Embed Size (px)
Citation preview
5EXCAVATIONS AT THE TO'AGA SITE (AS-13-1)
PATRICK V. KIRCH AND T. L. HUNT
INTRODUCTION
PRIOR TroTh coMmEN NTrr of fte Manu'aProject in 1986, our knowledge of the archaeol-
ogy and prehistory of the Manu'a Islands was lImitedto a few late prehistoric architectal sites and tosurface finds of stone adzes and flakes (Kikuchi 1963;Emory and Sinoto 1965; Clark 1980). No well-stratified occupation sites were known, and there wasno established sequence of occupation phases extend-ing back to the Ancestral Polynesian period, as hadbeen developed for Westem Samoa (Green andDavidson 1969, 1974). bdeed, previous archaeologi-cal reconmaissance in Manu'a had failed to locate anysites that contained prehistonc pottery and thus mightdate to the first millennium B.C., based on compari-sons with the Samoan sequence as defined for UpoluIsland. A major goal ofour 1986 reconnaissancesurvey of Ta'u, Olosega, and Cfiu islands was thus todetermine whether the appaent absence of ceramic-bearing sites was simply an artifact of archaeologicalsampling, or whether such early perod sites weretnuly absent in the Manu'a Group.
The surface find of a Polynesian Plain Waresherd in Ta'u Village on the first day ofour 1986reconnaissance was followed up by test excavations,revealing the presence of subsurface occupationdeposits dating to the Ancestral Polynesian period(Hunt and Kirch 1988). This discovery was sufficientto establish that the prehistory of the Manu'a Islands
would in general terms parallel that of the larger andbetter known Westem Samoan group. Moving fromTa'u to Ofu Island, we subsequently discovered apottery-bearing site at To'aga on the southem coast,where the Public Wo*ks Department had bulldozed alandfill dump and thereby exposed subsurfacedeposits. This area was within the site AS-13-1defined by aark (1980). We canied out a limitedtest excavation at the To'aga landfill in 1986, eover-ing pottery and other artifacts in situ (see below).Because of the significance of the To'aga materalsfor elucidating Manu'a prehistory, we expanded ourexcavations in 1987, revealing that the site was farmore extensive than originally thoughL A thirdseason of trnsect test excavations was carried out in1989 to assess the full area of this extensive anddeeply staified site. In this chapter, we present thedetails of these three excavation seasons, includingthe specific excavadon pxcedures used, as well asthe srtigraphy and depositional sequences revealed.Subsequent chapters provide detailed analyses of theceramics, other portable artifacts, and faunal mater-als, as well as discussions of radiocarbon chronologyand site geomorphology.
Field Methods: General Comments
Some aspects of field methodology which wereconstant in all field seasons may be brefly summa-rized. The prncipal sampling strategy used was that
44 The To'aga Site
of "systematic trasec " (Redman 1974; Kirch andYen 1982; Kirch 1988), with 1r-m excavation unitsgenerally spaced at 10m intervals. We orientedthese transets perpendicuarly to the coastine inorder to provide geomorphic proffles across thecoastal flat All trae pfeswee canied out to thereefflat andcoI to mean sea leveL Usng atlescopc level and stadia md, a srface elevatoprfile was obtained foreach trmuect. Observanwere also made of soil vanation and vegetationassociations along the trasect, as thse data indi-cated cuntland use and provided im clues asto the geomorphic history of the site. Thisstrategy of acquiring data (surface and excava-tion) along systematic transects has the advantageof producing results that can be mapped andinterpolated.
Whenever possible, excavation proceededaccording to natral stigraphy, although arbitraysubdivisions were made within thick strata Indi-vidual excavation blocks (refened to as "spits') weredesignated within strata, but never cross-cut strati-graphic boundaries. Detailed rwcords were main-tained on aarz recording forms (fig. 5.1), onwhich horizontal feames were drawn to scale and alllocalized finds were plotted according to x, y, and zcoo.rinates. Aftrexcavation, measuwd strat-grapic pofiles were dawn foreach excavationunit, and all sta were described in terms ofthickness, boundary, morphology, color, lithology,cultual conte, and other caracteristics. Colordesignations are from fte Munsell soil color charts(Munsell 1988). Most proffile descriptions weredone by Kirch to assure consistency (in 1989, Huntdescribed several units after Kirch left the field toinitiate a project in the CDook ls). Following thedrawing and description ofeach profile, a senres ofsediment samples were taken; sediment sampleswere taken from within stata, never cross-cuttngstratigraphic boundaiies. These samples weresubsequently analyzed in the University of Califor-nia, Berkeley, geacaeology laboratory (see Kirch,Manning, and Tyler, chapter 7).
All excavated sediment was sieved through 0.25inch mesh screens. Although smaller mesh (particu-larly 0.125 inch mesh) would have enhanced therecovery ofminute faunal remains, we opted againsttfhis screening stategy in the inreests of covering agreater area duing this testing phase. Given our
primary objective ofdetemuningt areal extent andnature of the subsurface deposits at To'aga, sufficientareal sanpling was judged to be a more importantconsideation than complete faunal recovery.During screening, however, we made perodicchecks ofthe small size fraction passing thrgh the0.25-inch mesh screens and were generally satisfiedthat the bulk of the faunal materals was beingretained. In addition, bulk sediment samples weretaken from strata in the areal excavation blocks, aswell as from some of the individual test pits (seeNagaoka, chapter 13). These samples allowed us toassess the frequency of minute faunal remains. Allvertebrate and invertebrate faunal materials caught inthe sieves were bagged and shipped back to thelaboratory for identification and analysis. Prelimi-nary sorting ofthe vertebrate fauna, as well asdetailed identifications of the avifaunal remains,were carried out by Dr. David Steadman ofthe NewYork State Museum (see chapter 14). Furfteranalysis of the non-bird vertebrates and oftheinvertebrate fauna was undertaken by Lisa Nagaokaofthe University of Washington (see chapter 13).
The numbering of stratigraphic units (distin-guished by roman numerals) is based primarily onsedimentological (rather than culturl) critera Eachsedimentological-lithological unit that was deter-mined to have been deposited eitheras a singleevent, or as several events all representing the samnesource and mode of deposition, was designated as a"layer." Subunits withn these sedimentologicallayers, including cultural occupadons, are designatedby letters. Hence, an occupation episode that iswholly incorporated within a calcaeous sand beachridge deposit, Layer III for example, might bedesignated as Layer HIB, with elturally sterile,but lithologically identical sands above and belowdesignated Layers hIA and IIIC. Thus, our layerdesignations emphasize fte geomorphological siteformation processes rather than simply the pesenceor absence of cultural materials.
In describing the lithology ofbeach rdgedepositional units, we paid special attention to ad-mixture of volcanic lithic grains with the dominantcalcareous grains. When volcanic grains are present,these give the sediment a 'salt-and-pepper' appear-ance. The signficance of this 'salt-and-pepper'lithology is that it reflects the availabiity of avolcanic sediment source from which sand grains
Excavation 45
MNa 'a Project, 19989 ''
Sieve& DIy cI4.et 0 &zt .L
yI__
MeanStartZ= *_cm-
PM. Sit As-i-S'IddaW
A"11111m 'r-41s0o5
Spit F ;
1 .. .. .;
Df~~Depths: Surfae Ciiatum 0O
.t-P
IN
End Ieve
Mea En| m*cm|!r
COMMENTS (Note sediment char~teristics, color;disturbances; samples taken; speclproblems):
tA~8ftC-4 -tVt (J STl &SALT' (tu44AaM foft(6-~~~~~ .~~.)rL
- $ OL~ jAB,e~i.*S 7.b^t u 468(
mVAIO6ete8)M}(~s 1' A LAAYEht5RP)tc.'oAn
msScr''So6(-T F'S -
- CliAkColF * , 74S,5
-SVAItrat &OlCIWA I;"? AAz VAN,*w
o ~~~~~~~~~~CJ ,r~u lm 1-5.Ud'I¢°~W/
_ Vw--To Rr'.AA-TtO%Z Ftw&V #Ai OLA. CbCgAC
->psli,o# fw'A Nr e.vTc: fS5)g
lb Re d Ceix
Ct- 5LIRP1,^PC"' P
- VST65CmA-ShApSIOL. 7-*A7- P 6C&AC-46
Recorder: C. mw,ae-ls
P I ALJW1
Figure 5.1 Example of the excavation recording form used in the 1987 and 1989 To'aga field seasons. This form
is for level 5 of Unit 20 on Transect 9.
0
0
I x
-mL
T
46 The To'aga Site
were produced by wave action along the fonnershoreline. Today, fte sandy beaches fng To'agaare almost pwely calcares. Volcanic grains arepresen only in a few spots, where volcanic head-landsp gh the coastal terrace and areexposed to wave action. The frequent presence of'salt-and-pepper' lithologies in deeply burieddeposits exposed by our excavation indicates alandform stage whm the coastal ten-ace was muchnarrower (prior to progradaton), and when substan-tially more volcanic material was available forincorportion into the sediment budget Thus, alongmost transects, there is a tran from deeper,earlier 'salt-and-pepper' sand lithology to pudelycalcareous lithology, reflec coastalionand removal ofmost volcan:ic source material fromthe sediment system. In chapter 7 we use pointcounting of sediment sampes to furtxr documentthe precise qutities ofvolcanic lithic grains instrata within various excavaton units.
1986 TEST EXCAVATION
TIe Toaga site (AS-13-1) was initially discov-ered duing te 1986 naissance survey, whenexamination of a deep bulldozer cutting made by thePublic Woiks Department for a sanitary landfilldistbed a buned cultual deposit contningPolynesian PaiOn Ware cermnics (Hunt and Kirch1988:168). The bulldozercutting lies atthe edge ofa fan ofmassive talus bouldes. It appears that thelandfill site is at the inland-most location possible onthis paricular section of the coastal flat A singletest pit (1 m2) was placed dirty adjacent (3 mwest) to the bulldozed area of the To'aga landfill.This locale had mained undistubed by the bull-dozer activities.
Excavation ofthe test pit (designated Unit A)revealed the following major stata:Layer I: This dark (2.5 Y 2V0) mucky sand mixedwith coliuvial clay is eniched with organic maer(contemporary A soil horizon). It contains coralpebbles, shell midden (mosdy Turbo spp.), andwaterwom basalt pebbles and cobbles. Layer Ireached a maximum depth of60-70 cm belowsurface. The contactwithLayer1isdiffuseovera1-3 cmzone.Layer U: This layer had motted pale yellow tograyish brown (2.5 Y 7i2 & 512) calcareous sand
containing coral and basalt pebbles and cobbles,shell midden (mostly Turbo spp.), and ceramics(four thickware sherds orly). Layer II rached amaximum depth of 135 cm below surface. Thecontact with Layer II is very diffuse. A singleadiocarbon date (Beta-19742) on Turbo shellyielded a conventional radiocarbon age of2350± 50B.P. (cal 28 B.C.-A.D. 108 at one s ard deviation;see chapter 6).Layer m: No culturl material was pent in thewhite (10 YR 8/2) calcareous sand of this layer.Excavation of test Unit A reached a maximum depthof 160cm below surface.
Subsquent woik in 1987 revealed ta thesemajor stratigraphic zones fit well within the geomor-phological sequence for the To'aga flat as a whole(see below). Artifacts collected frxm the bulldozedarea of the To'aga landfill and from UnitA weredescribed and illustrated by Hunt and Kirch(1988:169-76) and are included here in chapter 1 1.
THE 1987 EXCAVATIONS
The 1986 surface collections from the landfillsite, combined with the limited results frm the testexcavation, revealed the presence of earlyPolynesian occupation deposits in the To'aga area.Along with the discovery ofpottery at Ta'u Villageon Tau Island (Hunt and Kirch 1988), this was thefirst record of an early phase ofoccupation in theMarn'a Islands. With e concurence oftheAmedcan Samoa Historic Preservation Officer, wetherefore determined ta a major objective for asecond season of fieldwork in Manu'a should bemore intensive investigation of the To'aga site, withthe aplicaton of subsurface systemadc transecttting in order to determine whether undistubdpotteiy-bearing occupation deposits werepnt inthe vicinity ofte landfill site. Tibs second phase ofwork was caried out in 1987.
Excavation Procedures
Returning to the To'aga site in 1987, wefocused on the coastal flat immediately northeastofthe ladfill which had not been disurbed bybulldozing (fig. 5.3). As can be seen in the transectprofle in figure 5.2, this flat is about 125 m widefrom the base of the steep colluvial-alus slope to the
Eavatio 47
Figure 5.2 Elevation profile along the 1987 excavato transect, showing the positions of the main excavato and Units 2and 3, in relation to geomoaphic and pedologic feat.
prese shoreline. Using the systematic tranctstrtegy developed by Kirch for sub-surface sam-pling in similar coastal settings in Tikopia andNiuatoputapu islands (Kirch and Yen 1982; Kirch1988), we laid out a transect baseline extending
across the Toagacoastal fiat, at a location 60mnorthe of the Ofu landfill. The first ree unitsexcavated along the transect (at 0, 15, and 45 m fromthe base of the talus slope) revealed a complex anddeep cultual stratigraphy in Unit 1, but only shallowcultual deposits overlying calcareous beach sands inthe more seaward Units 2 and 3. A shovel test at105 m fardher seaward along this transect, near thecrst of the modem beach ridge, revealed a totalabsence of culural deposits, with only calcareoussand. These tests thus demonstated that the oldestcultunal deposits were to be found close to the baseof the steep talus and volcanic cliff, and most ofthe coastal flat consisted of culturally sterile coralsands and reef detritus, which had been depositedduring seaward progradation during the past 2-3 kyrB.P.
