I PIERO COMIN-CHIARAMONTI(I, '), LUCIA CIVETTA(2 ... · 510 P. Comin-Chiaramonti el al. Tertiary n 400°C and reacting with 100 % H3P04 by a Finningan Mat Delta E mass spectrometer

I

Eur J Mineral 19913 507-525

Tertiary nephelinitic magmatism in Eastern Paraguay Petrology Sr-Nd isotopes and genetic relationships with

associated spinel-peridotite xenoliths

PIERO COMIN-CHIARAMONTI(I ) LUCIA CIVETTA(2) RrCCARDO PETRINI(3) ENZO MICHELE PICCIRILLO(4) GIULIANO BELLIENI(S) PAOLO CENSI(I) PETER BITSCHENE(6)

GABRIELLA DEMARCHI(4) ANGELO DE MIN(4) CELSO DE BARRO GOMES(4 ) ANA MARIA CASTILLO(7) and JUAN CARLOS VELAZQUEZ(7)

(1) Istituto di Mineralogia Petrografia e Geochimica Universita di Palermo Via Archirafi 36 90123 Palermo Italy

(2) Dipartimento di Geofisica e Vulcanologia Universita di Napoli Largo S Marcellino 10 80138 Napoli Italy

(3) Istituto di Geocronologia e Geochimica Isotopica Consiglio Nazionale delle Ricerche Via Cardinale Maffi 36 56100 Pisa Italy

(4) Istituto di Mineralogia e Petrografia Universita di Trieste Piazzale Europa 1 34100 Trieste Italy

(S) Dipartimento di Mineralogia e Petrologia Universita di Padova Corso Garibaldi 37 35137 Padova Italy

(6) Institut fuumlr Mineralogie Ruhr-Universitat Postfach 1021484630 Bochum W-Germany

(7) Instituto de Ciencias Basicas Universidad Nacionaacutel de Asuncioacuten Ciudaacuted Universitaria San Lorenzo Asuncioacuten Paraguay

( ) Permanent address Istituto di Mineralogia e Petrografia dellUniversita Piazzale Europa 1 1-34100 Trieste Italy

(H) Permanent address Instituto de Geociencias Universidade de Sao PauJo Caixa Postal 20899 01498 Sao Paulo Brazil

Abstraet Plugs flows and dykes of nephelinitic (and ankaramitic) rocks occur near Asuncioacuten (Eastern Parashyguay 61-39 Ma) This magmatism occurs at the western boundary of the Paranaacute basin and is associated with NW-SE-trending rift and antiform structures Nephelinites contain variable amounts of crustal (sedimentary metamorphic and volcanic) and mantle (spinel-peridotite) xenoliths

The genesis of the Asuncioacuten nephelinites requires a manlle source geochemically and isotopically distinct from that represented by the spinel-peridotite nodules included in the lavas The most likely mantle so urce is a garnet peridotite charactenzed by small-scale heterogeneities at least in terms of Sr and Nd isotopes This mantle source was subjected to (1) low degrees of partial melting (eg 3 - 4 ) (2) enrichment in Nb Ba La Ce Sr and P relative to a primordial mantle

H is suggested that the enrichment in incompatible elements may be due to metasomatic processes related to a thermal anomaly responsible for the generation of the Lower Cretaceous Paran aacute flood lavas

The initial Sr isotope ratios of the Asuncioacuten nephelinites (Ro = 07036-07039) indicate a manlle source distinct from that of the Lower Cretaceous magmatism (Central-Eastern Paraguay alkaline magmatism Ro =

07073 tholeiitic flood basalts Ro = 07059)

0935-1221910003-0507 $ 475 1991 E Schweizerbartsche Verlagsbuchhandlung D-7000 Stuttgart 1

508 P Comin-Chiaramonti el al

On the whole the Cretaceous-Tertiary alkaline and ultra-alkaline magmatism of Central-Eastern Paraguay appears closely linked to rift structures trending NW-SE and WNW-ESE This may be an indication of a tectono-magmatic event(s) associated with stress-regime changes during the South America-Africa continental separation

Key-words Eastem Paraguay South America Tertiary nephelinites Mantle source metasomatism partial melting Sr-Nd isotopes

Introduction margin of the northern Parana Basin (Fig lA) The investigated Tertiary nephelinites are

Nephelinitic plugs flows and dykes dominate important since they represent an ultra-alkaline the Tertiary (61-39 Ma) magmatism in Eastern (Le Bas 1987) magmatism that occurred inland Paraguay near Asuncioacuten (Fig 1 Bitschene long after the South America - Africa continental 1987) This magmatism is controlIed by NWshy separation AIso they contain spinel-peridotite SE- trending rift structures and represents the xenoliths strongly enriched in incompatible eleshymost recent alkaline activity on the western ments (Comin-Chiaramonti el al 1986 border of the Parana basin (Livieres amp Quade Demarchi el al 1988) 1987) In tbis area a tephritic-phonolitic The present paper addresses (1) petrological magmatism of Upper Permian to Upper Cretashy geochemical and Sr-Nd isotope aspect bearing ceous age is also present (240-108 Ma Cominshy on the origin of nephelinite (2) petrogenetic Chiaramonti el al 1990) locally associated relationsbips between nephelinites and the with Cretaceous carbonatites (130-86 Ma Eby enclosed mantle xenoliths and (3) Sr-Nd amp Mariano 1986) Note that an important isotope characteristics of the subcontinental alkaline magmatism of lower Cretaceous to manUe sources involved in the generation of Eocene age (135 to 45 Ma Gomes el al the alkaline and tholeiitic magmas of the 1990) is also widespread around the eastern Paranaacute Basin

Fig 1 A Sketch map showing the post-PaJaeozoic occurrences -squares and circJes- of alkaline rock-types at the border of and within the Paranaacute Basin -squares and circles- (after Gomes el al 1990) 1 pre-Devonian crystalJine basement 2 pre-volcanic sediments (mainly Palaeozoic) 3 flood volcanics of the Sena Geral Formation (Lower Cretaceous) 4 post volcanic sediments (mainly Upper Cretaceous) 5 syncline-type structure 6 arch-type structure 7 fl exure-type structure 8 major structural lineament B Simplified structural map of Eastern Paraguay 1 antiform-type structure 2 synform-type structure 3 major faults 4 major structural lineaments Stippled area indica tes the extension of the stratoid tholeiitic volcanic rocks of the Serra Geral Formation E aste rn Paraguay (from Livieres amp Quade 1987 and Bellieni el

al 1986 modified) Dotted areas indicate the main occurrences of alkaline rock-types C Simplified geological map of the Ypacaray Valley and adjacent areas (Degraff el al 1981) PC Precamshybrian LS and US Lower and Upper Silurian respectively J Jurassic-Cre taceous T Tertiary nephelinitic occunences (unconformable on the Jurassic red sandstones of the Misiones Formation) f major faults 1) Cerro Verde Small plug (about 300 m in diameter and 20 m high) containing rare mantle (up to 2 cm across) and very abundant crustal (up to 100 cm across) xenoliths 2) Limpio Lava flow (about 8 m thick) with scarce mantte (up to 2 cm diam) and crustal (up to 25 cm diam) xenoliths 3) Remanso Castillo Subvertical NW-SE trending dyke 5 m thick 4) Nueva Teblada Lava flow (about 10 m thick) with abundant mantle xenoliths up to 20 cm across 5) Tacumbuacute SmalJ plug (about 200 m in diameter and 50 m high) which yields abundant mantle and rare crustal xenoliths (up to 7 cm and up to 50 cm across respectively) 6) Lambareacute Small plug (about 170 m in diameter and 55 m high) with abundant mantle xenoliths (up to 10 cm across) and rare crustal xenoliths (up to 30 cm in size) 7) Cerro Palintildeo Very small plug () with crustal xenoliths (up to 50 cm) and rare mantle xenoliths (up 2 cm across) 8) Nemby Plug (900 x 500 m and 80 m aboye the plain) with very abundant mantle xenoliths (ca 10-15 by volume and up to 40 cm across) and rare crustal xenoliths (up to 100 cm across)

Tertiary I

Analytical proced

Major and trace elernent con rocks were determiacutened by X-r (Bellieniacute el al 1983) miCfe compositions were analysed Comin-Cbiaramonti el al (1 986)

Sr iso tope compositions were Sr separation by standard ion-( matography The measured ~ were frationation-corrected to value of 01194 Repeated analy 987 Sr standard gave average 87S

14

Asur

~ ~t-)

Q

31

A (

Bue nos

matism of Central-Eastern Paraguay SE This may be an indication of a he South America-Africa continental

1antle source metasomalism partial

nortbern Parana Basin (Fig lA) igated Tertiary nephelinites are e tbey represent an ultra-alkaline ) magmatism that occurred inland Soutb America - Africa continental clso they contain spinel-peridotite ngly enriched in incompatible eleshylin-Chiaramonti el al 1986 J 1988) It paper addresses (1) petrological and Sr-Nd isotope aspect bearing Q of nephelinite (2) petrogenetic

between nephelinites and the jntle xenoJiths and (3) Sr-Nd acteristics of the subcontinental ~cs involved in the generation of

and tboleiitic magmas of the

1

res and circles- of alkaline rock-types at Games el al 1990) 1 pre-Devonian

3 flood vo1canics of the Sena Geral Upper Cretaceous) 5 sync1ine-type

s ructural lineament ructure 2 synform- type structure 3 iexclhe ex tension of the s tr atoid tholei itic Livieres amp Quade 1987 and Bellie ni el

ifle rock-types reas (Degraff el al 1981) PC Precamshyisic-Cretaceous T Tertiary nephelinitic Jnes Formation) f majar faults iexclh) containing rare mantle (up to 2 cm

m diam) and crustal (up to 25 cm dia m )

~ xenoliths up to 20 cm across which yields abundant m antle and rare

h abundant man tle xenoliths (up to 10 cm

I cm) and rare mantle xenoliths (up 2 cm

bundant mant le xenoliths (c a 10-15 by

m across)

Tertiary nepheliacutenitic magmatism in Eastern Paraguay

Analytical procedures 071027plusmn3 Standard deviations are expressed as 2a on the mean

Major and trace element contents of wholeshy Nd isotope composition analyses were carshyrocks were determined by X-ray fluorescence ried out following the chemical and spectromeshy(Bellieni el al 1983) microprobe mineral tric procedures described in Zindler el al compositions were analysed according to (1979) The 143NdlJ44Nd measured ratios were Comin-Chiaramonti el al (1986) corrected for fractionation to 146Nd144Nd =

Sr isotope compositions were measured after 07219 and normalized to the La Jolla Nd stanshySr separation by standard ion-exchange chroshy dard Standard deviations are expressed as 2a matography The measured 87Sr86Sr ratios on the mean were frationation-corrected to an 86Sr88Sr Carbon isotopic compositions were performshyvalue of 01194 Repeated analyses of the NBS ed on hand-picked carbonate grains purified in 987 Sr standard gave average 87Sr86Sr ratios of hot distilled water after vacuum heating at

56deg

24deg

A

bull gt 90 Ma

O 70-90 Na

O lt 70 Na

~~ 3 ~ 4LcJ

5~5X -lt1

7-lt1 B

bull O T

csJ J

~US EZ2l LS

1 1 pe

Figl

509

510 P Comin-Chiaramonti el al Tertiary n

400degC and reacting with 100 H3P04 by a Finningan Mat Delta E mass spectrometer The results are given in o per mil notation PDB-l is the reference standard leT standard devishyation is 0050

Petrography and mineral compositions

Nephetinites and ankaramites

The investigated rocks are nephelinites and subordinately ankaramites (Fig 2) according to De La Roche el al (1980) and nephelinites (CIPW Ab lt 5 wt and Ne gt 20 wt) according to Le Bas (1989)

Nephelinites and ankaramites are characterizshyed by olivine phenocrysts and microphenocrysts of olivine clinopyroxene and magnetite set in

a microcrystalline groundmass The latter is made up of clinopyroxene olivine opaques interstitial glass nepheline and very rare plashygioclase microlites Several samples show poikishylitic nepheline alkali feldspar and carbonates Sorne samples contain spinel-peridotite xenoshyliths (see below) associated with olivine pyroxene andor spinel xenocrysts and someshytimes also cryptocrystalline materials (sedimenshytary metamorphic and vokanic) and quartz xenocrysts derived from the crust (Demarchi el al 1988)

