structureless, containingiron concretions ; merging gradually into :

1355 B2 40-60 cm wet, yellowish brown (10YR5/6) silty clay loam, containing ironconcretions, structureless, lying irregular on limestone.

n

10

?n

J0

ko

50

60

Clay *10 20 3O ItO

Carbon %X ? 3.

Sat. *IP 20 30

t

1.-'

C.\ \Sa

\ Clav

\\

SIO,/1 i

A1.0,3. Il

S10,/Fe,0, ! Al,O,/r.,(0 10 2.0

PB3 4 5 6.

KC1

\

',H,C

'\

\

\

\

A1.0,

F.,0,\

\

\

SiO, \

r.,0, \

y

\

0

.10

JO

ItO

.50

60

depth depth

• 0 0

oo

Soil type: Black rendzina

A N A L Y T I C A L D A T A Sample Nrs. 410/12

I I Depth ! Particle size distribution ! ! Organic ! Cations adsorption complex !

Sample ! Hori-! in ! e a n d J e l l t ! cla* ! PH ] matter ! «• a e 1 - *• 1 0 ° S r a m ' %2 mm- 200,u 50/.- 2Qu- | ;

number zon. cm. 20Ou 5011 . 20>i 2u \ < 2p , H O KC1 ; C N C/N Ca Hg K Na TEB CEO S a t . CaCO,

i. I 4. 4- 1 + + 4- J— i S i iïi iii 4.410 A 0- 8 . . . 6.6 5.9 12.15 1.70 7.1 49.19 2.09 0.70 O.55 52.33 96.50 5^.2411 A°C 8-12 2 8 69 10 11 7.4 6.8 7.83 1.36 5.8 44.65 O.89 0.44 0.32 46.30 72.10 64.2 27.8412 C1 12- 25 24 6 55 8 7 7.7 7.1 2.00 0.24 8.3 21.59 O.36 0.18 0.I5 22.28 22.35 99.9 40.0

Chemical_and "iineralogical_analjrses_of_the_clay_fraction_(_<_2_microns_).

Sample I SiO Al 0 Fe,0 TiO CaO KO 1 1 S10 SiO Al 0 1! *• d i * •> *• *• I Total I *• > ! Clay minerals:

number I in weight percentages 1 ! &.Sl~ Fe_0 Te-,0 I

410 - - - . - . - . . .411 54.11- 20.78 2.76 2.01 O.I3 1.57 8I.36 4.43 52.28 11.81 M++ K+ An412 50.32 2O.78 7.8O 0.92 0.55 1.35 8I.72 4.12 17.20 4.18 M++ K+ An

Chemical 22al2Bes_o£ *otal_S°il sns»gle_C_<_2_mni^.

Sample 1 SiO, A1.0, Fe.O, TiO CaO K.O I 1Ignition1 SiO SiO Al-0 1

1 2 2 3 2 3 z E ! Total ! loss I —Z-Z !

tiumbor I in weight percentages I I Se ! *l2°j Fe2°3 fe2°3 '

410 37.32 6T36 3.81 "0.43" "5.21 0*57 53.70 9.98 26.12 2.62411 42.17 6.85 3.87 0.41 II.59 0.62 65.51 10.47 29.06 2.78412 28.21 3.91 1.66 0.22 36.91 0.45 71.36 12.27 45.32 3.69

DESCRIPTION AND ANALYSES OF THE SOIL PROFILE 8 9

Profile: 410/12.

Location: Molbakon. Elevation: 1820 m.Relief: gently' undulating terrain towards Tsop river; lower part of the

northern slope of the valley.

Vegetation: hardly any trees; garden patterns, with regeneration over someyears.

Parent material: limestone, cropping out in many places.Soil conditions: moist, good drainage.Soil type: black rendzina (discussion page 126).

410 Ao 0-8 cm moist, black (5YR1/1) loam; very rich in organic matter, veryfriable and crumbly structure, well rooted, containing limestone pieces,charcoal present ; merging vaguely into :

8-12 cm moist, very dark gray (5YR3/1) loam, rich in organic matter, crumblyto small angular blocky, containing limestone pieces, well rooted,containing charcoal ; merging quickly into :

12-25 cm moist, many limestone pieces and stones, with in between brown(10YR4/3-5/4) loam, poorly rooted; lying on limestone.

411 AiC

412 C

Clay *10 20 }0

Carbon %X 2 5 << 5 6 ? 9

Sat. %10 SO 30 "tO 50 60 70 80 9

Sat..

•C;

0

PH5 $ 7 a

KC3.

-.,.;\

0

10

20

emdepth

SiO,/Al,O,X ! 1

SiO,/Fe,0, iq ID

SiO,

A1.O-

. —SlOf- 10

-20

dapth

N A L Y T I C A L D A T A

Soil type: Podzol

Sample Nrs. 405/08

Sample

number

405406407408

Hori-

zon.

AA2B21RB22

1]11

Depth

it

CD

0-

5-10-40-

1

1.

5104080

l1j1

PtBe

2 mm-20qu

16931

articlemd200^50^

141464

B

|

j

1

ize

50pZOp

33392929

distributionsilt- 20,u-

24193616

I clayj

13192650

!1j

! H2

4.4.4.4.

pH

0

4558

!

J1

Kci ;

3.3.3.3-

3557

c

4.1.2.1.

Organic

m

31061254

atter

N

0.400.090.150.10

C/N

10.811.814.115.4

1

1

I

Ca

0.56trtrtr

Cationsm

Mg

0.790.350.360.49

aeq

K

0.680.180.240.63

adsorption complex. p. 100

Na J0.210.050.130.20

gram

TEB(S)

2.240.580.731.32

CBC(T)

16.83IO.3628.8337.01

Sat.(V).

13.5.2.3.

3656

,!

1

1

C

OPI

zWt—

STA

R

Chemical and mineralogical analyses of the clay fraction ( < 2 microns ) . O

Sample I SiO, Al 0 Fe,0 TiO OaO K O I I SiO SiO Al-,0 t §I d i d * I Total I ••• ? I Clay minerals: H

number I in weight percentages I 1 A12°'5 Fe2O:5 F e2°3 ' M

405 84.00 3.53 0.68 1.18 0.09 0.31 89.79 40.45 329.40 8.14 M Q + + An • w406 79.60 7.06 1.64 1.26 0.10 0.39 90.05 19.17 129.43 6.75 M Q + An o407 67.20 14.12 5.24 1.17 0.10 0.84 88.67 8.09 34.20 4.23 M + + Q + An PI408 54.43 17.25 8.69 1.01 0.09 I.I6 82.63 5.36 I6.7O 3.11 M + + CJ An Z

W>

Chemical analyses of total soil sample ( ( 2 m m * ) a M

Sample I SiO, Ai.O, Fe-O, TiO, CaO K,0 I llgnitionl SiO, SiO, Al,0, I <

I 2 2 3 2 3 2 2 I Total I loss I & — 2 - 2 ! Onumber I in weight percentages I I % 1 A1.0 Fe2°-j Fe2°î ' 2

405 85.80 0.99 0.62 0.60 0.11 0.07 88.19 147.33 3é9.O3 2.50 W406 91.39 1.49 1.20 0.64 0.10 0.09 94.91 104.26 203.09 1.95 >407 76.34 6.93 5.28 0.70 0.09 0.37 89.71 18.73 38.56 2.O6408 68.38 12.62 9.85 0.77 0.09 0.71 92.94 9.21 13.51 2.01

DESCRIPTION AND ANALYSES OF THE SOIL PROFILE 9 1

Profile: 405/08.

Location: Temnomabe sigin. Klevation: 2060 m.Relief: top of the mountain, gently sloping terrain.Vegetation: subzone of moss forest, primary medium to low forest, climbing

bambu, mosses and Zingiberaceae.Parent material: limestoneSoil conditions: wet; rootmat.Soil type: podzol (discussion page 125).

405 Ao 0-5 cm wet, humic, gray brown silty loam, médium rooted, weak subangularblocky; merging into:

406 A2 5-10 cm wet, white to light gray (10YR8/2) silty loam, angular blocky, poorlyrooted, with scattered gray brown mottles ; merging into :

407 B21 10-40 cm wet, yellow and light gray (ioYR.7/6-and-7/2) mottled silty loam,structureless ; merging gradually into :

408 B22 40-80 cm wet, brownish yellow (10YR6/8) silty clay, with yellow mottles;structureless.

0

10

20

jo

50

60

70 .

80

Clay %.10 20 y> 'to 50

Carbon *1 2

Sat. %3.0 20

••• y *

xClay 1 Clj

\

1.0

SlO./Al.O,9 1,0 gp y> 60

sio,/r.,o,O. 100Al, O , / F . , O,O 1 0 _

A1.0,

r.,0,

•sio,

»•.0,

. 0

.10

- JO

-SO

-50

-60

- 70

_ 80

dopth dapth

A N A L

Sample

number

413414415416417

Y

11

j

j

T I C

Hori-

zon.

AA°°A!B21B22

A

11•i11

•L DA

Depth

in

cm.

15- 00- 22- 25

25- 9595-115

T

!

i

j

A

Particlesand

2 mm- 200/1200/1

110441

50/1

14321

Bize1i

11

distributionsilt

50/1- 20/1-

20,1

8854544336

i 2AI

426242613

1

J

Clay

< 2»

66152549

1

i

1H,

64445

P

2o

.0

.5

.8

.9

.0

H

Soil

Sampl

1

t

I1

Kei ;

53443

.6 :

.6

.1

.0

.8

c

L2.2.1.0.0.

type:

e Nrs.

Peaty,

413/17

Organic

matt

N

68 0.37 0.19 0.58 0.40 0.

er

9523141313

C/N

13-310.38.54.53.1

brown podzolic

t1

1

Ca

38.901.130.310.161.47

soil.

Cations im.

Mg

4.94trtr0.030.05

. aeq,

K

3.0.0.0.0.

3742262951

ids

• P

orption. 100

1

Na I

0.0.0.0.0.

4606020202

S'con•am

TEB(S)

47.1,0,0.2,

.67

.61

.59• 50.06

lpleÎX

CEC(T)

99.17.13.17.21,

,48,84,35,07.96

Sat.(V)

47.99.04.42.99.4

11

I11

Of

OMZMwîntniT

AR

• " " gChemical and mineralogical analyses of the(_clay(_fraction_£i<( 2 microns ) , O

Sample I SiO, Al 0 Fe,0 TiO CaO K O I ! SiO SiO- Al,0 1 2I ' *• c •> " 3 *• £ I Total I c ' I Clay minerals: H

number ! in weight percentages I I Al,0 Fe 0 Fe,0 ! ££-2 î-î £-5 Z

413 42.11 22.77 1.82 1.45 Oil? 0.86 69.18 3.14 61.71 19.65 iM+ dK+ Q+ An ">414 64.21 16.65 2.87 2.55 0.17 1.08 87.44 6.59 59.67 9.05 iM Q n415 49.05 25.10 4.65 I.99 0.13 1.J1 82.23 3.32 28.13 8.47 iM++ Q++ An W416 42.72 27.06 8.78 I.62 0.12 1.47 81.77 2.69 12.97 4.83 iH+ Q+ An 2417 42.41 25.49 7.85 I.32 0.13 1.93 79.13 2.8J 14.41 5.09 iM+ An w

>

Chemlcal_analjees 2Î_Ï2Î2l.S°iî-S25EÎ£-^.^-?-î2îi"_». - 2Sample I SiO, Al 0, Fe.O, TiO CaO K,0 MnO I llgnitionl SiO, SiO A1.0, I

I £ d ' z > d d ! Total I loss I & ^ —^-2 I gnumber I in weight percentages 1 1 % I Al,0, Fe.O Fe,0 I S

^ , _, t , i ^ ^ ,__ ^ „__ £^J £^j __i - 2;413 9.25 4.95 1.80 0.08 4.42 0.30 0.02 20.82 3.18 13.70 4.31 P414 88.35 4.46 3.37 0.88 0.14 0.22 0.01 97.43 33.68 69.91 2.08 >

415 79.78 6.93 5.31 0.95 0.12 O.28 0.04 93.41 19.57 40.07 2.05416 71.18 12.87 8.O8 0.95 0.10 O.52 0.05 93.65 9.40 23.49 2.50417 57.20 23.27 10.03 1.10 O.17 1.29 O.08 93.14 4.18 15»21 3.64


Profile: 413/17.Location: Burning Mountains, south of Molbakon. Elevation: 2100 m.Relief: sloping terrain of mountain side.Vegetation: transition zone from Quercus band to moss forest, climbing bambu,

mosses.Parent material: limestone.Soil conditions: moist to wet; soil cover consists of a peaty rootmat.Soil type: peaty, brown podzolic soil (discussion page 126).

413 Aoo 15-0 cm wet, dark reddish brown (5YR3/2) peaty organic matter, stronglyrooted ; lies on :

414 Ai 0-2 cm wet, dark brown (10YR4/3) silt, medium rooted, humic, crumblystructure, containing pieces of decalcified coral remnants; merginginto:

415 AB 2-25 cm wet, yellowish brown (10YR5/4) silty loam, crumbly to subangularblocky, poorly rooted ; merging gradually into :

416 B21 25-95 cm wet, yellowish brown (10YR5/6) silty loam, subangular blockystructure ; merging gradually into :

417 B22 95-115 cm wet, yellowish brown (10YR5/7) silty clay loam, blocky tostructureless.

•10

0-

10.

20

30

ko

50

60

70

80

90

100

no

Clay X10 20 30 <tO 50 60

Carbon %X Z 3 * 5

Sat.«in an vi V* ço

3

11 ' 'X \

•' y

\ i \: .' \: •

; /

: :

'•:

; 1

I

1'.j I

\\\\

\\

\

\•^Clay

! 7 8

* 5

\

j

i

I

| i!ii

i

1: KC1 K, 0

S10./A1.0,0 1 2 3 * 5 6 7310,/Fe, 0, i AlÔj/Fe 0,0 10 20 TO 1*0 "iO 60 70

•• -V

111.

1| /1 '

«,0,

|

11

1S:

• - .

1 I1 \

/ /j

1

SiO,

P«,0, Fe.0, 41,0,

___^~-—

_

-

-

•

-

-

«adepth

•10

0

10

20

30

ko

50

60

70

80

90

100

110

cadepth


Soil type: fiendzina/brown podzolic soil

Sample Nrs. 422/25

Sample

number

422423424425

1

1 Hori-

zon.

AA°°ABC

Depth

in

cm.

20- 00- 1010- 1515- 60

1I11!

2 mm—200,11

_

211

Particlesand

50/1

_

42

3

size1

! 20^

_

554544

distributionsilt

_161714

I1

clay

< 2M

2335?8

!11!!

H2

_

6.6.

0

974

pH

KM

355

795

I

!1 C

2.1.1.

Organic

matter

N

_

83 0.4756 0.2041 0.21

C/N

6.07.86.7

Ca

8.9215.8321.32

Cations adsorption complexm

Mg

2.28tr

0.12

aeq

K

0.35O.380.41

p. 100

Na

0.110.180.27

11

gram

TEB(S)

11.6616.3922.12

CEC(I)

31.9331.6542.64

Sat.(V)

367551.851.9

1

111

SOI

r1

0

zft

ts.

m

Chemical and. mineralogical analyses of the clay_ fraction ( (. 2 microns ). OdH>i 1

mnmHse>

Sample I SiO,1 d

number 1

TiO. CaO

in weight percentagesTotal 1

SiO,

Fe2°3

Clay minerals:

423424425

484645

.42

.52

.89

21.25.25.

961088

356

.54

.61

.77

111

.81

.45

.45

0.0.0.

131415

0.0.0.

616966

76.47 3.75 36.47 9.73 M+

79.58 3-15 22.11 7.02 M+

8O.8O 3.OI 18.O8 6.00 M+

AnAn.An

zMOK-<

Z>

Sample I SiO, Al,0, Fe,O, TiO, CaO K.OTotal

number in weight percentages

llgnitionlt loss tI % 1

SiO,

422423

425

69.47 7.83

54.99 17.12

6.41 O.93 0.51 O.27

9.82 0.88 1.14 0.44

85.42

84.39

15.08 28.90 i.92

5.46 14.93 2.73


Profile: 422/25.Location: Mol Mountains, north of Molbakon. Elevation: 2150 m.Relief: sloping terrain of mountain side.Vegetation: upper zone of mountain forest. Pandanus, some climbing bambu.Parent material: limestone.Soil conditions: wet; generally shallow soils; soil cover consists of organic

material and rootmat.Soil type: rendzina/brown podzolic soil (discussion page 126).

422 Aoo 20-0423 Ai 0-10

firm subangular block}' to angular blocky structure ; merging into :424 AB 10-15 cm wet, yellowish brown (10YR5/6) silty clay loam, angular blocky

structure; lies irregular on limestone, (locally this horizon is 30-SO cm),

425 C 60 cm wet, yellowish brown (10YR5/6-8) silty clay loam, structureless, be-tween limestone joints and cracks.

cm wet, brown organic matter, strongly rooted ; lies on :cm wet to moist, dark brown (10YR4/3) silty loam, medium rooted,

•20

•10

0

10

20

30

50

Clay %10 20 30 40

Carbol SS1 2 1

Sat. %10 20 30 «\O 50

1

1

i

I

1

1

Clay \ Sat.:

1

• • • ~ .

/

KCl

1

1

i

SlO./Al.O,1 2 3

S10,/Fo,0, i

o m

Fo,0,

Lo,A1.0

210,

depth

•10

0

10

20

50

40

50

cmdepth

VO


Soi l type: Podzolized, drained, brown podzolic s o i l .

Sample Nrs . 435/38

Sample . Hori-

number

Depth

in

Particle size distributionBand ! eilt ! clay

2 nun- 209U ! 50,«- 20,u- !200*1 50/1 j 2 0 M 2^

I <

pH

Organic

matter

C/N

Cations adsorption complexm. aeq. p. 100 gram. •

Ca TEB(S)

CEC(T)

Sat.(V)

inO

POM

m435436437438

AA°BB??

0-5-

40-70-

5407080

352_

5 55 205 46 165 50 25

172818-

4456

.1

.9

.4

.6

3445

.3

.2

.3

.5

9511

.83

.47

.68

.84

1000

.24

.45

.28

.27

91266

.7

.2

.0

.8

1

312

.05tr.00.44

0000

.52

.20

.19

.03

1.340.520.270.48

0.240.160.120.22

3-0.3.

13.

15885817

725328

.40

.62

.90

4112

.4

.6

.4

71

Chemical and mineralogical analyses of the clay fraction ( ( 2 microns ). _ _ _ O

Sample I SiO Al,0, F e p 0 ^ T l o? C a 0 K?° ' ' S i 0? s i 0? U O 1 Ç

I d d i d "> 1 Total ! d ? 1 Clay minerals: ^

number ! in weight percentages ! I il 0 Fe2°-s F e 2 0 ^ ! •"

435 51 90 18.82 4.86 1.94 0.11 0.68 78.31 4.68 28.48 6.07 iM+ 0. An w436 48.73 22.35 9.56 I.69 0.10 0.72 83.24 3.71 I3.47 3.67 iM + Q An437 55.70 24.71 2.10 1.42 0.13 O.97 85.43 3.83 70.73 18.46 iM + Q + An pj438 - - - - - - . . . . iM + q An Z

So>

. rChemical analyses of total soil sample ( (. 2 mm.)« _ ^

Sample I SiO. -11,0, Fo.O, TiO, CaO K,0 1 llgnitionl SiO SiO Al,0 I Î d d ? d 3 d d 1 Total 1 lose I — d - ^ I o

number I in weight percentages 1 1 % 1 A 12°3

Fe2°3 F e2°3 ' ^

435 " 51.85 6.85 8.41 0.77 0.23 0.30 68.41 12.87 16.44 1.28 M436 51.28 14.68 3.33 0.84 0.16 O.39 70.68 5.93 41.06 6.92 >437 51.00 22.02 10.69 0.86 0.24 0.47 85.55 3.94 12.41 3.15438 50.43 21.04 10.21 0.79 0.77 O»47 83.71 4-.O7 13.17 3.24


Profile: 435/39-Location: Juliana Mountains. Elevation: 2550 m.Relief: sloping site on generally very steep northern slope.Vegetation: moss forest.Parent material: limestone.Soil conditions: wet; soil cover variable: 10 cm to 2 m organic material and

rootmat (peat).Soil type: podzolized, drained, brown podzolic soil (discussion page 127).