Following these iniitial tansect tests, Unit 1 wasexpanded into a larger excavation in order to effec-tively sample the deep stratigraphic sequence,including the in-situ deposits of Polynesian PlainWare ceramics. Units 4-9 were excavated, joiningwith Unit 1 to fonn a T-shaped trench asshown infigures 5.3 and 5.4. All units were dug trugh theLayer II calcareous sand deposit containing pottery,while Units and 6 werecaried deeper into under-
lying Layers HI and IV (see Stratigraphy, below).The third stage ofour 1987 excavation strategy
was to detennine the lateral extent of the earlypottery-bearing deposits southwest and northast ofthe main excavation, parallel to the base of the talus.Unit 10 was thus laid out 45 m southwest of thebaseline transect, as close to the base of the talus as
feasible (acmally set in among several massiverockfall boulders). This revealed a stigraphysimilar to that in the main trench, including deeplyburied cultural deposits with Polynesian Plain Wareand one fine, thin-ware sherd. Unit 1 1 was then laidout 45 m nonheast ofUnit 1. Unit 11 revealedceramic-bearing deposits, but these were tnncatedby a large, deep pit (probably a late prehistodc ua'imasi or breadfruit-fermentation pit), and so an
adjacent square, Unit 14, was opened to clarify thestratigraphy. In order to get as close as possible tothe base of the talus, another test was laid out 15 mnorthwestof Unit 11, atthe footofthetalus anddesignated Unit 12. In Unit 12, a massive deposit ofcolluvium and large angular boulders had to bepenetated to a depth of 1.8-1.9 m before we wereable to reach a thin deposit of calcareous sandcontaining four thin, fine-tempered potsherds (onerim and four body sherds). These test units indicatedthat early, pottery-bearing cultual deposits at To'agaextend over a distance of at least 105 m northeast ofthe Ofu landfill, in a narrow zone at the base of thecolluvial-talus slope.
A finalt, Unit 13, was opened in the centerof
oD
CL) OC
00E
*. : Beach ca. 2000 B.P.0 o 25m
Beach ca. 350BP
E0
a.
VERTICAL SCALE X4
48 The To'aga Site
-0
L..
z a)0 l
X (a
01 Lt
E0
0.I-
Uf)G)
C:
CDc
CMI-z
0
O-z
6:2
0
-4
z
F4
0
0
U
Ct)I-z
0 nC4._
Co
I)
/.:N
O..:
....
0
636CM
I-z
I-
z
0
d)'3>
)&Vol
.5
.8
Iz
As
o
*s
A
g
'I
Iza
-S
bO
1eIwI
0ol:
Ecavations 49
Figure 5.4 Excavation in progress in the 1987 main trench. Note the large talus boulder on the left. P. Kirchis recording the stratigraphy of the south face of Unit 1.
a low pavement ofwaterwom pebbles (such pave-ments are called 'ili'ili in Samoan) apparentlymarking a later prehistoiic house floor. Our objec-tive in excavating Unit 13 was to obtain a sample ofthis later prehistoric midden to contrast with theolder, ceramic-associated assemblage.
Stratigraphy ofthe 1987Main Excavation
Although the stratigraphy of the 1987 excava-tions varied from unit to unit, the most completedepositional sequence was revealed in the maintrench excavations (Units 1, 4-9), but was reflectedas well in Units 10, 11, 12, and 14. Seaward of themain trnch, Units 2 and 3 displayed simplerstratigraphic profiles, resulting from the laterprogradation of calcareous beach sands.
The westem profile of the 1987 main trench isfsown in figure 5.5, in which all ofte principaldepositional units are represented. The stradgraphicunits follow:Layer IA: The upper 15-20 cm portion of the upper
colluvium (10 YR 3/1.5) found here has beenheavily reworked by gardening. Various plantingpits or depressions are detectable in te secdon.Layer IB: This is a massive deposit of reddishbrown colluvium (10 YR 312), very compact, withno internal lensing or bedding evident. No charcoalflecking was observed. The deposit incorporatesnumerous angular to subangular weathered volcaniclithic fragments in the gravel-to-pebble size range.A small, lens-shaped pocket of slightly darker soilcontaining charcoal flecking was noted within LayerIB (designated Feature 1) and may represent agarden bum feature. This would suggest that LayerIB accumulated gradually and that the land surfacewas internittendy gardened during its deposidon.Layer IC: The basal 15-20 cm of the upper collu-vium (10 YR 2/1) makes up thissm. It issomewhat darker than e overlying Layer IB,containing dispersed flecks and chunks (5-10 mm) ofcharcoal. The deposit is associated with an earthoven feature in Unit 9, and the charcoal (which isconcentrated in a zone around the oven) appears to
50 The To'aga Site
~~~~~~~~~~~~~~~~~~~~~ 0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.
Il0_,_ fi0 ,| S *,b;''j].
- I- W
t W (w\ a 1ll @ _/z1 l, |; @ i \ rib t § .!~~~~~~~~~~\1lo.
t (f _ 1t_I- 5 -0\'' iCD~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~C
-D W--< -C_'t'S :'-\ I 0tt X 1- ox k l ° l< |j~~~~~~~~~~~~~~~~~~~~~~-LO .E0Z~~~~~~~~~~~~~~~~~~
±.1'm IIgN
o o °0Csh. I 0
- U; '~~~~~~~~~~~~~olmnSmpeiu
I-~~~~~~~~~~~~~~ E- z
Z ~~~~ Iii ~~~~~ ColumnSampleCut~~~~~~~~~~b
ci c~~ c~.
Depth in Meters |a
Exavations 51
have derived from oven rake outs. Some thick,coarse-tmpered pottery was also recovered fromthis deposit. It does not appear to have been apermanent occupation, however, and may representa short-term or intermittent occupation such as afield shelter on a former land surface.Layer H: This unit with its subdivisions representsa period of active deposition of a calcareous beachridge.Layer HA-1: A thin zone at the top of Layer HA,slightly darker and organically enriched (10 YR 512),this stratum contains anthrpophilic land snails andrepresents a phase of stabilizaton and vegetation ofthe Layer II sandy beach ridge. Some occupation inthe vicinity is suggested by the presence of a fewthick, coarse-tempered sherds and a thin scatter ofmarine shell midden.Layer HA: This deposit contains loose, calcareousbeach sand (10 YR 7/2), not compacted or cementedand lacking culul materials. Although most of thesediment consists of calcareous materials, there is asubordinate quantity of basaltic lithic grains, givingthe sand a distinct 'salt-and-pepper' appearanc.This indicates ta at the time of deposition therewere exposed volcanic headlands in the vicinity ofthe beach, providing a source for the basaltic sandgrains.Layer IIB: This principal pottery-bearing depositrepresents a perod during which the surface of theactively accumulatng sandy beach ridge wasoccupied. Lithologically, Layer IIB is similar to HAand IIC, but with the addition of organic/culturalmaterials due to human occupation making it bothdaiker (7.5 YR 4/2) and more compacted. Thedeposit contains shell and bone midden, largequantities of small sea urchin spines and test frag-ments, ceramic sherds (prmarily of thick, coarse-tempered ware), and other artifacts. It also containsantrpophilic land snails. The deposit is non-concentrated and probably accumulated over a fairlybrief span of time.Layer [IC: This layer, the basal component of theLayer II beach ridge consists, as with HA, of a 'salt-and-pepper' lithology with dominant calcareousgrains and a subordinate quantity ofvolcanic lithicfragments (10 YR 5/2). Toward the base of thisdeposit are numerous large coral cobbles and someangular volcanic cobbles, along with branch coralfingers and coral rubble. This material indicates a
relatively high energy deposidonal environmaet,such as storm activity along an exposed beach frnt.Thirteen sherds of thin, fine-tempered ware werepresent, although te deposit showed no evidence ofbeing an in-situ occupation locale.Layer II: Massive silty-clay colluvium (7.5 YR 3-4/2) with some incorporated subanguar lithicfragments makes up this layer. Occasional charcoalflecks are present, pariucularly nearte top of thedeposit. Nine thin, fine-tempered potsherds werealso incorporated in the deposit. It appears torepresent a single depositional event, resulting froma combination of mass-wasting ad fluvial spotof terigenous sediment from the colluvial slopeabove te site. A lower zone, designated Layer IIIB,incorporates some sand mixed frm Layer IV,presumably at the time of deposition. The presenceof charcoal flecking indicates burning of this slopeprior to fte deposition of fte sediment, pediaps dueto gardening or oter human disturbance.Layer IV: Here one encounters a mixed deposit offine-grained calcareous sand and reddish silt-clay(7.5 YR 5/4), apparendy culturally sterile.Layer V: This basal deposit of 'salt-and-pepper'sand (10 YR 8/2) includes marine shell and reefdetritus; fairly compact, and showing the initialstages of cementation probably due to frequentground-water wetting. The deposit represents anactive beach ridge depositional environment. Ityielded two sherds of thin, fine-tempered ware,which may have derived from a primary occupationlocus behind the beach (which would now be buredunder at least 10m of colluvium).
Excavation Units 2 and 3
The stratigraphies of Units 2 and 3, seaward ofthe main excavation, were essentially identical; thesection for Unit 3 (fig. 5.6) is typical:Layer I: This organically enriched, silty-clay loamis presently under cultivation. Lithologically, thedeposit is a mixture of calcareous sand (77%), silt,and clay-sized terigenous grains, the latter derivingfrom sheet wash erosion from the colluvial slope.Various planting depressions filled with loose,rewoiked soil are visible in the section. ITh depositalso contains fragments of marine shell midden fromoccupation in the vicinity. An earth oven featurewas exposed in the west face of the unit
52 The To'aga Site
UNIT 3: SOUTH UNIT 3: WESTAdz Section
0.0
004'402
0.5 c
0.
0
1.0
Figure 5.6 Stratigraphic section of the south and west faces of Unit 3. "C" indicates coral, and "V"indicates volcanic.
Layer II: Here one encounters loose, calcareousbeach sand which is culturally sterile. This deposit iscomposed wholly of calcareous grains and lacks the
'salt-and-pepper' combination of calcareous andbasaltic grains found in the Layer II deposit in themain excavation This absence indicates that by thetime of deposition of Layer 11 in Unit 3, the coastlinehad prograded sufficiently to buq the volcanicheadlands.
Excavation Unit 10
As shown in figure 5.3, Unit 10 was located 45m southwest of the 1987 baseline transect. The pitwas situated in a small clear space between severalvery large boulders, at the base of the steep talus.Our aim here was to get as close tothe talus aspossible, in the hope of exposing deeply buriedcultural deposits. This unit revealed a staigraphicsequence similar to that in the main excavationtrench. The north and east faces of Unit 10 are
shown in figure 5.7. The strata are descnrbed below:Layer IA: This upper pordon of tfie colluvium (5YR 3/2) is presently gardened and tius loose andreworked. Its silty clay loam includes angular lithicgravel. The contact with Layer IB is diffuse over a
2-3 cm zone.
Layer IB: This very compact deposit of clayeycolluvium (5 YR 4/4) contains subangular lithicfragments. Occasional charcoal flecks are prsentThere is no evidence that this zone had been re-worked by gardening, and it probably represents asingle depositional event. The contact with Layer ICis diffuse over a 2-3 cm zone.Layer IC: The basal porton of the colluvium (5 YR312), this deposit is similar to IA, and may representan older land surface that was gardened. It is lesscompact than Layer IB and contains someanthropophilic land snails (e.g., Lamellaxis gracilis).Also, some disturbances penetrate down into LayerII. The contact with Layer nI is distinct.Layer HA-1: This thin, discontinuous deposit ofcalcareous sand is enriched with organic matter andstained gray (color 5 YR 4/1). Land snails of severalgenera are present, indicating the fonner presence ofa stable land surface with vegetative cover. Thisdeposit is a former paleosol fonned on the old beachridge represented by Layer H. It reflects a phase ofstability capping the earlier phase ofbeach ridgeaccumulation. This paleosol must have formed afterpgration ofthe shoreline removed the sotve ofcal os sediment that had resulted in he deposiionof the deeper Layerldeposits. The cntact with LayerIIA is diffuse and gradational over a 3-4 cm zone.
I I I
Excavations 53
UNIT 10: NORTH
Stratigraphic section of thenorth and east faces of Unit 10.
Layer IIA: A culturlly sterile deposit of 'salt-and-pepper' sand (7.5 YR 7/2), this stratum is predomi-nantly calcareous but incorporates some volcanicgrains indicating the exposure of volcanic headlandsnear the site at the time of deposition. The deposit isfairly loose and was probably developed rapidlyafter the abandonment of the underlying Layer UBoccupation. The contact with Layer IIB is veryirregular but relatively sharp.Layer HIB: This is a ceramic-bearing occupationdeposit (7.5 YR 5/2). The parent lithology isessentially identical to Layer IHA. This layer repre-sents a period of occupation on the beach ridge whilete active deposition of sandy sediment continued,primarily through aeolian action. The deposit is
UNIT 10: EAST
stained grey with finely dispersed organic materialbut is very sparse in midden (not nearly so concen-trated as Layer IIB in the main excavation trench).The contact with LayerUC is diffuse.Layer UC: The mixture of calcareous sand andreddish clay (7.5 YR 5/4) found here prbablyresults from fluvial/hydraulic tnsprt of the clayfrom the talus upslope. It is culurally sterile. The
contact with Layer IIn is sharp but iregular.Layer m: This compacted deposit of reddishbrown clay-silt (5 YR 3/4) includes no larger lithicfragments, suggesting a fluvial rather than mass-wasdng mode of deposition. No charcoal fleckswere observed. This deposit appears to represent asingle depositonal event, perhaps associated with a
0.0
0.5
0at0
0.0
1.0 c.
a0
-1.5
2.0
54 The To'aga Site
storm or cyclone. The contact with Layer IV issomewhat diffuse and mixed.Layer IV: The 'salt-and-pepper' beach sand (10 YR812) of this layer incorporates larger coral cobblesand waterwom branch coral fingers. The layerrepresents a fairly exposed, high-energy beach nidgedepositional event.
Apart from shell and bone midden, Unit 10yielded little artifacul material. A few small flakesof obsidian were wecovered from Layer IIA-1, and asingle thinware body sherd (5.7 mm thick) with anorange (5 YR 5/6) slipped exterior came from LayerIIB.