Modal clinopyroxene (Cpx) ranges from 40 to 49 (Table 1) Cpx-microphenocrysls (02shy05 mm Mg 080 CpxM in Tables 1 2) are zoned aud rauge in colour from greenish yellow (core) to pink (rim) groundmass-Cpx laquo 02 mm Mg 075 CpxG in Tables 1 2) is stubby prismatic and ranges from pale yetlow to pink in colour Compositionally both micro-

Fig 2 Plot of the investigated nephelinites of Eastern Paraguay (ef Table 3) in the diagram of De La Roche el al (1980) Cireles Nemby nephelinites solid cireles other Asuncioacuten nephelinites In inset A field of Tertiary ultra-alkaline rocks of the Asuncioacuten area and B field of Mesozoic alkaline rocks of Central-Easte rn Paraguay SW of the Asuncioacuten area (Comin-Chiaramonti el al 1990) Rl = 4Si -l1(Na+K) - 2(Fe+Ti) R2 = 6Ca + 2Mg + Al

phenocrystic and groundmass ( to salites (Fig 3) the latter ha Mg ratio Clinopyroxene xenoGr) Mg 093 CpxIX in Tables 1 show spinel exsolutions and gliexcl These clinopyroxenes (diopsidE compositionally similar to the e dotite xenoliths Rare orlhopym (Mg 092 OpxIX in Table 2 nally prese nto

Modal olivine (01) ranges fre vol (Table 1) Ol-phenocrysls (F in Tables 1 2) are euhedral am 7 vol 05-2 mm) Ol-microp 82-77 OIlM in Tables 1 2) arl 6 vol 02-05 mm) grou~ (Fo 76-74 3-6 vol OlG ir shows euhedral to subhedral ou x enocrysls and the olivine of xenoliths have the same compositi

Table l Represeotative modal anal~

Eastern Paraguay

2

OVP 65 46

OlM 62 37

OlG 36 34

CpxX 15 05

CpxlM 09 60

CpxlG 46 1 366

MtfM 06 03

MtG 39 50

Nepheline 188 164

Glass 111 225

Apatite 05 05

Biotite

Carbonates

PI

Xenolilhs 03 05

Numbers as in Fig 1 01 olivine P phenocrysts M microphenocrysts

~-

iexclI

ystalLine groundmass The latter is of clinopyroxene olivine opaques glass nepheline and very rare pi ashy

iexclcrol ites Several samples show poikishyline alkali feldspar and carbonates pIes contain spinel-peridotite xenoshy

below) associated with olivine andor spinel xenocrysts and someshycryptocrystalline materials (sedimenshy111lOrphic and vo1canic) and quartz derived from the crust (Demarchi et

linopyroxene (Cpx) ranges from 40 fabJe J) Cpx-microphenocrysts (02shy1g 080 CpxIM in Tables 12) are range in colour from greenish yellow

pink (rim) groundmass-Cpx laquo 02 O 075 CpxG in Tables 1 2) is smatic and ranges from pale yellow colour Compositionally both microshy

phenocrystic and groundmass Cpx correspond to salites (Fig 3) the latter having higher Fe Mg ratio Clinopyroxene xenocrysls (03-2 mm Mg 093 CpxIX in Tables 1 2) occasionally show spinel exsolutions and glassy inclusions These clinopyroxenes (diopsides Fig 3) are compositionally similar to the Cpx of the perishydolite xenoliths Rare orthopyroxene xenocrysts (Mg 092 OpxIX in Table 2) are occasioshynally present o

Modal olivine (01) ranges from 7 to 16 vol (Table 1) Ol-phenocrysts (Fo 89-85 OlP in Tables 1 2) are euhedral and fractured (1shy7 vol 05-2 mm) Ol-microphenocrysts (Fo 82-77 OUM in Tables 1 2) are euhedral (1shy6 vol 02-05 mm) groundmass olivine (Fo 76-74 3-6 vol OlG in Tables 1 2) shows euhedral to subhedral outlines Olivine xenocrysts and the olivine of the peridotite xenoliths have the same composition (Fo 93-90)

Table 1 Representative modal analyses (vol ) and Eastern Paraguay

Tertiary nephelinitic magmatism in Eastern Paraguay

Ti-magnetite occurs as anhedral microphenoshycrysts (01 - 0 2 mm 0 3 - 07 vol MtM in Tables 1 2) and as groundmass phase laquo 01 mm 4 - 7 vol MtG in Tables 1 2) Spinel xenocrysts (Cr(Cr + Al) = 012-040 close to the range of spinel from mantle xenoshyliths) with Ti-magnetite rims are occasionally present Fine need1es of apatite are common biotite flakes and carbonate rhombohedra (both lt 001 mm) are occasional1y present in the groundmass

Mantle xenoliths

Mantle xenoliths (up to 45 cm in size) are spinel lhe rzolites harzburgites and dunites (Group 1 of Frey amp Prinz 1978) and correshyspond to the Cr-diopside series of Wilshire amp Shervais (1975) They usual1y have a protograshy

mineral size variation (mm) for nephelinites from

OVP 65 46 23 U~ 07 42 26 050-200 I TE

OJIM 62 37 23 21 07 26 65 47 015-0 50

OllG 36 34 38 55 55 43 30 008-015

CpxX 15 05 01 04 09 02 0 5 028-200

CpxJM 09 60 15 14 09 03 463 06 015-050

CpxJG 461 366 399 440 413 419 39 3 lt0 15

I

MtlM 06 03 07 04 07 06 03 010-023 51

M tlG 39 50 62 68 50 56 50 lt010

Nepheline 188 164 173 153 210 206 214 192

Glass 111 225 248 171 225 187 206 214

Apatite 05 05 07 01 04 04 01 03 laquo 010

Biotite 01 lt001

Carbonates 01 002-010 PI 02 002-010

Xenoliths 03 05 01 23 04 06 30 013-155Table 3) in the diagram of De La Roche ncioacuten nephelinites In inset A field of esozoic alka line rocks of Central-Eastern l R1

2 3 4 5 6 7 8 (mm) range

= 4Si - ll(Na+ K) - 2(Fe+Ti) R2 Numbers as in Fig 1 01 olivine Cpx clinopyroxene Mt magnetite PI plagioclase X xenocrysts P phenocrysts M microphenocrysts G groundmass

1000

511

512 P Comin-Chiaramonti el al Tertiary ne

Table 2 Average microprobe analyses of cJinopyroxenes (Cpx) orthopyroxenes (Opx) olivines (01) magneshytite (Mt) and nepheline

_______C~p_x____________ Opx __________0_1__________ Mt Nepheline

N X M G X N P M G M G

Si02 5513 5416 4787 4530 5484 4119 4030 3866 3809 4l94 Ti02 010 012 228 361 000 1892 2099

AI20 3 148 272 620 807 480 647 456 3509 FeO 233 233 627 740 518 859 1114 1912 2221 6625 6722 MnO 016 011 017 010 014 011 020 047 066 086 096 MgO 1766 1700 1415 1233 3292 4964 4778 4109 3837 362 283 CaO 2190 2172 2205 2261 117 002 009 051 059 091

Na20 099 091 050 023 001 1826 K 20 000 000 000 004 000 447 2e Cr203 085 085 029 012 092 137 081 NiO 040 026 016 011

SUM 10060 9992 9978 9981 9998 9995 9990 10001 10003 9749 9737 10067

10 Si lm1~ l ml~Im 1~OmOmom I~

Ti 0003 0003 0063 0102 0000 0505 0570 AIv 0021 0041 0230 0306 0109 0987 AIY) 0042 0075 0040 0050 0086 Fe3+ 0018 0000 0091 0066 0000 0000 0003 0017 0014 0680 0642 I p

IMg ==Fe2+ 0052 0070 0103 0166 0149 0174 0227 0394 0470 1286 1387 Mn 0005 0003 0005 0003 0004 0002 0004 0010 0015 0026 0029 Fig 3 Compositional variation of c1in( Mg 0945 0917 0780 0687 1691 l811 1758 1571 l490 0193 0154 Fe3+) conventional diagram (atoms ) Ca 0843 0842 0873 0906 0043 0001 0002 0014 0017 0024 X = xenocrysts M= microphenocrysts

Na 0069 0064 0036 0017 0001 0845

K 0000 0000 0000 0002 0000 0136 Pyrrhotite pentlandite and apaliCr 0024 0024 0008 0004 0025 0038 0023

dispersed grajns Very rare carbOIlNi 0008 0005 0003 0002 present as tiny euhedral crystals ThAl 0271 0194 character of the whole assemblage by the compositional variation oE e phase (Demarchi et a 1988) ie (atomic ratio) of the orthopyroxe

Total iron as FeO N = xenoliths X = xenocrysts P = phenocrysts M = microphenocrysts G = groundshy 118) is correlated to the Fo con mass olivine (90 to 93) to tbe MglFe

roxene (92 to 153) as well as to tt Al) ratio of the spjnel (010 to 060)

nular texture (Mercier amp Nicolas 1975 (Table 3) showing spinel exsolutions and occashy The blebs consist of a glassy mal nomenc1ature) No lava contamination is appashy sional glassy inc1usions ing olivine clinopyroxene and Cr-spi ren from petrographic mineralogical or cheshy 1 Orthopyroxene (Mg 091-092 3 to 26 tes They are considered to bave bee mical studies (Comin-Chiaramonti el a 1986 vo) is unzooed (Table 3) and rarely shows spishy melting of amphibole and phlogopi Demarchi el al 1988) Mantle xenoliths nel exsolutions Olivine (60 to 97 vol) Chiaramontielal1986) contain variable amounts of glassy patches corshy varies in composition from F090 (Jherzolites) to Equilibration temperatures and iexcl responding to the blebs of Maal0e amp F093 (dunites) (Table 3) Spinel (Cr(Cr + Al) the spinel-peridotite xenoliths Prinzlau (1979 see later) 010-060 06 to 4 vol Table 3) may be according to Mercier 1980) vary b(

Clinopyroxene (Mg 091-093 1 to 15 surrounded by microcrystalline glassy rims and 10510 C and 14-22 kbar respectively vo) is compositionally quite homogeneous blebs a diameter of 45 cm corresponding

pyroxenes (Opx) olivines (01) magne-

Mt Nephe line

M G M G

S66 3809 41 94

1892 2099

647 4 56 3509

~ 1 2 2221 6625 67 22

)47 066 086 096

109 3837 362 283

051 059 091

1826

447

137 081

U16 011

001 10003 9749 9737 10067

992 0993 1003

0505 0570

0987

017 0014 0680 0642

394 0470 1286 1387

010 0015 0026 0029

571 1490 0193 0154

014 0017 0024

0845

0136

0038 0023

003 0002

0271 0194

000 4000 4000 4000 4000

M = microphenocrysts G = groundshy

howing spinel exsolutions and occashy inclusions mene (Mg 091-092 3 to 26 gtned (Table 3) and rarely shows spishyions Oivine (60 to 97 vol) mposition from F090 (Iherzolites) to ~ s) (TabJe 3) Spinel (Cr(Cr + Al) 06 to 4 vol Table 3) may be by microcrystalline glassy rims and

Tertiary nepheJinitic magmatism in Eastern Paraguay

Ca OUacute

(1

Q

40 I I I

I I

I I JO I

I I I

1 (~-x

20 I

I

I

I 10

I I I I

2(1 30

Mg I P I Fe 2 ++ Mn + fe 3 +2 = 01 = b

bull Fig 3 Composi tional varia lion of clinopyroxene olivine and orthopyroxene in the Ca-Mg- (Fe2+ + Mn + Fe3+) conventional diagram (atoms ) N = xenoliths and microxenoliths X = xenoliths and microxenoliths X = xenocrysts M= microphenocrysts G = groundmass phases

Pyrrhotite pentlandite and apatite occur as of the largest xenoJith a density of 33 gcm3

dispersed grains Very rare carbonate may be and an origin at a depth of 60 km the transshypresent as tiny euhedral crystals The residu al port of the xenoJiths to the surface occurred in character of the whole assemblage is refl ected less than 10 hours (cf Spera 1984) by the compositional variation of each mineral phase (Demarchi el al 1988) ie the MglFe[ (atomic ratio) of the 118) is correlated to

orthopyroxene (97 to the Fo content of the

Whole-rock compositions

olivine (90 to 93) to the MgFe[ of clinopyshyroxene (92 to 153) as well as to the Cr(Cr +