435 Ao 0-5 cm wet, dark reddish brown (5YR3/2) peat, containing stones and siltyloam, crumbly structure ; merging quickly into :

436 A2B 5-40 cm wet, reddish brown (5YR4/3) silty clay loam, containing platy ironconcretions and completely decalcified limestone with a coralstructure, angular blocky structure ; merging gradually into :

437 B2 40-70 cm moist to wet, dark yellowish brown (10YR4/4) silty loam, containingdecalcified pieces of limestone, and small iron concretions, angularblocky to structureless, poorly rooted ; merging into :

438 ? 70-80 cm wet, dark yellowish brown (10YR4/4) clay, containing limestone,angular blocky with dark brown humic coatings on soil elementsand in cracks.

80-100 cm (void).

439 100-105 cm micro profile : 100-102 wet, dark reddish brown (rendzina) (5YR3/2)clay, rich in humus ; lying on :

102-103 wet, dark brown (7.5YR4/4) clay; lying on:103-105 wet, dark brown (10YR4/3) clay, lying on limestone. The whole

profile contains pieces of limestone.

0

10

20.

30

1(0

5 0 .

6 0 .

70 .

ao

Clay %10 20 30

Carbon %X 2 3

Sat. %

\

'\Sat.

\

\

\\1

^ l a y

* 5 i 7 8

pB? 't ;

• K C :

i\

9 19

6 ?

H, 0

\

\

\

SiO,/Al,O,1 2 3 5. 6 7SiO,/F.,0, .;p 1 0 30

1

11\

r»»jO,

// y

Is

\A 11°T

\

\

Ho,r.,0,

" ^

. 1 0

-?0

.30

.50

.60

depth depth

O

oo


Soil type: Acid brown forest soil (eol brun acide)

Sample Nrs. 81/84

Sample

number

Hori-

zon.

Depth IIII1

in

cm.

Particle size distribution !sand ! silt ! clay !

2 mm- 200« ! 50u- 20,u- ! !

Organic

matter


200/1 1 KC1 C/N Hg TEB(S)

CEC(T)

Sat.(V)

mO

OMZM

H

81828384

A. 0 - 5 15- 30 1

30- 50 150- 70

654243

192826

112527

5.1 4.24.9 4.05.0 3.9

4.650.710.43

0.60 7.40.14 3.10.10 4.3

8.340.570.31

1.39 1.90 0.070.19 0.66 0.040.29 0.42 0.04

11.70 29.03 40.21.4S 15.64 9.31.06. 14.27 7.4

Chemical and mineralogical analyses of the clay fraction ( ( 2 microns ). _ g

Sample ! SiO, Al-0 Fe,0 TiO CaO K O ! I SiO SiQ Al,0 1 g! ^ ^ 1 Total ! - - *• ' ! Clay minerals: ^

number I in weight percentages 1 I Al.,0 Teo0 Te 0 I >>.... . .„.„_..-....___. ------- - - - - - - -- ------ --£- _--_£ ._„.£..._..,...._.... __- — ___ -__ ........ M

81 54.75 25.49 2.01 1.38 0.11 3.21 86.95 3.65 72.64 19.89 I + + K+ Q++ An ^82 54.43 27.45 3.5O I.I8 0.10 3.39 90.05 3.37 41.47 12.30 I+ K Q+ An83 55.06 30.58 2.84 I.I6 0.11 3.6O 93.35 3.O6 51.70 16.9O I+ K Q+ An Q8 4 - - - - - - - - . - g

HSO

r1

Chemical_analy_ses of total soi^somple^^^^mm.^ ^

Sample I SiO Al-j0, F O O ° T T l Op O a O Kp° ' llgnitionl SiO SiO- Alp0, ' Î d d 3 d i ! Total I loss ! ' ! o

number I in weight percentages 1 I % I A1.0 Fe2°-5 Fe2°3 ' ög81 6.7.15 10.53 't.73 0.79 0.50 I.36 85.06 10.84 37.86 3.49 M82 70.53 14.17 5.95 0.88 0.20 1.71 93.44 8.46 31.61 3.74 >83 70.75 13.77 7.11 0.88 0.20 I.71 94.42 8.73 26.53 3.0484 - - - - - - - • . . .


Profile: 81/84.

Location: North of Katem. Elevation: 240 m.Relief: undulating, hilly part of mountain spur.Vegetation: newly occupied banana garden; irregular medium high forest.Parent material: siltstone.Soil conditions: most to wet; soil cover consists of an organic matter containing

rootmat.Soil type: acid brown forest soil (sol brun acide) (discussion page 131).

81 Ai 0-5 cm moist, very dark brown (10YR2/2) silty loam, firm, crumbly tosubangular blocky structure, well rooted, containing organic matter;merging into :

82 B21 5-30 cm moist, light yellowish brown (10YR6/4) silty clay loam, angularblocky structure, medium rooted ; merging into :

83 B22g 30-50 cm moist to wet, light yellowish brown (2.5Y6/4) silty clay, with grayand yellow small stains, angular blocky to deeper structureless, poorlyrooted ; merging into :

84 CG 50-70 cm wet, light gray (2.5Y7/2) siltstone, weak and structureless, withscattered brownish yellow mottles.

0

10

20 .

30

"to

50

Clay *10 20 3.0

Carbon %1 ? 3 't 5

Sat. %10 2p 30 'tO 50

ClaJx

\\

r.!'

I ;

;;1 !

Sat. .

'\

1I

11

pH4

SiO,/Al,O,1 2. ?SiO,/Fe,O,10 -20 30

Al, 0, /Fe, 0,0 10

't

llO

5,

50

JO

6

60

7

70

30

SiO,

Al,0,

Al,0^ V

Fe,0,

SiO,

Fe.O,

depth depth

8


Soil type: Weakly gleyed, brown podzolio soil

Sample Nrs. 90/94

Particle size distribution !sand 1 ailt 1 clay 1

200yU 50^2 , 20>l 2]a , < Zfi

pH

Organic

matter

N C/N


Ca Mg K TEB CEC S a t .(S) (T) (V)

O

owzMif)i—ic/)m>

9192931

0- 1010- 2020- 5050-110

110-130

46 28 13 4.9 3.9 2.71 0.55 4.9 1.55 0.52 0.79 0.02 2.88 16.57 17.4

3735

21 34 5.2 3.9 0.20 0.06 3.3 1.43 0.16 0.85 0.03 2.47 18.05 13.721 35 5.2 3.8 0.21 0.06 3.5 1.71 0.38 O.65 0.03 2.77 18.33 15.2

Chemical and mineralogical analyses of the clay fraction C < 2 microns ). O

d>

— z

Sample 1 S102

number 1

I SiO,

in weight percentagesI Total 11 1

56.96 24.31 4.15 I.I8 0.13 2.12

50.63 25.88 9.02 0.91 0.10 2.6355.06 27.O6 4.25 O.85 0.09 2.56

lltl. '

II Clay minerals:

9091929394

88.85 3.98 36.60 9.19

.17 3.33 14.97 4.50

.87 3-45 34.55 10.00

1MT An

AnAn

OM

Chemical

Sample

number

analjs(

1 SiO2

1

>.B O f

il.e

total eoil

»°3 F°2°3in weight

sample ( < 2 mm.).

TiO CaO K20

percentages!1

Total!Ignition!1 loss 11 % 1

S i 02

A12O,

sio2

Fe2O,!1

O

81.97 5.26 3.38 0.86 0.19 O.5690

92 - -93 71.59 11.7494 74.35 12.55

9.52 O.893.59 0.91

0.17 1.410.17 1.48

92.22

95.3293.05

26.49 64.67 2.44

10.37 20.0610.07 53.73

1.935.34

DESCRIPTION AND ANALYSES OF THE SOIL PROFILE I O I

Profile 90/94.

Location: Amjol, south of Katem. Elevation: 330 m.Relief: flat site of erosion terrace, lying on very steep scarp in the Digul valley.Vegetation: secondary forest (5 to 8 years), among gardens. On soil surface an

interrupted layer of litter.Parent material: limestone.Soil conditions: moist to wet; drainage medium to poor.Soil type: weakly gleyed, brown podzolic soil (discussion page 130).

90 Ai 0-10 cm moist, brown (10YR5/3) silty loam, slight humic, porously crumblyto subangular blocky, rooted ; merging into :moist, light yellowish brown (10YR6/4) silty loam, medium rooted,subangular blocky to blocky structure, poor humic ; merging graduallyinto:moist, brownish yellow (10YR6/8) silty loam, poorly rooted, blockystructure, very slightly mottled ; merging very gradually into :moist to wet, brownish yellow (10YR6/8) silty clay loam, with grayand many strong brown mottles, angular blocky to structureless;merging quickly into :

94 B3g 110-130 cm wet, light gray (2.5Y7/2) silty clay loam, with strong brownmottles, angular blockly structure to structureless.

91 B21 10-20 cm

92 B22 20-50 cm

93 B23g 50-110 cm

I O 2 SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

: ; i

•H Öh OO »

te

C0C0 4 - OI • • • .

OJ IA KMAtA oj ai I A

O H CMO rj f\J (M OJ

«c «< «$ m eq Q

O O

K~\oj

VD EN

IACO

tr\ r\JCO r-I

iHC^

O

-d-CN

tv.

§

H

rA

IA1!© ^D

E>-vû

'OH

OJ J-

O O

O~< I A

O O

CO CT.

H OJ OÎ • • •

- * H O

CO K M N C - ON

OJ rA K W

AJ ONVD - *

O

20-

O•H

1O

cO OH IA

1 1OcOH H

- *

LA

g

50-

O iH OJ H OJO H H OJ OJ

p5 M

•î 5

DESCRIPTION AND ANALYSES OF THE SOIL PROFILE IO3

Profile: 18/23.

Location: Iwur terraces. Elevation: 400 m.Relief: flat.Vegetation: primary boggy forest with lower to medium sized trees with thin

trunks, and high Agathis trees. Mosses on the trunks und on the soil cover, whichconsists of a mat of many laterally growing roots.

Parent material: alluvium of granodioritic origin.Soil conditions: wet.Soil type: podzol (discussion page 143).

18 Aoo 10-0 cm19 Ai 0-5 cm

20 A2 5-15 cm

21 Ü2ig 15-SO cm

22 Bi2g 50-100 cm

23 D over 100 cm

wet, rich in organic matter, brown, rootmat ; on :wet, dark gray brown (10YR3/2) loamy sand, strongly rooted,soft porously crumbly structure ; on :wet, lightly yellowish brown (2.5Y6/4) loamy sand with dispersedbrown mottles, soft angular blocky; with some stones; mergingquickly into :wet, brownish yellow (10YR6/6) coarsely sandy loam, with lighterand darker mottles ; containing stones ; soft angular blocky structure ;merging gradually into :wet, light gray (2.5Y7/2) silty clay loam with some brown mottlesand white spots (weathered minerals) ; containing stones ; structure-less ; lies on :wet, layer with cobbles, between which brown, silty clay loam.


IO4 SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

Profile 24/26.

Location: Iwur terraces. Elevation: 600 m.Relief: flat.Vegetation: secondary young forest, with undergrowth of grasses. Formerly

(two to three years ago) gardens.Parent material: alluvium originating from granodiorite.Soil conditions: moist to wet; fairly good drainage.Soil type: sol brun acide (discussion page 143).

24 Ai 0-10 cm moist, humic, very dark gray brown (10YR3/2) sandy loam; porous,crumbly structure ; well rooted ; containing gravel and stones ;merging quickly into :

25 A2B 10-30 cm wet, yellowish brown (10YR5/4) sandy clay; (semi-coated) sub-angular blocky structure ; medium rooted ; containing gravel andstones ; merging gradually into :

26 BC 30-110 cm wet, yellowish brown (10YR5/5) sandy clay, (semi-coated), sub-angular blocky ; on coarse sand ; containing gravel and stones.



Profile 48/52.

Location: Almun-Wending. Elevation: 780 m.Relief: flat to gradually sloping. High old terrace.Vegetation: medium high, moss forest, ferns, mosses.Parent material: conglomerate of sandstones.

Soil conditions: wet; peaty rootmat.Soil type: peaty aluminium podzol (discussion page 144).

48 Aoo 20-0 cm wet, dark reddish brown (2.5YR4/4) peaty matter; strongly rooted;lies on :

49 A11 0-10 cm wet, brown (7.5YR5/2) sand; rich in peptizised organic matter, loosestructureless ; small light gray mottles ; merging irregularly andquickly into :

50 A12 10-18 cm wet, very dark gray to dark brown (10YR3/1-3) loamy sand; poorlyrooted ; with yellowish brown mottles ; infiltrations of organic matter ;structureless ; merging irregularly and quickly into :

51 B21 18-50 cm wet, pale yellow (2.5Y8/4) sandy loam; hardened structurelessclods, brown root channels, very poorly rooted, merging into :

52 B22g 50-80 cm wet, yellow (2.5Y8/6) loamy sand ; with yellowish brown mottles ;containing coarse sand and stones.



Soi l type: Acid brown fores t s o i l ( so l brun acide)Sample Nrs . 1342A5

Sample

number

Hori-

Depth

in

Particle tsize distribution Isand 1 silt 1 clay !

m- 20QUpH

KOI

Organic

matter

0/N


Ca Mg K TEB(S)

CEO(T)

Sat.(V) O

MMin

1342

13441345

0- 10', 10- 30

30- 60:g 6o- 70

1 12 492 12 305 10 34^ 18 3?

15231515

23303626

't.3 3.4't.? 3.94.9 4.04.8 3.9

7.381.780.390.33

0.73 10.10.20 8.90.09 4.3O.O6 5.5

1.070.210.4?0.11

0.95 2.29 0.100.10 O.67 0.100.26 0.53 O.O50.10 0.37 0.05

4.41 41.79 10.1I.I8 21.83 5.4I.30 17.21 7.5O.62 18.02 2.6

Ohemical_and_mineralogical_analjrses_of_the_claj_£raction_(_<_2_Lmicrons_)i O

Sample I SiO •"•,°, Fe,0 TiO, CaO K O I I SiO SiO Al 0 1 S1 •* - I Total ! —=-2 ! Clay minerals: H

number 1 in weight percentages ! I ^2°? Fe2°3 Fe2°3 ' M_____ — —«__«____„«.™»____ — — _ — _ _ » _ _ _ _ _ _ — — _—__» — _____—_ — — «.««___ — __ — _ « — _ _ _ _ _ _ _ _ _ — _ — _ ——& — _ — __ ——& — —___„_£. — ___-_ —__^ —— — ____ — _ — — — — - — — — — - — ——— ——— ————— M

1342 52.85 25.10 3.20 1.77 0.10 2.11 85.13 3.58 44.04 12.30 I* IJ An w1343 4 3 . 0 4 2 9 . 8 0 7 . 0 8 1 .41 0 . 0 8 I . 6 1 8 3 . 0 2 2 . 4 6 1 6 . 2 1 6 . 6 0 I * < J A n n

1344 43.67 29.41 6.67 I.32 O.09 2.43 83.59 2.52 17.46 6.92 I+ Q An M1345 43.35 30.58 6.27 1.27 0.10 2.61 84.18 2.41 18.44 7.65 I+ 5 An Z

"3

Chemical analyses of total soil sample ( ( 2 mm.). _ RSample I SiO, A1.0, Fe.O, TiO, CaO K,0 I Hgnitionl SiO, SiO, Al-0, I . ^

I 2 Z 3 2 3 * 2 1 Total ! leas I —^-2 I onumber • I in weight percentages 1 I % I A 1 A Fe2°3 Fe2°3 ' 2

1342 57.54 10.76 6.75 O.96 0.16 0.81 76.98 "^ 9.09 22.73 2.50 m1343 59.52 17.12 8.50 1.02 0.10 0.86 87.12 5.91 18.67 3.16 >1344 59.52 18.59 8.79 1.04 0.08 1.48 89.50 5.44 18.06 3.321345 59.73 19.57 8.24 1.05 0.08 1.48 90.15 5.19 19.33 3-72

1345A 6I.43 18.10 7.29 1.05 0.08 1.97 89.92 5.77 22.47 3.89 1345A = a piece of shale outof subsoil


Profile: 1342/45.

Location: Nimdol. Elevation: 1300 m.Relief: sloping terrain.Vegetation: medium high forest, locally cut-down for gardens.Parent material: shales.Soil conditions: moist; organic rootmat, litter 3 to 5 cm thick.Soil type: acid brown forest soil (discussion page 133).

1342 Ao O-io cm moist, dark brown (10YR4/3) silty loam; humic; well rooted;crumbly to subangular blocky structure ; containing some stones ;merging into :

J343 A12 10-30 cm moist, yellowish brown (10YR5/6) silty clay loam; subangular blockystructure ; only thick roots present ; containing stones ; merging verygradually into :

1344 B2 30-60 cm moist, dark brown (7.5YR5/6) silty clay loam; angular blocky tostructureless massive ; containing stones ; merging gradually into :

1345 BCg 60-70 cm moist, reddish yellow (7.5YR6/6) silty loam; angular blocky tomassive; containing stones, and scattered some gray stains; irregularlying on gray shales.

0

10

20

TO

1(0

50

60

70

Clay *10 20 30 bo

Carbon %1 2. 3 ">

Sat. *10 20

at. / Cla

:. / '

y1/

:l

• \

S

--V"-""\\\

• \

j/

//

5 ( 7 8

SiO,/Al,O,1 ? 3 6. 7 8sio./y.jO, ; »1,0,/ F . ,0 ,0 10 20 30 <«

pH3 't 5

C.

\K C l '

V\s

r

iiii

0 1

11,0, 1

r.,0,

,/

s

A

r1

.0, ISI-.0, , ? .

I1

- - "

0.

o,

10

JO

30

.1«)

SO

60

7 0

depth dapth

N A L Ï T I C A L D A T ASoil type: Podzol/brown podzolic soilSample Nrs. 304/07

Particle size distribution 1sand ! silt 1 clay I

i i i20Qu

200,u50,u-2

pH

5QU . 20^ < KC1

Organic

matter

0/N


Ca Mg K Na TEB(S)

CEC(T)

Sat.(V)

Oh-1

OMzMui

301»J05306307

5- 00- 55- 25

25- 75

4.4 3.4 19.54.2 3.5 3.3

Chemical and mineralogical analyses of the clay fraction ( ( 2 microns ) . OCZH>

mnwzHwf•zwo

Sample I

number !

SiO, Al,0, Fe,0 TiO, CaO


111

Total

77.87,92,88

.32

.16

.33

.01

Si

Al2

3.2.5.2.

o?97772275

Si

Fe2

27.25.48.7.

o342228936

A1 2O,

Fe2°3

6.918.389.372.68

Clay minerals:

304305306307

45.47.64.42.

95981620

23.29.20.26.

52489012

45315

.47

.51

.50

.30

1111

.50

.62

.55

.19

0.0.0.0.

13100912

1223

.75

.47

.13

.08

II+

II

KKQ+

Cr

AnAnAnAn

Chemical

Sample

number

analyses

1 SiO2

1

of total soil

in freight

sample ( ( 2 mn

Ti0 ? CaO

percentages

i.).

K20 I11

Total(Ignition!! lose !1 % 1

SiO2

A12O3

sio2

Fe2°3 Fe20

11

DESCRIPTION AND ANALYSES OF THE SOIL PROFILE IOC

Profile: 304/07.

Location: Grote Beer Mountain, southern slope. Elevation: 1320 m.Relief: nearly flat site on southern slope.Vegetation: subzone of the moss forest or transition' to medium high thinly

stemmed trees.Parent material: slates.Soil conditions: moist to wet; soil cover consists of peaty rootmat.Soil type: podzoljbrown podzolic soil (discussion page 132).