Excavation Units 11114
As shown in figure 5.3, Units 11/14 werelocated 45 m east ofte baseline transect. Thislocation is among massive talus boulders where theground surface is relatively level. Excavation ofUnit 11 revealed a large pit feature over the entireunit which extended from the lower colluvium (ca.55 cm below surface), cutting down through calcare-ous sand layers to 2.25 m below surface. The fill ofthis pit contained 181 thickware sherds and 4thinware sherds (2 with red-slipped exterors). Fieldobservations indicated ta pottery came from thelower deposits adjacent to the pit and not frm thepit fill itself. As nonnal stratigraphy for this areacould not be discemed with the intnasion of the deeppit, Unit l1 was expanded into arectangulartrench(1 by 2 m) with the excavation of Unit 14. Unit 14exposed an undistrbed sraigraphic sequence, asfollows:Layer IA: The upper 20-30 cm of colluvium foundhere was dark brown (10 YR 312) and had beenreworked by gardening. This layer contains somecharcoal flecking (probably modem) and no pottery.Layer IB: This massive lower colluvium is verypoorly sorted and includes angular volcanic rockfragments with no evident bedding or lenses. Nocharcoal or other cultual materials were observed inthis dark brown (10 YR 312) layer.Layer IC: Thissm contained a dark grayish-brown (10 YR 3/1) mixture of clayey colluvium andcalcareous sand with abundant midden, includingshell, bone, pottery (309 sherds, with 304 [98%]thick-coarse, and 5 [2%] tiinware), and charcoal.This deposit was the source of the fill of the large pit
described for Unit 1 1, but in Unit 14, it made up adiscrete area between 54-75 cm below surface. Thislayer appears to represent a depositional eventcontemporaneous with Layer IC in the main trench(see above).Layer U: This calcareous sand deposit is enrichedwith organic matter and some eluviation of clayparticles from the clay-rich Layer IC above. Layer IIis brown (10 YR 5/3) and contains pottery (15thickware sherds) and a relatively sparse amount ofshell midden. This stratum is comparable to Layer IIin the main area excavation.Layer Im: Calcareous sand (10 YR 7-812) withwaterwom coral cobbles and unwom branch coralmakes up this layer. It contains little culturalmaterial and appears to represent a high energydepositional environment. Layer III compares inlithology and content to Layer IIC in the maintrench.Layer IV: This brown (7.5 YR 4/2) mixture ofsilty-clay colluvium and calcareous sand has someorganic matter. Few larger lithic cobbles or bouldersare present, suggesting a sediment that probablyrepresents sorting with surficial flow of the terrig-enous source, and wind (saltational) ransport of thecalcareous (beach ridge) source. A small hearthcomprised ofwaterwom coral boulders surroundinga shallow ash concentration was excavated at thesurface of this layer in Unit 14. Five thinware sherdswere ecovered from this stratigraphic boundary.Excavation was discontinued at the surface ofLayerIV due to time constraints at the end of dte 1987season.
Excavation Unit 12
Unit 12 was located 16m north and 45 m east ofUnit I inthe maintrench (see figure 5.3). he unit issituated on the colluvial slope amidst huge talusboulders. Excavation of this unit (chosen to pen-etrate the subsurface deposits as close to the talusslope as possible) proved to be hazardous given telarge boulders protruding from the unstablesidewalls of the pit, especially as the clayey sedimentdried and became friable. The stratigraphy of Unit12 was as follows:Layer IA: The upper colluvium (0-20/30 cm belowsurface) consists of an organically enriched, Ahorizon soil. The layer is dark brown (10 YR 3/1)
Exavtions 55
and has been rewoiked by recent gardening. Nocultural material was observed.Layer IB: The massive lower colluvium, darkbrown (10YR 3/2) in color, consists of very poorlysorted, large, angular rock fragments, with cobble-and boulder-sized clastics, in a clay-silt matrix. Nobedding or lenses of finer-grained sediment wereobserved, nor was any cultural material noted.Layer IC: This is the base of the colluvial deposit,distinguished by an incmase in fine-grained sedi-ment The boundary with Layer IB is gradual,reflecfing a continuous icreae ofclay and silt contetoward fte base ofLayer I. This day-loam aainssome calcamous sand (thoroughly intermixed) andangular volcanic rck frag , but these are re-
stricted to cobble-sized. Charcoal flecks andwaterwom coral gravel are present in small amounts.Small amounts of bone and shell were recoveredfrom this layer, but pottery was absent. Layer Iextends from the surface to 2 m below surface.Layer IC-1: This is a brown (10 YR 3/3) clay-loamwith calcareous sand thoroughly intermixed. LayerIC- I can be distinguished by both its greater calcare-ous sand content and the presence of pottery. Thepottery in this layer is predominantly thinware (25sherds, with 2 thick-coarse and 23 thinware) andincludes duee direct rims, one of them with red slipand an impressed lip. Shell and charcoal wererecovered in small quantities. The deepest (2.6 m)portions of this layer had no cultural materials.
The stratigraphy of Unit 12 was almost entirelycolluvial in origin. The upper pordons, free ofcultural materials, represent one or more rapiddepositional events, i.e., mass wasting of materialfrom the nearby steep volcanic cliffs. The clay-loamof the lowest portions of the sequence representsgradual accumulation of colluvial sheet wash duringa perod of occupation. Calcareous sand entered the
deposit through wind trasport (saltation) from the
active beach ridge, which was then much more
closely adjacent to this location.
Excavation Unit 13
Located 45 m east and 37 m south from Unit 1
in the main trench, Unit 13 was near the center of astone-faced, waterwom gravel-filled ('ili'ili) moundtypical of Samoan house foundation construction.The gravel mound measures 15 by 16 m across its
center and is nearly round in plan view. The moundis elevated approximately 25-30 cm above thesurrounding organically enriched and stable sandysubstrate. Excavation of Unit 13 revealed thefollowing stratigraphy:Layer I: This deposit of waterwom coral gravel('ili'ili) is mixed with a small prporton ofwaterwom volcanic gravel and with a finer, daickorganically enriched, sandy loam matrix (7.5 YR 2/0). A bottle glass sherd was excavated from thislayer, possibly indicating occupation of the housemound into the Historic period.Layer IB: This is a lighter colored (10 YR 5t2)sediment of the same texture as Layer I. The colordifference is due to a lower percentage of organicmatter. Ash, shell, and numerous sea urchin spineswere mixed into the gravel paving stones. Excava-tion of the lower part (3048 cm below surface) ofthis stratum exposed a small pordon of a humanburial cut from the floor surface (Layer I) of thehouse mound and extending into Layer II below.Only bones from the feet were recovered, theremainder of the burial lying outside of the excava-tion uit.Layer H: This stratum contains culrally sterile,white (10 YR 8/2). calcareous sand. Excavation wascompleted with the testing of this layer to 68 cmbelow surface.
Radiocarbon Chronology of the 1987 Excavations
Seven samples of charcoal and shell from the1987 excavation units at To'aga provide the basis fora radiocarbon chronology of the deposits in thevicinity of the Ofu landfill. The 1987 dates werereported in full by Kirch, Hunt, and Tyler (1989) andare discussed in detail in chapter 6.
The oldest dates are those for samples Beta-25035 and -25673, both frm Layer V of the maintrench, the basal calcareous beach sand whichyielded two thin, fine-tempered sherds. Bothsamples consisted of unweathered marine shellwhich were probably deposited at approximately thesame time as the sherds (details of these samples areprovided in Kirch, Hunt, and Tyler 1989:11-12; seealso Kirch, chapter 6). The samples yielded ovedap-ping ages at two standard deviations which indicatesa calibrated time range of between 3700-3300 calB.P. for the deposition of dtis beach sand which
56 The To'aga Site
contained the thin, fine-tempered ware potterysherds. While this age range is certainly early forhuman occupation in Westem Polynesia, it is notout-of-line with the earliest known dates for Lapitasites in the region (Kirch and Hunt 1988; Kirch1988, table 48).
Three samples are in direct association with thePolynesian Plain Ware assemblage (Beta-25034,-26464, and -25033), denrving from th Layer IIoccupation in the main trench and from its corelateddeposit in Unit 10. All three samples agree well inage and indicate a calibraed time range ofbetween2500-1900 cal B.P. for Xt main Polynian PlainWare occupation.
A terminus post quem for the use of ceramics atthe To'aga site is provided by sample Beta-26463,which derives from the base of an aceramic occupa-tion deposit which statigraphically postdates Layern in the main trench. This sample yielded a cali-brated age of 1389-1287 cal B.P.
The final sample (Beta-26465) was obtainedfrom the base of the aceramnic house mound tested byUnit 13 and yielded a calibrated age of 1122-950 calB.P. Since the platform is consructed on the presentland surface, it is evident that the sequence of coastalprogradation and of colluvial deposition in thevicinity of th main excavation had stabilized by thebeginning of the second millenniUM A.D.
The Depositional Sequence in the 1987Main Trench
The depositional sequence in the 1987 maintrench excavation at To'aga can be summadzed aste following series of stages:Stage 1 (3700-3300 Cal B.P.): The calcareous sandbeach represented by Layer V of the main trenchwas formed at a time when the island's shorelinewas close to the base of the talus slope. Thus,volcanic headlands were exposed to active waveerosion, yielding mixed calcareous-basaltic lithologysands. Human occupation in the vicinity of thebeach (presumably now buried under a considerabledepth ofcolluvium and talus) is suggested by thepresence of tin fine-tempered ware sherds.Stage 2 (> 2500 cal B.P.): The older beach ridge wasburied at this time by terigenous silt-clay fromupslope, with erosion initiated in part by humanclearance of the vegetation with fire, indicated bycharcoal flecking in the erosional deposit.
Stage 3a (ca. 2500 cal B.P.): Accumulation of thecalcareous beach ridge was renewed during thisstage, while the shoreline was still close to thetalus slope (revealed again by mixed calcareous-basaltic grain suites). Exposure to the activeshoreline is indicated by the large coral cobblesand reef detritus, representing one or more stormevents.Stage 3b (2500-1900 cal B.P.): Humans inhabitedthe active beach ridge surface (Layer IIB of the maintrench) during this time, resulting in the depositionof ceramics and midden.Stage 4 (2500-1900 cal B.P.): In this stage, thebeach ridge was abandoned as an occupation locus,and the accumulation of the beach ridge (Layer HA)continued.Stage 5 (ca. 1900 cal B.P.): The old beach ridgesurface stabilized during this stage. This is indicatedby the formation of an A soil horizon and thedeposition of anhopophilic garden snails (LayerIIA-I of the main trench). The stabilization presum-ably resulted from seaward progradation of theshoreline, thus removing the immediate source ofcalcareous sediment. At roughly this time, the basalsands represented by Layer II in Units 2 and 3 weredeposited.Stage 6 (< 1900 cal B.P.): During Stage 6 there wasadditional erosion and deposition of temgenoussediments from upslope in the area of the maintrench. The presence of ceramics and an earth ovenindicate a brief occupation event.Stage 7 (< 1900-1000 Cal B.P.): The progradation ofthe shoreline continued to its present position about125 m seaward of the main excavation locus.Gradual deposition of fine-grained terigenoussediments over the surface of the newly formedcoastal flat and the rewoiing of these depositsthrough gardening activities also occunred duringthis stage.Stage 8 (ca. 1000-100 cal B.P.): Human habitationdispersed across the expanded coastal flat duringStage 8, represented by the 'ili'ili pebble pavementtested by Unit 13 and by other surface culturalfeatures.
in sum, the depositional sequence revealed inthe 1987 excavations begins late in the secondmillennium B.C. with a coastal teriace only a fewtens ofmeters wide, and with a reef platformsubstantially wider than at present. This geomorphic
Excavations 57
situation fits well with evidence for a +1-2 m higherstand of the sea in the southwest Pacific at ca. 3 kyrB.P., as argued inchapter4. By about 1900 B.P., theshoreline had begun to rapidly prograde, associatedwith a drop in sea level to its present stand and withexposure of the reef crest leading to a higher rate ofcalcareous sediment production. The developmentof a coastal terrace more than 100 m wide wasaccompanied by the addition of fine terigenoussediments due to erosion and sheet-wash of thehigher colluvial slopes, forming a highly prducfivezone for intensive cultivation and habitation. lhere-fore, the morphodynamic model of coastal teracefonnation outlined above in chapter 4 is closelysupported by the stratigraphic and radiometric datafrom the 1987 excavations
Swnmary fthe 1987 Excavaions
The program of excavations carried out in 1987was successful in establishing the presence ofundisturbed, well-stratified prehistonic occupationdeposits in the To'aga area. The basal occupationlayers contained Polynesian Plain Ware ceramics,including a fine, thinware pottery dating to the mid-first millennium B.C. The 1987 excavations alsoestablished a sequence of geomorphological changein the To'aga area, indicating substantial coastalprogradation and consequently deep burial of thepottery-bearing deposits under recent calcareousdune ridge and colluvial slope-wash deposits.
By the close of the 1987 season, it had becomeclear that the subsurface archaeological resources ofthe To'aga area-especially te deeply buried,pottery-bearing deposits-were far more extensivethan originally thought. The 1987 excavation unitshad revealed the presence of culural deposits overan area of at least 4,000 i2, but without reaching thehorizontal boundaries of these layers. Because of thegreat significance of the To'aga site for Samoanprehistory, it was clearly essential to establish thefull areal extent of the subsurface archaeologicalfeatures at this extensive and well-staified site. Athird phase of excavations was therefore required,applying the systematic tansect strategy of subsur-face testing over the whole extent of the southeemcoastal plain on Ofu Island, extending from te Ofulandfill site and adjacent 1987 excavations eastwardtowards Fa'ala'aga. Potentially, this entire coastal
strip neady 2 km long and varying between 50 to100 m wide, might contain subsurface archaeologi-cal deposits; this could only be determined drughsubsurface testing. Such a testing prgrmn wasproposed to the Historic Preservation Office ofAmerican Sanoa in 1988 and implemented by athird field phase of the Manu'a Project in 1989.