Nephelinites and ankararnitesAl) ratio of the spinel (010 to 0 60) The blebs consist of a glassy ma trix containshy

ing olivine c1inopyroxene a nd Cr-spinel microlishy The average compositions of the investigated tes They are considered to have been formed by rocks are given in Table 4 melting of amphibole and phlogopite (Cominshy In general MgO content is negatively correshyChiaramonti et al 1986) lated with Si02 AJ 20 3 Na20 and K20 and is

Equilibration temperatures and pressures of positively correJated with CaO and FeO[ the spinel-peridotite xenoliths (calculated (Fig 4) The Nemby nepheJinites at similar according to Mercier 1980) vary between 944- MgO content are distinct from the others in 105PC and 14-22 kbar respectiveJy Assuming haviug Jower Ti02 and CaO and higher P20 5 a diameter of 45 cm corresponding to the size and Na20 contents

513


Table 3 Chemical compositions of coexisting phases in bleb-free (BF) and bleb-bearing (BB) xenoliths (after Demarchi el al 1988) amphibole (AMPH) and phlogopite (PHLOG) compositions (from Wilkinson amp Le Maitre 1987) used in the mass balance calcuJations

01 Opx

BF 3192 3269 3192 3269

Si02 Ti02 AI 2O)

FeO

MgO CaO

Na20 K20

Cr20)

4123

930 4994

003

4108

805

5009 003

5686

007 333

580

3377 049

005

024

5660

002 270

519

3394 047

054

BB 3198 3304 3198 3304

Si02 Ti02 AI2O)

FeO

MgO

CaO

Na20 K20

Cr20)

4154

891

4922 004

4026

840

4938

000

5604

005

347

567 3322

057

005

024

5721

002

193

533

3436

042 005

038

Trace-element variations relative to MgO (Fig 5) display well defined trends in the Nemby samples These latter show increasing Sr Ba La Ce Y and Nb for decreasing MgO coupled with decreasing Ni and Cr Rb remains virtually constant (av 59 plusmn 2 ppm) The nephelinites of the other localities show scattered variations mainly for La Ce Zr and Nb Note that the least differentiated nephelishynite (n1 of Table 4 Mg 069) has the highest incompatible element contents

The compositional variations of the Nemby samples are compatible with fractional crystallishyzation Mass balance calculations (major eleshyments) show that the transition from sample 8 (Mg 0674) to sample 12 (Mg 0638) yields Lres2 = 088 this requires the extraction of olivine (39 OIP of Table 2) clinopyshyroxene (92 CpxlM of Table 2) and magneshytite (26 MtM of table 2) The incompat-

AMPH PHLOGCpx Sp

Tertiary ne

Ntilde RgCO~ N ~~~~~ I~ ~ ~ N Sdeg cri ~~--

sr 2 ~ ~ g3 Noiexcl28 ~~

11 ~N=6O-s0 e

~~8~ ~~~r ~~ I ~ ~0i~6O~ -

8 ~ ~ ~~8iexcl~ ~ ~ U ~r-j lt26oS e

N S=~~ H ~~ ~ ~sect ~ ~N j= ~~ ~Vl-

DO

1-1 o N (1 N e gtO or ~Vr V gtO(I-lC N shy

lN( 60t - - __

(l y) c (j 00 Viexcl rXl - ltl N tlor rjO -

~N 6 S=v

~ i g 8 ~~~8 ~ N S6 ltXi = i

~~ ~

~ iquest

iexcl-1 ~~ 8~ 1 2~~ ~~ ~N=C~~ Vi c

iexcls

3192

5302

031

568 257

1532

2092 147

001

082

3198

5132

045

584

279

1542 2010

137

001

076

ible

3269 3192 3269

5354

005 270

217

1662

006

5653 1063

2070

006 4172

1065

1874

4398

074

1410

390

1799

4101

018 1349 260

2603 2197

096

001

103 1238 2758

1075

348

056

158

3304 3198 3304 BLEBS

5476

003

399 217

1618 2276

094

001

087

012

5767

898

2079

1070

014

4354

1298

1894

24 01

4421

045

783

651

2857 418

130

190 400

trace element calculatedobserved

001

032

1000

082

ratios (Rayleigh fractionation partition eoeffieients after Bristow 1984) range on the whole between 095 and 118

In general the LalY ratio of the nephelinites inereases with the degree of siliea undersaturashytion i e CIPW Ne + Le + Cs Note that the nephelinites are strongly enriched in LREE (ehondrite normalized values La = 235-329 Ce = 177-245 Nd = 82-110) relative to HREE (Yb = 7-11 Lu = 7-10 S Table 4)

Manlle xenolitbs

Representative eompositions of the mantle xenoliths enclosed in the nephelinites are listed in Table 5 They refer to different peridotite suites with or without blebs (BB- and BFshysuites respectively) A detailed diseussion of

-- --] oooo~io6~ o ooooer -) o ln gETU(lgt(lgt rr --] ~n~ -~ ln g --1 ~ 0 00 iexcl Q ~ 0 - vgt 1-- o iexcl N o Uuml(1l bull ~J

= N gVl~Sy~~~~~~-joEJ iexcl r o C r cJu ~ ~g~ ~8

ln N ~ lnlt ~ (1l (J lt ~ 3 (lgt T (lgt O- omiddot (lgt ~ lt-gt ~ o QOOJO lt-gt N 0000amplt[(1) -~(lZ(tl~~tOI~ ~ gt ~~6 Uuml J~O Uuml N(1)o~middot oo~ C) OOO-JN 00 00 o vgtVJ 0~ g 5 8 z

(oshy ~ (3 + ~ ~ 00 - g n l J ~ set 3 eJ r lj ~ (lgt o ~~~~~ ~ 2 ~ ~ lt-gtlt-gt - -~ 9 o ~ ~ e o c 1 O Qiacute OJNvgtO lt-gt -l ~ 5= - ~ N

C) oo~ ln iexcl a -J o a- (1) (ti c --lOO(lgt(O+O aiJiexcliexcl - 00 2 00 JVlNO D~N(ll (lO ~~ ~~g~g (1) (t (1) (J

~o ~ g D s- ~ g O tll

0--- CJ o ( T () amp- o omiddot o-N r ~ ~ gt--gt iexcl~iexcliexcl (lgt ziexcliexcl (lgt JJ Cgt

O- tJj ~ ~ g iexcl iexclOOO -lOiexcl tI1 OWO -l vgt-fQW

(ntilde to ~ ( gt-1 P-OsectJ ()~ 6io~uvoo~t0 tll Vlv~~oo~ZD (f) 00000 VlO o Of 00o I () iexcliexcl (1) ~ e o- (lgt T o lt OOQOO-J t)VI

O-~NJ (1)0 (1)(1)(1)~~]~g- ~~0J T IiexclQ(l 3

gt---gt N gt--- -fomiddot O- 5 ~ 3 ~ ~ ~ l g ~ amp ~ ~ OOOOONvgtOI-- -- (1) VJ ~ J r _ ~J o~middot iexcliexcl ooo~6oo-oto~3 ~ tn ~~ S g N ONvgt 00001-- o lIj M (O o tTlg~~ (1)r~r-- I (D o (1)

Table 4 Average analyses of nephe linites from Easlern Paraguay

Vgt

Jogt

~ r

O r r shyO el

-71 Cl~ ~ Q)

8 5shy3 ~

O (1)

~ y =go Q)gt Vl 5

-00 deg033 tll

~ (0 gtl_ o l _ Vgt _

o 8shy Vgt

~t rgt (O ~

CERRO RI iANSO NUEVA CERRO LIMPIO TACUMBU LAMBARE NEMBY

vERDE CASTILLO TEBLADA PATINO

I(n ~ 2) 2(n ~ 2) 3( ~ 1) 4( ~ 2) 5(n ~ 4) 6( ~ 2) 7(n ~ 1) 8( ~ 2) 9(n ~ 6) lO(n ~ 14) 1I(n ~ 6) 12(n ~ 2)

SiO 4152 4337 44 35 4283 4345 4242 438 1 43 10 4453 4378 43 72 4470 TiO~ 268 255 224 218 263 256 238 2 11 213 220 220 209 AIOacute 1243 1400 16 05 1337 1485 13 52 14 74 1346 1367 14 03 1430 14 81 FeOl 1142 1108 1017 1128 1055 1162 1002 1113 1047 1062 1060 1012 MnO 024 022 018 024 018 022 018 022 020 022 021 02 1 MgO 1221 985 803 1043 965 IIl9 1007 1077 9 99 952 901 869 CaO 1260 1090 11l2 1148 1128 1096 12 06 1087 1062 1072 1070 1004 ~ Na20 472 580 545 535 517 505 1 15 575 553 57 1 602 636 2 KO 094 126 148 169 143 129 069 14 7 171 196 198 178 iexcliexclPO 124 097 093 lll 081 117 090 11 2 11 5 124 126 120 lt Co 54 48 50 58 46 53 49 J

(1)Cr 492 389 398 432 377 550 542 609 549 530 515 491 Ni 284 228 154 277 182 320 207 292 277 258 250 254 gshyBo 1289 1055 J031 1011 1253 1000 1090 11141 1005 1066 1090 1144 ~ Rb 55 38 56 56 71 41 22 60 58 56 60 60 Sr 1278 1109 1102 1079 1104 1081 1016 1061 1089 iexcl1I6 11 23 1150 ~ La 133 107 81 102 84 112 81 112 114 122 122 129 Nd 49 49 66 49 63 Ce 192 160 141 185 133 178 145 172 183 191 19 1 192 a

iexcloYb 19 16 19 15 15 (]O Lu 027 024 028 022 032 a Z r 307 294 200 286 222 288 161 259 230 237 234 280 eY 27 29 29 25 20 29 26 27 34 34 34 32 iexcl Nb 125 93 94 100 90 109 89 91 106 112 113 128 a O r 000 745 876 215 846 763 408 608 1011 113 1 1045 JO53 Ab 000 158 428 000 063 008 440 000 342 000 000 45 1 J

An 994 844 14 93 745 1306 1039 1504 655 7AI 684 6 13 658 tTl iexcliexclLe 436 000 000 6 16 000 000 000 205 000 0 19 098 000

Ne 2161 2570 2264 2A 51 2334 2309 2120 2634 23 48 2616 27 58 2669 Cgt

eCs 112 000 000 000 000 000 000 (100 000 000 000 000 Di 3293 3183 2778 34 01 3041 2937 3140 3242 3056 3099 31 43 2872 J

0 1 1981 157 1 13 18 1667 15 13 1956 1528 1774 1624 1525 1 ~ 2 1 1422 O MI 244 236 2 18 241 226 248 215 238 223 228 226 216 iexcliexclfI 509 485 426 4 14 499 486 452 401 401 418 418 397 iexcliexcl Ap 293 229 220 272 192 277 2 13 265 272 293 298 284 (]O

e iexcliexcl

Mg lt(1) 0687 0646 0619 0655 0653 0664 0674 0665 0662 0648 0636 0638 (2) 0692 0651 0624 0660 0658 0669 Ooacute79 0670 0667 0653 0641 0643

Fe20 621 456 384 439 447 468 399 445 407 417 409 402 FeO 548 666 640 7 06 613 669 613 682 647 654 660 6 19 LO 246 234 199 200 269 211 187 234 206 202 206 207

Sum 9965 9948 9929 99 47 9933 9921 9932 9962 9929 9928 9926 9930

Total iron as FeO Data normalized lo 100 on a volatile-free basis Fe20 i FeO = 017 for CIPW norm calculation Mg number (Mg) MgI(Mg + Fe2+) Fe20olFeO ralios of 017 for (1) and 020 for (2) Original Fe203 FeO LOI and sum are also given Numbers 1 to 8 as in Fig 1 numbers 8 10 12 from Nemby hill averaged for diffe re nt MgO contenlsbull REE data from Bilsche ne (1987) Number of analysed samples is given V1 in brackels V1

bull bull bull

bull bull bullbull

bull bull

bull bull

bull bull bull

516 P Comin-Chiaramonti et al

1shy

1shy

FeO

bull bull bull o

o o o o bull

bull bull CaO

bull O O

bull bull bull bull

OO O bull bull

-

-

-

-

1shy

1shy

bull

AI203

O

o middot bullO middot 0 bull O bull bull P20S

bull

O O

O O

bull O

bullbullbull bull bull -

-

-shy

-

Ti0 2

bull bullbull-0deg

O O bull O

bull bull N~O

bull deg0

O 0 O

bull bull bull bull bull -

--

-

-

-

bull3

Si02

I

O 0912 10

O 7O 8 11 5middot~ O

I I I

bull6

I

bull1

K2 0

bull3

I

12 11

0 0

I

10 9 4 O O bull O

8 smiddot 2f

6bull I I

1bull -

-

8 10 12 8 10 12

MgO

Fig 4 MgO (wt) vs majar element (wt) diagrams far the nephelinites of the Asuncioacuten area Numbers as in Table 4 symbols as in Fig 2