304

305

Aoo

Ai5-O

0-5

306 A2

307 B2g 25-75

cm wet, dark reddish brown peaty rootmat, merging quickly into :cm wet, gray brown (10YR5/2) clay, with brownish yellow and reddish

yellow mottles ; weak, angular blocky to structureless ; medium rooted ;merging into :

5-25 cm wet, light gray brown (10YR6/2) clay, with yellow mottles;structureless ; poorly rooted ; containing stones ; merging into :

cm wet, soft, structureless, reddish yellow (7.5YR6/8) clay with somescattered small light yellowish brown streaks ; containing stones ;sharp boundary on gray slates.

SiO./AljO, •1 2 3 't

S10,/Te,0,0 W 30 30 V>

0

10

20

30

1*0

50

60

70

11

1

1

1 ^

".O, /

y

-

depth

- 50

. 60

- 70ID

depth


S o i l t y p e :

Sample N r s .

Low huraic gley

308/10

I

Sample Hori-.

Depth

in

number

Particle Bize distribution Isand 1 silt 1 clay I

2 mm- 200^ ! 50fx- ZOp- ! !200/1 5qu J 20/1 2/1 J < 2ji J KC1

! Organic1I1

matter

N C/N


Ca Mg TEB(S)

CEC(T)

Sat.(V)

OIM

OM

zMen

308309310

A

c°8C 2 G

5 - 0 10 - 5 15- 75 1

31017

724l21

18

3126

61735

4.2 3.24.0 3.34.5 3.6

10.534.670.51

1.69 6.2O.28 lé.70.07 7.3

trtr

trtr

0.37 0.09O.29 0.02

- 59.13 -0.46 18.74 2.5O.31 18.33 1.7

Chemical and mineralogical analyses of the clay fraction ( ( 2 microns )• goz

npi•z

Sample I SiO,

number I

TiO,

in weight percentagesTotal

SiO,

JÎÙL

SiO,

l:fj. liti.Clay minerals:

308309310

36.59.49.

398168

82230

.63• 35

.58

012

.79• 31.29

31

3

.36

.60

.30

000

.13

.09

.10

1.2.

3.

3980

48

508789

.69

.96

.43

742

.17

.55

.76

122.121.57.

837485

172620

.14

.76

.95

I + KI + KI+ G

h+ Cry Cr

Cr

AnAnAn

Chemical

Sample

number

analyst

I SiO2

1

ÎS Of

Al

total soil

2°3 Fe2°3

in weight

sample ( ( 2 nu

TiO CaO

percentages

K20I1

Total(Ignition!1 loss 1! % 1

sio2

A12O3

SiO2 Al.

Fe 20 3 Fe.0 !

308 36.00 0.99309 77.84 2.97310 74.84 12.13

0.41 0.70 0.15 0.260.26 1.36 0.10 0.39I.58 1.35 0.09 1.65

388291

.51

.92

.64

6116

61.82 234.15 3.7944.55 798.30 17.9210.49 126.31 12.04

ZPI3;

OG

I

DESCRIPTION AND ANALYSES OF THE SOIL PROFILE I I I

Profile: 308/10.

Location: top of the Grote Beer Mountain. Elevation: 1730 m.Relief: flat terrain over a short distance (50 m).Vegetation: moss forest, low to medium high forest, mosses, pandanus.Parent material: slates.Soil conditions: wet; rootmat in moss layer.Soil type: low humic gley (discussion page 132).

308 Aoo 5-0 cm wet, peaty, strongly rooted, very dark brown (7.5YR3/2) silt; softand friable ; merging quickly into :

309 CiG 0-5 cm wet, light gray (10YR6/1) silty loam; with very lightly yellowmottles ; soft structureless ; ; poorly rooted ; merging quickly into awhitish, very thin band, on :

310 C2G 5-75 cm wet, light gray (10YR6-7/1) silty clay loam; with some brownishyellow streaks; very poorly rooted.

Clay *10 20 30 VO

Carbon *6 7 8 9 10

Sat.«

50

70

depth

Clay /

\

810,/Al, 0,1»?BIO,/T.,20 *0«,0,/ï.0

'%

19

* J 6

80 100 WO

2P

7

11(0

o

- 10

. 20

. 5°

. 50

. 6o

. 70

endepth

N A L Y T I C A L D A T A

Sample

number

I Depth!

'II

zon.. cm*

Hori- in

"•I

Particle size distribution 1sand 1 silt ! clay I

2 mm- 200/1 ! 50>i- 2Qu- ! |200/1 •yOfi \ ZOn 2fX \ ( Zp.

I 1

PH

KC1

SoilSampl

! c

type:e Nrs.

Organic

matter

N

Shallow,

565/69

C/N !

podzolic 5-Ley

Cationsm

Ca Mg

aec

K

soil

adso• P-

Na

100 gram

TEB(S)

CEC(T) .

Sat(V)

inO

OM

M

H

365

367368369

A""12- 00- 33- 88- 18l8-deeper

3.93.94.13-93.'t

3.03.13.53.5

22.312.92.01.21.1

Chemical and mineralogical analyses of the clay fraction ( ( 2 microns ). Q

SSample I!

number I

SiO, Al-0 Fe,0 TiO Ca


1!1

Total11I

O l a y m i n e r a l s :

nMZto

r

Chemical analyses of total soil sample_(_<_2_miiO «_ M

Sample I SiO, Al 0 Fe,0, TiO CaO KO 1 I Ignition! SiO SiO Al 0 1 ^1 d * i d i d d I Total I lose I —^-^ I o

number I in weight percentages 1 I % 1 Al-0 Fe,0 Fe->°-, ' G- i.-î --5 --5 S

365 42.45 6.85 0.64 1.03 0.17 1.12 52.26 10.54 176.87 16.78 m366 62.27 11.74 0.52 1.50 0.10 1.37 77.50 9.02 319.32 35.40 >367 65.87 19.O8 0.79 1.41 0.09 2.64 89.88 5.87 222.34 37.88368 63.76 23.48 0.84 1.20 0.09 3.O8 92.45 4.62 202.40 43.81369 62.49 22.50 O.95 1.14 0.08 3.26 90.42 4.72 175.41 37.16


Profile: 365/69.

Location: mountainspur to Antares massif. Elevation: 2125 m.Relief: top of the spur, which is very steep on either side.Vegetation: moss forest.Parent material: bluish clay- or siltstone.Soil conditions: wet. Soil cover consists of a deep peat layer. Sampling was

possible because a tree had fallen down and had taken its root system with it.Solum is structureless and soft.

Soil type: shallow, podzolic gley soil (discussion page 134).365 Aoo 12-0 cm wet, very dark brown (10YR2/2) peaty material; lying on:366 Ao 0-3 cm wet, very dark gray to dark gray brown (10YR3/1-4/2) clay; medium

rich in organic matter ; merging, irregular waving, quickly into :367 Ai 3-8 cm wet, light gray (10YR6/1) clay; merging quickly into:368 CiG 8-18 cm wet, dark greenish gray (5GY4/1), clay, soft structureless; lying

on:369 C2 over 18 cm moist to dry, dark greenish bluish gray (5BG4/1) stratified, fairly

hard claystone.


Soil type:

Sample Nrs.

Peaty, ortstein podzol

335/39 - 34OB

Sample

number

3353363373383393408

1

111

Hori-

zon.

A „

Al

I

t11

+

Depthin

cm

20-++

0-2-

2.5-80

.

015522.5

15

Particle size distribution 1sand I silt ! clay !

2 mm- 200M ! 5qn- 2Qu.- ! !pH

200/1 50/1 20M <

Organic

matter

C/N

Cations adsorption corm. aeq. p. 100 gram

Ca Mg K Na TEB(S)

iplex

CEC(T)

Sat(V)

OPO

wwM

wC/J

oc

4.2 -4.1 -

35 24 22 9 10 4.7 3.8 2.82 0.19 14.8

47 23 25 1 4 5.2 4.8 0.38 0.02 19.0

tr 0.19 0.13 0.02 0.31 18.70 1.66

tr 0.19 0.08 0.05 0.32 8.56 3.74

Chemical and mineralogical analyses of the clay fraction ( ( 2 microns K

Al,0, Fe,0, TiO, CaO K,0 ! II

Sample I SiO.

number I

Fe.O,"3 2 3 2

in weight percentagesI TotalI

1Clay minerals:

3353î633733833934OB

31.01 37.65 1.91 5.46 0.12 0.20

14.02 55.16 2.91 0.96 O.30 O.65

76.35 1.40 43.32 30.92 K++ G+

74.00 0.43 12.85 29.88 <3+

Chemical

Sample

number

analyses

1 SiO2

1

of total

in V«

soil

light

sample ( (. 2 mm.

TiO CaO

percentages

).

K2° !11

Totalllgnitionl1 loss 1I % 1

SiO2 sio2 11i

33533633733833934OB-

S.8369.6942.9061.8565.87

_3.44

12.9612.4714.1712.55

_1.352.02

29.567.646.04

_0.211.09O.8OO.580.53

_0.220.861.622.584.24

_0.442.843.052.843.01

_14.89.90.89.92.

4946406624

828412-

_4.369.145.857.428.85

_17.4491.983.87

21.5929.08

_4.00

10.060.66

' 2.913.29

nMia

W

O

azw>

DESCRIPTION AND ANALYSES OF THE SOIL PROFILE I I 5

Profile 335/39-40 R.

Location: Top of the Antares Mountain. Elevation 3250 m.Relief: flat part of a top.Vegetation: grasses, mosses, other short herbs; alpine meadow region.Parent material: granodiorite.Soil conditions: drainage poor; forming of peat and locally small fens.Soil type: peaty, ortstein podzol (discussion page 136).

Aoo 20-0 cm335 15 cm wet, brown peat layer, with some sand, intensively rooted; un-

dulating merging into :336 5 cm wet, dark brown peat,with some sand ; rooted ; a little undulating ;

quickly merging into :337 Ai 0-2 cm wet, grayish (10YR5/2) humic sand; poorly rooted; on:338 B2ir 2-2y2 cm wet, rusty coloured, ironpan with a rough and uneven surface ; on :339 Ci 2J4-I5 cm moist, yellowish (10YR8/3) sand; consisting of rotten rock material.340R C2 ca. 80 cm parent material, solid rock.

A N A L Y T I C

Sample

number

340341342343344

Hori-

zon.

AASCp

°3

A

1

11

L D A

Depth

in

CG

0-10-18-35-50-

a.

1018355070

T

11j

A

2 mm-200/!

17372442-

Particlesand

200/150/1

23212522-

size distribution

11j

50/120M

35263828-

jilt

• 20,11-2/1

14896-

111

clay

< 2 M

11842-

!

Ijh

5455

pH

0

.0

.g

.0

.0

-

Soil type:Sample Nrs.

KC1

4444

C

.0

.2

.2

.2-

8.0.0.0.

-

Acid brown forest soil (sol brun

340/44

Organic

matt

N

57 0.79 0.61 0.03 0.

-

er

C/H

78 11.011 7.206 10.201 3.0

-

- 340R

Ca

0.21trtrtr-

acide)

Cations adsorption compl«m

MS

O.360.190.080.19-

aeq. p. 100

K Na j '

0.86 0.11O.18 0.04 •O.I3 0.040.13 0.07-

gram

TEB(S)

I.540.410.250.39

X

CEC(T)

311194

72800871

Sat.(V)

4328

9583

j

1

c

Pc(r

u.ir

H>

Chemical and mineralogical analyses of the clay fraction ( < 2* microns ). _ . O

Sample I SiO- Al 0 Fe->°, Ti0, CaO K O 1 ! SiO SiO Al,0 ! • 2;! ^ ^ ! Total I —=-2 1 Clay minerals: H

number I in weight percentages I ! ^l?^-* ê2^3 Fe2^3 ' ^

340 41.46 34.12 4.55 2.98 0.13 0.23 83.47 2.07 24.30 11.76 dK++ <"341 39.87 34.90 6.4? 2.47 0.13 0.21 84.05 1.94 16.43 8.46 dK++ G o342 35.26 37.27 2.43 1.05 0.17 O.32 76.50 1.61 38.70 24.04 dK++ G+ M343 44.46 40.89 2.44 0.85 0.19 O.37 89.20 1.85 48.60 26.27 dK++ G 33 4 4 - - - - - - - - . . M

55Chemical analyses of total soil sample ( ( 2 mm«). ^ _ MSample I SiO, A1.0, Fe,0, TiO, CaO K.O 1 llgnitionl SiO, SiO Al,0, I <

! 2 2 ' Z > 2 2 I Total ! loss ! —^-2 ! Onumber I in weight percentages 1 I % \ Al-0 Fe,0 Fe,0 I 2

i-2 i-2 1-2 2!340 56.41 11.34 7.21 0.71 1.00 2.45 79.12 28 8.46 20.86 2.47 M341 53.56 11.74 15.34 0.77 1.00 2.50 84.91 14 7.76 9.31 1.20 •"342 63.18 12.15 8.86 0.68 1.20 2.56 88.63 9 8.84 19.02 2.15343 61.22 16.19 7.07 O.61 1.42 3.11 89.62 7 6.43 23.09 3.59344 63.90 17.00 7.19 0.62 1.29 3.05 93.02 6 6.39 23.70 3.7134OR 65.87 12.55 6.04 0.53 4.24 3.01 92.24 - 8.85 29.08 3.29


Profile: 340/44.

Location: top of the Antares Mountain. Elevation: 3290 m.Relief: slope of about 300, on the rolling to flat surface of the top.Vegetation: grasses and other short herbs; alpine meadow region.Parent material: granodiorite.Soil conditions: moist, drainage good.Soil type: acid brown forest soil (discussion page 135).

0-10 cm moist, dark brown (10YR3/4) loam; rich in organic matter; wellrooted; crumbly structure; merging into:

10-18 cm moist, reddish brown (5YR4/4) sandy loam ; poorly rooted ; containingvery thin, platy iron concretions ; firm crumbly to sübangular blocky ;merging into :

18-35 cm moist, yellowish red (5YR5/6) sandy loam ; very loose crumblystructure ; poorly rooted ; merging gradually into :

35-50 cm moist, light yellowish brown (10YR6/4) sandy loam; loose struc-tureless to crumbly ; merging into :

50-70 cm moist to dry, light gray to white (10YR7/2) loamy sand; rather looseand structureless ; rotten rock.

340

341

342

343

344

Ao

AB

C i

C2

Cs

Clay %10 20

Carbon %

1 a

S1O,/A1,O,1 Z 3

SiO,/Fe,O,

20

30

50

illECl

i !i !Hi0

i !: 1

i

/ ' •

S10,

»1,0,

^ <J

Fa,O,

-

\

\

\ -30

dapth depth

Il8 SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

+ + dominant, + sub-dominant, (no special mark) present in small quatities.The indication + , by absence of an other dominant clay mineral, is given incases of weaker and broader basal reflections on the X-ray records. As mentionedabove, interstratified units of other minerals can be present at random in thelattice, e.g. montmorillonite with illite eels.

CHAPTER XII

DISCUSSION OF THE SOILS

The soils of the lowland.

Under the prevailing very wet climatological conditions in the lowland, soildevelopment is greatly dependent on the drainage conditions. The latter arenormally poor in the flat areas but also in the hilly regions gley phenomena dueto poor drainage were observed. Profile 191/95 is a variant of the soil type whichcovers large parts of southern New Guinea in the middle Digul plain. The higherparts of an old, intersected table landscape (see also page 22 Muyu and Man-dobo landscape), in the neighbourhood of Digul, lie about 10 m to 20 above sealevel, which gradually slopes in northwestern direction, so that near the foot ofthe steeply rising Central Mountain Range we find a wide zone of over hundredsof kilometers with bog and half-bog soils (REYNDERS, 1961). WHITE (1928)compares the landscape with similar lowlands occurring in the coastal zones ofSumatra and Borneo.

In the depressions new sediments are deposited, with the result that close tothe rivers levees are formed, which are bordered by depressions or swamps. Thewater lines of these swamps border at the fringe of the old intersected plateau,which brings out scorpion-shell-shaped surfaces. South of the broad, meanderingchannel of the Digul this old landscape is found in a small strip, but moresouthward in the Marau-river area the land is lower and consists of shields within between large swamps (REYNDERS, 1961, SCHWAN, 1962).

The soils of the plateaus are laterized. However, the profiles show variation inmorphology, depending on the amount of iron present in the original sedimentsat the groundwater level, and on swampy conditions of some terraces during acertain period of the year.

The original sediments have been transported over great distances and weredeposited partly by rivers different from those flowing nowadays through thewide depressions. Probably the sediments have been weathered and eroded severaltimes. This assumption is supported by the mineralogical composition of theheavy fraction of the soils. The data given in table VI (Nrs 2450/56) of the Mappiregion, indicate even poorer soils than do the figures of a profile in the TanahMerah area (Nrs. 191/95). Compared to the sediments of the middle Digulbasin, they show still poorer mineralogical composition towards the mouth of theriver. The result is that the iron content in the soils, present in minerals as wellas hydroxides and oxides decreases in the direction of the Arafura sea. The soils

DISCUSSION OF THE SOILS IIO,

and especially the top horizons are coloured more reddish inland, more rosy half-way, and often yellowish near the mouth of the Digul (see VAN SOELEN, 1956).These soils must be classified as red and yellow latosols respectively, withwhitish kaolinitic subsoils. The lower shield landscape of the Marau-river area,mentioned above, must be younger. Probably the sediments were supplied by the.southern currents of the Arafura Sea coming from the Australian continent (notethe mineralogical composition given in table VI of the Nrs. 1301/08, sampled byRAZOUX SCHULTZ, 1952).

Another factor influencing the morphology of the soil profile is the internaldrainage of the soils. This is partly dependent upon the height above the riverlevel in the neighbourhood, partly upon the extension of the elevation itself.

Some profiles show very deep reddish-brown horizons (150 cm), others haveshallow, red top horizons (25 cm), but they all have white subsoils, which are moreor less mottled. This has also been reported by HEKSTRA and VALETTE (1961) andMOUTHAAN (1962).

In some regions, e.g. Mappi (VAN SOELEN, 1956) parts of the woodedhigher table landscape are even marshy during a short interlude, due to the veryhigh rainfall. In this case the topsoil has a brownish colour over some decimeters,owing to the penetration of dispersed humus.

In the depressions of the southern lowland bog and half bog soils occur, whileon lower shields and in northwestern direction bleached soils dominate.

P r o f i l e 1 9 1 / 9 5 .

Profile Nr. 191/95 offers a good example of the soils in the flat lowland, wherethe drainage conditions are poor. In several places in the surroundings of TanahMerah an undulating layer of coarse, sandy material with cobbles was found at adepth of two to four meters beneath the soil surface. The acidity of the soil ishigh, which corresponds with the base-saturation. A point of interest is that theadsorbed calcium is low, but that magnesium is relatively high.

The granulometric analyses show a marked increase of the clay fraction withdepth, showing two maxima, namely at 18 cm to 50 cm and deeper than 115 cm.These two maxima are reflected in the total analyses of the fine earth. The ratiosof silica and aluminium oxide of the clay fraction decrease with depth to about18 cm to 50 cm, and increase in deeper horizons. T h i s m e a n s t h a t i n t h et o p s o i l t h e r e i s a p o d z o l i c p r o c e s s , w h i c h i s s u p e r i m p o s e do n t h e e a r l i e r p r o c e s s of l a t e r i z a t i o n . The behaviour of theiron is indicative: there is an effect of leaching in the top horizons, which ismuch more expressed in the total analyses than in the clay data. On the other hand,the amount of iron is very high, and it seems unlikely that the total quantityoriginated in the sediments, from which the top horizon was derived. Possibly theiron dissolved in the groundwater under anaerobic conditions was moved upwardto the phreatic level and subsequently oxidized and precipiated (see page 49).An analysis made of a 4 cm large, platy iron concretion out of the sample Nr 192,


rendered 36 % Fe2C>3. The total amount of iron in the whole top soil thereforeprobably will be higher than given in the total analyses of the fine earth.

The leaching of aluminium is stronger than that of iron, which points to agreater action of the carbondioxide in the soil than of humus compounds.