THE 1989 TRANSECT EXCAVATIONS
1989 Excavation Procedures
The prmary objectives of the 1989 field seasonat To'aga included-mong other things-the arealdefinition of the fuill extent of subsurface archaeo-logical deposits witin the coastal terrace and thefurter elaboration of a morphodynamic model ofsite fonnation processes. These goals dictated thecontinued use of a systemadc tract sanplingstrategy, with excavation transects spaced along thefull extent of fte coastal terrace (as far to the north-east as Fa'ala'aga). In order to maintain accuratespatial control on the test units to be excavated alongthese ransects, our first task was to establish abaseline. This was staked out at 100m intervals,following the course of the dirt road that paallels theshoreline trughout te To'aga area. A zero ororigin point was established where this baselinebisected tX 1987 trmnsect (which was designatedTransect 1); from this 0-point, the baseline extended300m to the southwest, and 1500m to the norheast.Each 100-m interval along the baseline was identi-fied as a potential transect-intersection point forsubsurface testing, and tansects were labeled fron 1to 19. Transects 2-3 extended southwest from theorigin point (Transect 1), while tansects 4-19extended to the norheasL
Choice of specific trans for test excavationwas dictated by several factors, including permissionfrom local landowners, locations of gardens (we didnot wish to disturb active Alocasia garden sites),presence of 'sacred' sites (in particular, the Tui Ofutomb complex), as well as te usual constraints oftime and budget. Over the course of the field season,we were able to excavate test units along six of thepotential sampling tansects: Transects 3 (200mW), 5 (100m E), 7 (300m E), 9 (500m E), 11 (700m E), and 17 (1300m E). The locations ofthesetransects, and their relationship to te baseline, am
58 The To'aga Site
diagrammed in figure 5.8. (Note that in this figurethe scales for the baseline and te trinsects aredifferent.) These trants thus cover a total areaextending 1.5 kn from southwest to nonheast, andin every case across te lateral extent of the coastalterrace.
Prior to the commencement of excavation, eachselected traect was cleared of obscuring vegeta-tion, and a transe baseline staked out at 10-mintervals. A continuous elevation profile along theUtnsect was then surveyed using a telescopic leveland stadia rod. These surveyed proffles providedvaluable infonnation on the geomorphic structure ofthe coastal terrace. In order to ascenain the relation-ships between surface and subsurface geomorphicfeatures and modem sea level, each tansect profilewas also surveyed down to the shoreline, and outonto the reef fiat.
A total of 16 -iM2 units were excavated alongthe six tranwcs listed above. Virtually all unitsextended to at least 1.5 m below surface, and someunits reached depths as great as 2.9 m before cultur-ally sterile sediments were exposed. Thus fte totalexcavated volume was approximately 32 m3.Excavation units were numbered sequentially in theorder that they were iniidated, beginning with Unit 15and ending with Unit 30.
In the following pages, the 1989 excavations aredescribed by trasect, beginning with Transect 3 atthe southwestem end ofthe coastal terrace andprogressing towards the norheast to Transect 17.
Transect 3
Transect 3 is situated 200m to the west of the1987 excavation area (Transect 1); between Transect3 and Transect 1 lies the bulldozed landfill sitewhere pottery was first discovered during the 1986reconnaissance survey. The surveyed elevationprofile ofTransect 3 is shown in figure 5.9, with thelocation of the single st, Unit 27, excavated alongthis transect. The ground surface along Transect 3 iscomposed of clayey colluvium with numerousvolcanic cobbles and boulders scattered over tesurface. The vegetation consists predominantly ofcultivated bananas.
Excavation Unit 27
This test excavation is situated 42m inland ofthe road. The profile of the east face is shown infigure 5.10. The following strata were identified:Layer I: This dari brown colluvial clay containsangular and subangular basalt cobbles. Charcoalflecks were present thughout in low frequency.LayerI: An orange-brown-stained calcareous sandmakes up this layer. The lower part ofthis stmcontains many coral and basalt pebbles and cobbles.The distribution of ese larger clastics suggests astorm or other high-energy depositional event,followed by a more gradual accumulation of thefiner-grained sands in the upper portion of thedeposit.Layer MIIA: The brown-to-tan calcareous sand inthis statum exhibits some "peppenrng" of volcanicgrains. The straum also contains many angular andsubangular basalt cobbles and boulders, shell, andcoral rubble.Layer hIB: This layer is composed ofbrown sandyclay with angular to subangular basalt cobbles,rounded coral cobbles, and shell. The clay compo-nent of this sand is higher than in Layer lIA,although the boundary separating the two strata isdiffuse and unclear. Layer IIIB produced the bulk ofthe cultural material in Unit 27, between about 175-214 cm below surface. This cultual materalincluded more than 6 kg of shell midden, 120 fishbones, and some turtle (see Nagaoka, chapter 13).The lower part ofLayer EB was sterile, and excava-tion was discontinued at 225 cm below surface.
Unit 27 yielded a variety ofprehistorc arifacts.iMese include pottery, pieces ofobsidian (probablynatural), basalt (from Layers H and IIA), and an adzbutt fragment from Layer IRA. Layer I did notcontain any artifacts. A total of 95 sherds wasrecovered, with the following strafigraphic distribu-tion: Layer 11, 5 thickware sherds; Layer IIA, 80sherds (5 [23%] thinware, 57 [71%] thickware);Layer HIB, 10 sherds (3 [309] thinware, 7 [70%]thickware).
No radiocarbon dates were processed from Unit27. On the basis of the ceramics recovered, how-ever, the occupation in Layer HsB could date to
avationh 59
q~~~~~~~~~~~~~~~Y
LL~~~~~~~~~~~~~~~~~~~~~~~~~
0 ~~~~~0-
LL~~~~~~~~i
-l) I
*U, S ~~~~ gioesuleji 4
\%*%%N%~~~j<(I) 1;ISUSJ1LV~~~~~~~~~~~~~~~~~~
> LLco ) S0) ~~ ~ ~ ~ ~ ~ E0
0~~EM0
0~~~~~~i
60 The To'aga Site
w0.
4 0 0 W
cnD2co-lC CM 0) CD~~C) C
C~~~~~
0w-0
CO
12 -3
-4
-50 10 20m TRAN
-92A0CD)0Q.xw t'
LI.LI.w
[SECT 3
Figure 5.9 Elevation profile along Transect 3, showing the location of Unit 27 in relation to geomorphic features.
approximately 1000 B.C. Only a single occupationphase is indicated (in Layers IIIA and IIIB), fol-lowed by fte accumulation of calcareous sands,mixed with increasing quantities of termgenous, clay-silt sediment in the higher parts of the stratigraphiccolumn. The concentration oflarge clastics in thelower part ofLayer II is probably the result of ahigh-energy storm event. In the most recent deposi-tional phase, the locality has been capped by 60-70cm of colluvium.
Transect 5
Transect 5 lies 100m east of the 1987 baselinewhich incorporates the main excavation trench(Units 1, 4-9) and Units 2 and 3. In 1989, Transect 5was largely in second growth vegetation, with someAlocasia and bananas near the talus slope. Theelevation profile along Traect 5 is shown in figure5.11.
Excavations along Transect 5 commenced withthree units, designated Units 15, 16, and 17, spaced10m apart After these units had been completedand their statigraphic proffles correlated, it becameapparent that the most inland test, Unit 15, hadexposed a deeply buried, thin cultnal depositcontaining a few sherds of thin, orange-slippedpottery. Seeking to sample more of this earlydeposit, another excavation (Unit 28) was opened 10
m farther inland, where the talus slope began to risesteeply. However, in this pit the massive uppercolluvial deposit extended filly 2.4 m deep, makingexposure of the underlying calcareous sandy stratathat contained cultual materials exceedinglydifficult. (Nonetheless, we did manage to carry theexcavation down to 3.6 m, a risky matter in an un-reinforced lxI m pit!) We therefore retmned to theUnit 15 excavation, and expanded it with 1I-mextensions north (Unit 29) and west (Unit 30). Theexcavation of these extensions was complicated bythe partial collapse of the expanded pit walls at onepoint. Notwithstanding this setback, we carried teexcavation of these extensions down to 2.5 m,thereby exposing a larger sample of the early culuraldeposits. Our persistence in seeking an enlargedsample of this deeply buried material was justifiedsubsequently by the msults of 14C dating of acharcoal sample from Layer nI of Unit 28. The resultof 3257-2879 cal B.P. is the oldest date for unques-tionably in-situ cultural materal obtained from theTo'aga site. Indeed, this sanple is penecontempora-neous with the submerged Lapita site of Mulifanuaon Upolu Island.
Excavation Unit 17
Unit 17 was the most seaward excavation alongTrnsectS, situated 56 m inland from the baseline
Excavations 61
UNIT 27: EAST FACE
' " ~~II
~~~Sherds
.,,OD
'): ok ) :?
0.0
0.5
1.0 00.'0
a0.
1.5
2.0
Figure 5.10 Stratigraphic profile of the east face ofUnit 27.
along the road. A detailed profile of te west face isshown in figure 5.12, and an 'exploded' profile ofthe entire unit in figure 5.13. This unit was ofparticular note because of the exposure of a sequenceof gravel house floor pavements ('iliill) in Layer III,associated with several post molds and a hearth. Thestratigraphy as wecorded on the west face was asfollows:Layer I: This 'greasy' midden deposit of sandy clayloam contains much dispersed coral 'iliili gravel andshll middenm It has a very dark gray color (10YR 3/1).Ihecontact with Layer is gradational over 2-3 an.Layer fl: A compact deposit of 'ili'ili gravel occurs
here in an ashy, brown (10 YR 5/3), sandy matix.This appears to be a tick, artificialy laid housefloor deposit and contains well-preserved shellmidden. Four post molds visible in te explodedsection (fig. 5.13) are filled with Layer II materialand were cut thrugh the undedying Layer IIIpavements. In addition, a hearth visible in the eastand south profiles lies at the contact of Layers II andIll.Layer m: This thick deposit is made up of duteesuccessive ili'ili pavements, laid directly over eachother. The paving matenals range from smallwaterwom coral pebbles (ca 0.5-1 cm diameter)down to very coarse coral sand (1-2 mm diamneter).There are discontinuous bands of black ash and finecharcoal trughout the deposit as well, probablyderiving frm hearth rake-out events. The lowestpavement (Layer HIC) lies dircly on Layer IVA,with a very sharp, abrupt, flat contac All of thepavements were pale brown (10 YR 7/3). Theindividual sub-components were: IIA, faidty cleancoral gravel; HIB, coral gravel mixed with sand andashy beds; and HIC, coarse coral sand and gravel infine beds. These ree gravel deposits presumablyrepresent successive repavements of a house floor.Buck (1930:68) describes the traditional Samoanpractice of "levelling off the upper surface of theplatform within the house and covering it with smallstones ('iitiI). ....he larger coral gravel was pickedout on the beach and carried up in baskets. It oftentook some time to get a sufficient quantity. ASamoan woman pickdng over the coral gravel mightremind one of a woman of a higher culture selectinga carpet."Layer IVA: This deposit consists of strong brown(7.5 YR 5/6) calcareous sand with a mixture of finevolcanic silt-clay. The admixture of silt-claysuggests surficial alluvial deposition of fine-grainedsediment emanating from one of the colluvial fansinland, perhaps after a torrential rain. Some charcoalflecking is also presentLayer IVB: The grayish brown (10 YR 5/2)calcareous sand of this deposit has small dispersedcharcoal flecks. The deposit had been distubed bythe deposition of Layer IVA, and is thereforediscontinuous. It represents an old paleosol horizonon top of the beach ridge following stabilization.The contact with Layer V is iregular and diffuse.Layer V: This is a massive, structureless deposit of
62 The To'aga Site
6E 4C0-W 2
co
0-
(0-O -4I2
w
cn0c-J0(0)CO)-j Lll
Ico)IL(I')a _:
D DLL
ww
-t
0 20 40m& a . .a
TRANSECT 5
Figure 5.11 Elevation profile along Transect 5, showing the locations of Units 28, 15, 16, and 17 in relation togeomophic features.
cD
C*
0)c
.)Cu(0)co
0)qm
fine to medium-graired calcareous sand (white, 10YR 812) with a minor component of volcanic lithicfragments. It is cultally sterile. The contact withLayer VI is gradational.Layer VI: This layer contains coarse-grainedcalcareous sand (white, 10 YR 812) with a greaterfrequency of volcanic lithic grins. The deposit alsoincorporates two distinct bands of fist-sized coralcobbles.Layer VII: Composed of fine-grained sand with adistinctly 'salt-and-pepper' mixture of calcareousand volcanic grains, this layer maiked te base of theexcavation which was reached at 225 cm belowsurface.
Unit 17 did not produce a large quantity ofcultural materials. One bone ofSus scrofa fromLayer I was the only identifiable vertebrate faunalspecimen. Shell midden was present in Layers I-Ill,with the highest concentration in Layer III (seechapter 13 for details).
Unit 17 yielded a single fishhook fragment (thepoint of a jabbing hook) from Layer II. No potterywas recovered from this unit, suggesting depositionof dtese strata after the abandornent of pottery
production in Manu'a.
Excavation Unit 16
Unit 16 was positioned 10m farther inlandalong Transect 5 from Unit 17. The straigraphicprofile of the west face, shown in figure 5.14,follows:Layer IA: This is the A horizon-garden soil. On thesurface one finds much leaf litter with numerousanthropophilic snails in the genera Subulina,Lamellaxis, Succinea, and Pleuropoma.Layer IB: The very dark gray (10 YR 3/1) sandyloam here is a cultural midden deposit. Parentmateral consists primarily of calcareous sand, with aminor component of fine clay-silt. The dar1k graycolor results from the inclusion ofmuch finelydispersed charcoal and other organic material. Thelayer contains much shell midden (9.4 kg) and somedispersed 'ili'ili gravel. The contact with Layer IC isgradational.Layer IC: The very daik grayish brown (10 YR 3/2) calcareous sand in this stratum has some finecharoal flecking. The layer appears to represent an
Exavataons 63
UNIT 17: WEST FACE
* :. I X . - ; ;
0~~~~~~~~~~~f ...','0,.-
WBWA
Branch Coral* VI.
Coral CoWes
. ' ' *. .
* VII..~~~~*..
0.0
0.5
0
1.0 c._
a0
1.5
2.0
extremely non-concentrated culturl deposit. Ityielded a few sherds during excavation, and onesherd was visible in situ in the west wail duringprofile recording (see figure 5.14). Several volcanicfire-altered oven stones were also noted in this layer.Except for its slightly darker color, this deposit islithologically hardly distinguishable from Layer II.It probably represents the old beach slope frontingeither the Layer IIB or LayerUD occupadons in Unit15. The lower contact with Layer IV is gradationaland unclear.Layer IV: The white (10 YR 8/2) fine grainedcalcareous sand in this deposit contains volcaniclithic grains ('salt-and-pepper' sand).