70 bullbull O000 O bull

-bull bull Rb

bull

O

bull - O bullO ltfl

bull Sr

bull O O

bull middot o O

Omiddot

bull Ba

bull O O

00 O

bull bull

Ni

9 0 8 1110 0 bull

3 616 0 O 7

bull I smiddot4 II I

Cr

bull 1

110

30

90

1200

30

1000 20

300 1200

200 1000

180

300

140

200

120

600

100

400

bullO

bullO O O bull O Nb

bull 00 O~bull omiddot bull y

bull middot0 bull bull O

O 00 Zr

0- O 0middot0middot bull bull

Ce

0 0 9 bull1

10

12 0 11 O 8 6

bull O 2

bull bullmiddot4

bull3 S La

8 10 12 8 10 12

MgO MgO

Fig 5 MgO (wt) vs trace element (ppm) diagrams far the nephelinites of the Asuncioacuten area Numbers as in Table 4 symbols as in Fig 2

Tertiar) ni

Table 5 Representative end-membeJ and BB mantle suites respectivey mantle xenoliths (Demarchi el al 19

BF Suite 3192 3269

Si02 4468 4366 Ti02 006 001 AI~03 256 077 FeO 788 766 MnO 012 011 MgO 4137 4610 CaO 227 071 Na20 010 005 K20 009 006 P20S 002 000

Cr 2968 2379 Ni 2131 2377 Ba 10 2 Rb 3 2 Sr 11 13 La 3 3 Ce 5 4 Zr 13 12 Y 4 1 Nb 6 6

the xenolith compositional varial in C omin-Chiaramonti et al (1986 chi el al (1988) We point out her bearing xenoliths are signifieantl~ K20 (up to 049 ) and inee ements

Sr Nd and e isotop

lnitial 87Sr86Sr ratios (Ro) of se linites range from 070362 to O present-day 143Nd144Nd ratio s 051262 to 051280 (Table 6) Sam (eg Limpio) or high (eg e contents of crustal xenoliths have Ro values (ie 070378 and 070 ively) These data and the absence correlations between Ro and SiC and Ba as well as their rapid surface suggest that the investigat tes were not appreciably modifie components (i e granitic compone

11

10

16 1shy

12

28

24

43

41

12

10

13

09

6

5

2

ll

bull ----l 12 o

) o o J 10

~ 13 J O

O bull

O

bull tO

O O bull bull O J 5bull

10 9 4 8 O O bull O 6

O 1 -i 2

S 1bull2 7

~ 10 12

eliniles of lhe Asuncioacuten area Numbers as

bullO

bull00 O bull O Nb

OOO iexcl bull O Y

bull

O bull bull O

0deg 0 bull Zr

bull00 O 0 0bull

bull bullbull Ce

10 bull1 12deg1 1

0 0 6bull

8 6 O bull

2 4

5 7 La3 bull Ibull 8 10 12

Tertiary nephelinitic magmatism in Eastern Paraguay 517

Table 5 Representative end-members analyses of BF The mantle xenoliths enclosed in the nephelinishyand BB mantle suites respectively from Asuncioacuten tes have Sr and Nd isotopes (Petrini unpublished manlle xenoliths (Demarchi el al 1988) data) which differ from those of the nephelinishy

tes These differences are important (eJ Fig 6) BF Suite BB suite and indicate that the mantle source(s) of the 3192 3269 3198 3304 nephelinitic magmas was isotopically distinct

from that represented by the enclosed mantle Si02 4468 4366 4497 4270 xenoliths

Ti02 0 06 0 01 009 002 When the Ro values of the nephelinites are

AI2O) 256 077 246 126 plotted against KlAr age a temporal trend

FeO 788 766 784 782 becomes apparent (Fig 7) Between 60 and 40

MnO 012 011 012 012 Ma Ro value continuously increases with age MgO 4137 4610 3993 4557 apart from the Cerro Patintildeo samples This CaO 227 071 301 101 trend suggests slightly different nephelinite Na20 010 005 026 024 sources K20 009 006 043 0 36 Carbonate from nephelinites have 8J3C rangshyP20 5 002 000 005 004 ing from -52 to - 790 (av -70 plusmn 09 0

Table 7) in agreement with an origin from the Cr 2968 2379 2396 3182 mantle (-7 plusmn 10 Pineau amp Mathez 1990)

Ni 2131 2377 2081 2321

Ba 10 2 31 36 Discussion and conclusion Rb 3 2 7 7

Sr 11 13 44 73 In general there is a consensus that nephelishy

La 3 3 4 3 nitic magmas are generated by low degrees of

Ce 5 4 7 5 melting and high CO2(C02 + H 20) ratios in

Zr 13 12 15 12 garnet peridotites which are enriched in incomshy

Y 4 1 5 3 patible elements prior to or during melting Nb 6 6 7 8 (eg Eggler 1978 Frey el al 1978 Boetshy

tcher el al 1979 Menzies amp Murthy 1980 Bristow 1984 Wyllie 1987)

Spinel peridotites strongly enriched in incomshythe xenolith compositional variations is given patible elements may also be suitable parental in Comin-Chiaramonti el al (1986) and Demarshy materials for the genesis of strongly alkaline chi el al (1988) We point out here that blebshy melts (eJ Roden el al 1984 Roden 1987) bearing xenoliths are significantly enriched in Thus it is important to test if at least in terms K20 (up to 049 ) and incompatible elshy of major and trace elements the studied nepheshyements linites may have originated from mantle sources

similar to those represented by the enclosed spinel-peridotite xenoliths which are enrichedSr Nd and e isotopes in incompatible elements

lnitial 87Sr86Sr ratios (Ro) of selected nepheshy The high Mg-number (064 - 069) and the linites range from 070362 to 0 70392 while high Cr (377-609 ppm) Ni (154-320 ppm) and present-day J43NdI44Nd ratios vary from Co (48-58 ppm) contents indicate that the 051262 to 051280 (Table 6) Samples with low investigated nephelinites approach the composhy(eg Limpio) or high (e g Cerro Verde) sition of a primary magma from the manUe In contents of crustal xenoliths have very similar fact it is sufficient to add 3-6 wt of olivine Ro values (ie 070378 and 070381 respectshy F088 (OlP of Table 2) to obtain nephelinites ively) These data and the absence of significant with an Mg-number of 071 (theoretical correlations between Ro and Si02 Rb K20 nephelinite Table 8) and Ba as well as their rapid ascent to the Mass balance calculations assuming a spinelshy

MgO surface suggest that the investigated nephelinishy lherzolite xenolith strongly enriched in incomshytes were not appreciably modified by crustal patible elements as a mantle source (ie

lelinies of lhe Asuncioacuten area Numbers as components (ie granitic components) BB3198 mineral and bulk rock compositions

Table 6 Initi al 87S r86S r (Ro) a nd present day 143Nd144 Nd ratios of se lecled samples of ultra-a lka line rocks from Ihe Asuncioacuten area V1

LOCALITY AGE (Ma)

CERRO VERDE 570t23

LIMPIO 502t 19

LAMB AREacute 489 t22

NUEVA TEBLADA

46 3 t 20 NEMBY 457t18

TACUMBUacute 413t16

REMANSO CASTILLO

406t 16

CERRO PATINO 388t 20

shy(X)

SAMPLE 3080 3082 3097 3103 3209 3213 3283 3068 3083 3399

SiOz TiOz AlzO] FezO] FeO MnO MgO CaO NazO KzO PZ05 LO

Sum

Co Cr Ni Ba Rb Sr La Ce Zr Y Nb

4003 258

1198 627 546 023

11 77 1215 4 55 091 119 244

9956

53 480 277

1258 55

1278 130 188 300 27

122

4188 246

1352 460 664 021 951

1052 560 122 094 229

9939

385 223

1050 39

1111 105 157 288 29 96

4105 248

1310 458 680 021

1084 1062 489 125 113 205

9900

57 544 317 991

41 1070

111 176 285

29 108

4148 2 11

1295 448 714 023

10 10 1112 5 18 164 111 185

9939

428 274

1004 56

1066 101 183 282

25 99

4252 205

1341 402 648 020 954

1045 580 146 118 219

9929

58 648 273 980

59 1013

116 176 234

33 101

4191 216

1369 347 722 020 889

10 84 555 1 93 122 212

9920

539 242 990 50

1030 106 180 237

36 101

4247 209

1320 407 678 020 988

1046 462 226 116 207

9926

500 253 968

50 1063

119 186 225 33

105

4184 253

1430 451 617 017 929

10 86 498 138 078 259

9940

50 371 179

1237 70

1082 82

131 218

20 89

4298 217

1555 384 640 018 778

1078 528 143 090 199

9929

48 398 154

1031 56

1102 81

141 200 29 94

4252 232

1440 399 613 017 977

1171 500 067 087 187

9932

46 542 207

1090 22

1016 81

145 165 26 89

j

() o

ordfl n ~ Q) Q)

3 o amp ~

~

R(87SrJ86Sr)o 070381t1 070378t l 070374t1 070369t l 070363 t1 070362t1 070369 tl 070365 t3 070367t1 070392t1

14]Ndl l44 Nd 0512729t6 0512624t 12 0512803t6 0512800t20

0512760t 10 0512655 t 8 0512746t6 0512753t7

Mg 0690 0650 0676 0655 0665 0644 0665 0654 0624 0679

QtQl _ ero o l eS ~ ~3()~ O o _ _ 1 o ~ o 2 ~_ Vl ~ l o ol 1gt-0 ~ g ~ 5 middot r g 3 = () cr _ - ()~ ~2 ~ ~_ cFo ~

0~~3 - iquestoz3~ ~ ~ ~ ~

g ~

o

o w I

o

o w 00

I

o

o w ltDIr I

~ 3 ~ ~ ~ g 1 ~~ a~~~ ~~6- 2 -~0 cn~QQ~ (l Or 1 o

11 2 5- amp o 3 iquest o Ol - iexcl 2 ~ o ~ lt O = ~ t~wcc32~z-l ~ _ o x o O o ~ e ntilde g ~ ~ g ~ ~ ~ sect ~ ~~ 2s Vl (tl o ro CIl (ti

~ tn 3 ~ = __ 2 g ~ w ~ ~ ~ 2shyfr ~ g g g 5 0

-lt t ~ ~ ~ a tJJ=tgto-ltc ~~ ~~g2

= u- lt-ro

l-~

= lt-ro --

p lt-ro

ltLgt

70) gl o-J (l)

iexcliexcl lt J (l)