Under the prevailing acid conditions, by weathering of sediments rich in silicaunder impeded drainage conditions, kaolinite could be expected. The small amountsof illite may be a result of weathering in periods of pronounced dryness. Anotherproblem is why chlorite is found between 5 cm and 50 cm. This clay componentin which iron is predominant (see page 51) must have been newly formed. Theiron accumulated in this zone, where the decomposition of minerals will begreat, combined with the relatively higher concentrations in magnesium willhave contributed to the formation of chlorite. In this profile another effect isobserved too. At the bottom an increase of clay and iron is found. If this is theresult of leaching through occasional rainfall during or at the end of a dry period(see page 5), the profile shows, be it weak, characteristics of a groundwaterlaterite (BALDWIN and THORP, 1940).

The laterite is a podzolized kaolinitic laterite with gleyed subsoil or a podzolizedgley laterite.

P r o f i l e 2 0 4 / 0 8 .

The soils in the more elevated hilly parts of the lowland are fairly welldrained. Locally, in the subsoil small white spots may occur, which are due togleying. Two soil profiles, namely Nrs. 204/08 and 222/26 are given.

Profile Nr. 204/08 shows some gleying in the subsoil at the depth of morethan 120 cm. The soil reaction is very acid, accordingly the saturation of theadsorption complex is very low. The uppermost 5 centimeters of the topsoil seemto have been supplied from elsewhere. Several ratios calculated from the fineearth and clay analyses and also the total iron content deviate. This could beexplained by assuming this surface supply. The clay percentages of the differenthorizons do not differ much. According to the analyses of the clay fraction thetopsoil is podzolized, while the lower horizons are laterized: the decrease of theSiO2/Al2C>3-ratios with depth is succeeded by an increase. The silica/iron oxidevalues show a weak reflection of podzolization, and deeper laterization being morepronounced. The aluminium is leached much more than the iron, which can not onlybe deduced from the calculated ratios, but also from the presence of gibbsite in thesubsoil. This leaching of both silica and aluminium, the prevailing acidity and theequal clay percentages in the various horizons seem to contradict one another insome.aspects. The acidity is very high, so that the podzolization must be active. Thesharp decrease in content of organic matter and the fairly constant C/N-ratiosare in accordance with the transport of aluminium. Laterization may occur whenthe pH increases, e.g. by evaporation of carbon dioxide during warm and dryperiods. Silica which is set free may recrystalize into cristobalite. However, thesepedogenetic processes cause a decomposition of the clay in the topsoil, which was

DISCUSSION OF THE SOILS 121

not found in the analytical data. This leads to the conclusion that the originalprofile is probably truncated, so that the original A-horizons have been eroded.Nevertheless, according to the features dealt with above, the soil must be classifiedas a podzolized latosol.

P r o f i l e 222J26 .

Profile Nrs. 222/26 shows many similar characteristics. Podzolization is present;however, the podzolized solum is much deeper. The carbon values decreaseless quickly with depth, which is in accordance with this observation. The increaseof aluminium with depth is much stronger. Free gibbsite is found in the subsoil andthe total analyses show marked low silica/aluminium oxide ratios. The yellowish towhite concretions in the deeper horizons were analysed and appeared to consistmostly of AUO3 (see: table on page 72 total analysis concretion). The decom-position of the top-horizons is clearly demonstrated in the percentages of theclay fraction throughout the profile.

The soil is classified as a deeply podzolized latosol.Comparing several profiles, taking into consideration the various field

characteristics, the following picture emerges.Proceeding to a more northern direction of the district the brownish top zone in

different profiles is gradually deeper, or in other words: the highest reddish horizonin the profiles occurs at greater depth with rising elevation and increasingprecipitation. Illustrative is also that RAZOUX SCHULTZ (1954) classified the non-eroded soils, east of the Kau river in the Muyu district, as brown to yellowish-brown silty clays. The brownish toplayers have a thickness of 60 cm to 75 cm.

The brown colour is due to the organic iron compounds. The uppermost reddishhorizon corresponds to the beginning of the laterization in the profiles.

The following series present the location, elevation and depth of the uppermostreddish (colour: 5YR5/6) horizon.

UppermostLocation Profile Elevation reddish horizon

OgemkapaDjononggo *)WamponUmkubun

215/21

204/08

222/26

232/42

80 m100 m

160 m

300 m

35-85 cm25-60 cm60-100 cm

100-230 cm

On hill tops, in road cuttings, made for the Kamka road between Mindiptanäand Woropko, it is clearly visible that platy iron concretions forming a stone-linebetween 75 cm and 100 cm, which wedges out into the actual soil surface. Theymust have been formed in a period that the water table was much higher andthe landscape had not yet been eroded, hence before the uplift of the country. Inthe northern part of this soil unit we find many whitish concretions, being sandy

*) eroded.


gibbsite concretions, on the surface. Here the erosion must have been active. Tothe north the landscape ends into sharp edges, indicating that the possibly morenorthward lying similar soils must have been eroded. As the erosion is still active,and the contemporary podzolization is increasing in northern direction, we mayinfer that in acid parent material under very wet climatological conditions, pod-zolization is the prevailing soil forming process in the tropical lowland. Moreover,it is quite well possible that the laterization is a much older process, which isonly slightly active or not active at all in the northern parts nowadays. In thatcase the podzolization is active in laterized parent material. This subject will bereferred to again in the section on the Mountain area on page 129.

The most active laterization will have taken place under earlier, monsoon type,climatological conditions.

P r o f i l e 2 4 5 / 4 8 .This profile was sampled in a depression in the middle of a weakly sloping

site, and it is derived from limestone. Generally the soils in the region, in whichthe profile was found, are very wet, clayey and brownish-yellow, with gray andrusty streaks or mottles. Gley phenomena occur as high as the topsoil.

The clay fraction consists of interstratified montmórillonite and sub-ordinatequartz and cristobalite. The latter will be the recrystalized weathering products(silica) of the clay (EDELMAN et al., 1939; DUPLAIX et al., i960; BEUTELSPACHERet al., 1961 and MILNER, 1962). This weathering corresponds with the low pH-values and the low saturation of the adsorption complex, as well as with theincrease with depth of the amount of clay.

The C/N-ratios are very low, which must be due to the presence of ammonia.Possibly some aluminium has been leached from the top-horizons, which resultsin the decrease of the silica/aluminium oxide ratio in the horizon between 20 cmand 90 cm. Also iron is washed out to deeper horizons. Except for the lowesthorizon in the profile, aluminium is less mobile than iron. This can be accountedfor by the action of humus. The increase of the clay fraction with depth, as wellas the leaching of sesquioxides indicate a podzolization process.

The soil has been classified as a brown podzolic soil, with gley features inthe subsoil.

The soils of the limestone area.Except for profile Nr. 245/48, which is discussed in the soils of the lowland,

and the profiles Nrs. 85/89 and 90/94, which are discussed in the soils of the Katemarea, the other soils studied in the limestone area will be dealt with in this para-graph. These profiles are found in the Digul Mountain landscape and the UpperOk Tsop landscape.

P r o f i l e 2 6 5 / 6 8 .Profile Nr. 265/68 is situated on a small, flat site in the higher parts of the

slopes of the Ok Tsop valley and a valley of the Digul limestone shield, debouchinginto the former.


In the Digul Mountains landscape the profile represents the soils which do notshow an evident whitish A2-horizon. The morphological changes between thehorizons of the profile are gradual.

The clay fraction increases with depth. The soil reaction is acid, but less thanin many other profiles. The saturation of the adsorption complex is moderate.The horizon between 10 cm and 22 cm is more strongly leached than the otherones. The silica/sesquioxides ratios of the clay fraction show a marked decreasewith depth. The clay fraction consists of montmorillonite and quartz. The formeris dominant, and as the X-ray picture does not show very strong defraction lines,the montmorillonite will be weathered or some interstratified mixtures are present.The quartz is seen in the clay fraction throughout the entire profile. The titaniumcontent in the clay is fairly high; anatase lines were noticed in the X-ray records.

Morphological and chemical characteristics evidently point to podzolation.The total analyses of the fine earth do not correspond with the clay analyses and

the other chemical data. This deviation will be discussed at the end of the sectionon soils of the limestone area. The analyses of the clay fraction, the texture andthe adsorption complex combined with the morphological characteristics of theprofile justifies the classification of brown podzolic soil.

In the higher limestone mountains of the Star Mountains south of the OrionMountains range and including the latter, an evident bleaching of the sub-surfacehorizons was found in the deeper soil profiles. The degree of weathering mayvary. This will be discussed in the following pages with regard to the profiles155/57» I352/55 an<i 405/08. The whitish or A2-horizon, developed under a humicA^horizon and overlying a brownish B-horizon, was encountered in many placesin the region mentioned above. During a one-day trip in the limestone landscapesouth of the Sibil valley similar profiles were augered as those sampled at thenorthern side of the valley. An example was also given by REYNDERS (1958)in his preliminary report on a short visit to the Sibil valley. However, the majorityof the soil profiles is very shallow and consists of a moder-like to peaty, wet andacid surface layer, varying in depth between some centimeters and some decimeters,held together by a wicker-work of roots of the vegetation. The mineral fractioncontent of this layer is generally low. It is situated irregularly upon and betweenthe limestone blocks and fragments of the parent material. This soil type is anacid mountain rendzina or peaty rendzina.

P r o f i l e 155 /5 7-In profile Nr. 155/57 the limestone is weathered into clayey material as is

shown in the lower horizon. The clay mineral formed is montmorillonite. Themarkedly low percentages of clay in the uppermost horizons are due to thedecomposition of the clay fraction as a result of the low pH. The saturation isfairly low. Although the latter increases with depth, the acidity remains high.With the exception of some larger pieces of limestone, the finer soil parts donot contain remnants of parent material and the calcium is for the greater part


leached. The montmorillonite in the top soil is strongly weathered, while theamounts of this mineral in the clay fraction increase with depth. The silica thatis set free partly crystallizes into cristobalite and quartz. The aluminium isleached; a part into the B-horizon, but another part disappears through lateraltransport.

The free aluminium and the silica in the top soil may give rise to new clayminerals, as found in other profiles. Similar formation of clay minerals havealso been reported by VAN BAREN (1941). Certainly there is a lower silica/aluminium oxide ratio in the A^horizon than was observed in the A2-horizon.

In the whole profile iron is more leached than aluminium, on account of theaction of humic compounds. In the B-horizon the soil will be relatively enrichedby iron. Here a double process takes place. There will be a lateral movement ofdrainage water over the parent material and also the leaching of the soil profileitself; both contribute to the iron content. The increase of the saturation of theadsorption complex by predominately calcium, causes the precipitation of the ironcompounds and it is possibly also the reason for the weak increase in the carboncontent.

The data of the chemical analyses of the total fine earth, which show a sharpdecrease in SiO2/Al2C>3-ratio, are to be explained with a view to the tremendousincrease in clay in the lowest horizon. The increase in A12O3 which is responsiblefor the decrease of the ratio is directly related to this increased clay content. It isfinally interesting to note that this is about equal to the total increase of ironin the fine earth of the whole profile, a fact clearly indicated by the Al2O3/Fe2C>3-ratios.

The soil is a strongly podzolized brown earth and is classified as a podzol.

P r o f i l e 1 3 5 2 / 5 5 .

This profile resembles the profiles Nrs. 155/57 and 265/68. The morphologyof the profile is in between the two other ones: the second horizon shows morepodzolic features than that of the latter, but less so than the former profile. Thesoil reaction is acid, which corresponds to the fairly low saturation of theadsorption complex. The silica/aluminium oxide ratios of the clay fraction indicatean evident podzolization, which leads to decomposition of the clay minerals, andcan be deduced from the grain size analyses. In the clay fraction montmorilloniteis dominant, though in the top horizon of the profile this mineral is weathered.Quartz is present in the clay fraction in the whole profile. The amount of quartzseems to correspond to the leaching process in the various horizons as it decreaseswith depth.

The iron content in the clay fraction decreases with depth. This behaviour doesnot correspond to the other data, which point to a pronounced podzolic process.The total analyses of the fine earth indicate a laterization of the profile.

Apart from the morphological and chemical characteristics, the composition ofthe heavy mineral fraction raises a problem. The top horizons show a conspicious

II

IIV

VII

1.5 4 5 10 15

II I I I

15 10 5 4 1.5

VIII

ACuKa

F i < r . X. M i n e r a l s o f l l i c d a y f r a c t i o n . I . q u a r t z ; 1 1 . q u a r t z ; I I I . d i s o r d e r e d k a o l i i i i t i 1 ; I \ " . i l l i l c ;\". i n u n t m o r i l l o t i i t f ; u i d c r i s t n i i a l i t e ; \ 1. g i U b s i t e ; \ 1 I . n u m t m o r i l l o n i t e a n d t j i i a r t z ; \ l l l .

î i n a l a s c . ( I w i l l i N i - f i l t e r , l l - V I l l u n f i l i e r t , ] f u r / 3 - r r u l i a t i o n ) .

Fig. g. X - r a \ • 1 ï f m i c t i o n r eco rds ai tlic cl.'iv fract ion nf jirnfili:tlt'LTt'iising ;tiul iiKintmnrilkiiiilc iiicreasinii with ik-

405,'oX.


amount of minerals of volcanic origin. This complicates the genetic picture, as nowit has to be decided whether the podzolic process superimposed on the process oflaterization has been influenced by this addition of weatherable minerals, or thatthis contamination took place in a final stage of this type of soil formation.

This may indeed be concluded from the chemical data of the profile underdiscussion. A younger influx of volcanic minerals has taken place, by which thebehaviour of the iron content in the clay fraction can be explained.

The profile shows some characteristics of an acid brown forest soil, but alsothose of an intergrade between a brown podzolic soil and a podzol, developed on alatosol. The profile is polygenetic without doubt.

P r o f i l e 4 0 5 / 0 8 .

This profile represents a strongly podzolized soil. The profile was found on thecrest of a mountain ridge. The top horizons are relatively well drained, thesubsoil shows some features of impeded drainage. The circumstances are favour-able to the accumulation of humus, which is also found in the carbon analyses. TheC/N-ratios here are also indicative; they increase with depth (see page 44). Thevery acid reaction and consequently very low base saturation, causes severedecomposition of the clay fraction. This is very clearly illustrated and revealed bythe X-ray diffraction records. The montmorillonite content increases with depth,while quartz predominates in the top soil and decreases greatly with depth (seeFig. 9). Iron is more strongly leached than aluminium, as could be expected incases of humus transport. The total analyses of fine earth correspond with the dataof clay analyses. This very strongly podzolized brown podzolic soil (a pronouncedA2-horizon is present) is classified as a podzol. However, it should be notedthat the parent material of this podzol was not a sandy sediment, but thepodzolization that led to the development of the actual profile was superimposedon a rather heavy brown podzolic.

The profiles Nr. 410/12 and Nr. 422/25 are relatively young and shallow. Theparent material of limestone is exposed in several places. The soils have beenformed after a period of erosion, which in this region is introduced by the activityof man.

The mineralogical data indicate a very high amount of titanite, which had notyet been observed in other places in the Star Mountains. Authigenic titanite maybe formed from titane bearing chloritic minerals (compare profile Nr. 81/84),decomposition products of parent rock rich in amphiboles in presence of lime(MILNER, 1962). In the Upper Tsop valley the geological map indicates theIwur formation, containing siltstones and shales, which forms a transition intothe underlying New Guinea limestone. Although the calcareous rock is croppingout, the profile must have been derived from the lower strata of the Iwur for-mation or uppermost beds of the limestone as follows from the mineralogicalassemblage which characterizes the soil.

I2Ó SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

All conditions to favour the formation of titanite are therefore present.

P r o f i l e 4 1 0 / 1 2 .

This profile is very rich in organic matter; it has a good structure and, exceptfor the top-horizon, the amount of limestone fragments is very high, while thereaction is neutral to weakly alkaline and the saturation is fairly high.

On the limestone mountain slopes generally shallow and very acid, peaty ormountain rendzinas are found (see page 123). Profile Nr 410/12 possibly showssome resemblance to these soils, but it is less leached and less acid.

Some characteristics may be discussed. As could be expected in a youngand shallow soil the clay fraction decreases with depth. However, some decom-position is already evident, as is demonstrated in the silica/sesquioxides ratios.Montmorillonite is dominant and kaolinite is sub-dominant.

The total analyses of the fine earth show a higher content of aluminium andiron in the top layers, which is related to the percentages of clay and organic matter.According to the morphology as well as the chemical characteristics the soilis classified as a black rendzina.

P r o f i l e 4 2 2 / 2 5 .

This profile represents the much more developed and leached stage of soildevelopment. The soil reaction is acid in the topsoil and still neutral in the subsoil.The saturation of the adsorption complex is much lower, the clay content ishigher than that of the rendzina, and the decomposition of the clay is evident. Freecalcium carbonate is not found in the soil, and the total analyses indicate fairlylow calcium oxide values. The decomposition of the clay fraction is shown in thesilica/sesquioxides ratios too. Aluminium is partly leached and silica is left, leadingto the formation of quartz, which was analyzed in the clay fraction. The aluminiumhydroxide may crystallize to gibbsite, which has been found, but it probablycombines also to kaolinite. Iron is more strongly leached than aluminium asa result of the activity of humus compounds, which are still high. The profile isclassified as an intergrade between a rendzina and a brown podzolic soil.

At corresponding elevations podzols are usually found on limestone. Thepresence of this younger genetic stage is due to rejuvenation caused by erosion.

P r o f i l e 4 1 3 / 1 7 .

This profile is derived from limestone parent material, and is developed in thelower part of the moss forest under a peat layer. It shows many characteristics ofstrong leaching or podzolization. The soil reaction is very acid except in the peatytop soil. The saturation of the adsorption complex agrees with these values.The clay fraction increases strongly with depth, marking a decomposition in thetop horizons (or at least a greater decomposition in the top horizons than in thelower ones). Also the silica/sesquioxides ratios correspond with this behaviour. Theydecrease with depth. In accordance with the decomposition of the clay and the

DISCUSSION OF THE SOILS \2."J

leaching of aluminium out of the top horizons, the amount of quartz is highestin the surface layers and the interstratified montmorillonite, which is the dominantclay mineral, shows less distinct X-ray reflections, due to disturbance or pro-nounced weathering in the higher horizons. Very illustrative is the clay analysisof the second horizon (0-2 cm), in which no sharp lines in the X-ray records wereobserved. The minerals must have been strongly affected and disordered anddecomposed, while the amount of amorphous material is fairly high.

A different position we find in the peat layer or the top horizon. Here a highersaturation, a higher pH, and a higher aluminium content is found than wasexpected. From the total analysis follows that the ignition loss is about 80percent. A number of analyses demonstrated that in the organic material the totalpercentages of aluminium or iron, or both, increase. These elements can be setfree by the decomposition of the organic matter, so that not only the amounts ofelectrolytes are increased, but through combination with ever present silicium,also new formation of clay minerals may occur.

The total analyses agree with the other data discussed above. Combining theanalytical data with the morphology of the profile, the soil is called a peaty brownpodzolic soil.

P r o f i l e 4 3 5 / 3 9-This profile represents the highest soil sampled near the Juliana Mountains.

The soil, formed in the moss forest zone, is derived from limestone. However,the mineralogical composition of the heavy sand fraction indicates the influenceof volcanic sediments. The amount of hornblende is fairly high. On the otherhand, some metamorphic influence is present (compare the percentages oftitanite), which is not noticeable in the other weathering products of limestone. Ashas already been said of profile Nr. 422/25 the parent material must be relatedto the transition zone of the New Guinea limestone formation and the Iwurformation (shales, etc.). The profile shows an interesting morphology, thedissolution of the limestone beneath causing a kind of tunnel, which serves as asub-terranean drain. Seepage water, containing decomposed organic material,flows through this hole. This water undoubtedly will have had some influence onthe profile and on the parent material.

At the bottom of the sub-terranean drain, on the limestone, a kind of micro-rendzina was found. On the other hand, the lower horizons of the profile abovethe hole, contain more organic matter than is generally met with in the subsoil(compare Nr. 413/17). Particularly the lowest horizon (70-80 cm) shows a slightincrease in the carbon content already observed in the field. This observation mustbe mentioned first in order to understand the anomalies of the profile. We areup against several points which can be of importance for the genesis of the profile.The soil conditions before and after the formation of the tunnel will be different,especially with regard to the internal drainage. Moreover, the influence of thelateral flowing drainwater must be taken into account. The pH's of the top-horizons


are low, which correspond with the other profiles. However, the acidity decreaseswith depth, and the total of exchangeable bases increase. This might be attributedto influence of drainage water containing calcium.