Unit 16 produced considerable culual material,including 741 fish bones, as well as rat, turtle, andbird bones. Shell midden was most heavily concen-trated in Layer I (9.4 kg), with lesser quantities in thedeeper layers. Full details of the faunal analysis arepresented in chapter 13.
Unit 16 yielded a worked Tridacna shell(possibly an adz preform) and a shell scraper fromLayer IB. Artifacts from Layer III include a shellbracelet fragment, a Turbo shell fishhook fragrnent,obsidian (including a red and black banded speci-men), and basalt flakes. In all, forty-four sherds wasrecovered from Unit 16. These include twelvethickware sherds in Layers I and H, one of which (inLayer I) has a parallel-rib, paddle-impressed exteriorsurface. Layer III yielded twelve (37%) thinwaresherds and twenty (63%) thickware sherds.
Figure 5.12 Stratigraphic section of the west face ofUnit 17.
old stable surface (paleosol A horizon) of the formerbeach ridge. The surface is somewhat disturbed andrewoiked by the overlying Layer IB occupation.The contact with Layer II is irnegular, and root castspenetat from Layer IC into Layer II, indicative ofvegetation on the former stable surface.Layer II: This white (10 YR 8/2), massive, stuc-ureless deposit of very fine-grained calcareous sandincorporates some fine volcanic lithic fragments. Atthe base of Layer II is a zone of fist- to head-sized,waterwom coral cobbles indicative of a high-energystonn event. The contact with Layer Ill is veryunclear and gradational.Layer m: This is a very pale brown (10 YR 7/3),
Excavation Units 15129130
As indicated above, Unit 15 was excavatedalong withUnits 16 and 17 on Trnsect5. When adeeply buried, thin cultural deposit containing thin,red-slipped pottery was encountered, we decided toexpand Unit 15 by excavating two adjacent squares,designated Units 29 and 30. The straigraphydescribed below, and shown in.figure 5.15, is that ofthe west face of Unit 15.Layer IA: The upper 10 cm of Layer I is composedof dark reddish brown (2.5 YR 3/4) colluvium. Thisupper zone is slightly humic, with anA soil horizonat the surface. The deposit is a poorly sorted, veryrubbly mixture ofvolcanic sand and clay, full ofangular to subangular gravel and small cobbles.This deposit is the tongue ofa colluvial fan emanating
64 The To'aga Site
UNIT 17
w N E
~~ ~ ~ Po tm ld
VI
V.
Figure 5.13 Exploded stratigraphic section of all faces of Unit 17, showing postmolds and hearth associated withLayer II.
from a small hanging valley above the Le'olo cliff.Layer IA grades into IB.Layer IB: Although almost identical to Layer IA,this layer lacks the organic, humic component. Thelower 5-10 cm of IB is noticeably more clayey, witha lower frequency of larger clastics.
Layer II: This 'greasy' midden deposit is a verydark gray (5 YR 3/1). The parent material is prima-rily calcareous sand with some silt-clay admixture.The dark color and greasy textu result from theincorporation ofmuch finely dispersed ash, charcoal,and other organic material. The deposit containsabundant fist-sized, volcanic, fire-altered ovenstones. Shell midden is also present (3 kg) but issomewhat chalky and chemically degraded. The
contact with Layer IB is straight and abrupt; thatwith Layer lIIA-I is irregular, varying from abrupt togradational. The high carbon content and thepresence ofoven stones suggest that this layerrepresents a cookhouse activity area.
Layer IIA-1: The reddish-yellow (7.5 YR 6/6)calcareous sand of this deposit has pockets ofpinkish-gray sand (7.5 YR 6/2). In addition toconsiderable mottling, various irregulanties addisturbaces appantly resulted from the Layeroccupation on an old, stabilized beach ridge surfacerepresented by this layer. Root casts extend fromIIIA-l into iIIA. The contact with Layer IIIA isshaip but highly irregular. This layer is interpretedas a formerly vegetated, stabilized dune surface(paleosol).Layer IIA: This sterile deposit of white (10 YR 8/2) calcareous sand is well-sorted with a medium-sized (2 phi) mode and has a minor admixture ofvolcanic lithic grains ('salt-and-pepper'). Thecontact with Layer IUB is very sharp but highlyirregular ('wiggly').Layer IUB: This pale brown (10 YR 6/3), verynon-concentrated occupation deposit is indicatedprimarily by its slightly darker color and the
S0.0
0.5
co000
1.0 c
c
1.5
2.0
I I
Excavations 65
UNIT 16: WEST FACE
...S,.IB: Voicanlci Boule
IC
. . .U* * II-
I Root Mold
Coral Cobbles
(9
Vocanic Oven Stones *
IV* 6. Iv.
Water Table
r 0.0
0.5
1.0to0
._
a0a
1.5
2.0
2.5
Figure 5.14 Stratigraphic section of the west faceof Unit 16. Black squares indicatesediment sampling locations.
Thinware
Layer II
Layer IIIALayer IIIBLayer IIID
3 5%8 24%7 13%19 38%
presence of some marine shell midden. Thedeposit is medium- to coarse-grained, and lesswell-sorted than Layer IIIA. The lower contactwith Layer IIIC is irregular and slightly moregradational than the top contact. Lithologically,this is the same as Layer IIIA.Layer mc: The white (10 YR 8(2). calcareoussand of this stratum is essentially identical toLayer IIIA but contains a higher frequency ofcoarse grains (I phi).Layer IUD: In Unit 15, this deposit appearedonly discontinuously, as pockets in the west faceof the section. These were pale brown (10 YR 6/3), very similar to the Layer IIIB deposit. In theeast face of Unit 15, the zone was continuous.This is the deposit that yielded thin, fine-tem-pered, red-slipped pottery, together withthickware, during excavation.Layer IV: The coarse- to very coarse-grained,white (10 YR 8(2) calcareous sand that is foundhere is poorly sorted, having a considerablemixture of volcanic lithic grains ('salt-and-pepper' appearance) and some small volcanicpebbles. The deposit also contains consider-able quantities of branch coral fingers (waterrolled) and coral pebbles. The presence of theselarger grained sediments and the lack of sortingsuggest that this was a relatively high en-ergy, exposed beach depositional environ-ment.
Excavation of Units 15(29/30 yielded anarray of artifacts that include two shell fishhooktabs (Layers II and IIID), cut pearlshell (LayerII), a shell bracelet fragment (Layer IIIB), anunfinished fishhook (Layer IIIB), and numerousflakes of basalt and obsidian (Layers II, IIIB, andIIID).
A total of 200 sherds was recovered fromthese units. The distribution of these sherds bylayer was as follows:
Thickware
58264831
95%76%87%62%
Total
61345550
66 The To'aga Site
UNIT 15: WEST FACE
.Trkdacnai,'OvenStones
. 0 ,.I' A.-
_L~fB>U/mc. !
0 v .IV0
M.
Figure 5.15 Stratigraphic section of the west faceof Unit 15. Black squares indicatesediment sampling locations.
Two thickware direct rims from Layer HIA have
impressed lips, which appear to have been madewith a carved paddle. Red slip is resticted tothinware (2 sherds only) from Layer II). As thefrequencies above indicate, there is a generl trendtoward increasing relative frequency of thickware inproporton to thinware over time in this unit.
Excavation Unit 28
Unit 28 was excavated 10m farther inland from
Unit 15 in an effort to trace the deep Layer IIIDoccupation in Unit 15, inland underte steeply nsingcolluvial fan. Clearly, the depth of colluvialoverburden which would have to be removed wassubstantial, making this the most inland position inwhich excavation could be attempted witout the useofheavy machinery. The stratigraphy describedbelow is that of the norh face.Layer I: This massive deposit ofdark reddish-brown (25 YR 312) clayey colluvium is between2.2-2.4 m thick and contains numerous, large,angular volcanic cobbles and boulders. No beddingor lenses were present, although clay contentincreases toward the base of the stratum. Free ofcultural material, this colluvial deposit representsone or more events of mass wasting (landslides)from the adjacent volcanic cliffs.Layer HA: This discontinuous zone (pockets) ofcalcareous sand has been discolored (7.5 YR 6/6) byeluviation of clay from the colluvium above (LayerI). A small amount of cultural material was recov-ered, including pottery, shell and bone midden, andcharcoal.Layer TIB: The white (10 YR 812) calcareous sandin this stratum has waterwom coral cobbles and afew coral boulders. This layer contains a minoradmixture of volcanic sand grains ('salt-and-pepper'lithology) as well as cultural material.Layer IC: The pale brown (10 YR 6/3) calcareoussand of Layer HC is similar to IIB in origin, but isdistinguished by a darker color explained by teaddition of organic matter and some clay, resultingfrom human occupation. Its relatively abundantcultural material includes midden ad pottery (seebelow). Layer IIC of Unit 28 is comparable to LayerIlD of Units 15129/30.Layer mI: This layer is a white (10 YR 812). coarse-grained calcareous sand with abundant waterwomcoral cobbles and fresh (unwom) brnch coralfingers. Layer III yielded less cultural material thanIIC and clearly is culurally sterile at its lower depths(3.3-3.4 m below surface).
Artifacts from Unit 28 came primarily fromLayer IIC. These include worked shell, basalt flakes,obsidian flakes, an echinoid-spine abrader, and dueeCypraea shell dorsa found artificially nested to-gether, which may be parts of an octopus lureapparatus (see Kirch, chapter 1 1).
A total of 127 sherds was recovered, with thefollowing stratigraphic distribution:
v-k Q ,
Excavatio 67
ThinwareLayer IIALayer IIBLayer IIC
7 30%51 49%
Thickware
The decline in thinware in proportion to thickwareover time is notable, as is the overll decrease indensity of ceramics. Included in the above sherdcounts are two thinware rims from Layer IIB, andnine thinware and five thickware rms from UC.
One of the thickware rims has an impressed lip.Eight thinware sherds, all from Layer IIC, carry a redor orange slip. Since the ceramic assemblage fromLayer HB dates to 1308-930 cal B.C. (Beta-35601),Layer UC must be of equal or possibly greaterantiquity. This suggests that in the Manu'a Islands,te ceramic trnsition from Early Eastem Lapita(calTying dentate-stamped decoration) to thin,plainware must have occurred relatively rapidly atthe end of the second millennium B.C.
Radiocarbon Datesfrom TransectS
Three 14C age deterninations were obtainedfrom Transect 5 samples. Ihe oldest date (Beta-35601) comes from charcoal at the Layer IVIllinterface in Unit 28, associated with the early, thin,red-slipped pottery. This sanple has an age of 3257-2879 cal B.P. at one standard deviation. A sample ofmarine shell midden (Turbo setosus) from a
cookhouse activity zone, Layer II in Unit 15, isassociated with thick, coarse-tempered pottery. Thisyielded an age of 1631-1477 cal B.P. at one standarddeviation (Beta-35924). The third sample (Beta-35600) was obtained from the Layer Ill 'ili'ilipavement in Unit 17. This sample, which had noceramics associated, yielded an age of 1256-1007 calB.P. at one standard deviation. Further details ofthese radiocarbon dates and their implications are
provided in chapter 6.
Transect5: Sunmary of the Depositional Sequence
The correlation diagram of the Transect 5
excavation units (fig. 5.16) also shows the relation-ship of these units to contemporary shoreline and sea
level features. The general depositional sequencealong Transect 5 can be reconstructed as follows:Stage 1 (> 3200-2800 cal B.P.): A narrow coastal
bench at the base of the steep talus was fomied. Theactive shoreline at this time would have been in the
vicinity of Units 16-17, considerably inland of the
modem shoreline. The 'salt-and-pepper' lithologyofthe beach ridge sediments indicates exposure ofvolcanic headlands along the coasline, providing a
source of volcanic lithic grains. In addition, thepresence of larger clastics (coral cobbles, branchcoral fingers) indicates a fairly high energy shore-line.
Stage 2 (ca. 3200-2800 cal B.P.): Humans began tooccupy the narrw bench formed during Stage 1,resulting in non-concentrated midden deposits thatcontain thin, fine-tempered, orange- or red-slippedpottery in Units 28 and 15129/30. The main area ofoccupation was probably farther inland from Unit28, and thus is now deeply bured under talusrockfall and colluvium. The deposits exposed inUnits 28 and 15/29/30 appear to represent theseaward periphery of such an occupation, down theslope of the former beach ridge toward the oldshoreline. Archaeological exposure of the putativemain occupation zone would require the use ofheavy machinery, since as much as 5-15 m
overburden ofboulder talus and colluvium wouldprobably have to be removed.Stage 3 (ca. 2800-2000 cal B.P.?): Deposition ofcalcareous sands onto the beach ridge continued,with significant seaward progradation of the shore-line occuning late in this phase which resulted in thedeposition of the basal deposits in Units 16 and 17.During this stage, a second occupation phaseresulted in the midden deposit of Layer IIIB in Units15129/30.Stage 4 (ca. 2000-1600 cal B.P. ?): A stabilizedland surface formed during these four centuriesover the now wider and prograded coastal terrace,marked by the paleosol horizon (Layer IIIA-I inUnits 15/29/30; Layer IC in Unit 16; Layer IVBin Unit 17).Stage SA (ca. 1600-1400 cal B.P.): The stabilizedcoastal terrace in the vicinity of Units 16 and 15/29/30 was occupied during this terminal phase ofceramic manufacture and use on Ofu Island. The
116
52
100%70%51%
Total1
23103
68 The To'aga Site
UNIT 15 UNIT 16 UNIT 170.0
- 0.5
1.0
1.5 e002
2.0 *r
2.5
3.0
3.5
Figure 5.16 Stratigraphic correlations between Units 15, 16, and 17 on Transect 5.