Tertiary nephelinitic magmatism in Eastern Paraguay iexcll 519

r-ONO V)lJ)C)OshyOON~OOvONOON S o -c-c

-r~ON - OO V)()vOOO ~O No-shy-8 ~ N

Or-O NN ~ COOa-r-()r- OOCO() - NOO -(-1 - N

C)coO()OC)V)()VIV)DVO - OONnC NO- S- N shy

N OOOOOt--01I ~OV)()OOOt)C)O No S1l-N shy

MOr-COlllOrlO O nshy__ Vr-Mf)O

NO S--N -lt

) -t -r 00 - () N lJ) Ogt I r-OV)Cl O OOCO NOgt

N S S--N

r- O O lE) O- ce Oltfr- -r- OONO

)(lt)0 S--N

)C)OOIIV) r-- ooa--o gt()V) ()11 CV)OONOshy)N ~ - N

~r-OOV OOOOOO r- N Or- V)lf)r--CiOOONN f N Sj s--) shy

)Za)~ vJ 8Ngt-Z

+1 ~ lt=gt ltshy6

+1 D lt)

lt=gt

+1 v -D

lt=gt lt-

+1 oshy-D lt)

lt=gt

+1 D lt-

+1 D lt) o 6

+1 Oshy-D

=

-+1 lt)

lt=gtltshy6

+1 00 = lt-

+1 c O

o

c

~ ()

iquest rl

+1 v ltshy v

6

D +1

-D

Ntilde v

lt=gt

00 +1 V v -D N

S +1 o -D ~ V

-D O

~~ 0= ~O ~Ssect

V

6

S +1

-D S V

= -D +1 OshyN N V

6

-o Z iexcl iexcl f

oshy 6

~ D

6

-D

v -D

~ -D 6

v -D

V V

D (C 6

~ 6

$ 6

oacute

(143144) ~d

05129

05127

05125

0705 Ro Fig 6 143Nd l44Nd (present day) vs Ro (87S rj86S r initial ratios) diagram for Asuncioacuten ultra-alkaline rock-types enclosed mantle-xenoliths (Petrini unpublished data BB and BF = Bleb-bearing and Bleb-free suite respectshyively) and Mesozoic tholeiitic basalts of Central-Eastern Paraguay (Corda ni el al 1988 L-Ti and H-Ti lowshyand high-titanium suite respectively) Other fields SP = SI Paul rocks (Roden el al 1984) FN = Fernando de Noronha Quixaba Formation (Gerlach el al 1987) AB = Abrolhos (Fodor el al 1989) Ro relative to Mantle Array and Bulk Earth (after Faure 1986) calculated at 41 Ma assuming RbSr ratio = 0025 and 87Srf86Sr = 07047 for present day Bulk E arth

~ I

-Z~~nit

Asunltioacuten mantle xenolilhs

(DBB o BF)

0704

Ro +CPce 070391shy

070381shy tcv

f +LA

070371shy -ff- RC

-f--I Ma

I

60 50 40 Fig 7 Ro vs age (Ma) di agram (ages after Bitschene 1987) for nephel inites from the Asuncioacuten area CC Cerro Confuso phonolitic plug 2 km south of Cerro Verde hill (Ro after Bitschene 1987) CV Cerro Verde LI Limpio LA Lambareacute NT Nueva Teblada N Nemby T Tacumbuacute R C Remanso Castillo CP Cerro Patintildeo) Bars indica te 20 for Ro and 10 for the age


Table 7 iexcliexcl13Co (vs PDB-1) values of carbonates from selcelcd neph elinite sa mples

Sample iexcliexclIJCo Sample iexcliexcl13Co

3199 3213

3252

3260

-687 - 707

-764

- 792

3263

3313A 3222

3288

-522

-739

-687

-734

Table 8 Calculated theoretica l parent melts (Mg 071) for Asuncioacuten nephelinites (see tex t for explanashytion)

13 14 15 16

Si02 4159 4231 4366 4296

Ti02 261 241 228 199 Al20 3 1212 1275 1410 1270

FeO 1141 11 59 1007 1113 MnO 024 022 018 022 MgO 13U 1331 U72 1285

CaO 1228 1033 1154 1026

Na20 460 476 493 543 K20 092 122 066 139

P20S 121 110 086 106

Co 57 67 51 61

Cr 515 612 587 676

Ni 358 546 309 492

Ba 1257 943 1043 983

Rb 54 39 21 57

Sr 1246 1019 972 1002 La 130 106 78 106

Ce 188 168 139 163

Zr 300 272 159 245

Y 26 27 25 26

Nb 122 103 85 90

The original nephelinites are from Table 4 and the added olivine (011P) from Table 2 Theoretical nephelinites are the following n13 = nl + 253 wt 01 n14 = n5 + 577 wt 01 n 15 = n7 + 437 wt 01 n16 = n8 + 563 wt 01

in Tables 3 and 5 respectively) show that the degree of melting necessary to produce a theo retical nephelinite ranges from about 5 to 6 The best solutions (L res2lt 02) yield the following solid residua 01 = 624-661 Opx = 198-201 Cpx = 103-11 9 Sp = 001shy004 Phlog = 26-29 The incompatible elshy

ement contents in the source were calculated using a batch melting equation The partition coefficients used in the calculations are listed in Table 9

The results (Fig 8A) show that the so urce of the theoretical nephelinite should be enrichshyed (15 - 4 times) in Ti Ba P Nb Ce La and Zr and depleted in Y relative to the contents in Iherzolitic xenoliths enriched in incompatible elements (BB) Thus the Asuncioacuten nephelinites cannot be generated by melting of spinel Iherzolites of the type represented by the enclosed spinel-Iherzolite xenoliths

As a further test we assumed that the harzburgitic xenolith BB3304 enriched in incompatible elements (mineral and bulk rock compositions in Tables 3 and 5 respectively) represents a possible mantle residue The minshyeral assemblage calculated from mass balance (L res2 = 01) is 01 = 813 Opx = 117 C px = 36 Sp = 12 Amph = 09 and Phlog = 13 In this case assuming 2-6 melting the calculated element contents relative to those of the theoretical nephelinites are distinctly higher (2-3 times) for Ba P and Ti and lower (by ea 05) for Y (ef Fig 8B) Similar results are also obtained assuming that the lherzolitic xenolith BB3198 is a solid partial melting resishydue with 2-6 of melting

Thus melting models suggest that it is unshyIikely that the associated harzburgitic and lherzolitic xenoliths enriched in incompatible elements represent solid partial melting residua related to the generation of the theoretical nephelinite

Considering garnet-peridotite sources (whole-rock and mineral compositions after Harris el al 1967 Chen 1971 MacGregor 1977 Bristow 1984 Dautria el al 1987 Wilkinson amp Le Maitre 1987) the generation of the Asuncioacuten theoretical nephelinites may be modelled for 3-6 degrees of partial meltshying for major elements only Calculated contents of incompatible elements in the source normalized with respect to primordial mantle (Nelson el al 1986) yield (eg for 4 meltshying) the following enrichment factors Rb =

13-44 K = 1-3 Zr = 1-19 Sr = 2-3 P = 31-46 Ce = 33-45 Ba = 6-9 La = 5-8 and Nb = 84-14

The geochemical a nd Sr-Nd isotope data as well as the me lting models show that the Asuncioacuten nephelinites are not derived from sources similar to the enclosed spinel-peridotite

Tertiary n

Table 9 SoliciI

01 Opl

Rb 00001 OOC Ba 00001 001 K 00002 OOC Nb 00010 01 5 La 000044 000 Ce 000030 000 Sr 00010 001 P 0043 001 Zr 001 003 Ti 0D10 OlOt y 00010 0081

01 olivine Opx orthopyroxene C amphibole Source data Hanson 19 al 1984 Villemanl el al 1981 Prill

U1 tlJ U shy

o ~

Vl

O tlJ

9 ~

~ o u

~ e

tlJ L Q tlJ e

tlJ O o E

4

3

L shyo e tlJ x 2

O tlJ 01 01 o gt

O

SS 3198 as mantl~ sou 6 m~lting

So Nb C~ P

Rb K La Sr

Fig 8 A spidergrams of calculated r neph eliniles 13 to 16 Table 8) normal here as mantJe source B spidergram 35 melting and Ihe BB3304 harzburg

al Tertiary nephe linitic magmatism in E as tern Paraguay 521

ntents in the source were calculated Table 9 Solidliquid partition coefficients used in the melting models latch melting equation The partitio n ts used in the calculations are listed ) sults (Fig 8A) show that the source ~oretical nephelinite should be e nrichshy4 times) in Ti Ba P Nb Ce La and lepleted in Y relative to the contents itic xenoliths enriched in incompatible (BB) Thus th e Asuncioacuten nephelinites le generated by melting of spinel s of the type represented by the spinel-Iherzolite xeno liths furth er test we assumed that the

itie xenolith BB3304 enriched in ible elements (mineral and bulk rock ions in Tables 3 and 5 respectively) ts a possible mantle residue The minshymblage calculated from mass balance = 01) is 01 = 813 Opx = 117 Cpx Ip = 12 Amph = 09 and Phlog = his case assuming 2-6 me lting th e d element contents relative to those heoretieal nephelinites are distinctly ~-3 times) for Ba P and Ti and lower J5) tor Y (cf Fig 8B) Similar results obtained assumin g that the Iherzolitic BB3198 is a sol id par tial melting resishy2-6 of melting melting mod els suggest that it is unshy

hat the associated harzburgitic and ie xenoliths enriched in incompatible represent so lid parti al me lting residua to the generation of the theoretical iexclIacutete jering garnet-peridotite sources middotock and mineral compositions after tal 1967 Chen 1971 MacGregor 3ristow 1984 Dautria el al 1987 )11 amp Le Mai tre 1987) the gene ratio n Asuncioacuten theoretical nephelinites may ~ lIed tor 3-6 degrees of partial meltshy

major elements only Calculated of incompatible elements in the source zed wi th respect to primo rdial mantle el al 1986) yield (e g for 4 meltshy

fo llowing enrichment fac tors Rb =

K = 1-3 Zr = 1-19 Sr = 2-3 P =

Ce = 33-45 Ba = 6-9 La = 5-8 and 4-14 eochemical and Sr-Nd isotope data as

the melting models show that th e in nephelinites are not derived fr om similar to the enclosed spinel-peridotite

01 Opx Cpx Gar Sp Phlog Am ph

Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020

01 olivine Opx orthopyroxene Cpx c1inopyroxene Gar garnet Sp spinel Phlog phlogopite Amph amphibole Source da ta Hanson 1977 lrving 1978 Frey el al 1978 Pearce amp Norry 1979 Ottonello el

al 1984 Villemant el al 1981 Prinzhofer amp Allegre 1985 Ewart amp Hawkesworth 1987

4 rBB 19 0 mooH 0 A 6 melting

l ltIl Qgt U J

~I 3 3 O Qiexcl 9I J u

lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti

Rb K La Sr Zr y Rb K La Sr Zr y

4 1- BB 3304 as mantll rlsiduum B 35 melting

Ba Nb Ce p Ti

Fig 8 A spidergrams of ca lculated mantle source compositio ns relative to theoretical nephelinites ( model nephelinites l3 to 16 Table 8) norm alized to the composition of BB3198 mantle lherzolite (Table 5) assumed here as mantle source B spidergrams of theore tical nephelinites normalized lO calculated liquid assuming 35 melting and the BB3304 harzburgite (Table 5) as res iduum

i


xenoliths On the co ntra ry ga rnet-peridotite sources are preferred because these types of middot source allow a simpler ex planation for the 200

strong and variable fractionation between LREE and HREE (vari able amounts of garnet in the residua) Note that ga rnet-peridotite 1shysources also require important enrichments in 100 1 1 incompatible elements relative to a primordial o i middot1

I 1 ~ mantle I J Incompatible eIement enrichment may be Q)

1 iexcl I broadly associated with metasomatic processes

~

e SO i I yo ro i Iinvolving fluids andor small volume melts (eg E ltgt- - i JMenzies el al 1987 Erlank el al 1987) 11Whatever the origin of these fluids there is in shy

O gagreement that the source was probably in the O

deeper parts of the Iithosphere or upper astheshy E nosphere and that such fluids like ly derived a

from volatile-rich alkaline mel ts Q)Assuming an average hea t flow value of 58 amWm2 for the Parana Basin (Hamza 1982) in 10E

Eocene times and a peridotite solidus with ro Ul

CO2(C0 2 + H2) of 08 (Wyllie 1987) volatileshyrich f1uids could be related to partially melted diapirs generated mai nly at depths less than 200 km Thus a wide zone of mantle metasoshymatism may extend between the lower part of Ba Nb Ce p TI

the lithosphere up to the solidus ledge (Wyllie Rb K la Sr Zr y

1987) The existence of primary carbonates of Fig 9 Spidergrams of Asuncioacute n oephe linites (sol id

mantle origin in the Asuncioacuten nephelinites sugshy and open circles Nem by and Cerro Pa tintildeo respectishygests a COTbearing perido tite source with vely) a nd M esozoic alkaline rocks (triangles sorne H20 component The small enrichment tephryte dykes of Sapucai area D e Mio uopublishshyin Zr rela tive to Nb in the mantle source could ed data) normaJized to primordial manlle (values be due to Zr-Nb decoupling occurring at a partishy from Ne lsoo el al 1986 i e ppm Rb = 069 cular CO2(C0 2 + H20) ratio (Watson 1979 B a = 681 K = 240 Nb = 075 La = 071