The clay analyses point to a decomposition of the clay and leaching of thesesquioxides out of the top horizon. Deeper in the profile (40-70 cm) these oxideshave moved out much more. The iron is more mobile than the aluminium, whichindicates that the leaching has taken place because of organic combinations. Thestrong increase of the aluminium oxide/iron oxide ratios from the second to the thirdhorizon can be accounted for in two ways. First, there is a relative accumulationof iron an aluminium in the second horizon, and secondly, as a result of theincreasing drainage conditions with depth and the intermittent lateral percolationof humus containing drainwater, iron is more leached than aluminium.

Possibly the increase of quartz found in the clay fraction in the horizon between40 and 70 cm is also a result of this process. The better drainage conditions in thesubsoil may cause a kind of hidden podzol in the topsoil, which could explainthe iron accumulation mentioned above.

The total analyses of the fine earth show an increase of the sesquioxides withdepth, with the exception of the lowest horizon. This characteristic is more markedlyindicated by the silica/aluminium oxide ratios. A kind of A2-horizon between 5-40cm is reflected in the analytical data of the fine earth.

The combined data allows the conclusion that a podzolic process was presentbefore the tunnel was formed.

Comparing the total analyses of the clay and the fine earth, we may con-clude that the original profile had shown much resemblance to, for instance,profile Nr. 413/17, which is a peaty brown podzolic soil. In a later stage this soilwas undermined and.other processes were introduced, which are reflected in theclay analyses.

As a name for this profile one might propose a podzolized, drained, peaty brownpodzolic soil, though this name denotes contaminations. However, excluding theanomaly of the profile the original soil type is a brown podzolic soil under peat.

The soils that are dominating in this region on the flanks of the JulianaMountains and which are found in the uppermost meter, are mountain peat soils.

G e n e r a l d i s c u s s i o n of t h e l i m e s t o n e soi ls .

The profiles can be divided into two groups as far as the topopraphy is concerned,namely a group of the Nrs. 265/68, 1352/55, and a group of the Nrs. 155/57, 4I3/I7>422/25, 405/08.

The first group is found in places where there is little erosion or none at all,as on mountain ridges or small and higher plateaus in the Digul Mountains area.The second group is found on mountain slopes of the Digul Mountains area,or at higher parts north of the Orion Mountains range.

The marked differences are formed by the amounts of iron concretions, whichare very high in the first group and decreasing with depth. Moreover, the light


part of the sand fraction (spec, weight below 2.9) contains pieces or aggregatesof chalcedone, which are present throughout the profiles without a certain trend,or increasing with depth. In the total analyses the iron content decreases with depth.The clay contains quartz, but without an increase or decrease of the percentagesin the profile being evident. The second group has very few or no iron con-cretions in the sand fraction. The total analyses as well as the clay analyses showan increase of the iron with depth. The amount of chalcedone particles in the sandfraction decreases with depth, while the quartz content in the clay fraction showsthe same change. Generally the behaviour of the various elements in the totalanalyses as well as in the clay analyses correspond to each other and both indicatea podzolization process.

However, in the first group, the total analyses and the distribution of ironconcretions and chalcedonic parts show characteristics of laterization, with theexception that aluminium is strongly leached and gibbsite aggregates are not found.

The analyses of the clay fractions indicate an evident podzolization. The coarseconcretions are relatively inert, having a small reactive surface (they are alsohighly resistant against hydrochloric acid treatment). Their presence cannot be theresult of the podzolic leaching process. They must be a relic of another geneticprocess.

Here some other observations and studies merit to be mentioned. In thesouthern part of the Digul landscape reddish soils and red iron oxide crusts wereobserved, though these soils were found at an elevation between 1500 m and 2000 m.The phenomena of the fossil river beds in these regions have been mentionedalready (see page 30). In other places in the Digul landscape, in some valleys, apavement of large iron concretions (iron shot or peas) were noticed. The samedistribution of iron concretions occurred on limestone in the lowland, in otherdistricts of New Guinea, e.g. Biak and Ayamaru, in the latosolic soils derivedfrom limestone.

Taking into account these considerations and the characteristics of the soilsof the second group and their topographical position one may conclude that thesoils concerned have a polycyclic genesis, which must have started as laterizationin an earlier period and which is at present podzolic. The laterization must havebeen active before the uplift of the limestone mountains. Since that époque theerosion has been very severe. Consequently these older soils will only beencountered on tops and plateaus.

The younger, eroded places, should, and indeed do, have soils which agree muchmore with the actual pedo-ecological circumstances. We consequently arrive atthe same conclusion as VERSTAPPEN (i960), but on a quite different basis, thatthe Digul Mountains limestone area is a raised and eroded old landscape.

The soils of the Katem area.

The soils of the Katem area are divided into two groups, namely the soilspresent on the mountains, slopes or spurs, and those on the recent sediments on the


terraces. These sediments are dealt with in the section on the mountain sediments.The other soils will be discussed below.

P r o f i l e s N r s . 8 5 / 8 9 a n d 9 0 / 9 4 .

In the field the two profiles Nr. 85/89 and Nr. 90/94 show great similarities.The former was found at the top of the steep scarp (elevation 550 m), whichhere forms the eastern side of the Digul valley; the samples Nr. 90/94 were takenon the top of an erosion terrace (330 m), halfway the same scarp, between thetop and the Digul. In the field both profiles seem to have developed out oflimestone parent material, which is exposed in the very steep slopes. The minera-logical composition of the heavy sand fraction corresponds indeed with that of othersoils derived from limestone. The mineralogical composition of the clay fraction,however, shows some variations. The clay of the profile Nr. 85/89 on the top ofthe scarp contains illite and kaolinite, while the lower profile Nr. 90/94 hasinterstratified montmorillonite.

Another difference is found in the grain size distribution. Profile Nr. 85/89contains fairly high amounts of sand, while the other profile has a heavier texture,which is comparable with that of other soils derived from limestone. The soilin the highest place will be the weathering product of the transition zone of theKau limesone formation, which upward becomes more sandy, and the Buruformation (BÄR et al., 1961). The latter formation is not indicated on the geo-logical map, because of its reduced thickness. In the Buru formation blue-greyshales and silstones occur, which can give rise to mica-like minerals. However, theBirim formation, sketched on the geological map of the location concerned, beginswith a strong influx of volcanic material. The mineralogical composition of theheavy sandfraction does not show this influence.

Of either profile some samples are lacking, but as it is the only materialavailable from this part of the Star Mountains (300 m to 500 m), it was analysedand an effort was made to classify the profiles.

The morphology of the two is very similar. The top layers are lighter in texturethan the lower horizons. It was impossible to check the field observations as to thetexture, as the mechanism of the increase of the clay fraction could not be verifiedby laboratory analyses. The lighter texture of the top soils in mountainous or inhilly terrain is mostly not only the result of decomposition or leaching, but it mayalso be effected by the force of the rain, through which the clay is partly washedout and transported over the soil surface to lower sites (river). Nevertheless, theacidity of the soils and the saturation degree is fairly low, so that decompositionof the clay fraction is also possible and podzolization may be present. Thefigures of the clay fraction, predominately those of profile Nr. 90/94, confirmthis point of view.

In both profiles in the subsoil gley phenomena are present, namely a kind of"marmorization", being small mottles or stains. Taking together the morphology

DISCUSSION OF THE SOILS I3I

of the two profiles and the chemical data available, the soils can be classified asweakly gleyed, brown podzolic soils.

P r o f i l e 8 1 / 8 4 .

The soils in the area north of the Ok Irin were studied and sampled in severalplaces. The parent material consists of grayish-bluish siltstone. In many cases itwas difficult to establish the right depth, at which the parent material or thepartly decomposed rock began. The same is demonstrated in the profile concerned.Although the soil is fairly soft up to a depth of about JO cm, the real solum isshallow, and it reaches to about 30 cm. The lower parts are very wet and soft andthey consist of partly decomposed parent material. This parent material may beslightly metamorphosed, which can be inferred from the high amounts of chloritepresent in the sandfraction. An interesting fact is, that in the clay fractionillite is dominant and kaolinite appeared to be a sub-dominant clay mineral.Moreover, some quartz was present, but as could be concluded from the analysisof the partly decomposed parent rock it is probably already present in the clayfraction of this material. A slight increase of quartz, in comparison with the lowerhorizon, was found in the top horizon. As the percentages of hornblende are fairlyhigh, one may expect that magnesium is present in the profile. As the chloriteminerals increase with depth, they will, by inference have been decomposedin the topsoil by the genetic soil process. The question arises, why chlorite is notmet with in the clay fraction. Study of the X-ray films, made clear that no normalchlorite is present, or at the utmost in very small quantities. Possibly in this silt-or claystone there is a kind of chlorite with structural characteristics which arevery much related to those of illite, or otherwise the formation of this mineral inthe parent material or the decomposition of it did not lead to chlorites of clay-sizedimensions.

The impermeability of the siltstone is high. The result is a very moist to wetsubsoil and promoting erosion in this region. On the aerial photos and in the fieldlandslides indeed were observed. The soil is acid in reaction, and the saturationof the adsorption complex is low. From the analyses of the clay fraction theleaching of sesquioxides out of the top horizon can be deduced. Although the ironis more mobile than aluminium (which is due to the acting organic combinations),the variations between the two higher horizons are fairly low.

In conclusion: although the soil is fairly shallow and rather young, somepodzolization is observed. The soil is classified as an acid brown forest soil or"sol brun acide" (acid brown earth).

The susceptibility to erosion of the soils developed on the sloping siltstones hasbeen mentioned already. This results in lithosolic conditions, and indeed, in manyplaces rankers were observed. On the other hand, where the terrain is less sloping,and erosion is less active, in our case the Ok Kair region at the other side ofthe river Digul, on the siltstones and claystones brown podzolic soils will occur.


The soils of the Grote Beer Mountains.

On these mountains the soils are weathering products of slates and shales ofthe Kembelangan formation. The erodibility on this parent material must be high,for the majority of the soils consists of shallow solums, composed of a layer of2 cm to 10 cm of partly decomposed organic matter, lying on a wet, darkbrownto yellowish-brown loamy horizon, rich in gravel and stones, varying in depthfrom some centimeters to some decimeters, and lying upon and between rockfragments or on the solid rock. The northern flanks of the mountains are steepand they do not carry a soil cover. They consist of stony, intersected slopes. Onthe southern sides many landslides were encountered, exposing sloping flat surfacesof hundred and more meters of bare rock. The very acid and strongly leached soilis an alpine or peaty ranker.

At a few places deeper soil profiles were found and sampled. Two representativeprofiles are given, namely profile Nr. 304/07 of a weakly sloping part on thesouthern side and profile Nr. 308/10 at the flat top ridge.

P r o f i l e 3 0 4 / 0 7 .

The morphology of profile Nr. 304/07 shows characteristics of a podzolizedsoil with gley features. Particularly the A2-horizon, 5 to 25 cm, is stronglyleached. This can be deduced also from the silica/sesquioxides ratios. In the B-horizon there is an increase of sesquioxides and especially of iron.

In the clay fraction illite is dominant, while the humic top soil also contains somekaolinite. In the A2-horizon as well as in the B-horizon the X-ray reflections ofillite are less evident. Here quartz and cristobalite are met with too. Probably thesupply of the soil surface plays an important part. New formation of clay mineralsmay be present; moreover, it is highly possible that the whole profile is more orless colluvial. Nevertheless, it gives an example of the prevailing conditions.

The soil profile is an intergrade between a podzol and a brown podzolic soilwith gley phenomena.

P r o f i l e 3 0 8 / 1 0 .

This profile is the only deeper profile sampled and analysed in this area whichcan be called residual. The morphology is that of a gley soil. The chemicalcharacteristics show a very acid reaction and a very low saturation of the adsorptioncomplex. The percentages of organic matter in the topsoil are high and theydecrease quickly with depth. The C/N-ratio is very low. Due to the wet conditions,higher amounts of ammonia are present and therefore the C/N-ratio will grow less.The increase in the value of the second horizon may be the result of a stronglyincrease of fulvic acids in this horizon. The leaching in the profile is very severe.This is demonstrated by the various figures. The iron content is very low, andthe silica/iron oxide ratio decreases with depth. The same is observed in thesilica/aluminium oxide ratios. The aluminium content increases with depth, and


in the subsoil gibbsite was found to occur. The amounts of quartz and cristobalitedecrease with depth. They result from the decomposition of the clay mineralsin the topsoil. The aluminium that is set free acts with silica, which leads to theformation of kaolinite. The total analyses of the fine earth correspond to thedata of the clay fraction, with the exception of iron in the top-soil. Although lowin total amount, the iron must be present in fairly high quantities in the organicmaterial, as a result of which the Si02/Fe2C>3-ratio is suppressed.

The profile is a low humic gley soil.

Profile Nr. 1342/54, sampled south of the Yagum Mountains is derived fromparent material consisting of shales of the Kembelangan formation. This profileis the only deeper and undisturbed profile sampled on this formation. Becauseof its relation to the soils and parent material on the Grote Beer Mountains it willbe discussed in this paragraph.

P r o f i l e 1 3 4 2 / 4 5 .This profile has fewer differences between the horizons than many other

profiles in the Star Mountains have. The soil reaction is acid and the saturation ofthe adsorption complex is low. The percentages of clay in the granular analysesdo not show great variation. The clay analyses also are very similar, except forthe data of the topsoil (0-10 cm). Here it is clear that aluminium as well as ironare leached. The aluminium oxide/iron oxide ratios indicate that more iron isleached out of the top horizons than aluminium is, which is due to the differencein mobility of the humic compounds of the elements. The data of the otherhorizons do not vary greatly. The whole picture indicates a slight podzolization.The clay minerals are as expected; illite is dominant and small amounts of quartzand anatase were detected. The total analyses of the fine earth do not showgreat variations, so that it corresponds to the behaviour of those of the clayfraction. The potassium content is an exception. Potassium is strongly leached. Theanalysis of a piece of (partly affected?) shale.indicates that the percentages of thiselement present in the parent material are fairly high.

The profile is an acid brown forest soil.

The soils of the Ant ares Massif.The Antares Massif rises within a fairly short distance from an elevation of

about 1000 m to a height of 3600 m above sea-level. The parent material isvarying, but exept for the top, this is of minor interest for the soil genetic study,as will be explained below. The mountain slopes can be divided in three mainzones, namely the foot zone from iooo m to 1700 m, the middle zone from 1700 mto 3000 m and the top, above 3000 m.

Generally the foot zone is so steep that, as at some sites of the Grote Beer Mts.,no well developed profiles are found. Shallow rankers are present and lithosolswithout an organic horizon. Locally bare rock is exposed, in other places colluvialmaterial occurs, which is very rich in stones. In some places rankers were

134 S 0 I L GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

encountered where the solum consists of a layer that is composed of a mechanicalmixture of raw humus and mineral parts. This is due to colluvial soil transport,which mixes the undecomposed litter to the bottom of the layer.

Summerizing it may be said that the soils in the foot zone of the Antaresconsist of rankers, lithosols and bare rock.

In the middle zone we find a moss forest belt. Here the greater part of the soilis peat, which varies in depth between some centimeters and four or fivemeters. This peat is very acid and is composed of a rather loose accumulationof litter, mosses, trunks of fallen trees, which is held together by a wicker workof predominately less-branched roots.

In some places mineral soil was found. In a small depression an accumulationof very white sand, comparable with "silver sand", formed a kind of soil. Hereall the finer parts were washed away by action of the very acid humic drainwater.Pure quartz sand forms the residue.

In other places a thin moss-peat layer lying on the granodioritic rock wasstudied. At the bottom of the spongy moss packet a blackish organic transitionlayer of one or two centimeters was observed which contained some white quartzgrains.

Halfway the mountain on a spur, a micro profile on claystone was sampled.This profile, see Nr. 365/669, was exposed, because of a fallen tree, which hadbeen blown down, together with its complete root system. The samples taken of theprofile were very small, and only a total chemical analysis could be made.

In the field the micro profile shows features of podzolization. An organichorizon, Aoo, is succeeded by an A0-horizon, merging quickly into a bleachedA^horizon, lying over the parent material. This podzolic character is confirmedby the analytical data. The ratios of the total analyses demonstrate an increase ofaluminium with depth. The iron content is very low, but it also increases withdepth. An exception was found in the top-layer, but this higher value was dueto the iron in the high amounts of organic matter. Similar findings were made inother samples rich in organic material, and on very wet soils. The analysis ofsample 369 was made of the parent material of bluish clay- or siltstone. Thepotassium content is high and the clay minerals present are predominately illite, andin the top horizons quartz and cristobalite are present (compare profile Nr. 81/84).It is hardly possible to classify this soil, because of the overlying deep peat layer.The soil proper is probably a kind of shallow podzolic gley.

On the top of the Antares we came across an alpine meadow vegetation exceptfor the higher parts where bare rock is found without a soil cover. On the slopesnear the top the granodiorite rock was covered with a shallow mantle of veryacid and wet peat of the moss vegetation (0-10 cm: pH 4.4, ignition loss 54%;10-13 cm: pH 4.5, iginition loss 13%). Similar kinds of peaty mountain rankerswere also observed in the zone just below the bare rock present on the highestpeaks.

DISCUSSION OF THE SOILS Iß5

In the alpine meadow belt two profiles were sampled and analysed, namelyprofile Nr. 335/39 occurring on a flat site and profile Nr. 340/44 in a sloping part.The latter will be discussed first, being the younger profile. Sample Nr. 340Rwas taken from the hard rock at another place.

P r o f i l e 3 4 0 / 4 4 .

This profile may be relatively young. The parent rock is fairly deeplydecomposed as a result of the primary weathering of the feldspar. A comparisonof sample 340R (solid parent material) and sample Nr. 344, being loose rottenrock, shows an evident difference in the calcium content, which is much higherin the non-weathered rock.

The granodiorite has the following composition (BÄR et al., 1961): plagioclase(oligoclase Ab8O-An2o — andesine Abso-An5O) 40-50 volume percent; hornblende10-15 v°l- %'• biotite 8-10 vol. %; orthoclase 10-14 vol. %; magnetite 4-9 vol.%; quartz 15 vol. %. The calcium may originate from the plagioclases and thehornblendes, noting that andesine is highly weatherable and oligoclase andhornblende both medium. The weatherability of orthoclase is low (MOHR and VAN

BAREN, 1959). This may be the explanation of the difference in behaviour ofcalcium and potassium (see also next profile 335/39).

Different processes will occur owing to the weathering, leaching and newformation. The primary weathering of feldspars takes place in an abrasion pH of8 to 9. This means (see page 48) that the layer of weathering of the feldsparsilica is mobile and aluminium immobile. However, the pH of the soil solutionis about 5. The mobility of silica will be low outside the sphere of the abrasion pH,and the aluminium hydroxide is near its iso-electric point. Under these conditonsthe formation of kaolinite is favoured. The leached aluminium hydroxide recrystal-lizes into gibbsite, which is encountered in the lower horizons. The silica/aluminiumoxide ratios decrease with depth and the lowest value is found to concur with thehighest amounts of gibbsite. Iron is less mobilized than aluminium, which pointsto the weathering mainly of feldspars.

The soil reaction is acid and the saturation of the adsorption complex is verylow. Besides the accumulation of iron in the top horizons, the small platy ironconcretions in the sub-surface horizon between 10 cm and 18 cm are of interest.In the entire profile the moisture content decreases with depth. The humic toplayer or sod may periodically be wet. This layer is also strongly leached (comparethe absence of gibbsite). A podzolization under anaerobic conditions takes place inthe top horizon. The lower horizons are aerated again. The humus (iron)compounds are transported over small distances after which they precipitate andoxidize (see page 44 dealing with humus transport). A discontinued fragmentaryformation of iron pan-flakes will be the result. The drainage of the surface wateris rather free, so that the conditions which favour the seggregation of platy con-cretion occurs only for short periods. The grain size analysis also points to a youngweathering process, greater amounts of clay being present in the top horizon.

i 3 6 SOIL GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

The various data of the clay analysis are reflected by the total analysis of thefine earth.