Layer II deposit in Units 15129/30 is interpreted as a
cookhouse activity area, while the contemporaneousLayer lB in Unit 16 is a concentrated midden.Stage SB (ca. 1300-1000 cal B.P.): Acermicoccupation on the coastal terrace in the vicinity ofUnit 17 resulted in the construction of a low housemound fonned by several successive gravel ('ili'ili)pavements.Stage 6 (< 1000 cal B.P.): A tongue of clay-siltcolluvium was deposited out onto the coastal ten-ace,probably due to increased up-slope forest clearance,agriculural acdvity, and subsequent erosion. At thistime the coastal terrace was used for tree-croppingand shiffing cultivadon, continuing into te presentera.
The stratigraphic sequence along Trnsect 5 andits corelation to modem sea level, as well as the keytopographic features of the contemporary coastline(reef flat, active beach ridge) also provide keyevidence for testing the morphodynamic modeldeveloped in chapter 4. As indicated in figure 5.16,the oldest cultural deposit at TransectS is the LayerIIID occupation in Unit 15, yielding thin, fine-tempered, orange-slipped pottery, between 180-200cm below surface. In Unit 28, this occupationappeared at the base ofLayer II, between 290-300cm below surface, and was 14C dated to 3257-2879
cal B.P. When corelated to modem sea level, thisoccupation zone lies at virtually the same elevationas mean high tide and about 1.8 m above the reefflat. These elevation relationships provide incontro-vertible evidence for tectonic subsidence, as the insitu cultural matenials in Units 15 and 28 werecleatly deposited on a narrow terrace or beach ridgethat must have been at least 1 m, and more likely 2m, above te sea level at 3 kyr B.P. Given a +1-2 mhigh sea level stand at 3 kyr B.P., this means ftat fteTo'aga site has undergone between 2-3 m of tectonicsubsidence over fte past three thousand years, assuggested by the morphodynamic model developedin chapter 4. In other words, ifwe retrodict theelevation ofte early beach-ridge occupation at 3kyr B.P. to +3 m (based on our hypothesized subsid-ence rate of 1 m/kyr), this would put the occupationsurface between 1-2 m above the 3 kyr B.P. sea level(which itself was +1-2 m above the present level).The altemative hypothesis-that there was notectonic subsidenc-would require the depositionofthe occupation deposit under water, a physicalimpossibility given the sedimentological evidence.In short, the Transect 5 stratigraphic profile stronglyconfilrs several key elements of the morpho-dynamic model of coastal terrace fonration devel-oped in chapter 4.
Excavation 69
Transect 7
Transect 7 is situated 300m east of the 1987excavation area. The coastal terrace here is fairlynarrow, only about 65 m from the crest of the activebeach ridge to the base of the steep talus slope. Theelevation profile along Transect 7 is shown in figure5.17 (a vegetation transect is given in chapter 2,fig. 2.5). The area was primarily in bananagardens under coconut and breadfruit trees in1989.
Two tests were excavated along this transect, 10m aparL Unit 18 was located at the base ofthe talusslope, while Unit 19 was situated on the flat depres-sion in the center of the arboricultural zone. Unit 18was excavated to 1.4 m below surface, at whichdepth the presence of large basalt boulders forced usto tenninate the excavation. Unit 19, on the otherhand, was taken to a depth of 2.2 m, and a thin, non-concentrated cultural deposit was exposed near thebase.
Excavadon Unit 18
The following strata were discemible in Unit 18:
Layer IA: This massive deposit of colluvial clayhas numerous inclusions of subangular to angulargravel and pebbles. It is weak red to dusky red(2.5 YR 3-412) and very compact and sticky.Layer IB: This layer contains the same material asLayer IA, but with an admixture of snall quantitiesof calcareous sand grains. Some charcoal flecking(arge chunks) was observed in a 10 cm thick zonebetween Layers IA and lB. The boundary betweenIA and IB is gradational over this zone of charcoalflecking. The contact with underlying Layer II isdiffuse and inregular, over a 2-3 cm zone.Layer II: Fie-grained calcareous sand with someclay admixture due to eluviation from Layer IBmakes up Layer l. This pale brown (10YR 6/3) layerincorpomtes massive volcanic cobbles and boudderswhich forced a temiination ofthe excavation.
Excavation Unit 19
Unit 19 was positioned 45 m inland of thecoastal road, in a relatively level area, sunrounded bya few large talus boulders. The stratigraphy of thewest face is described below and is illustrated infigure 5.18:
Figure 5.17 Elevation profile along Transect 7, showing the locations of Units 18 and 19 in relation to geomorphicfeatures.
6w0.
4 coCIOD
E 2<
2OCu
111
0c
0 -2-m
-4
-6J
c w
W aCo CC
a) I-1
wwcr.
TRANSECT 70 10 20mI
coIV,, 0)
9-
:L-l 4-0c c
:3
70 The To'aga Site
UNIT 19: WEST FACE
.
InIY
.~~IB
Turtio ~
VI
Figure 5.18 Stratigraphic section of the west face ofUnit 19. Black squares indicate sedimentsampling locations.
Layer IA: This dark reddish brown (5 YR 3/2),poorly sorted colluvial deposit has some subangularvolcanic pebbles, but the general absence of gravelsuggests deposidon of the sand to clay-sized par-ticles by sheet wash at the margin of a colluvial fan.Layer IA grades into IB over a 5 cm zone.
Layer IB: This strum contains reddish-brown (5YR 5/3), fine clay mixed with calcareous sand. The
calcareous sand component increases with depth.The contact with Layer II is sharp and only slightlyirregular.Layer U: The very pale brown (10 YR 7/3), veryfine-grained calcareous sand of this layer is cultur-
ally stenle. This deposit appears to represent a faidylong period of beach ridge stability, probably undervegetation. (The very pale brown color is virtuallyidentical to that of beach ridge deposits underPannus and Hibiscus just inland of the modembeach.) The contact with Layer III is diffuse andirregular.Layer IH: This stratulm is composed ofpale brown(10YR 6/3), medium- to fine-grained calcareoussand which is well-sorted with scattered coral andvolcanic pebbles and cobbles. Layer III is barelydistinguishable from Layers n and IVA. The contactwith Layer IVA is very irregular. Layer IIn appearsto represent another phase of beach ridge stability.Layer IVA: The white (10 YR 8/2), medium- tofine-grained calcareous sand of this layer is well-sorted, lacks larger inclusions, and is cultuallysterile.Layer IVB: This layer with its very pale brown (10YR 7/3), medium- to fine-grained calcareous sand,probably represents a period of beach ridge stability.Layer V: The color of this cultural deposit rangesfrom dark grayish-brown (10 YR 4/2) to grayish-brown (10 YR 512). This non-concentrated middenconsists of medium- to fine-grained calcareous sandstained with charcoal and ash. There are consider-able quantities of dispersed charcoal flecks andcharred wood fragments, some quite large (5-10 cmdiameter). A Turbo shell fishhook was excavatedfrom Layer V at 164 cm below surface. No potterywas present The contacts with Layer IVB and withVI are both quite irregular but fairly distict.Layer VI: This layer contains white (10 YR 8/2),coarse- to fine-grained calcareous sand and iscultally sterile. Excavation was terminated at 220cm below surface. An auger was then used to coreto a depth of 385 cm below surface, at which pointthe water table was encountered. No cultualmaterials were observed in the augured sediments.
Unit 19 was notable also for the presence of alarge pit, sectioned in the east and south faces of thesquare, as shown in figure 5.19. The pit, which wascut from Layer I down trugh Layers II and HI intoLayer IV, has a mixed fill incorporating Layer IBsediment. The pit is straight-sided, with a flat base.There is no evidence of burning or use as an ovenpit, nor was the feature filled with midden or trash.In shape and size, the pit is consistent with Iua'imasi, subterranea silos for the fernentation and
Excavation 71
UNIT 19
E
Figure 5.19Stratigraphic section ofthe east and south facesof Unit 19, showing thelarge pit cut from Layer Iinto Layers II-IV.
storage of breadfruit paste or masi (Buck 1930:132-33; Kirch 1984:132-35; Cox 1980). This function isalso suggested by the presence of large volcaniccobbles in the pit fill; such cobbles are used to caplua'i masi pits after filling with breadfruit. The
To'aga area is dotted with shallow circular depres-sions, ranging from 1-2 m in diameter, which ourinfonmants described as fonner masi pits.
Unit 19 produced a modest faunal sample (seeNagaoka, chapter 13), and a Turbo shell fishhookfrom Layer V. No other arfifacts or pottery werepresent. Although charcoal and Turbo shell sampleswere collected from LayerV for radiocarbon dating,these have not been processed due to budgetarylimitations. We are thus uncertain wheter te
absence of pottery in LayerV reflects samplingenror, or whether this deposit post-dates the cessationof pottery use on Ofu (i.e., after about 1500 cal B.P.).
Transect 9
Transect 9 was positioned 500m east of the
baseline origin point. Inland of the road, the coastaltenrace here was in dense banana plantations underbreadfruit and coconut. No surface archaeologicalfeatures were evident, other thwa a filled-in lua'imasi pit (1.5 m diameter, 30 cm deep depression)between Units 21 and 22. The elevation profilealong Trnsect 9 is shown in figure 5.20.
We initially laid out three units for subsurfacesampling along Transect 9: Units 20, 21, and 22,situated at 10m intervals. Unit 20 was posidoned atthe base ofthe talus slope, with Units 21 and 22 onthe flat between the talus and the road. Unit 20penentated a thick series of cultual deposits betweenabout 1-2.6 m below surface, yielding an aray ofthin, fine-tempered ceramics (some with notchediims) and thickware, as well as fistooks, onaman,and odter antifacts. We therefore decided t expand thistest in order to enlarge our sample of the compara-tively rare cultual materals recovered from thesedeposits. Unit 23 was dterefore opened adjacent toUnit 20 on the north (inland) side (fig. 5.21). Thus atotal of4 m2 was excavated along Transect 9.
S0.0
0L.00
-1.0 *E
0
-2.0
I I I
72 The To'aga Site
Figure 5.20 Elevation profile along Transect 9, showing the locations of Units 20/23, 21, and 22 in relation to
geomorphic features.
Excavation Units 20/23
The stratigraphy of this 1x2 m excavation wasrecorded along the west and north faces, as depictedin figure 5.22, and described below:Layer IA: This stratum consists ofdusky red (2.5YR 312) colluvium; the upper 10 cm is humic gardensoil. The very poorly sorted, compact, sticky, very
plastic sand-to-clay material has abundantsubangular volcanic gravel- to cobble-sized inclu-sions. The contact with Layer IB is gradational.Layer IB: This dark reddish-brown (5 YR 3/2)massive colluvial deposit is poorly sorted and hasabundant larger volcanic clastics. Calcareous sandgrains and occasional charcoal flecks are dispersedth}oughout. The deposit also contains a low fre-quency of dispersed, chalky shell midden (due to
chemical decomposition in the humic soil matrix)and occasional waterwom MiMi'ili coral pebbles.These cultural materials suggest some low intensityuse of the area during the perod of colluvial deposi-tion. This deposition was presumably gradual andincremental, and not a single event. The contactwith Layer IC is gradational over a 2 cm zone.
Layer IC: The dark reddish-brown (5 YR 3/3),compact, sticky silty-clay of this stratum lacks largerpebble-sized inclusions. The clay appears to repre-
sent a single depositional event, presumably result-
ing from sheet wash (fluvial mode of deposition)following heavy rains. The contact with Layer IIA isabrupt and slightly irregular.Layer IHA: This stratum is composed of darkreddish-brown to reddish-brown (5 YR 34/4),coarse- to fine-grained, poody sorted, calcareoussand mixed with fine clay-silt and is marked byabundant charcoal flecking. This appears to repre-
sent a paleosol or fonmer stable surface of the beachridge. The contact with Layer IIB is gradational.Layer UB: This layer contains yellowish-red (5 YR5/6) to reddish-yellow (7.5 YR 7/6) well-sorted,medium- to coarse-grained, structureless calcareoussand mixed with reddish clay and is culturally sterile.The clay content decreases with depth, with the baseof the layer consisting of nearly pure, medium-grained sand. The contact with Layer IIIA is abruptand irregular.Layer MA: This cultural midden deposit is verydaik gray to very dark grayish-brown (10 YR 3/1-2)and has a sandy loam texture. The dark coloration ofthe calcareous sand matrix results from a highcarbon and organic content. This layer was associ-ated with a large earth oven feature, from which a
14C sample was obtained (see below). The oven andadjacent sediment contained heavy concentrations(more than 2 kg) of the spines of the large slate-pencil sea urchin (Heterocentrotus mamnillatus) and
6
0 C
1C cO- 22 0c
C I-0 \lc- 2 -L
co L'IW-4
-6 rI,T A A
F-J
wwCc
u 1U 20m 11AtIobrikl :iXTOVrP a
Excavations 73
Figure 5.21 Expansion of Unit 20 into Unit 23; removalof the thick colluvial deposit in progress.
of fire-altered volcanic oven stones. This stratumclearly represents a cookhouse or food preparationactivity area The contact with Layer IIIB is grada-tional.Layer IUB: In this layer, a dark brown to brown(10YR 4/3), thick, cultural midden deposit ofcalcareous sandy loam incorporates numerous, large,subangular, volcanic cobbles. Near the top of thelayer is a distinct lens ofcompact grayish-white ash,about 1 cm thick. This ash lens was discontinuousover the lx 2m excavation unit. The ash lens iscapped by 1-2 cm of clean white beach sand,probably an artificially deposited house floor. LayerilB contned a heavy concentration ofshell and bonemidden, ceramics, and other portable artifacts. Thecontact with Layer IIIC is gradational over 5-10 cm.
Layer mC: Subangular volcanic pebbles andcobbles are contained in the light yellowish-brown(10 YR 6/4) calcareous sand midden of this stratum.The matrix consists of coarse- to medium-grainedcalcareous sand. This layer is essentially a lowerfacies of Layer IIIB, distinguished primarily by alower concentration of midden and organic staining.The contact with Layer IV is gradational.Layer IV: The white (10 YR 8/2), coarse- tomedium-grained, 'salt-and-pepper' sand (calcareousgrains with an admixture of volcanic liftic grains) ofLayer IV contains abundant large clastics consistingof branch coral fingers, and waterwom volcanicpebbles and gravel. It is culturally sterile.