Haggerty el al 1986) Different H20-C02 proshy Ce = 185 Sr = 237 P = 92 Nd = 137 Zr = 111 Ti = 1300 Y = 469)portions at different depths might expla in the

compositional differences among th e Asuncioacuten nephelinites

The metasomatic event(s) might be linked We e mphasize that the Sr isotope ratios of to the thermal anomaly responsible for the the Asuncioacuten nephelinites (Ro = 07036 shygeneration of the Parana Basin flood tholeiites 07039) are distinctly lower than those of (ca 140-120 Ma) 1t is interesting to note that th e lower Cretaceous alkaJine magmatism of the metasomatic processes responsible for the Central-Eastern Paraguay (Sapucai-Ybituruzuacute form ation of the South African phlogopite-K area 07073 plusmn 00003 age = 128 plusmn 8 Ma richterite peridotites occurred 90-150 Ma ago Bitschene 1987) and even those of the adjoinshyafter the peak of basal tic flood volcanism in ing Paran a flood basalts to th e East (Ybytushythe Karoo province at ca 190 Ma (Waters amp ruzuacute-Ciudad de Leste area R o = 07059 plusmn Erlank 1988) 00002 age = 132 plusmn 12 Ma Bitschene 1987

RO_143Nd I44 Nd variations (cf Fig 6) show Piccirillo el al 1988) Tbis indicates that the that the f100d basalts of the Parana Basin (Corshy Tertiary a lkaline magmatism of Paraguay origshydani el al 1988 Piccirillo el al 1989) are inated from a more depleted mantle source related to mantle so urces isotopically distinct distinct from sources feeding th e Cretaceous from those of th e nephelinites and enclosed magmatism Such mantle source diffe rences mantle xenoliths might be responsible for the existence of a pro-

Tertiary m

Fig 10 Cre taceous Gondwanala[d sI a(05S Africa aod Brazil (1 Aragua Torres Syoclioe 5 R io Grande Arel U ~Itra-a lka lioe K Kimberli1e) RI Modified after Le Bas (1987) SourcQ Gomes el al 1990

nounced negative Nb anomaly in t ~

alkaline magmatism but not in the Tertiary nephelinites (Fig 9)

If reference is made to the di alkaline and ultra-alkaline Mesoz tiary magmatism in SE-Brazil as Angola-Namibia counterpart (Fig that both show NW-SE and NE respective ly Notably the alkalilH trends transversalIy to the general the mid-ocean ridge and does n~

main structural grain of the cry meol This indicates -as suggestcd (1987)- that the distribution of SU

Tertiary alka lioe magmatism Vas constrained by stress regime varia to the opening of the SOllth Atl than by ancient structllrallineamcn

Acknowledgements The authc benefitted from the critical revicw suggestions of Dr A Cundari

Thanks are due to the Brazili CNPq FAPESP and FINEP an agencies CNR and MPI (40 ) support The CNR is acknowlcdge ing the installation and mainten microprobe laboratory at Cagliar The authors are indebted to Prol for assistance in microprobe work

1 I

Tertiary nephelinitic magmatism in Eastern Paraguay 523al

1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr

idergrams of Asuncioacuten nephelinites (solid cireles Nemby and Cerro Patintildeo respectishyj Mesozo ic alkaline rocks (triangles Iykes of Sapucai area D e Min lnpublishshynormalized to primordial mantle (values

son el al 1986 ie ppm Rb = 069 K = 240 Nb = 075 La = 071

Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)

nphasize that the Sr isotope ratios oiacute ncioacuten nephelinites (Ro = 07036 are distinctly lower than those of ~r Cretaceous alkaline magmatism of Eastern Paraguay (Sapucai-Ybituruzuacute 7073 plusmn 00003 age = 128 plusmn 8 Ma e 1987) and even those of th e adjoinshyna flood basalls to the East (Ybytushydad de Leste area R o = 07059 plusmn 1ge = 132 plusmn 12 Ma Bitschene 1987 eL al 1988) This indicates that the alkaline magmatism of Paraguay origshy

rom a more depleted mantle source trom sources feeding the Cretaceous sm Such mantle source differe nces responsible iacuteor lhe existence of a pro-

W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK

I Fig 10 Cretaceous Gondwanaland showing the opening of the South Atlantic Ocean and main Iineaments across Africa and Brazil (1 Araguaia-Paranaiba-Cabo Frio 2 Ponta Grossa Arch 3 Rio Piquiri 4 Torres Syncline 5 Rio Grande Arch) The major occurrences of alkaline complexes are shown CA alkaline U ultra-alkaline K Kimberlite) RGR Rio Grande Rise WR Walvis Ridge MS Mossamedes Swell Modified after Le Bas (1987) Source data Smith amp Gomes el al 1990

nounced negative Nb anomaly in the Cretaceous alkaline magmatism but not in the investigated Tertiary nephelinites (Fig 9)

If reference is made to the distribution of alkaline and ultra-alkaline Mesozoic and Tershytiary magmatism in SE-Brazil as well as in the Angola-Namibia counterpart (Fig 10) we note that both show NW-SE and NE-SW trends respectively Notably the alkaline magmatism trends transversally to the general N-S trend oiacute lhe mid-ocean ridge and does not iacuteollow the main structural grain of the crystalline baseshyment This ineacutelicates -as suggested by Sadowski (1987)- that the distribution of such MesozoicshyTertiary alkaline magmatism was tectonically constrained by stress regime variations related to the opening of the South Atlantic rather than by ancient structurallineaments

Acknowledgements The authors greatly benefitted from the critical review and helpful suggestions of Dr A Cundari

Thanks are due to the Brazilian Agencies CNPq FAPESP and FINEP and to ltalian agencies CNR and MPI (40 ) for financial support The CNR is acknowledged for financshying the installa tion and maintena nce of the microprobe laboratory at Cagliari University The authors are indebted to Prof Garbarino for assistance in microprobe work

Briden 1977 Sadowski 1987 Piccirillo el a 1989

References

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Bellieni G Comin-Chia ramonti P Marques LS Martinez LA Melfi AJ Nardi AJR Picshycirillo EM amp Stolfa D (1986) Continental flood basalt from the central-western regions of the Parana plateau (Paraguay and Argentina) petrology and petrogenetic aspects N ] B Miner Abh 154 111-139

Bitschene PR (1987) Mesozoischer und Kanozoisshycher anorogener magmatismus in Ostpa raguay arbeiten zur geologie und petrologie zweier Alkashyliprovinzen PhD Dissertation Heidelberg Unishyversity Heidelberg 317 p (unpublished)

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524 P Comin-Chiaramonti el al Tertiary riexcl

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Cordani UG Civetta L Mantovani MSM Petrini R Kawashita K Hawkesworth Tayshy101 P Longin elli A Cavazzini G amp Piccirillo EM (1988) Isotope geochemistry of flood volshycanics from the Parana Basin (Brazil) In The Mesozoic flood volcan ism from the Parana bazi n (Brazil) petrogenetic and geophysical aspects EM Piccirillo and A J Melfi ed IAG-Usp Sao Paulo Brazil 157-178

Dautria JM Liotard JM Cabanes N Girod M amp Brigueu L (1987) Amphibole-rich xe noshylith s and host alkali basalts petrogene tic consshytraints and implications on the recent evolution o( the upper manlle ben ea th Ahaggar (Central Sahara Southern A lgeria) Contrib Mineral Petrol 95 133-144

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Eggler DH (1978) The effect of COz upon partiacuteal me lting of peridotite in the system NazO-CaOshyAlzOrMgO-SiOrCOz to 35 kb with an analysis of melting in a peridotite-HzO-C02 syste m Amer l our Sei 278 305-343

Erlank A J Waters FG Hawkesworth cJ Haggerty SE Allsopp HL Rickard RS amp Meozies MA (1987) Evidence for mantle metasomatism in peridotite nodules from the Kimberley pipes South Ahmiddotica In Manlle Metashy

somatism MA Menzies and C J H awkesworth ed London Academic Press 221shy309

Ewart A amp Hawkesworth cJ (1987) The Pleistoshycene-recent Tonga-Kermadec are lavas inte rpreshytatio n of new iso topic and Rare Earth data in terms of a depleted mantle source model 1 Petrol 28 495-530

Faure G (1986) Pri ncipIes of Isotope Geology llnd ed Wiley amp Sons Inc New York 589 p

Fodor RV Mukasa SB Gomes CB amp Corshydani UG (1989) Ti-rich Eocene basa ltic rocks Abrolhos Platform offshore Brazil 18degS Petroshylogy with respect to South Atlantic magmatism 1 Petrol 30763-786

Frey FA amp Prinz M (1978) Ultramafic inclusions from San Carlos Arizona petrological and geoshychem ical data bearing on their petrogenesis EPSL 38 129-176

Frey FA Gree n D H amp Roy SD (1978) lnteshygrated models of basal pe trogen esis a study of guartz tholeiites to olivin melilites from South Eastern Australia utilizing geochemical and expeshyrime ntal petrological da ta 1 Petrol 19463-513

Gerlach D C Stormer J C Jr amp MueJler PA (1987) Isotopic geochemistry of Fernando de Noronha EPSL 85 129-144

Gomes CB Ruberti E amp Morbidelli L (1990) Carbon atite complexes from Brazil a review 1 South Am Earh Sei 351-63

Haggerty SE Erlank AJ amp Grey LE (1986) Metasomatic mineral titan ate complexing in the upper mantle Nature 319 761-763

H amza V M (1982) Thermal structure of South American continental lithosphere during Archean and Proterozoic Rey Eras Geoeienc U 149shy159

Hanson GN (1977) Geochemical evolu tion of the suboceanic mantle l geol Soe London 134 235-253

Harris P G Reay A amp White LG (1967) Cheshymieal composit ion of the upper mantle 1 Geoshyphys Res 726359-6369

Irving AJ (1978) A review of experimental studies of crystallliguid trace element partit ioning Geoshyehim Cosmoehim A ea 42 743-770

Le Bas MJ (1987) Ultra-alkaline magmatism with or without rifting Teeonophysies 143 75-84

- (1989) Nephelinitic and basanitic rocks 1 Perol 30 1299-1312

Livieres RA amp Quade H (1987) Distributioacuten regionaacute l y asentamiento tectonico de los compleshyjos alcalinos del Paraguay Zbl Geol Paloon Teil 1 78 791-805

Maal0e S amp Prinzlau 1 (1979) Natural pa rtial melting of spine l Iherzoli te 1 Perol 20 727shy741

Macgregor LD (1977) Mafic and ultramafic xenoshyliths from the Kao KimberJite pipe In Proc

Second Inl Kimberlite eonf a OA Menzies ed 2 156-172

Menzies MA amp Murlhy VR I metasomatism as a precursor a alkali ne magmas Isotopic cidl Sei 280A Jackson Volume 62

Menzies M Rogers NV Hawkesworth ej (1987) l

enrichment processes in lil hosp an effect of asthenosphere-lith tion In Manlle Metaso matisrn and ej H awkesworth ed L Press 313-359

Mercier J C (1980) Single-pyrox metry Tectonophysies 16 1-37

Mercier J e amp Nicolas A (l 975 fablics of upper-mantle pcridoli t by xenolilhs from basa lt s 1 Per

Nelson DR Mceulloch MTmiddot S The origin of ultrapolassic rocks Sr Nd and P isolopes Ceoeiacute Aea 50207-217

Ottonello G Erns VG Joron J Earth and 3-d transition eJcmenl peridotil ic rocks 1) peridolite Alps 1 Petrol 25243-372

Pearce J A amp No rry MJ (1979 implications of Ti Zr Y and Nb trib Mineral Perol 69 33-47

Piccirillo E M eivena L Pctrini A Bellieni G eomin-ehiaran gues LS amp Melfi AJ (1 989) lions within lh e Parana continen seg uences as evidence for di regions and variable cruslal conteacute mical Geol 75 103-122

Piccirillo E M e ornin-Chiaratnomi r Civctta L Margues LS Melfi R Raposo MB amp Stolfa D (J ne lic aspects of continental tlood suites Irom tIJe Parana Basin (B Mesozoic fl ood volcanism of the petrogenelic and geophys ical aspe cirillo and AJ Melfi ed IAG-U Brazil 179-205