The profile is that of an acid brown forest soil.

P r o f i l e 3 3 5 / 3 9-The top horizons of this profile consist of peat. They are very wet and lie on

a thin and hard iron pan (sample 338), beneath which the sand is well-drainedand relatively dry.

The question arises, why do we meet here with an iron pan, whereas in profileNr. 340/44 only the beginning of an iron pan was observed.

This difference is due to the drainage conditions. Profile 335/39 is situated ona flat site on which the rain water will stagnate much longer than on the top ofprofile 340/44, on sloping terrain. Because of this stagnant water, the top soilremained wet longer; the soil was leached more severely, podzolization wasstronger, and the circumstances for the formation of peat became favourable. Thedecomposition of the top horizons was subsequently increased so that a continuousiron pan could be built up which contributed to increased water accumulation.As a result we find on the top of the Antares a small fen which contained somedecimeters of water. The material on the bottom of this fen was sampled andanalysed: the peaty top layer (0-10 cm) was light brown in colour, the moisturecontent (1050 C) was 80%, the ignition loss 91%, and the pH (H2O) = 4.3.The sub-surface layer (10-50 cm) was dark brown in colour, watercontent 85%,ignition loss 85% and pH = 4.3. Then followed the iron pan beneath which theregolith is weakly moist to dry.

TABLE VIII

Mineralogical composition A2- and C^horizon of profile 335/39.

u0

.0

Ëc

Sam

ple

1 hor

izon

Mutual

quar

tz

orth

ocla

s

percentages 1)

<u

mic

rocl

in

inte

rmed

:pl

agio

cla

biot

ite

Weight

CO

*O

Öu<u

HF

in p

faCOH. l (0

U

o

MF

in p

percentages

faCOH

O

O

<Da

NM

F in

2 )

faH

0

Ü

MF

in p

337339

4528

46 1

23 —

6

33

23)

l657

I2-5

0.1

4-5

5-6 2

35

1) analysed by MOUTHAAN.2) H F : heavy fraction ; TSF : total sand fraction ; MF : magnetic fraction ; NMF : non-

magnetic heavy fraction ; THF : total heavy fraction.3) bleached biotite.

DISCUSSION OF THE SOILS I37

The profile 335/39 is classified as a peaty ortstein podzol.An analysis of the total sandfraction of the A2-horizon and the Q-horizon is

given in table VIII. The weathering of the intermediate plagioclases as well as thebiotite is demonstrated clearly. The weight percentages of the ratios of the heavyfraction and those of the magnetic fraction to the total sand fraction and the totalheavy fraction illustrates that under conditions of severe weathering (peaty water)the decomposition of the magnetite is very great and that this mineral is much moreattacked than the hornblende and orthoclase. However, in spite of the strongweathering of intermediate feldspars in the A2-horizon the percentage of thenon-magnetic fraction in this horizon is lower than that in the C^-horizon, so thatthe decomposition of hornblende must be important too.

Mountain sediments.

In the Star Mountains region in many cases deposits do not occur along theriver because of the narrow V-shaped valleys and the torrential character of mostrivers in this area. In some valleys colluvial mantles may temporarily occur, beforebeing swept away in periods of intense rainfall. In other cases one may meet witha kind of irregular low terraces along the rivers, consisting of shallow, stonydeposits. The soils developed on this material are young alluvial soils with only anAi-horizon, due to decomposition products of the herbaceous vegetation occurringin those places. Sedimentary soils, which occur more extensively, are found onlyin a couple of valleys, namely the Sibil valley and the Ok Iwur-Ok Irin regioneast of the settlement Katem. Also in the Ok Silaga valley there is a smallribbon of sediments, in which this river meanders, as was neatly shown on theaerial photographs.

The investigations of the mountain sediments are not as complete as those of theother soils, being restricted to the fine earth. The interesting part of the case isthat in the Sibil areas as well as in the Katem area the sediments can be dividedaccording to three phases of age.

S o i l s of t h e S i b i l v a l l e y .

I n t r o d u c t i o n .In the Sibil valley three terraces can be observed lying 10 m to 15 m above each

other (see Fig. 10, p. 138).The lower terrace corresponds with the present course of the river, which

disappears in a ponor in the eastern mountains that close the valley.The middle terrace was deposited when the Sibil left the valley in north-eastern

direction through the small gorge, and disappeared in a ponor at the end. Thesoil type found on the terrace can be followed up to a strongly rising limestonewall at the foot of which such a hole was detected. There were possibly also otherponors because the same deposits have been noticed in the south-eastern cornerof the valley.


The higher terrace was deposited in a period that the Sibil river probablyran on the top of the limestone mountains, which, at present, close the valleyat the eastern side. These mountains have been strongly remolded by laterkarst-formation.

In the north-eastern direction, following the gorge mentioned above, no outletfor a river on a higher level is found. This place is surrounded by high mountainridges.

The higher terrace is very small, the middle terrace has the greater extension,and the lower terrace forms a zone of changing width along the meanderingSibil river.

In all three terraces dolines are found. Especially at the foot of the northernOrion Mountains chains of dolines occur.

At present the soil conditions in the three terraces are not the same, and in eachof them we find variation. In the lower terrace very young and stony partsalternate with sandy or loamy deposits. Layers of cobbles are frequently spottedin the subsoil. Near the foot of the middle terrace peaty deposits form a smallzone as a result of the stagnant water in this place.

On the middle terrace the profiles near the edges and round the dolines aredrained or moderately drained. The soil in the center of the terrace is relativelywell drained, i.e. in the top layers. The terraces are relatively old, which can be

Cultivated areas

Fig. 10. Eastern part of the Sibil valley and cross-section. Ti : higher terrace, T2 : mediumterrace, Tv : disturbed terrace.


concluded from the presence of large and deep sinkholes in every terrace level. Inthe two higher terraces peat occurs at different depth, viz. two or three metersbelow surface.

The sediments of the terrace originate from the weathering products of thelimestone mountains surrounding the Sibil valley and the Kembelangan sandstoneformation, cropping out at some places at the northern slopes and which was alsoobserved in the disturbed terraces at the southern flank. The iron content of thesoils is mainly derived from the glauconite present in the last mentioned formation.

S o i l s of t h e l o w e r t e r r a c e .

The profile partly analysed (Nr. 127/31) shows the following characteristics.Under a peat layer (with a percentage or organic matter which can be oxydizedin chromic acid of 35 to 40 %, and a total ignition loss of 60 %) , several graycoloured layers (dark gray 5-20 cm, light gray 20-45 c m ) c a n be recognized inwhich gley phenomena are visible. At the bottom of the profile there are moresandy layers deeper than 45 cm. The reaction in the profile is strongly acid, ascould be expected in wet soil conditions under peat. The contents in organicmaterial decrease rapidly with depth. The SiO2/Al2O3-ratios in the profile showless differentiation as could be expected perhaps in the total analyses of asediment. The increase in the subsoil is due to the more sandy texture. Theother ratios do not show a pronounced trend which would point to a definitegenetic process. Possibly some mobile iron is transported to the layers between5 and 45 cm, in which it is accumulated as a result of oxidation in periodsof dryness. The ground water fluctuates between the soil surface and this depth.

In the subsoil kaolinite was found in the presence of some goethite. The highpotassium content is probably to be ascribed to the influence of organic matter.

Morphological and chemical characteristics point to a fairly young soil profile,representing a peaty, alluvial gley soil.

S o i l s of t h e m i d d l e t e r r a c e .

The middle terrace generally has wet soils which are shallow drained near theterrace brim and round dolines and which generally are very wet to inundated inthe parts in the center. This terrace had a large extension. It was found in theeastern branch of the Sibil valley, but also west of the Ok Atem and Ok Aitjekrivers, frequently strongly disturbed by sinkholes. Sites were sampled where theprofile was not interrupted by lenses of cobble stones or peat. The morphologyof the profile at the edges (Nr. 1/6) is that of a podzol. The reaction is very acid.The pH-values are inferior to those of the lower terrace, probably due to leaching.This leaching of iron and aluminium is very well expressed in the ratios of thetotal analysis. The precipitation of iron in the B2-horzon can be deduced fromthe Si02/Fe203-ratios. Iron is more strongly leached than aluminium. The clayfraction of this profile consists of destructed kaolinite in the A-horizons and kao-


linite in the B- and BC-horizons. Moreover, gibbsite is found throughout the wholeprofile, while in the A-horizon cristobalite is present.

The carbon percentage is high in the rootmat top layer and decreases rapidlyin the lower horizons. However, a small increase is found in the B-horizon. Thehardening observed in the A2-horizon must be the result of silica cementation.The subsoil is strongly gleyed. This soil is a shallow iron-humus podzol on agleyed subsoil.

The soils in the center of the middle terrace show quite a different morphology

(Nr. 104/08). The lack of higher vegetation also proves that the soil must haveother properties.

The acidity is still greater than that of the former profile. The almostcontinuous wetness and leaching resulted in a very poor soil. The soil horizon undera shallow peaty root layer is infiltrated with organic material, but at a depth of30 cm a rapid decrease in the carbon content occurs. This is very markedly visiblein the field on account of a very thin whitish sandy horizon (see profiledescription), a characteristic'that already points to podzolization. The leachingof iron is more regularly divided over the profile than it is the case with soils atthe edges of the terrace. The same is found for the behaviour of the aluminium.Small deviations are the result of variations in texture. In the whole profile theiron must have been leached much more than aluminium. The thin, white horizonat a depth of 29-30 cm will have, lower amounts of iron and aluminium thanthe underlying horizons.

The very strong acid reaction in combination with the waterlogging circumstan-ces could have a poisoning effect on the vegetation. According to MÜCKENHAUSEN,in stagnant water and large quantities of aluminium present in acid humic waterthis effect may be evident (personal comminucation). The presence of freealuminium agrees with a similar observation in the profile at the edge of theterrace. The profile is classified as a podzolic stagnogley. "Podzolized" is addedhere because of the severe leaching of the iron.

S o i l s of t h e h i g h e r t e r r a c e .

The morphology of the profile of the higher terrace is that of a podzol (Nr.117/22). Pictures of similar profiles are supplied by STEPHENS (1953) andKUMADA (1961).

The carbon content in the generally very acid soil profile decreases quicklywith depth. The top horizon is formed by a peaty rootmat (ignition loss about60%). Marked accumulation of humus in the B-horizon was not found. Therewas a conspicuous leaching of iron and aluminium throughout the profile, withrelatively accumulated in the B-horizon.

D.T.A. proved the presence of kaolinite and goethite in the clay fraction of thesubsoil.

It seems justified to draw the conclusion that, in accordance with the total iron

DISCUSSION OF THE SOILS I4I

percentages in comparison with those of the lower terraces, this profile has neverbeen in the leached state of the stagnogley of the middle terrace. Although, thegeneral condition of the subsoil will be wet, the strong fluctuation of the groundwater causes a rather broad layer where the iron is accumulated. The profile is a(ground water) podzol.

The following general conclusion seems justified.

The three terraces have soil profiles which show a marked difference ingenetic development, due to age and drainage conditions. The severe weatheringin the two higher terraces causes a decomposition of the clay minerals, by whichsilica and aluminium hydroxide is set free. The silica is partly recrystallizedinto cristobalite, alumina into gibbsite, with some disordered kaolinite. Theleaching of aluminium hydroxide is fairly slow as a result of the impededdrainage conditions especially in the subsoil. As additional fact may be men-tioned that in those places where there is hardly any drainage (in the center ofthe wider middle terrace) aluminium is so concentrated that there is a poisonouseffect on the vegetation, so that trees grow only at the edge of the terraces, e.g.Araucaria spec.

In the subsoil of the older profiles with some drainage the aluminiumcontent increases relatively as compared to iron. The latter will accumulate in thezone of the fluctuating water level, or will be leached. The last assumption is provedby the large segregations of reddish-brown iron along the bottom half-face of theterrace (see page 49 the mobility of iron under anaerobic circumstances).

Another interesting point is that the sediments that are decomposition productsof the surrounding limestone mountains do not contain fragments of this rock, eventhe amount of calcium is very low. Free carbonate was observed only in the coarsesand of the riverbed of the present course of the Sibil.

A l l u v i a l s o i l s of t h e Ok I w u r r eg ion .

In the Ok Iwur region alluvial deposits occur, originating from the foot of theAntares and streching in southern direction. Because of the rising of the southernlowland, these sediments split at the great bend of the Iwur river to the east andto the west in a zone between the Ok Irin and the Ok Iwur, and along the OkTarup (see aerial photo analysis, page 27). Near the scarp, eastward of Katem,and in the Iwur bend, mentioned above, there are some higher terraces whichare built up of older sediments.

Younger deposits lie between the Ok Irin and Ok Iwur, and the youngestsediments are met with along the upper course of the Iwur and further eastwardalong the Ok Tarup.

In the younger deposits an interesting difference is found in the field as wellas on the aerial photographs.

The sediments along the Ok Tarup show agricultural patterns and many erosionfeatures. These two phenomena are lacking in the deposits between the Ok Iwurand the Ok Irin and in those northward along the Ok Iwur towards the Antares


Mountains. In the field the characteristics of the profiles of the Tarup regionindicate a younger age of the soil than of those along the banks of the Ok Iwur.The soils of the Tarup region are less wet, the humic top horizon is less acid andbetter mixed up with the mineral soil components. Thin-sections made of soilaggregates show a mull micro morphology. The Ok Iwur soils are wetter and thelitter forms a peaty top layer. This causes a mor to moder-like humus whichintroduces podzolization.

Small terraces are found locally at the mountain spurs northward of the Ok Irinand near Almun-Wending near the great bend in the Iwur river about 12 km eastof Katem. The soils which occur on these terraces are the oldest stage of thesediments in the Ok Iwur region. They are strongly leached. They carry avegetation type which is comparable with the moss forest. The soil is covered witha peat layer.

Based on the history outlined above the three stages of soil development weresampled.

Before, however, elaborating these facts, it should be remarked that greatdifferences in mineralogical composition of the same fraction occur, both of thevarious soils as of the different horizons in each soil.

The sediments are originating from the igneous parent material of theAntares Massif, but exceptionally other influences can be traced, e.g. in the topsoil of profile 18/21.

The sample Nr. 19 (sample 18 consists of peat) contains chlorite, which mayoriginate from a sedimentary deposit from the northern mountain spurs in aperiod that the Irin river had not yet cut into the younger sediments south of them.

A still greater difference is found in the profile Nr. 48/52. The heavy mineralassemblage in the top soil consists for 85 percents of tourmaline, zircon and rutile,while in the subsoil pyriboles make up the same percentage. This leads to theconclusion that we have to do with two sediments of different origin. However,in the entire profile more or less rounded sandstones (gravel size) were found,so that in this respect no variations were observed. Some chemical characteristicsof the profiles and the assemblage of the heavy minerals will be considered.

The highly to medium weatherable volcanic minerals show a marked decreasein the mutual content of these minerals in the topsoils of the profiles Nrs. 24/26,18/21 and 48/52. However, the variations in the subsoils of the profiles 24/26 and48/52 are less. Comparing the silica/sesquioxides ratios, we observe that the differen-ces between top- and subsoils are the highest in profiles 18/21 and 48/52, while thefigures of the subsoils of the profiles do not vary greatly. These differences agreewith two other phenomena, namely first the morphological variations in eachprofile and second the degree of weathering of the respective profiles. The soilreaction of the most severely weathered profiles is very acid. The leachingin profile Nr. 48/52 with mor humus of the moss forest peat must play an importantpart. These facts lead to the conclusion that the mineral composition of the profilescould be influenced by the extremely severe soil-forming processes. The author

DISCUSSION OF THE SOILS I43

could find no reasons against it. We have to do here with an example of extrememineral weathering in soils. Besides, higher up in the Star Mountains similarphenomena are encountered. The nearly total decomposition of the clay mineralswas found, compare sample Nrs. 156, 405/07 and 414. In other profiles theamounts of transparent heavy minerals was extremely low. These argumentsseem to justify the opinion that the original parent material of the profilesconcerned was fairly homogenous.

P r o f i l e Nr . 2 4 / 2 6 .

The morphology of this profile shows little variation. The colour does notchange very much throughout the profile. Probably some clay transport has takenplace, though this characteristic was not very evident in the field. In the totalanalyses made, the data obtained show only small deviations. A pronounceddecrease of the silica/sesquoixides ratios was not found. The weak increase ofaluminium with depth may be caused by an increase of the clay fraction, or byan increase of aluminium itself with depth. Also some iron is leached. Thealuminium oxide/iron oxide ratio is difficult to explain because of lack of figuresabout the grainsize distribution and the chemical data of the clay fraction. Theorganic material is mixed up with the mineral soil components, which wasobserved in a thin-section. There is some doubt about the exact position ofthis soil. Its classification as a sol brun acide seems to be justified.

P r o f i l e Nr. 1 8 / 2 3 .

The sediments lying more westward are leached more strongly and themorphological characteristic of the profile is that of a podzol under influence ofground water. The soil reaction is very acid. The carbon content decreases withdepth and the morphological B-horizon (15-50 cm) does not show an increase inorganic material. The higher carbon content in the subsoil may be the result oflaterally flowing humus containing drainwater. In the B-horizon the iron isaccumulated. The total analyses of the fine earth reflect the texture of the horizonas far as an increase of clay corresponds with an increase of aluminium oxide. Thepodzolization process can be deduced from the silica/sesquioxides ratios.

The profile is classified as a (ground water) podzol.

P r o f i l e N r.- 4 8 / 5 2.

The oldest deposits are found on a higher terrace and are represented by profileNr. 48/52. This profile is severely leached. The pH-values are very low. As aresult of the fairly coarsely textured top horizons, the decomposition products ofthe overlying peat layer penetrate into the sub-surface horizons. This effect masksthe presence of an evident A2-horizon, which (10-18 cm) shows a dark graycolour.

The aluminium and iron are strongly leached, so that the A-horizon is almostfree from these elements.

144 S O I L GENESIS STAR MOUNTAINS CENTRAL NEW GUINEA

The clay fraction in the A-horizons consists predominantly of quartz withsubordinate kaolinite. X-ray analysis revealed also anatase. In the B-horizongibbsite is dominant and there are minor percentages of kaolinite. Because of thevery acid reaction in this horizon the clay mineral kaolinite will have beenstrongly attacked. The aluminium is leached and forms gibbsite in the lowerhorizons, while silica is left in the topsoil, which produces quartz.

This strongly podzolized profile has a low iron content. In most podzolsiron is accumulated in the B-horizon, but in this case the amount of aluminiumaccrued.

Because of the morphological characteristics and some chemical data theprofile is classified as a peaty, aluminium podzol.

CHAPTER XIII

THE SOIL MAP.

The soil map is the result of the field observations, the aerial photo inter-pretation and the soil analyses. The field observations were carried out duringsome trips along long traverses, in which the points of study or the possibilitiesof movement were restricted. Only in some places a detailed terrain surveycould be made. The most detailed information on the total landscape or of theinterrelationship of soil units was obtained from the study of the aerialphotograps, allowing of a comparison and grouping together of initiately separatedunits. The study and the analyses of the soil profile provided detailed informationon the soil genetic processes and made it possible to classify the soils.

The soil map is based on the criteria mentioned above. In the following list all thesoil landscape units distinguished are registered with the soil types studied in thefield and with those which could be expected on an inter- and extrapolation basisof the characteristics found by aerial analyses.

The symbols listed with the landscape units and with the soil types correspondwith the symbols given on the map, so that this map can be used with thedescription of the landscape analysis as well as with the soil map.

The azonal soils have symbols beginning with o (zero); the intrazonal soilsare indicated with symbols beginning with i (one) and the soil types, whichform a toposequence or, in other words, which are the result of the vertical zonalitypresent in the wet, tropical mountain regions, have symbols which begin with2 (two).

The annotations a, b, c and d indicate the various origins of similar soil types.The soils developed on limestone are indicated with a, the soils on alluvium with d,the symbols b and c are used for soils derived from miscellaneous parent material,sometimes including limestone and alluvium. In some cases deeper phases aredistinguished by use of a different letter.