An earth oven was exposed in Layer IIIA ofUnit 23, as noted above, and is illustrated in figure
74 The To'aga Site
UNIT 20w
UNIT 23w
UNIT 23N
IA XI I 1 1 1v 1IN
ILBE K' K K'~~~~~~~Ahen
v~~~~~~
C3~~~~
Stratigraphic section of the west and north faces of Units 20f23. Black squares indicate sedimentsampling locations. "C" indicates coral; "V" indicates volcanic.
5.23. The oven consisted of a circular pit, with adiameter in excess of 80 cm, and a depth of 38 cmfrom the rim to the base. The oven pit fill consisted
of fire-cracked volcanic oven stones (fist-sized) witha few larger stones at the base, charcoal, and ash.Both the oven fill and the sunTounding middencontained large quantities of echinodenm spines and
Thinware
Layer IIBLayer IIIALayer IIIBLayer IIIC
5
85032
10%8%21%28%
test fragments, particularly of the slate-pencil sea
urchin (Heterocentrotus mammllats), and severalsmaller echinoid species.
Units 20/23 yielded a large sample of potteryand a number of noteworthy portable artifacts. Atotal of 499 sherds was recovered, with the followingstratigraphic distribution:
Thickware
4587
19181
90%92%79%72%
Total
5095241113
0.0
000
1.0 c
2.0
.2.0
Figure 5.22
Excavations 75
Figure 5.23 View into Units 20/23, showing circular pit orpostmold features filled with Layer IIB sedi-ment, exposed at the contact with Layer IIIC.
These frequencies confinn a decrease in thinwarerelative to thickware also noted from other tmnsects(see above). The sherd assemblage from Units 20/23includes one Wtckware rim from Layer IIB, sixthickware rims and one thinware rim from LayerhIA, twelve thickware and six thinware rims fromLayer HIB, and five thinware rims from Layer HIC.None of the thickware rims have impressed lips, andall were recovered from Layer IIIB. Of499 sherds,15 are red-slipped (on thinware only) and wererecovered from Layers IIIA, IIIB, and IIIC. Onesmall thinware body sherd from Layer IIIC hasincised lines on the exterior, but no pattem isdiscemible.
Several Turbo-shell fishhooks were recoveredfrom Layer III, including one with a distinctly bent
shank similar to early Eastem Polynesian fonns (seeKirch, chapter 1 1 for further discussion). The butt ofa plano-convex section adz (Samoan Type V) wasexcavated from Layer IIIB. Layer IIIC produced anunfinished ring of Tridacna shell which evidentlybroke in half during the process of manufacture. Atthe contact of Layers IIIB and IIIC, we also recov-ered an abrading stone designed for the manufactureof small Conus-shell beads. All of these finds arefurther described and illustrated in chapter 11.
Excavation Unit 21
Unit 21 was positioned 10m seaward of Units20/23, at essentially the saime elevation above sealevel. The profile of the south face is illustrated in
76 The To'aga Site
figure 5.24, and described below:Layer IA: This dusky red to weak red (2.5 YR 34/2) massive colluvial deposit is pnimanly clay withsome large volcanic cobbles and talus boulders andsome smaller subangular volcanic inclusions. It isvery sticky and plastic. Small quantities of chalkyshell midden are dispersed thrughout the deposit.The contact with Layer IB is very gradational over10-15 cm.Layer IB: In this mixture of fine clay and calcare-ous sand, the sand content increases with depth.Some shell midden was noted near the top of thedeposit, but the layer becomes culturally sterle nearthe bottom. There are many discretely dispersedflecks and chunks of wood charcoal, probablydeposited with the clay, and suggestive of forestclearance/burning up slope. The contact with LayerIIA is quite irregular and somewhat diffuse.Layer HA: This stratum is composed of very palebrown (10 YR 7/3) calcareous sand. There is aminor lithological component of volcanic lithicgrains.Layer UB: The sandy midden deposit of Layer IIBis grayish-brown to dark grayish-brown (10 YR 4-5/2). Contacts with both Layers IIA and IIC areirregular (wavy) but fairly distinct. This depositcontains large quantities of Heterocentrotusmamillas spines, some fire-altered volcanicstones, shell midden, bone, and ceramic sherds. Thislayer appears to correlate with the thick Layer IIImidden deposit in Units 20/23, being a seaward'pinching out' of this occupation zone in the direc-tion of the former beach slope.Layer IIC: The white (10 YR 8/2), fine-grained,calcareous sand of this stratum has a minor compo-nent of volcanic lithic grains. The layer is culturallysterile and represents a beach slope depositionalenvironment.
The Layer IIB midden yielded a large faunalassemblage, including 13.1 kg of marine shell, 1,803fish bones (including a large number of spines of thepuffer fish Diodon hystrix), rat, bird, and turtle (seeNagaoka, chapter 13 for further details).
Unit 21 yielded several artifacts of worked shelland a shell omnament (see Kirch, chapter 11), allfrom Layer IIB. Pottery from IIB includes three(15%) thinware and 17 (85%) thickware sherds. Norims, decorated sherds, or red-slipped sherds werepresent.
UNIT 21: S FACE
I7IhIA nic Slab l Turb
/+I -ItE 2 i/+IA
Volcanic
f~~~/,:7|ImA
HA . .ER.
Oven Stones
0* A2
uc Coral
.~~~~,:~
0.0
-0.5
1.0to
I._0
0.0
-1.5
-2.0
2.5
K-
Figure 5.24 Stratigraphic section of the south faceof Unit 21. Black squares indicatesediment sampling locations.
Excavation Unit 22
Unit 22 was positioned 10 m further seawardfrom Unit 21, and at a slightly higher ground
Excavation 77
elevation (on the inland slope of the present beachridge). The noith face of Unit 22 is illustated infigure 5.25 and described below:Layer I: The very daik grayish-brown (10 YR 3/2),sandy loam of thissm has a 'greasy' texture.The deposit consists primarily of calcareous sandwith a minor component of fine silt-clay. Dispersedtrughout is chalky shell midden and some 'ili'iligravel. The deposit becomes daiker toward the base,with increasing charcoal and ash content. Thecontact with Layer II is diffuse and irregular.Layer U: Considerable coral and basalt waterwom'ili'ili gravel is dispersed throughout this brown (7.5YR 5/4) sandy midden. There is some charcoalflecking, especially in the bottom of a shallow pitfeature at the base of the deposit. The contact withLayer III is sharp but irregular.Layer m: The white (10YR 8/2), medium-grained,calcareous beach sand of this stratum with its minorcomponent of volcanic lithic grains is culturallysterile.
UNIT 22: N FACE
. 1..r. rt.r~F-.--nic ni
16 V c
olcani V~~~~ Tur60
.SCharcoalConcentration
O) .* . >.1..
.
. ~ ~ .
. . b Charcoal
mI
I 0.0
No ceramics were present in this unit.
Radiocarbon Datesfrom Transect9
Three 14C age detenminations were obtainedfrom Transect 9, all on samples excavated from Unit23. Charcoal from the large earth oven in Layer IIA(Beta-35602) yielded an age range of 2845-2612 calB.P. at one standard deviation. This sample was indirect association with a ceramic assemblagecomposed of 8% thinware and 92% tickware. Asecond sample (Beta-35603) of dispersed charcoalflecks from d sratigraphically older Layer IIBcultual deposit yielded an age range of 2917-2382Cal B.P. at one stadard deviation. A large singlevalve of Tridacna maxima shell (Beta-35604) fromLayer IIlB was also dated, yielding an age range of2444-2289 cal B.P. at one standard deviation. Alldte samples from Unit 23 ovetlap at one standarddeviation, suggesting that the deposition ofLayersIIIB and IIIA occurred fairly rapidly, possibly over aspan of only one or two hundred years. Furterdetails on all samples are provided in chapter 6.
Swnmary of the Transect9 Depositional Sequence
Figure 5.26 is a correlation diagram of the strataexposed in the Transect 9 excavation units. Thisdiagram also shows the elevational relationshipsbetween these strata and the modem sea level andreef-shoreline features. Evidence from the
0.5 Transect 9 excavation data suggests the following* depositional sequence:
Stage 1 (> 2800 Cal B.P.): A narrow coastal terrace% or bench with a mixed calcareous-volcanic lithic.= sand lithology was fonned. At this time the active
shoreline was probably in the vicinity of Units 21-22.
1.0 Stage 2 (ca 2800-2300 cal B.P.): The occupaion ofthe nanow coastal terrace formed in Stage 1 resultedin the accumulation of the thick pottery-bearingLayer III strata in Units 20/23. The Layer IIBdeposit in Unit 21 represents a seaward diminutionof this occupation down the former beach slope.The shoreline itself was presumably no more thm
1.5 10-20m funher seaward of Unit 21 at this stage.Stage 3 (ca 2300-1900 cal B.P. ?): The rapidprogradation of the coastal terrace was initiated by
rth face an increase in the biogenic/calcareous sedimentFigure 5.25 Stratigraphic section of the noof Unit 22.
78 The To'aga Site
Figure 5.26 Sigraphic correlations between Units 20/23, 21, and 22 shown in relation to a schematic elevationprofile of Transect 9. The horizontal dimension along this transect is schematic and arbitrary, whilethe vertical dimension is expressed in meters above and below mean high water.
budget. Ihis resulted in the sterile calcareous LayerUB sand deposit in Units 20q23 (conrelated withLayerHA in Unit 21 and Layer HI in Unit 22),capping the earlier pottery-bearing occupation.During this stage, the shoreline prograded substan-tially, and active accumulation of calcareous sedi-ments in the vicinity of Units 20-21-22 subsequentlyceased.Stage 4 (ca 1900 cal B.P. ?): Following progradationof the shoreline, the coastal terrace in the vicinity ofthe excavation units was stabilized, with the surfacecovered by vegetation. This is indicated by the
stable paleosol surface represented by Layer HA inUnits 20123.Stage 5 (< 1900 cal B.P.): At this time colluvialclays and larger volcanic clasfics were depositedonto the coastal tenrace. The presence of charcoal inthese clays suggests forest cleane and buming on
the talus slope inland of the site. These humanactivities thus initiated increased rates of erosion.Stage 6 (< 1900 cal B.P.): The mixed colluvial-calcareous soil of the coastal terrace was used forsubsistence gardening and for dispersed habitationduring Stage 6.In sum, the depositional sequence of Transect 9closely replicates that of the 1987 excavationlocality, and that of Transect 5, as describedabove.
The elevational data from Transect 9 also fullysupport the morphodynamic model outlined in
chapter 4, and argued above for Transect 5. As canbe seen in the correlation diagram (fig. 5.26), theStage 2 occupation is no more than I m above themodem high water mark, and some 3.5 m below themodem beach ridge. Given a + 1-2 m higher sealevel stand at 2-3 kyr B.P., the Stage 2 habitationswould have been awash if they were not at a higherelevation than at present. Retrodicting a subsidencerate of about 1 m/kyr puts these habitation surfacesat 1-2 m above the then sea level, which also fits thelithological-sedimentological data (see Kirch,Manning, and Tyler, chapter 7). Thus, the incorpo-ration into our morphodynamic model of a tectoni-cally induced subsidence rate for Ofu Island of ca. Im/kyr is supported by the Tansect 9 stratigraphicdata.
Transect 11
Transect 1 1 lies 700m east of the baselineorigin-point (the 1987 excavation locality). Here thecoastal tenrace is quite broad and flat, neatly 100mwide from te present shoreline to the base of thetalus slope. The elevation profile is depicted infigure 5.27. Only a single excavation, Unit 26, waslocated here, some 60m inland from the baseline.The soil along Transect I I is more sandy than atTransects 9 or 5, lacking the colluvial clay compo-nent except very close to the talus slope. Thevegetation consists of tree crops (coconut and
CN4&fi CNJ ci ,Higher Berm
2
Ceramic Zone -o2 Ceramic Zone Post- 1900 BP Progradation
-1 ve t
Approx. Shoreline-2 ¢ at 3000 BP
-3
IVegetation Line
0 v-
Excavation 79
Figure 5.27 Elevation profile along Transect 11, showing the location of Unit 26 in relation to geomorphicfeatures.
breadfruit) with bananas, but aroids are absent,reflecting tfie sandy, edaphic conditions.
The stratigraphy of the west face of Unit 26,shown in figure 5.28, follows:Layer IA: The dark grayish-brown (10 YR 3/2)sandy loam in this layer is culturally sterile. A thickroot mass was present in the upper 5 cm. This zone
contains abundant shells of several terestrialmolluscs, including Subulina, Lamellaxis, andPleuropoma. The contact with Layer IB is grada-tional over 3-4 cm.Layer IB: This very dark gray (10 YR 3/1), non-concentrated midden deposit is lithologicallyidentical to Layer IA. There is some charcoalflecking, and the texture is slightly 'greasier' than
Layer IA due to carbon and organic material. Somefist-sized, volcanic fire-altered stones were noted.The contact with Layer IHA is iregular but distinctLayer HA: This stratum contains a white (10 YR 8/2), massive, stnuctureless deposit of cultually sterilecalcareous, medium-grained sand. There is anirregular, diffuse contact with Layer IIB.Layer JIB: The pale brown (10 YR 6/3), faintlydarker calcareous sand in this zone is apparently an
old, stabilized A horizon paleosol within the beachridge depositional sequence represented by Layer II.
Layer UC: The white (10 YR 8/2), coarse-grained,culturally sterile sand ofthis layer has a 'salt-and-pepper' lithology (mixture of calcareous and volca-nic grains).
Little cultural material was recovered durng the
excavation of Unit 26. Layer lB, the major source,yielded slightly more than 2 kg of shell midden. Nopottery was present in any of the layers. One brokenTurbo shell fishhook was recovered at the Layer IB/IIA contact. No radiocarbon dates were obtainedfrom this unit. The Layer IIB deposit may possiblycorrelate with the phase of progradation and subse-quent coastal terrace stability at ca. 1900 cal B.P.identified fiom other trnsects. This could not beverfied in the absence of radiometric dates, how-ever. If a ceramic period occupation were ever
present in the vicinity of Transect 11, it would havehad to have been inland of Unit 26, and thereforenow deeply buried beneath the steep talus rockfall.