Pineau F amp Mathez E A (1990) ( in xenoliths from lhe Hualalai Vo and the generation of iexclsotopie Vi

chim Cosmochim Acta 54 217-2 Prinzhofer A amp Allegre ej (1 9

peridotites and the mechanism of I EPSL 74 251-256

Roden F M (1987) RbSr and Sn metasomatic manlle implications metasomatized mantle in lhe p Na20-rich alkaline basa lts In Mal

al

sm M A Menzies and eJ sworth ed London Academic Press 221shy

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(1986) PrincipIes of [soto pe Geology d Wiley amp Sons lnc New York 589 p Y Mukasa SB Gomes CB amp CorshyUG (1989) Ti-rich Eocene basaltic rocks hos Platform offshore Brazil 18degS Petro shyvith respect to South Atlantic magmatism -01 30 763-786 amp Prinz M (1978) Ultramafic inclusions an Carlos Arizona petrological and geoshycal data bearing on their petrogenesis L 38 129-176 Green OH amp Roy SD (1978) [nteshyl models of basalt petrogenesis a study of tholeiites to olivin melilites from South -11 Australia utilizing geoche mica l and expe shylal pelrological data 1 Petrol 19 463-513 Oc Stormer J C Jr amp Mueller PA 1 lsotopic geochemistry of Fe rnando de Iha EPSL 85 129-144 8 Ruberti E amp Morbide lli L (1990) Iflatite complexes fro m Brazil a review 1 Am Earlh Sci 3 51-63 SE Erlank A J amp Grey JE (1986)

iexclomatic mineral titanate complexing in the mantle Nalure 319 761-763

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naacutel y asentamien to tectonico de los compleshyIcalinos del Paraguay Zbl Ceol Paloont t H7S 791-805 S amp Prinzlau l (1979) Natural parti al ng of spinel Iherzolite 1 Peumiddoto 20 727shy

)r IO (1977) Mafic and ultramafic xeno shy(rom the Kao Kimberlite pipe In Proc


Second Int Kimberlile Conf F R Boyd and H OA Menzies ed 2 156-1 72

Menzies MA amp Murth y VR (1980) Mantle metasomatism as a precu rsor of the genesis of al kal ine magmas l so topic evidence Am Jour Sci 280A Jackson Volume 622-638

Menzies M Rogers N W Tindle A amp Hawkesworth eJ (1987) Metasomatic and enrichment processes in tithospheric peridotites an effect of asthenosphere-l itllOsphere interacshytio n In Mantle Metasomatism MA Menzies and eJ Hawkesworth ed London Academic Press 313-359

Mercier Je (1980) Single-pyroxene thermobaroshymet ry Tectonophysies 16 1-37

Mercier le amp Nicolas A (1975) Textures and fabrics of upper-mantle perido tites as illu stra ted by xenolilhs from basalts 1 Petrol 16 454-487

Nelson D R McCulloch MT Sun S-S (1986) The origin of ultrapotassic rocks as infe rred from Sr Nd and P isotopes Ceochim Cosnzochim Acta 50207-217

Ottonello G Ernst WG Joron JL (1984) Rare Earth and 3-d transition e lement geochemistry of peridotitic rocks 1) pe ridotite from Western Alps Petra 25 243-372

Pearce J A amp Norry MJ (1979) Petrogenetic implications of Ti Zr y and Nb va ri ations Conshytrib Mineral Petro 69 33-47

Pieciri llo E M Civetta L Petnni R Longinelli A Bellieni G Comin-Chiaramonti P Marshyques LS amp Melfi A J (1989) R egiona l variashytions within the Parana con tinental flood basal sequences as evidence for different mant le regions and variable crustal con tamin ation Cheshymica l Ceo 75 103-122

Piccirillo EM Comin-Chia ra monti P Bellieni G Civetta L Marques LS Melfi AJ Pe lrini R Raposo MB amp Stolfa D (1988) Petrogeshyne tic aspec ts of continental flood basalt-rhyolite suites from the Paran a Basin (Braz il ) In The Mesozoic flood volcanism of the Parana Basin pe trogene tic and geophys ical aspects E M Picshyci rillo and AJ Melfi ed [AG-Usp Sao Paulo Brazil 179-205

Pineau F amp Mathez E A (1990) Carbon iso topes in xenoliths from the Hualalai Volcano Hawai i and the generation of iso topic va riability Ceoshychim Cosmocluacutem Acta 54 217-227

Prinzhofer A amp AlIegre e J (1985) Residual peridotites and the mechanism of partial melting EPSL 74 251-256

Roden FM (1987) RbSr and SmNd ratios of metasomatic mantle impl ications for the role oE metasomatized manlle in the petrogenesis of Na20-rich al ka line basa lts In Mantle metasomashy

tism a nd a lka line magmatism E M Morris and JD Pas teris ed Soco Ceo Amer Sp p 215 127-138

Roden MH H art SR Frey F A amp Melson WG (1984) Sr Nd and Pb isotopic and REE geochem istry o f SI Paul s R oeks the metamorshyphic and me tasomatic development of alkali basalt manlle source Conribo Minera Petral 85 376-390

Sadowski GR (1987) A possible relation between pul ses o f pl at form ac tivation and plate kinemashylics Teclonophysics 143 43-58

Smi th AG amp Briden Je (1977) Mesozoic and Cenozoic paleocontinental Maps Cambridge Univ Press 63 p

Spera F J (1984) Carbon dioxid e in petrogenesis 111 role of volatiles in the aseent of a lk aline magmas with specia l reference to xenolith-bearshying mafic lavas Contrib Minera Petral 88 217-232

Ville mant B Jaffrezic H Joron J L amp Treuil M (1981) Distribution coefficients of major and trace elemen ts fractional erystalliza tion in the alkali-basa lt seri es of Chaine du Puys (Massif Central Franee) Ceochim Cosmochim Acta 45 1997-2016

Waters F G amp Erlank AJ (1988) Assessment of the vertical extent and distribution of mantle metasomatism below Kimberley South Africa J Petral Special Li thosphere Issue p 185-204

Watson E B (1979) Zircon saturation iD felsic liq uid experimen tal resu lt and applications to trace element geochemistry Contrib Mineral Petral 70 407-419

Wilkinson J FG amp Le Maitre R W (1987) Upper mantle amphiboles and micas and Ti02 K20 and P20s abund ances and 100 Mg(Mg + Fe2lt) ratios of common basalts and andesites implica tions for modal mantle compositions Petral 28 37-73

Wilshire H G amp Shervais J W (1975) AI-augite and Cr-diopside utramafic xenoliths in basal ti c rocks from the Wes tern United States Phys Chem Earlh 9257-272

WyJlie PJ (1987) Volcanic rocks boundaries from experimental petrology Fortsehr Min eral 65 249-284

Zindler A H art SR Frey F A amp J acobsen SP (1979) Nd and Sr isotope ratios and REE ab un shydances in R eykjanes Peninsula basalts Evidence for mantle heterogeneity beneath iexclcelando E P SL 45 249262

Received 7 June 7990 Accepted 17 January 1991

525


On the whole the Cretaceous-Tertiary alkaline and ultra-alkaline magmatism of Central-Eastern Paraguay appears closely linked to rift structures trending NW-SE and WNW-ESE This may be an indication of a tectono-magmatic event(s) associated with stress-regime changes during the South America-Africa continental separation

Key-words Eastem Paraguay South America Tertiary nephelinites Mantle source metasomatism partial melting Sr-Nd isotopes

Introduction margin of the northern Parana Basin (Fig lA) The investigated Tertiary nephelinites are

Nephelinitic plugs flows and dykes dominate important since they represent an ultra-alkaline the Tertiary (61-39 Ma) magmatism in Eastern (Le Bas 1987) magmatism that occurred inland Paraguay near Asuncioacuten (Fig 1 Bitschene long after the South America - Africa continental 1987) This magmatism is controlIed by NWshy separation AIso they contain spinel-peridotite SE- trending rift structures and represents the xenoliths strongly enriched in incompatible eleshymost recent alkaline activity on the western ments (Comin-Chiaramonti el al 1986 border of the Parana basin (Livieres amp Quade Demarchi el al 1988) 1987) In tbis area a tephritic-phonolitic The present paper addresses (1) petrological magmatism of Upper Permian to Upper Cretashy geochemical and Sr-Nd isotope aspect bearing ceous age is also present (240-108 Ma Cominshy on the origin of nephelinite (2) petrogenetic Chiaramonti el al 1990) locally associated relationsbips between nephelinites and the with Cretaceous carbonatites (130-86 Ma Eby enclosed mantle xenoliths and (3) Sr-Nd amp Mariano 1986) Note that an important isotope characteristics of the subcontinental alkaline magmatism of lower Cretaceous to manUe sources involved in the generation of Eocene age (135 to 45 Ma Gomes el al the alkaline and tholeiitic magmas of the 1990) is also widespread around the eastern Paranaacute Basin

Fig 1 A Sketch map showing the post-PaJaeozoic occurrences -squares and circJes- of alkaline rock-types at the border of and within the Paranaacute Basin -squares and circles- (after Gomes el al 1990) 1 pre-Devonian crystalJine basement 2 pre-volcanic sediments (mainly Palaeozoic) 3 flood volcanics of the Sena Geral Formation (Lower Cretaceous) 4 post volcanic sediments (mainly Upper Cretaceous) 5 syncline-type structure 6 arch-type structure 7 fl exure-type structure 8 major structural lineament B Simplified structural map of Eastern Paraguay 1 antiform-type structure 2 synform-type structure 3 major faults 4 major structural lineaments Stippled area indica tes the extension of the stratoid tholeiitic volcanic rocks of the Serra Geral Formation E aste rn Paraguay (from Livieres amp Quade 1987 and Bellieni el

al 1986 modified) Dotted areas indicate the main occurrences of alkaline rock-types C Simplified geological map of the Ypacaray Valley and adjacent areas (Degraff el al 1981) PC Precamshybrian LS and US Lower and Upper Silurian respectively J Jurassic-Cre taceous T Tertiary nephelinitic occunences (unconformable on the Jurassic red sandstones of the Misiones Formation) f major faults 1) Cerro Verde Small plug (about 300 m in diameter and 20 m high) containing rare mantle (up to 2 cm across) and very abundant crustal (up to 100 cm across) xenoliths 2) Limpio Lava flow (about 8 m thick) with scarce mantte (up to 2 cm diam) and crustal (up to 25 cm diam) xenoliths 3) Remanso Castillo Subvertical NW-SE trending dyke 5 m thick 4) Nueva Teblada Lava flow (about 10 m thick) with abundant mantle xenoliths up to 20 cm across 5) Tacumbuacute SmalJ plug (about 200 m in diameter and 50 m high) which yields abundant mantle and rare crustal xenoliths (up to 7 cm and up to 50 cm across respectively) 6) Lambareacute Small plug (about 170 m in diameter and 55 m high) with abundant mantle xenoliths (up to 10 cm across) and rare crustal xenoliths (up to 30 cm in size) 7) Cerro Palintildeo Very small plug () with crustal xenoliths (up to 50 cm) and rare mantle xenoliths (up 2 cm across) 8) Nemby Plug (900 x 500 m and 80 m aboye the plain) with very abundant mantle xenoliths (ca 10-15 by volume and up to 40 cm across) and rare crustal xenoliths (up to 100 cm across)

Tertiary I

Analytical proced

Major and trace elernent con rocks were determiacutened by X-r (Bellieniacute el al 1983) miCfe compositions were analysed Comin-Cbiaramonti el al (1 986)

Sr iso tope compositions were Sr separation by standard ion-( matography The measured ~ were frationation-corrected to value of 01194 Repeated analy 987 Sr standard gave average 87S

14

Asur

~ ~t-)

Q

31

A (

Bue nos






1










m across)





56deg

24deg

A

bull gt 90 Ma

O 70-90 Na

O lt 70 Na

~~ 3 ~ 4LcJ

5~5X -lt1

7-lt1 B

bull O T

csJ J

~US EZ2l LS

1 1 pe

Figl

509













Eastern Paraguay

2

OVP 65 46

OlM 62 37

OlG 36 34

CpxX 15 05

CpxlM 09 60

CpxlG 46 1 366

MtfM 06 03

MtG 39 50

Nepheline 188 164

Glass 111 225

Apatite 05 05

Biotite

Carbonates

PI

Xenolilhs 03 05


~-

iexclI











Mantle xenoliths



OVP 65 46 23 U~ 07 42 26 050-200 I TE

OJIM 62 37 23 21 07 26 65 47 015-0 50

OllG 36 34 38 55 55 43 30 008-015

CpxX 15 05 01 04 09 02 0 5 028-200

CpxJM 09 60 15 14 09 03 463 06 015-050

CpxJG 461 366 399 440 413 419 39 3 lt0 15

I

MtlM 06 03 07 04 07 06 03 010-023 51

M tlG 39 50 62 68 50 56 50 lt010

Nepheline 188 164 173 153 210 206 214 192

Glass 111 225 248 171 225 187 206 214

Apatite 05 05 07 01 04 04 01 03 laquo 010

Biotite 01 lt001

Carbonates 01 002-010 PI 02 002-010


2 3 4 5 6 7 8 (mm) range


1000

511





Si02 5513 5416 4787 4530 5484 4119 4030 3866 3809 4l94 Ti02 010 012 228 361 000 1892 2099