In the tropics the climate is warm, while the humidity varies. The zonal soils of

THE SOIL MAP I45

the tropical region will be the soils that are primarily influenced by the warmclimate and the vegetation that is in equilibrium with that climate. However,in mountainous regions, the topography will influence the climate and vegetation,so that different climatological zones or belts are formed. Although these climato-logical changes are the result of the topography, the soils developed under thevarious climates and corresponding vegetation types in these belts are the resultof the climatological zonality in these mountain regions. However, the consequenceof this reasoning is, that in some cases intrazonal soils or azonal soils accordingto the standard principle of zonality, are classified in mountainous areas as zonalsoils, as they are in equilibrium with their environments, especially with regardto climate and vegetation.

Some examples will be given. The only soil that can be formed in the mossforest zone is the peat soil. Rankers, rendzinas, lithosols (skeletal soils), solsbruns acides on top of the mountains are primarily the result of climate and the(lack of, or impossibility of growth of) vegetation. These soils are thereforeclassified as zonal soils. However, the same soils occurring in the low land, belongto the azonal and intrazonal soil types.

SOIL LANDSCAPES, REGIONS AN SOIL TYPES

THE SOUTHERN LOWLANDS AND UPLANDS.

R e g i o n s . S o i l s .

L. T h e M u y u a n d M a n d o b o l a n d s c a p e .Li The south-western swampy 14b half bog soils, humic gley soils,

regions, (o-io m) alluvial soils.L2 The Tanah Merah region, I7d podzolized gley latentes; on

(5-30 m) alluvium.L3 The Mindiptana region, 21c podzolized latosols; on alluvium.

(20-50 m)L4 The Woropko-Ninati region, 2id deeply podzolized latosols; on

(50-300 m) alluvium.L5 The Northern Muyu region, 22d brown podzolic soils; on alluvium.

(300-600 m)L6 The Umkubun region, 16c yellowish-brown, heavy textured

(300-400 m) gley soils; on alluvium.L7 The Welkozigibi region, 22a brown podzolic soils, rendzinas;

(300-500 m) on limestone.L8 The Red Digul region, 13b sols bruns acides, brown podzolic

(300-500 m ) soils, rankers; on silt- and clay-stone.

L9 The Koreon, (300-450 m) 13c sols bruns acides, rankers; on an-désite.


R R i v e r z o n e s . (0-200 m)

Ri The river zones along theDigul,

R2 The river zones along the Kauand Muyu,

R3 The river zone along theMandobo,

R4 The river plains and terracesin Mandobo district andWelkozigibi region,

U. T h e O k I w u r l a n d s c a p e .

Ui The Iwur terrace region,(200-700 m)

U2 The Tarup terraces region,(300-600 m)

U3 The Digul accumulation ter-race region, (200-400 m)

U4 The Digul erosion terraceregion, (200-500 m)

U5 The Irin terrace region,(400-800 m)

U6 The Ok Irin upland region,(200-800 m)

U7 The Ok Bouw region,(400-800 m)

U8 Steeply rising slopes,

T H E MOUNTAINS.

D. T h e D i g u l M t s . l a n d s c a p e .

Di The Southern Digul Mts.region, (1000-150001)

D2 The Arim Mts. region,(1500-2500 m)

D3 The Ok Kair region,(500-1000 m)

D4 The Upper Ok Kair region,(1000-1500 m)

14c half bog soils, gley soils; on recentalluvium.

14c half bog soils, gley soils; on recentalluvium.

I4d half bog soils, gley soils; onalluvium and drowned latosol.sols bruns acides, gley soils; onalluvium.

24c peaty podzols; on alluvium.

I5d gray brown podzolic soils; onalluvium.

I5d sols bruns acides, gley soils; onalluvium.

22a brown podzolic soils, rendzinas;on limestone.

23b peaty, aluminium podzols; onconglomerate.

13b sols bruns acides, rankers, brownpodzolic soils; on silt- and clay-stone.

22a brown podzolic soils; on limestone.

01b bare, rocks, lithosols; on limestone.

22/3a brown podzolic soils/podzols in-tergrades on fossile latosol; onlimestone.

24a peat soils; on limestone.

22b brown podzolic soils, sols brunsacides, rankers; on silt- and clay-stone.

l ie bare rocks, lithosols, rankers; onsilt- and claystone.

T H E

D5 The Northern Digul Mts.region, (1000-2500 m)

D6 The Songgam region,(500-1000 m)

D7 The Awitagoh region,(2500-3000 m)

D8 Steeply rising slopes,(200-3000 m)

T h e S i b i l r e g i o n :51 The Upper Sibil region,

(1400-1800 m)

52 The higher Sibil terraces,(1280 m)

53 The medium Sibil terraces,(1260 m)

54 The lower Sibil terraces,(1230 m)

SOIL MAP

23a podzols; on limestone.

147

22c brown podzolic soils (on fossilelatosol); on limestone.

11a bare rocks, lithosols, acid rend-zinas; on limestone.

01b bare rocks, lithosols; on limestone.

12a lithosols, rendzinas; on limestone.

23d podzols; on alluvium.

i6d gley soils, podzols, podzolized

gleys; on alluvium.14c gley soils, half bog soils, alluvial

soils.

T. T h e U p p e r D i g u l o r O k T s o p l a n d s c a p e .

T i The top zone of the mountainchains, (2000-2500 m)

T2 The moss forest zone,(2000-3000 m)

T3 The mid-mountain forest zone,(1200-2000 m)

T4 The shifting cultivation zone,(1000-2000 m)

T5 Very steeply rising slopes,(1000-3000 m)

T6 The Ok Mimka region,(1000-2000 m )

Ty The Ok Tse region,(1000-2000 m)

S e d i m e n t s :

55 Sediments along Ok Silaga,(ca. 2000 m)

56 Sediments on terraces,(1800 m; 1300 m)

16b peaty low humic gley soils; onlimestone.


22a brown podzolic soils, peaty pod-zols; on limestone.

12a rendzinas, lithosols; on limestone.

01b bare rocks, lithosols ; on limestone.

13c sols bruns acides, rankers; onshales.

11b bare rocks, lithosols; on sandstone.

14c half bog soils, gley soils, alluvialsoils.

i6d podzolized gley soils; on alluvium.


B. T h e O k B o n l a n d s c a p e .The Yukmondi Mts. region:Bi the higher parts, (2000-

3000 m)B2 the lower parts, (1000-

2000 m)

B3 The Grote Beer Mts. region,(900-1700 m)

B4 The top zone of mountainchains, (1700 m; 3000 m)

The Antares region:B5 The mid-mountain forest zone,

(1200-1700 m)

B6 The moss forest zone,(1700-3000 m)

B7 The alpine meadow zone,(3000-3600 m)

B8 The Sini-Mimi Mts. range,( 1100-3000 m)

B9 Steeply rising slopes,

( 1000-3000 m)

T h e r i v e r b a n k s :

S8 Colluvium along Ok Bon,

(900-1300 m)

T4 Along the Ok Tsop, (1000 m)


23a peaty podzols; on limestone.

I2c rankers, brown podzolic soils; onshales.

16b peaty, low humic gley soils; onshales.

12b rankers, lithosols, sols brunsacides; on shales and miscella-neous parent material.

24b peat soils; on miscellaneous parentmaterial.

25b sols bruns acides, rankers, peatyortstein podzols, bare rocks; ongranodiorite.

12b rankers, sols bruns acides, brownpodzolic soils; on shales.

Oib bare rocks, lithosols; on miscel-laneous parent material.

14c colluvial soils, alluvial soils, litho-sols; on alluvium and colluvium.


J. T h e J u l i a n a M t s . l a n d s c a p e .

J i Top, ice and snow zone,(4500-4700 m)

J2 Bare zone under top,(4000-4500 m)

J3 Alpine meadow zone,(3700-4000 m)

J4 Moss forest zone, (2000-3700 m)

J5 Glacial valleys, (3000-4000 m)

27 (no soil)

26 bare rocks, lithosols; on limestone.



16b peaty, low humic gley soils; onalluvium.

CHAPTER XIV

CONCLUSIONS

The study on the soil genetic sequences in the Star Mountains region allows us tomake a few general conclusions, namely:1. on the soil types,2. on the clay minerals.

i. Soil types.From sea level to eternal snow (4500 m) the dominant soil-forming process is

podzolization, because of the intense leaching caused by the high precipitation, andthe decreasing temperature with height. Apart from local mountain climatic differ-ences the soil types on limestone seem to range to higher elevations than cor-responding soils on metamorphic rocks and granodiorites. Probably this is dueto the higher permeability of the limestone (karst phenomena) which, comparedwith the other parent materials, causes a lower humidity of the soil climate.

The following sequences are found.

Z o n a l s o i l s (see Fig. 11).

On (old) a l l u v i u m :0-300 m podzolized latosols (21)

300-600 m brown podzolic soils (22).

SCHEMATICAL RELATION

BETWEEN ELEVATION AND SOIL TYPES

baching of Rp°3 \ \ | l [ l l | moderate

Fig. 11. Relationship between elevation and soil types in the Star Mountains area andsouthern lowland.


O n r e c e n t a l l u v i u m :200- 700 m peaty podzols (24)

1280 m do.

O n l i m e s t o n e :200-1000 m brown podzolic soils (22)

1000-2000 m peaty podzols (23)2000-3700 m peat soils (24)3700-4000 m rendzinas, lithosols (25)40OO-4500 m bare rocks, lithosols (26)over 4500 m (no soils, ice (27)).

O n s i l t s t o n e , c l a y s t o n e , s h a l e s :500-1000 m brown podzolic soils (22)

1000-1700 m lithosol (podzol/brown podzolic soils (12);1700-3000 m peat soils (24).

O n g r a n o d i o r i t e:1700-3000 m peat soils (24)3000-3500 m sols bruns acides (26)35°°"36oo m (bare rocks (26)).

On various parent material the following azonal (0) and intrazonal (1) soilassociations were detected:association (01) : bare rocks, lithosols, on limestone, sandstone, silt- and claystone;association (11): bare rocks, lithosols, rankers, rendzinas, on limestone, sandstone,

silt- and claystone;association ( 12) : rendzinas, lithosols, rankers, sols bruns acides, brown podzolic

soils, on limestone, shales, granodiorites;association (13): sols bruns acides, rankers, brown podzolic soils, on andesite,

silt- and claystone, shales; ;association ( 14) : half bog soils, gley soils, alluvial soils, lithosols, on recent allu-

vium, older alluvium, colluvium;

association (15): sols bruns acides, gley soils, on alluvium;association ( 16) : peaty low humic gley soils, gley soils, podzols, podzolized gley

soils, yellowish-brown heavy textured gley soils, on alluvium,limestone, shales;

association (17): podzolized gley laterites, on alluvium.

2. Clay minerals.

In comparing the main clay minerals, namely montmorillonites, illites andkaolinites, the parent rock, and potassium and calcium found in the clay fraction,the following may be stated:

CONCLUSIONS 151

Montmorillonite is always dominant in the clay fraction in the soil profilesderived from limestone;

Illites occur when the parent rock consists of claystone, slates and shales;Kaolinites are present in the weathering products of granodiorite, or in other

words, in soils derived from acid igneous rocks;Kaolinite is also dominant in the low-lying alluvial sediments, which have a very

poor and stable heavy mineral assemblage in the sand fraction.The conclusion may be drawn that in the Star Mountains region the presence of

the main aluminium silicate clay minerals is directly related to the parentmaterial. The weathering conditions of the rock, that is at the bottom of the soilprofile, is decisive for the clay minerals formed. In most profiles these mineralsare broken down.

In table IX a number of results of the clay analyses are grouped according toan equal nature of the minerals in the clay fraction met with in various profilesand according to the parent material. The data of all horizons is summarized andthe average taken. The number of horizons used for calculation is given in thetable. The several values are, of course, rough figures of relative value, as theweight given to each horizon and each profile is equal, irrespectively of whetherwe deal with an A- or B-horizon. Neverthless, these values show most interestingtrends.

For montmorillonite, dominant in the clay fraction, the silica/aluminium oxideratio lies between 4.6 and 2.6; in very strongly weathered profiles, e.g. profile405/08, this ratio is very high (18.3) because of a high amount of silica (quartz,cristobalite, etc.); if kaolinite is also present the ratio is lower (see profile 422/25),except for large percentages of organic material in the profile (Nrs. 410/12).

The calcium content although generally low is higher than that of the clay inwhich illite is found. Potassium is much lower than in the cases where illite ispresent. In those profiles where montmorillonite shows less distinct basal reflec-tions in the X-ray diffraction records, due to the weathering or to interlayeredmineral parts in the lattice, iM, the potassium content is higher (compareNrs. 90/94 and 245/48, 265/68, etc.). Probably some interlayered parts are occu-pied by illite units.

The high amount of potassium in Nr. 410/12 (black rendzina) is due to thehigh content of organic matter.

For illite as the principal mineral in the clay fraction, the SiO2/Al2O3-ratiosshow an average between 2.7 and 3.9. Here also free silica in the clay fractionincreases these values. The potassium averages are relatively high, which couldbe expected for illites. The calcium amount is low.

With kaolinite dominant, the SiO2/Al2C>3-ratios are lower than the former onesand range between 2.5 and 1.6. In the case of higher ratios there is illite, withlower ones gibbsite is found in fairly high quantities, while the values of about 2.2contain some free silica.

Potassium is low in the well-drained soils in the lowland, but higher in the clay


TABLE IX

Clay minerals as related to rock and average values of some oxides in the clayfraction.

Profiles Number of SiO2/Al2O3 K2O CaOhorizons % %

M + + . Q. Cr. on limestone:155/57, i352/55405/08

iM+ Q. on limestone:245/48, 265/68, 4i3/ I7. 435/38M+ + . K+ (Q) on limestone:422/25410/12 (shallow)

iM+ on limestone:90/94

I + . Q on shales:1342/45I + + . K. Q on claystones, shales81/84, 304/07, 308/10

I + + . K + + on limestone:85/89

K + + . Cr. G on alluvium:204/08, 222/26

K + + . I on alluvium:19^95K+ + . G + + on granodiorite:335/39, 340/44

74

15

32

3

4and slates:

10

2

1 0

5

6

4.6418.27

3-99

3304-55

3-59

2-74

3-93

3-65

2.20

2.50

1-55

0.50

0.68

1.09

0.652.92

2.48

2.19

2-73

1.16

0.14

!-59

O-33

0.16

O.IO

0.14

0.14

0.68

O.II

0.09

O.II

O.II

0.09

0.19

0.17

fraction of the soils which have waterlogged conditions. Calcium oxide is found inhigher percentages in the poorly drained profiles than in the well-drained ones.

SAMENVATTING

In de periode van april tot en met september 1959, werd een deel van het centrale berglandvan Nieuw Guinea, met name het Sterrengebergte en omgeving, door deelnemers aan de Sterren-gebergte Expeditie onderzocht. De onderzoekingen werden over een breed spectrum van weten-schappen uitgevoerd, waarbij in het bijzonder de verschillende aspecten van de antropologie, dezoologie, de botanie, de geologie en de geodesie werden bestudeerd. Voor het bodemkundiggedeelte was de auteur verantwoordelijk.

De opzet van de bodemkundige studie was het nagaan van de genese van gronden, voor-komende in het tropisch hooggebergte. Dank zij het feit, dat de hoogste top in het betrokkengebied met eeuwige sneeuw is bedekt en de auteur de gelegenheid werd geboden een tochtvanuit het laagland naar het bergland te maken, was het mogelijk het gegeven onderwerp uitte breiden. Hierdoor werd een overzicht verkregen van de bodems, welke zich uit verschillendmoedermateriaal, vanaf zeeniveau tot aan de eeuwige sneeuw nabij de evenaar, hebben ont-wikkeld. In totaal werden 9.500 km2 verkend en in kaart gebracht.

De resultaten van de bodemkundige onderzoekingen zijn in dit werk neergelegd. De fysischefactoren, die van belang zijn bij de bodemvorming zijn behandeld in de eerste hoofdstukken,namelijk hoofdstuk II Klimaat, III Geologie, IV Vegetatie en in hoofdstuk V een aantalandere factoren zoals de Mens en de Fauna. In de hoofdstukken VI en VII, handelende overde Luchtfoto interpretatie en Landschapsanalyse, worden vrij gedetailleerde gegevens over detopografie verstrekt. In combinatie met de bodemvormende factoren worden verscheidene bodem-landschapseenheden onderscheiden, die de basis vormen van de bodemkaart. In hoofdstuk VIII,Verwering enBodemvorming, wordt aandacht besteed aan de organische stof, het kleitransport,de afbraak van klei, de uitspoeling en mobiliteit van silicium, aluminium en ijzer in de bodem,het titaangehalte zomede de voorwaarden voor de vorming van een aantal kleimineralen.

In hoofdstuk IX wordt een overzicht gegeven van een aantal bodem typen van andere gebergte-streken in de wereld.

In de volgende twee hoofdstukken worden, behalve de morfologische beschrijvingen van degeselecteerde bodemprofielen, tevens de analytische gegevens gepresenteerd. Hoofdstuk Xbehandelt speciaal de mineralogische samenstelling der zandfracties. Naast de resultaten vanhet zware mineralen onderzoek worden ook nog die der gehele zandfractie besproken, terwijltevens aandacht wordt besteed aan de in het zand voorkomende magnetische fractie.

Van alle onderzochte profielen worden in hoofdstuk XI uitvoerige fysische en chemischeanalysecijfers gegeven. Deze dragen bij om het genetisch proces van het bodemprofiel te onder-kennen en te karakteriseren. In het bijzonder wordt hierbij aandacht besteed aan de verande-ringen die in de kleifractie der diverse horizonten optreden, met name de relatieve toe- ofafname van of silicium ôf sesquioxiden. De in de kleifractie aangetroffen kleimineralen wordeneveneens vermeld. De beschreven en geanalyseerde bodemprofielen worden in hoofdstuk XIInog aan een nadere discussie onderworpen. De benaming der bodems wordt gebaseerd op zowelde morfologische profielkenmerken als de chemische eigenschappen.

In hoofdstuk XIII, handelende over de bodemkaart, worden de in hoofdstuk VII genoemdebodemlandschapseenheden en de aangetroffen bodemtypen gecorreleerd en tot een bodemgene-tische kaart verwerkt. Tot slot worden in hoofdstuk XIV nog enkele conclusies gegeven metbetrekking tot de systematiek van het voorkomen van zonale, azonale en intrazonale bodems opverschillend moedermateriaal, terwijl een hergroepering der aangetroffen kleimineralen demogelijkheid biedt nog enige opmerkingen te maken omtrent de verwantschap van deze mine-ralen met het moedergesteente en de chemische samenstelling van de kleifractie tot de gevondenkleimineralen.

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Chim. 58. pp. 453 (cited by Bonifas 1959).ALIEV, H. A. i960. On the vertical zonality of soils of the great Caucasus eastern part

(Azerbaijan SSR). Proc. 7th. Intern. Congress of Soil Science, Madison, USA i960Vol. IV pp. 325.

American Society of Photogrammetry. i960. Manual of Photo Interpretation.ARENS, P. L. 1951. A study on the Differential Thermal Analysis of clays and clay-minerals.

Thesis Wageningen.A. S. T. M. 1962. X-ray powder data file 1962. Special technical publication 48-L, 7. Balti-

more Md.BALDWIN, M. and THORP, J. 1940. Laterite in relation to Soils of the Tropics. Annals Ass.

of Am. Geographers, Vol. 30, 1940, pp. 163-183.BÄR, CH. B., CORTEL, H. J. and ESCHER, A. E. 1961. Geological results of the Star Mountain

Expedition. Nova Guinea. Nr. 4, pp. 39.BEUTELSPACHER, H. und VAN DER MAREL, H. W. 1961. Kennzeichen zur Identifizierung von

Kaolinit, „Fireclay"-Mineral und Halloysit, ihre Verbreitung und Bildung. TonindustrieZeitung. 85 Heft 22 pp. 517 und Heft 24 pp. 570.. 1961 Über die amorphen Stoffen in der Tonen verschiedener Böden. Acta UniversitatusCarolinae. Geologia Suppl. I pag. 97.