Transect 17
This was the most easterly of our 1989 excava-tion transects, situated 1300m east of the baselineorigin-point. Transect 17 mnsjust slightly west ofthe low gap over the island's central ridge atFa'ala'aga. At this easterly end of the To'aga coastalterrace, the reef flat is quite narrow; thus the coast-line is exposed to greater wave energy, particularlyduring storms and cyclones. The beach frontingTransect 17 consists of coarse sand and gravel, rathertha the finer-grined sands typical of locationsfarther to the west Also,.the modem beach sedi-ments at Fa'ala'aga contain a high percentage of
w
3 -a
-
4co 00 O-1-m0 -2 I0
CO -3 I
-4 w0 10 20m
'C
)
ccm
U.w
TRANSECT 11
80 The To'aga Site
UNIT 26: W FACE
Figure 5.28 Straigraphic section of the west factof Unit 26. Black squares indicatesediment sampling locations.
volcanic clastics, derived from the exposed volcanicheadland at the eastem tip of Ofu (a control sampleof this modem beach sediment is described inchapter 7). These particular geomorphologicalfeatures are likewise reflected in te litology of te
two units, 24 and 25, excavated along Trnsect 17.The elevation profile along the trnset is shown infigure 5.29, indicating the positions of the twoexcavated pits just seaward of the talus slope.
Excavation Unit 24
Unit 24 was situated 1 14 m inland of thebaseline (along the coastal road) and about 10 mfrom te base oftX talus slope. The talus hereconsists entirely of large subangular boulders,without a colluvial clay component. The groundsurface at Unit 24 was sandy loam with a cover ofcoconut and breadfruit. The stratigraphy of the northface of Unit 24, shown in figure 5.30, follows:Layer IA: This stratum contains dark brown (10YR 3/3) sandy loam (A honzon) developed underHibiscus tiliaceus, banana, breadfiuit, and othervegetation. The parent material consists wholly ofcoarse- to medium-grained calcareous sand. Thecontact with Layer IB is irregular and slightlydiffuse.Layer IB: Light yellowish-brown (10 YR 6/4),coarse- to medium-grained, calcareous sand with avery minor volcanic component makes up thisstratum. Also, there is slight humic staining. Thecontact with Layer IC is gradational.Layer IC: This white (10 YR 812). very coarse- tocoare-grained sand contains lenses of waterwomcoral, volcanic gravel, and waterwom branch coralfingers. The sand is dominantly calcareous but witha strong secondary mode of volcanic lithic grains.TMe contact with Layer ID is fairly sharp andregular.Layer ID: Coral, gravel, and rubble with waterwombranch coral fragments, in a matrix of coarse-grainedsand make up this stratum which appears to repre-sent a single, high-energy depositional event. Thecontact with Layer IE is sharp and distinct.Layer IE: The coarse- to medium-grained 'salt-and-pepper' sand of this layer has scattered waterwomcoral and volcanic gravel- to cobble-sized clastics.Layer IF: This stratum contains volcanic, lithic,coarse-grained sand with a slightly dominantcalcareous mode. The deposit incorporates largecobbles of waterwom basalt and cobble-sized coralhead shingles. It represents a very high-energybeach, with constant input of volcanic sourcematerials to the sediment budget.
The depositional sequence in Unit 24 reveals agradual transition from a very high-energy, exposedbeach directly at the base of the talus slope, then to alower-energy beach resulting from progradation,and finally to the formation of a stable coastal tenrace
......1 . .1.. . 1 1* . ...
*~ ~ ~ . . . . 0 _. X e.: :: . :.~~~(9 ...:..110.-.
Excavatio, 81
Figure 5.29 Elevation profile along Transect 17, showing the locations of Units 24 and 25 in relation to geomor-
phic features.
UNIT 24: W FACE
*IA
Root Mold
LB
'. O
~E
o IC
0.0 with soil development under vegetation. Threeceranic body sherds (1 thickware, 2 thinware) wererecovered from Layer LB of Unit 24. One of these isparticularly unusual in that it is thick, coame-tempered pottery yet with a very clear red-slippedexterior surface. While thickware is obviouslycontemporaneous with early thinware assemblages,
0.5 ilufing those witi red slipping, this is the only
thickware sherd from the To'aga site with a red slip.0
2a4._
9
Figure 5.30 St secto of dte west fae of
Unit 24. Black squares indicate sedimentsampling lbcatio. "4C" indicae coal;
"V"i vocanic.
Excavation Unit 25
Unit 25 was positioned 10m seaward of Unit24. The stratigraphy of the north face, shown in
figure 5.31, is:Layer IA: The very dark grayish-brown (10 YR 3/2) sandy loam of this stratum has some subangular,fist-sized, volcanic stone inclusions (not fire altered).The contact with Layer LB is gradational over 2-4cm.
Layer IB: The black (10YR 2/1) sandy loam of thislayer is a very 'greasy' textued cultural deposit ofcalcareous sand with a heavy carbon and organicmateral component Shell midden and fire-alteredvolcanic stones are present. The contact with LayerIHA is fairly disdnct and slightly inregular.Layer IC: The daik grayish-brown (10 YR 4/2) tovery dark grayish-brown (10 YR 312) sandy loam ofthis deposit appears to be identical to Layer IA. Itprobably represents a fairly long period ofcoastal
W-0
cor 0-6 :30
e 4
6.2
W U-
0 U-.0 -2 W
o -4
I-
-Jw
a:
0 20 40m TRANSECT 17
82 The To'aga Site
UNIT 25: N FACE0.0
IA
4* TB :o.:
1.5
Base:of Excavation at2.1 ma.
ofU 25 Bl;/ squaresCoralGraveli* and Branch Coral - * ,
. O* o ° / ° %'0'' ~~~~1.5
***Base of Excavation at 2.10 m
Figure 5.31 Sltlga_ secd of th ot facofUnit 25. Black squaresidctsediment sampling loations.
terrace stability under vegetation, with gradualaccumulation. The contact with Layer IIA is distinctand slightily irregular.Layer HlA: This layer contains pale brown (10 YR6/3), coarse-graied sand with a marked 'salt-and-pepper' appearance due to a heavy mixture ofvolcanic grains. In the northeast comer of the unitthere is a facies of sand matrix incorporafing water-rolled coral and volcanic gravelpebbles. Thecontact with Layer IEB is sharp but slightly irregular.Layer JIB: The white (10 YR 812), coarse-grained,'salt-and-pepper' sand of this stratum has a lens ofwater-rolled coral rubble and gravel (incorporatingbranch coral fingers) at about 145 cm below surface.
The heavy carbon content ofLayer IB is sugges-tive of cookhouse activity. This interpretation is alsosupported by the presence of fire-altenred volcanicoven stones. No pottery was present in Unit 25.
SUMMARY AND CONCLUSIONS
A detailed discussion of the results of our dueeseasons of excavations at the To'aga site is bestdefened to te concluding chapter of this volume(see Kirch and Hunt, chapter 15). Here we confineourselves to a brief summary ofseveral key points:
1. Areal extent qfthe To'aga site. One ofourpnmary objectives during the 1989 excavationseason was to determine the full horizontal extent ofthe subsurface cultural deposits at To'aga. Throughthe use of systematic tnsect sampling, we havebeen able to ascertain that buiied cultural depositsdating as early as ca. 3000 cal B.P. extend contnu-ously from Transect 3 to Transect 9, a distance ofsome 700 m. Between Transects 9 and Ilthedensity of cultual materials declines significantly,but some culturl materals were present in Unit 26along Trauect 1 1. Transt 17 also yielded a verylow density ofculual materials. We were restrictedby the local landowners from testing the 600-m gapbetween Transects 11 and 17 because of the pres-ence of the sacred-and rather feard-Tui Ofutomb and other surface cultural remains in this area.Based on our transect results, we can now state tasubsurface archaeological deposits are presentthrughout the entire To'aga coastal flat as far asFa'ala'aga, but that the main pottety-bearing, concen-trated midden deposits are restricted to the areabetween Transects 3 and 9. The bured deposits areconcentrated in a narrow band, extending no morethan about 30m seaward from the present base ofthe talus slope. Shovel tests in vanous localities inthe present beach ridge (on both sides of the road)revealed no archaeological materials. We are alsocertain that cultual deposits extend inland under thesteep talus for an unknown extent. The greatthickness of e talus and colluvium, however,prevents testing of these deposits without the aid ofheavy machinery which was not available to us. Itwould probably require fte removal of as much as15 m of massive talus-olluvial overburden toexpose some of these buried occupation deposits.
2. Testing o.fthe morphodynnic model. Themorphodynamic model of coastal terrace fonnationoutlined in chapter 4 has been substantively sup-ported by our stratigraphic and radiometric data fromthe various tansect excavations. In particular, wehave been able to confirm that Ofu Island has been
Excavations 83
undergoing subsidence at a rate of 1-2 m/kyr duringthe late Holocene. Rapid progradation and fonna-tion of the coastal terrace occurred during the period1900-1000 cal B.P., largely due to an increase in themarine-biogenic sediment budget. Thus, occupationdeposits dating earlier than 2000 cal B.P. are con-fined to a very narrow, fonner bench or beach ridgesituated at the base of the talus slope.
3. The O.fu cultural sequence. The culturalmaterials recovered from our varous transectexcavations also provide the basis for outlining acultural sequence for Ofu Island. This sequence
commences at about 3000 cal B.P. with colonizationof the island by makers of a ceramic complexincluding both thin and thickware vessels. While noclassic dentate-stamped Lapita pottery has beenrecovered at To'aga yet, the early ceramic assem-
blage from AS-13-1 fits well within the Lapitoidceramic series (see Kirch 1988). Other portableartifacts, such as Type V basalt adzes and shellannbands, are also similar to Early Eastem Lapitaassemblages from Tonga and Fiji.
Over the period from 3000-1900 cal B.P., theTo'aga site was continuously occupied, and the
ceramic assemblages reveal a gradual shift indominance from thinware to thickware. At around1900 cal B.P., a rapid progradation of the shorelinecommenced, resulting in the construction of the
present coastal terrace. Also, the deposition ofterrigenous sediments onto the coastal terraceincreased, creating a prime zone for horticultural andarboricultural activities. During the past twomillennia, the To'aga coastal terrace has been heavilyutilized for such subsistence pursuits, althoughhabitations dispersed over the terrace continued to beoccupied, evidenced by such features as the 'ili'ili
house mound tested by Unit 13. In chapter 15 wediscuss this sequence in greater detail, and compareit with the sequence defined for Westem Samoa.
REFERENCES CITED
Buck, P. H. [Te Rangi Hiroa] 1930. Samoan Mate-rial Culture. Honolulu: Bemice P. BishopMuseum Bulletin 75.
Clark, J. T. 1980. Historic preservation in AmericanSamoa: Program evaluation and archaeological
site inventory. Report prepared for the Amen-can Samoa Government. AnthrpologyDeparment, Bernice P. Bishop Museum,Honolulu.
Cox, P. A. 1980. Masi and tanu 'eli: AncientPolynesian tehnologies for the prservationand concealment of food. Pacfic TropicalBotanical Garden Bulletin 10:81-93.
Emory, K. P., and Y. H. Sinoto 1965. Preliminaryreport on the archaeological investigations inPolynesia. Report prepared for the NationalScience Foundation. Anthropology Depart-ment, Bemice P. Bishop Museum, Honolulu.
Green, R. C., and J. M. Davidson, eds. 1969.Archaeology in Western Samoa, Vol. 1. Bulletinof the Auckdand Insfitute and Museum.
. 1974. Archaeology in Western Samoa, Vol. 11.Bulletin of the Auckland Institute and Museum.
Hunt, T. L., and P. V. Kirch 1988. An archaeologicalsurvey of the Manu'a Islands, AmericanSamoa. Journal ofthe Polynesian Society97:153-83.
Kikuchi, W. K. 1963. Archaeological surface ruinsin American Samoa. Unpublished M.A. thesis,University of Hawaii, Honolulu.
Kirch, P. V. 1984. The Evolution ofthe PolynesianChiefdoms. Cambridge: Cambridge UniversityPress.1988. Niuatoputapu: The Prehistory ofaPolynesian Chiefdom. Thomas Burke Memo-ral Washington State Museum Monograph No.5. Seattle.
Kirch, P. V., T. L. Hunt, and J. Tyler 1989. Aradiocarbon sequence from the To'aga site, OfuIsland, American Samnoa. Radiocarbon 31:7-13.
Kirch, P. V., and D. E. Yen 1982. Tikopia: ThePrehistory and Ecology ofa PolynesianOutlier. Honolulu.: Bemice P. Bishop Mu-seum Bulletin 238.
Munsell Soil Color Charts 1988. Munsell Color,MacBeth Division of Kollmorgen InstrumentsCorporation. Baltimore.
Redman, C. L. 1974. Archaeological SamplingStrategies. Reading, Mass.: Addison-WesleyModule in Antwpology, No. 55.
![INDEX.* [digitalassets.lib.berkeley.edu]digitalassets.lib.berkeley.edu/anthpubs/ucb/text/ucp008-009.pdf · Keruk, 277, 283, 294, 311, 336, 337, 358. Kimul Chehenish, 103. Kish, 102,](https://img.pdfslide.us/doc/110x75/5cc16c2188c99315158c0e6a/index-keruk-277-283-294-311-336-337-358-kimul-chehenish-103.jpg)
![anthropology] - Spotlight exhibits at the UC Berkeley …digitalassets.lib.berkeley.edu/anthpubs/ucb/text/kas044...by students who had completed less than half of a one quarter introductory](https://img.pdfslide.us/doc/110x75/5af030a97f8b9ad0618dbade/anthropology-spotlight-exhibits-at-the-uc-berkeley-students-who-had-completed.jpg)
![INDEX.* [digitalassets.lib.berkeley.edu]digitalassets.lib.berkeley.edu/anthpubs/ucb/text/ucp006...Buckingham's island, 206. Bucknell ranch, 188. Buckner creek, 143, 259; moun-tains,](https://img.pdfslide.us/doc/110x75/5afedb927f8b9a864d8f89bb/index-s-island-206-bucknell-ranch-188-buckner-creek-143-259-moun-tains.jpg)