BEVERSLUIS, A. J. 1927. Grondgesteldheid en landbouwmogelijkheden in het Boven Digoel-gebied, omgeving Tanah Merah, Zuid Nieuw Guinea. Unpublished report.

BLOOMFIELD, C. 1950. Some observations on gleying. Journ. Soil Science Vol. 1, No. 1, pp. 205.. 1953. Sesquioxide immobilisation and clay movement in podzolized soils. Nature. London.Vol. 172. pp. 958.• !953- A Study of Podzolization I. The mobilization of iron and aluminium by Scots Pineneedles. Journ. of Soil. Science Vol. 4 No. 1 pp. 5.. 1953. A Study of Podzolization II. The mobilization of iron and aluminium by leaves andbark o f A g a t h i s a u s t r a l i s (Kauri). Journ. of Soil Science Vol. 4 No. 1 pp. 17.. 1954. A Study of Podzolization III. The mobilization of iron and aluminium by Rimu( D a c r y d i u m c u p r e s s i n u m ) Journ. of Soil Science Vol. 5 No. 1 pp. 39.. 1954. The study of Podzolization IV. The mobilization of iron and aluminium by pickedand fallen Larch needles. Journ. of Soil Science Vol. 5 No. 1. pp. 46.. 1954. A Study of Podzolization V. The mobilization of iron and aluminium by Aspenand Ash leaves. Journ. of Soil Science Vol. 5 No. 1 pp. 50.

BOERMAN, W. E. 1949. Klimaat. Noordduyn's Wetenschappelijke Reeks No. 25.BONIFAS, M. 1959. Contribution à l'étude géochimique de l'altération latéritique. Mémoires du

Service de la Carte Géologique d'Alsace et de Lorraine — Université de Strasbourg.No. 17.

BRINDLEY, G. W. 1951. X-ray identification and crystal structures of Clay Minerals.Mineralogical Society. London.

BRONGERSMA, L. D. en VENEMA, G. F. i960. Het witte hart van Nieuw Guinea. Scheltens enGiltay.

BROWN, G. 1955. The effect of isomorphous substitutions on the intensities of (O O 1)reflections of mica- and chlorite-type structures. Mineralogical Magazine Vol. XXX No.229 pp. 657.. 1961. The X-ray identification and Crystal structures of Clay Minerals. MineralogicalSociety. London.

BURINGH, P. i960, see : Manual of Photo Interpretation.

LITERATURE 155

CORRENS, C. W. 1940. Über die Löslichkeit von Kieselsäure in schwach sauren und alkalischenLösungen. Chemie der Erde, Band 13 pp. 92.. 1961. Chemische Verwitterung der Mineralen. Fortschritt der Mineralogie Band 39, Heft2 PP- 339-. 1961. The experimental chemical weathering of Silicates. Clay minerals Bull. Vol. 4.No. 26 pp. 249.. 1962. Beobachtung über die Bildung und Umbildung von Tommineralen bei der Zersetzungvon Basalten. Colloques Int. du Centre Nat. de la Recherches Scientifiques No. 105.

COSTER, CH. 1941. Begroeiing, Grondsoort en Erosie. Landbouw XVII. No. 8/9. pp. 551.DEB, B. C. 1950. The movement and precipitation of iron oxides in podzol soils. Journ. of Soil

Science Vol. 1 pp. 112.Dept. of National Development. Div. of Regional Development 1951. The Resources of the

Territory of Papua and New Guinea. Vol. I and II. Canberra, A.C.T.DESHPANDE, T. L., GREENLAND, D. J. and QUIRK, J. P. 1964. Role of iron oxides in the bounding

of soil particles. Nature. Vol. 201. No. 4914. pp. 107.D'HOORE, J. 1953. De accumulatie van vrije sesquioxyden in tropische gronden. Thesis Gent.

. 1953. L'accumulation des sesquioxydes libres dans les sols tropicaux. Publ. I.N.E.A.C.Série Scientifique No. 62.

Di GLERIA, J., KLIMES-SZMIK, A. and DVORACSEK, M. 1962. Bodenphysik und Bodenkolloidik.Ungarischen Akad. Wissensch. Budapest.

DiKERSON, R. 1925. Climate of the Philippines during tertiary and quaternary time. Verhande-lingen van het Geol. Mijnbouwk. Gen. voor Ned. en Koloniën. Geol. Serie Dl. VIII pp. i n .

DUCHAUFOUR, PH. 1957. Pédologie. Tableaux descriptifs et analytiques des sols. École Nat. desEaux et Forets. Nancy.. i960. Précis de Pédologie. Masson & Cie. Paris.

DUPLAIX, S., DUPUIS, J., CAMEZ, TH., LUCAS, J. et MILLOT, G. i960. Sur la Nature desMinéraux argileux inclus dans les calcaires sénoniens de l'angoumois. Bull. ServiceCart. Géol. Alsace Lorraine Tome 13 fasc. 4 pp. 157.

EDELMAN, C. H., VAN BAREN F. A. en FAVEJEE, J. CH. L. 1939. Mineralogische onderzoekingenvan kleien en kleimineralen. I. General discussion of the mineralogical composition of claysand qualitative X-ray analysis of some Dutch clays. Mededeelingen van de Landbouwhoge-school deel 43. Wageningen.

EDELMAN, C. H. 1933. Petrologische provincies in het Nederlandsche Kwartair. Amsterdam.FINCK, A. 1963. Tropische Böden. Parcey. Hamburg.Fox, R. L., DE DATTA, S. K. and SHERMAN, G. D. 1962. Phosphorus solubility and availability

to plants and the aluminium status of Hawaiian soils as influenced by liming. Int. SoilConference New Zealand. Francetown.

GRIM, R. E. 1953. Clay mineralogy. McGraw-Hill. London.HARDON, H. J. 1936. Podsol-profiles in the tropics. Nat. Tijdschrift Ned. Indie No. 96 pp. 25.

. 1939. Onderzoek naar de samenstelling van de kleifracties van de voornaamste grondtypenvan Ned. Indië. Mededelingen Alg. Proefstation v. d. Landbouw No. 37 Buitenzorg.. 1940. De dehydratatie van de kleifracties van de belangrijkste in Ned. Indië voorkomendegrondtypen in verband met hun mineralogische samenstelling. Med. Alg. Proefst. v. d.Landbouw No. 39. Buitenzorg.

HARRISON, J. B. 1934. The katamorphism of igneous rocks under humid tropical conditions.Imp. Bureau of Soil Science. Harpenden. pp. 79.

HEKSTRA, G. en VALETTE, J. 1961. Verslag van een bodemkundige verkenning in het Digoel-Bian gebied. Unpublished report — Agric. Research Station. Hollandia. West New Guinea.

HiGASHi, T. and AOMINE, S- 1961. Weathering of montmorillonite in tuffaceous shales undersevere leaching. Soil Science and Plant Nutrition Vol. 7 No. 2. pp. 66.. 1962. Weathering of montmorillonite in soils. Soil Science and Plant Nutrition,Vol. 8 No. 1 pp. 7.


JACKSON, M. L. 1957. Frequency distribution of clay minerals in Major Great Soil Groups asrelated to the factors of soil formation. Proc. of the sixth Nat. Conf. on Clays and Clayminerals Berkeley (Cal.) Mon. 2 pp. 133.. i960. Soil chemical analysis. Englewood Cliffs. N.J.

JASMUND, K., 1955. Die silicatischen Tonminerale. Verl. Chemie. Weinheim.JoNGERius, A. and SCHELLING, J. i960. Micromorphology of organic matter formed under the

influence of soil organisms, especially soil fauna. Transactions of 7th Inter. Congress ofSoil Science. Vol. II. pp. 702.

JoNGERius, A. 1962. Arbeiten aus dem Gebiet der Mikromorphologie des Bodens. Red. H. J.Altemüller und H. Frese. Verlag Chemie. Weinheim.

KALKMAN, C. 1963. Description of the vegetation types in the Star Mountains region. WestNew Guinea. Nova Guinea. Nr. 15. pp. 247.

KELLER, D. W. 1958. Argillation and direct bauxitization in terms of concentrations of hydrogenand metal cations at surface of hydrolyzing aluminium silicates. Bull. Am. Ass. PetroleumGeologists Vol. 42 No. 2 Febr. 1958 pp. 233.

KELLEY, W. C. 1956. Application of differential thermal analysis to identification of thenatural hydrous ferric oxides. The Am. Mineralogist. No. 41. pp. 353.

KOPPEN, W. und WEGENER, A. 1924. Die Klimate des Geologischen Vorzeit. Berlin.KOVDA, V. A., YAKUSHEVSKAYA, I. V. and TVURYUKANOV, A. N. 1964. Micro-elements of the

soils of the Union of Soviet Socialist Republics. Unesco 49. Paris.KRAUSKOPF, K. B. 1959. The geochemistry of silica in sedimentary environments. Soc. Econ.

Pal. Min. Spec. publ. No. 7 pp. 4.KUBIENA, W. L. 1948. Entwicklungslehre des Bodens. Verlag Springer. Wien.

. 1950. The soils of Europe. Th. Murby-London.KUMADA, K. 1961. Soils of the North Japanese Alps. Pedologist (Japan). Vol. 5. No. 2.

pp. 2,KUNZE, G. W. 1955. Anomalies in the ethylene glycol solvation technique used in X-ray dif-

fraction. Proc. Third Nat. Conf. on Clays and Clay Minerals. Publ. 395. pp. 88. Nat. Acad.of Science.

LACROIX, A. 1913. Les latérites de Guinée et les produits d'altération qui leur sont associés.Nouv. Archives Museum Hist. Natur. Serie V, pp. 255.

LAM, H. J. 1945. Fragmenta Papuana Sargentia, V. Contributions from the Arnold Arboretrumof Harvard University.

LANE-POOL, C. E. 1925. The forest of Papua and New Guinea. Empire Forestry Journal,Vol. 4 pp. 206.

LENEUF, N. 1959. L'altération des Granites Calco-Alcaline et des Granodiorites en Cote d'Ivoireforestière et les sols qui en sont dérivés. O.R.S.T.O.M. Paris.

LINDEMAN, J. C. 1953. The vegetation of the coastal region of Suriname. Thesis. Utrecht.LOVERING, T. S. 1959. Significance of accumulator plants in rock weathering. Bull, of the Geol.

Soc. of America, Vol. 70 pp. 781.LUCAS, J., CAMEZ, TH. et MILLOT, G. 1959. Détermination pratique aux rayons X des minéraux

argileux simples et interstratifiés. Bull. Serv. Cart. Als. Lorraine Tome 12, fase. 2, Stras-bourg pp. 21.

LUNT, H. A., SWANSON, C. L. W., and JACOBSON, H. G. M. 1950. The Morgan soil testing

system. Bull. 451. Connecticut Agric. Exp. Station.LYFORD, W. H. 1946. The morphology of the brown podzolic soils of New England. Soil

Science Society of America. Vol. 11. pp. 486.MACKENZIE, R. C. 1957. The Differential Thermal Investigations of Clays. Mineralogical

Soc. Clay Minerals Group. London.Manual of Photo Interpretation, i960. American Society of Photogrammetry.Meteorological and Geophysical Bureau 1957-1960. Several annual reports. Government of

Neth. New Guinea.

LITERATURE 157

MiLLOT, G. i960. Silice, Silex, Silifications et croissance des cristaux. Bull. Serv. Cart. Géol.Als. Lorr. T. 13, fasc. 4 pp. 129.

MiiLNER, H. B. 1962. Sedimentary Petrography. Vol. I and II. Allen & Unwin Ltd. London.MOHR, E. C. J. 1944. The soils of equatorial regions. Translated by R. L. Pendleton. Ann. Arbor.MOHR, E. C. J. and VAN BAREN, F. A. 1959. Tropical Soils. Van Hoeve — Den Haag.MOUTHAAN, W. L. P. J. 1962. Bodemvruchtbaarheidsrapport van het Digoel-Biangebied. Un-

published report — Agric. Research Station. Hollandia. West New Guinea.MÜCKENHAUSEN, E. 1962. Entstehung, Eigenschaften und Systematik der Böden der Bundes-

republik Deutsland. D.L.G. Verlag — Frankfurt.PAPADAKIS, J. 1961. Climatic tables for the world. Buenos Aires.PEDRO, G. 1962. Experimental research on the weathering of crystalline rocks and the

geochemical characterization of pedogenetic phenomena. Transactions of the Nat. SoilConf. New Zealand.

PEECH, M. and ENGLISH, L. 1943. Rapid microchemical soil tests. Soil Science 57, pp. 167.RAZOUX SCHULTZ, F. H. N. 1952. Terreinverslag van de bodemkundige opname van een deel

van het kustgebied van Merauke. Unpublished report —• Agric. Research Station. Hol-landia. West New Guinea.. 1954. Kort verslag van de bodemkundige verkenning van het gebied tussen Kao enMoejoe rivieren. Unpublished report — Agric. Research Station. Hollandia. West NewGuinea.

REYNDERS, J. J. 1958. Kort overzicht van een bezoek aan de Sibil. Unpublished report of theAgricultural Research Station. Hollandia. West Nieuw Guinea.. i960. Voorlopige mededeling van het agrogeologisch onderzoek in het Sterrengebergte.Tijdschrift Kon. Ned. Aardr. Gen. Dl. LXXVII. No. 2. pp. 162., 1961. The Landscape in the Marau and Koembe district. Comm. Neth. Soil Survey Inst.— Auger and Spade XL. 1962. Shifting cultivation in the Star Mountains area. Nova Guinea. Nr. 3. pp. 45.. 1962. A brief report on the occurrence of peat in Netherlands New Guinea. Comm.Netherl. Soil Survey Inst. Auger and Spade XII.. 1964. Toepassing van röntgenspectrografie in de bodemkunde en geologie. ChemischWeekblad No. 2. Dl. 60. pp. "13.

RICHARDS, P. W. 1952. The Tropical Rainforest. Cambr. Un. Press.RODE, A. A. 1962. Soil Science. Translated from Russian. Israel Program for Scientific

Translation. Jerusalem.RUSSELL, E. J. 1950. Soil Conditions and Plant Growth. (Revised by E. W. Russell) Longmans,

Green and Co. New York.SACHEZ CALVO, M-C. 1963. Kennzeichnung von Guinea-Tonen durch Röntgenstrahlen und

ultrarote Absorption. Int. Clay Conf. pp. 155.SCHACHTSCHABEL, P. i960. Fixierter Ammoniumstickstoff in Löss- und Marschböden. Trans-

actions. 7th. Intern. Congress of Soil Science. Madison. Vol. II. pp. 22.SCHAUFELBERGER, P. 1952. Die praktischen Probleme der tropischen Bodemkunde. Acta Tropica.

Sep. Vol. 9, Nr. 1.SCHEFFER, F. und SCHACHTSCHAEEL, P. i960. Lehrbuch der Agrikulturchemie und Bodenkunde.

Teil I Bodenkunde. Ferd. Enke Verlag Stuttgart.SCHWAN, J. 1962. Een samenvattende bodemkundige verkenning van het Merauke-kustgebied.

West Nieuw Guinea. Unpublished report of the Agricultural Research Station. Hollandia,New Guinea.

SCHUFFELEN, A. C, MULLER, A. and VAN SCHOUWENBURG, J. CH. 1961. Quick tests for soil andplant analysis used by small laboratories. Neth. Journ. Agric. Science. Vol. 9. No. 1. pp. 2.

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. 1953. A manual of Australian soils. C.S.I.R.O., Australia. Melbourne.

. 1961. The soil landscapes of Australia. C.S.I.R.O. Australia. Melbourne.TAN KIM HONG and VAN SCHUYLENBORGH, J. 1959. On the classification and genesis of soils,

derived from andesitic volcanic material under a monsoon climate. Neth. Journ. Agric.Science, Vol. 7. No. 1. pp. 1., . 1961. On the classification and genesis of soils developed over acid volcanic materialunder humid tropical conditions II. Neth. Journ. Agric. Science. Vol. 9. No. 1. pp. 41.

TAVERNIER, R. and SMITH, G. D. 1957. The concept of Braunerde (Brown Forest Soil) inEurope and the United States. Advances in Agronomy. Vol. IX pp. 217.

TAVERNIER, R. and MÜCKENHAUSEN, E. i960. The soil map of Western Europe on scaleI : 2.500.OOO. Proc. 7th Intern. Congress of Soil Science, Madison U.S.A. Vol. IV, pp. 44.

THORP, J. and BELLIS, E. i960. Soils of the Kenya highlands in relation to land forms. Proc.7th Intern. Congress of Soil Science, Madison U.S.A. Vol. IV, pp. 329.

TiURiN, I. V., Rozov, N. N. and RUDNEVA, E. N. i960. International soil map of EasternPart of Europe. Proc. 7th Int. Congress of Soil Science, Madison U.S.A. Vol. IV, pp. 36.

TURC, L. 1954. Le bilan d'eau des sols. Annales de l'Institut National de la RechercheAgronomique. le part pp. 491.. 1955. Le bilan d'eau des sols. Annales de l'Institut National de la Recherche Agronomique.2ieme part.. 1955. Le bilan d'eau des sols. Sols Africains. Vol. III No. 1 pp. 138.

VAN BAREN, F. A. 1934. Het voorkomen en de betekenis van kali-houdende mineralen inNederlandse gronden. Thesis. Wageningen.. 1938. Doel en methode van het röntgenografisch klei-onderzoek. Landbouw 11 pp. 659.. 1939. Mineralogisch en chemisch onderzoek van kristallijne kleibestanddelen. De Ingenieurin Ned. Indië. IV. Mijnbouw en Geologie, 6e jaargang No. 3 pp. 29.

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VAN BAREN, F. A. and KIEL, H. 1956. The mineralogy of an apparently autochthonous soilprofile in French Equatorial Africa. Vlth. Intern. Congress of Soil Science. Paris. II. 16.

VAN DER MAREL, H. W. 1956. Toepassing van de röntgendiffractie-methode bij het bodem-onderzoek. T.N.O. — Nieuws. No. 121.

VAN DIJK, J. W. 1951. Plant, Bodem en Bemesting. Deel I. Wolters — Groningen.VAN DER EYK, J. J. 1957. Reconnaissance soil survey in Northern Surinam. Thesis. Wage-

ningen.VAN DER MERWE, C. R. and WEBER, H. W. 1963. The clay minerals of South African soils

developed from granite under different climatic conditions. South African Journ. Agric.Science. 6. pp. 411.

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VAN SCHUYLENBORIGH, J. and VAN RUMMELEN, F. F. F. E. 1955. The genesis and classificationof mountain soils developed on tuffs in Indonesia. Neth. Journ. Agric. Science. Vol. 3.pp. 192.

VAN RUMMELEN, F. F. F. E. 1955. The clay fractions of some limestone soils of the Rembanghills and Madura (Indonesia). Proc. Nat. Acad. of Science (India) Allahabad. Vol. 24.Sect. A. Part II.

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LITERATURE 159

VAN STEENIS, C. G. G. J. 1937. De invloed van den mensch op het bosch. Tectona. Deel 30.pp. 634.

VERSTAPPEN, H. TH. i960. Preliminary Geomorphological Results of the Star Mountains Expe-dition 1959, Central Neth. New Guinea. Tijdschrift Kon. Ned. Aardr. Gen. Deel 77, No.3, PP- 306.. i960. Julianatop en Antares. De Berggids. November.. 1964. Geomorphology of the Star Mountains. Nova Guinea (in preparation).

ViLENSKii, D. G. 1957. Soil Science. Coll. Publ. House. Min. of Culture. Moscow.ViNOGRADOv, A. P. 1959. The Geochemistry of Rare and Dispersed chemical Elements in Soils.

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lands New Guinea. Verh. Kon. Ned. Geol. Mijnb. Gen. XX, Geol. Serie.VON ENGELHARDT, W. 1940. (Cited by Bonifas 1959).WHITE, J. TH. 1928. Verslag omtrent een onderzoek van 3 series profielmonsters van gronden

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A PEDO-ECOLOGICAL STUDY OF SOIL GENESIS IN THE TROPICS ... · of soil genesis in the tropics from sea level to eternal snow star mountains, central new guinea proefschrift ter verkrijging