AI20 3 148 272 620 807 480 647 456 3509 FeO 233 233 627 740 518 859 1114 1912 2221 6625 6722 MnO 016 011 017 010 014 011 020 047 066 086 096 MgO 1766 1700 1415 1233 3292 4964 4778 4109 3837 362 283 CaO 2190 2172 2205 2261 117 002 009 051 059 091

Na20 099 091 050 023 001 1826 K 20 000 000 000 004 000 447 2e Cr203 085 085 029 012 092 137 081 NiO 040 026 016 011

SUM 10060 9992 9978 9981 9998 9995 9990 10001 10003 9749 9737 10067


Ti 0003 0003 0063 0102 0000 0505 0570 AIv 0021 0041 0230 0306 0109 0987 AIY) 0042 0075 0040 0050 0086 Fe3+ 0018 0000 0091 0066 0000 0000 0003 0017 0014 0680 0642 I p


Na 0069 0064 0036 0017 0001 0845








Mt Nephe line

M G M G

S66 3809 41 94

1892 2099

647 4 56 3509

~ 1 2 2221 6625 67 22

)47 066 086 096

109 3837 362 283

051 059 091

1826

447

137 081

U16 011

001 10003 9749 9737 10067

992 0993 1003

0505 0570

0987

017 0014 0680 0642

394 0470 1286 1387

010 0015 0026 0029

571 1490 0193 0154

014 0017 0024

0845

0136

0038 0023

003 0002

0271 0194

000 4000 4000 4000 4000




Ca OUacute

(1

Q

40 I I I

I I

I I JO I

I I I

1 (~-x

20 I

I

I

I 10

I I I I

2(1 30

Mg I P I Fe 2 ++ Mn + fe 3 +2 = 01 = b










513



01 Opx

BF 3192 3269 3192 3269

Si02 Ti02 AI 2O)

FeO

MgO CaO

Na20 K20

Cr20)

4123

930 4994

003

4108

805

5009 003

5686

007 333

580

3377 049

005

024

5660

002 270

519

3394 047

054

BB 3198 3304 3198 3304

Si02 Ti02 AI2O)

FeO

MgO

CaO

Na20 K20

Cr20)

4154

891

4922 004

4026

840

4938

000

5604

005

347

567 3322

057

005

024

5721

002

193

533

3436

042 005

038



AMPH PHLOGCpx Sp

Tertiary ne



11 ~N=6O-s0 e

~~8~ ~~~r ~~ I ~ ~0i~6O~ -

8 ~ ~ ~~8iexcl~ ~ ~ U ~r-j lt26oS e

N S=~~ H ~~ ~ ~sect ~ ~N j= ~~ ~Vl-

DO


lN( 60t - - __


~N 6 S=v

~ i g 8 ~~~8 ~ N S6 ltXi = i

~~ ~

~ iquest

iexcl-1 ~~ 8~ 1 2~~ ~~ ~N=C~~ Vi c

iexcls

3192

5302

031

568 257

1532

2092 147

001

082

3198

5132

045

584

279

1542 2010

137

001

076

ible

3269 3192 3269

5354

005 270

217

1662

006

5653 1063

2070

006 4172

1065

1874

4398

074

1410

390

1799

4101

018 1349 260

2603 2197

096

001

103 1238 2758

1075

348

056

158

3304 3198 3304 BLEBS

5476

003

399 217

1618 2276

094

001

087

012

5767

898

2079

1070

014

4354

1298

1894

24 01

4421

045

783

651

2857 418

130

190 400


001

032

1000

082



Manlle xenolitbs











O-~NJ (1)0 (1)(1)(1)~~]~g- ~~0J T IiexclQ(l 3



Vgt

Jogt

~ r

O r r shyO el

-71 Cl~ ~ Q)

8 5shy3 ~

O (1)

~ y =go Q)gt Vl 5

-00 deg033 tll

~ (0 gtl_ o l _ Vgt _

o 8shy Vgt

~t rgt (O ~



I(n ~ 2) 2(n ~ 2) 3( ~ 1) 4( ~ 2) 5(n ~ 4) 6( ~ 2) 7(n ~ 1) 8( ~ 2) 9(n ~ 6) lO(n ~ 14) 1I(n ~ 6) 12(n ~ 2)





Ne 2161 2570 2264 2A 51 2334 2309 2120 2634 23 48 2616 27 58 2669 Cgt

eCs 112 000 000 000 000 000 000 (100 000 000 000 000 Di 3293 3183 2778 34 01 3041 2937 3140 3242 3056 3099 31 43 2872 J


e iexcliexcl

Mg lt(1) 0687 0646 0619 0655 0653 0664 0674 0665 0662 0648 0636 0638 (2) 0692 0651 0624 0660 0658 0669 Ooacute79 0670 0667 0653 0641 0643

Fe20 621 456 384 439 447 468 399 445 407 417 409 402 FeO 548 666 640 7 06 613 669 613 682 647 654 660 6 19 LO 246 234 199 200 269 211 187 234 206 202 206 207

Sum 9965 9948 9929 99 47 9933 9921 9932 9962 9929 9928 9926 9930


bull bull bull

bull bull bullbull

bull bull

bull bull

bull bull bull


1shy

1shy

FeO

bull bull bull o

o o o o bull

bull bull CaO

bull O O

bull bull bull bull

OO O bull bull

-

-

-

-

1shy

1shy

bull

AI203

O


bull

O O

O O

bull O


-

-shy

-

Ti0 2

bull bullbull-0deg

O O bull O

bull bull N~O

bull deg0

O 0 O


--

-

-

-

bull3

Si02

I

O 0912 10


I I I

bull6

I

bull1

K2 0

bull3

I

12 11

0 0

I

10 9 4 O O bull O

8 smiddot 2f

6bull I I

1bull -

-

8 10 12 8 10 12

MgO



-bull bull Rb

bull

O

bull - O bullO ltfl

bull Sr

bull O O

bull middot o O

Omiddot

bull Ba

bull O O

00 O

bull bull

Ni

9 0 8 1110 0 bull

3 616 0 O 7


Cr

bull 1

110

30

90

1200

30

1000 20

300 1200

200 1000

180

300

140

200

120

600

100

400

bullO

bullO O O bull O Nb



O 00 Zr


Ce

0 0 9 bull1

10

12 0 11 O 8 6

bull O 2

bull bullmiddot4

bull3 S La

8 10 12 8 10 12

MgO MgO


Tertiar) ni


BF Suite 3192 3269




Sr Nd and e isotop


11

10

16 1shy

12

28

24

43

41

12

10

13

09

6

5

2

ll

bull ----l 12 o

) o o J 10

~ 13 J O

O bull

O

bull tO


10 9 4 8 O O bull O 6

O 1 -i 2

S 1bull2 7

~ 10 12


bullO

bull00 O bull O Nb

OOO iexcl bull O Y

bull

O bull bull O

0deg 0 bull Zr

bull00 O 0 0bull

bull bullbull Ce

10 bull1 12deg1 1

0 0 6bull

8 6 O bull

2 4











Ni 2131 2377 2081 2321














LOCALITY AGE (Ma)

CERRO VERDE 570t23

LIMPIO 502t 19


NUEVA TEBLADA

46 3 t 20 NEMBY 457t18

TACUMBUacute 413t16

REMANSO CASTILLO

406t 16


shy(X)

SAMPLE 3080 3082 3097 3103 3209 3213 3283 3068 3083 3399


Sum


4003 258

1198 627 546 023

11 77 1215 4 55 091 119 244

9956

53 480 277

1258 55

1278 130 188 300 27

122

4188 246

1352 460 664 021 951

1052 560 122 094 229

9939

385 223

1050 39

1111 105 157 288 29 96

4105 248

1310 458 680 021

1084 1062 489 125 113 205

9900

57 544 317 991

41 1070

111 176 285

29 108

4148 2 11

1295 448 714 023

10 10 1112 5 18 164 111 185

9939

428 274

1004 56

1066 101 183 282

25 99

4252 205

1341 402 648 020 954

1045 580 146 118 219

9929

58 648 273 980

59 1013

116 176 234

33 101

4191 216

1369 347 722 020 889

10 84 555 1 93 122 212

9920

539 242 990 50

1030 106 180 237

36 101

4247 209

1320 407 678 020 988

1046 462 226 116 207

9926

500 253 968

50 1063

119 186 225 33

105

4184 253

1430 451 617 017 929

10 86 498 138 078 259

9940

50 371 179

1237 70

1082 82

131 218

20 89

4298 217

1555 384 640 018 778

1078 528 143 090 199

9929

48 398 154

1031 56

1102 81

141 200 29 94

4252 232

1440 399 613 017 977

1171 500 067 087 187

9932

46 542 207

1090 22

1016 81

145 165 26 89

j

() o

ordfl n ~ Q) Q)

3 o amp ~

~


14]Ndl l44 Nd 0512729t6 0512624t 12 0512803t6 0512800t20

0512760t 10 0512655 t 8 0512746t6 0512753t7

Mg 0690 0650 0676 0655 0665 0644 0665 0654 0624 0679


0~~3 - iquestoz3~ ~ ~ ~ ~

g ~

o

o w I

o

o w 00

I

o

o w ltDIr I

~ 3 ~ ~ ~ g 1 ~~ a~~~ ~~6- 2 -~0 cn~QQ~ (l Or 1 o


~ tn 3 ~ = __ 2 g ~ w ~ ~ ~ 2shyfr ~ g g g 5 0


= u- lt-ro

l-~

= lt-ro --

p lt-ro

ltLgt

70) gl o-J (l)

iexcliexcl lt J (l)








NO S--N -lt


N S S--N


)(lt)0 S--N



)Za)~ vJ 8Ngt-Z

+1 ~ lt=gt ltshy6

+1 D lt)

lt=gt

+1 v -D

lt=gt lt-

+1 oshy-D lt)

lt=gt

+1 D lt-

+1 D lt) o 6

+1 Oshy-D

=

-+1 lt)

lt=gtltshy6

+1 00 = lt-

+1 c O

o

c

~ ()

iquest rl

+1 v ltshy v

6

D +1

-D

Ntilde v

lt=gt

00 +1 V v -D N

S +1 o -D ~ V

-D O

~~ 0= ~O ~Ssect

V

6

S +1

-D S V

= -D +1 OshyN N V

6

-o Z iexcl iexcl f

oshy 6

~ D

6

-D

v -D

~ -D 6

v -D

V V

D (C 6

~ 6

$ 6

oacute

(143144) ~d

05129

05127

05125


~ I

-Z~~nit


(DBB o BF)

0704

Ro +CPce 070391shy

070381shy tcv

f +LA

070371shy -ff- RC

-f--I Ma

I





3199 3213

3252

3260

-687 - 707

-764

- 792

3263

3313A 3222

3288

-522

-739

-687

-734


13 14 15 16

Si02 4159 4231 4366 4296

Ti02 261 241 228 199 Al20 3 1212 1275 1410 1270

FeO 1141 11 59 1007 1113 MnO 024 022 018 022 MgO 13U 1331 U72 1285

CaO 1228 1033 1154 1026

Na20 460 476 493 543 K20 092 122 066 139

P20S 121 110 086 106

Co 57 67 51 61

Cr 515 612 587 676

Ni 358 546 309 492

Ba 1257 943 1043 983

Rb 54 39 21 57

Sr 1246 1019 972 1002 La 130 106 78 106

Ce 188 168 139 163

Zr 300 272 159 245

Y 26 27 25 26

Nb 122 103 85 90










Tertiary n

Table 9 SoliciI

01 Opl



U1 tlJ U shy

o ~

Vl

O tlJ

9 ~

~ o u

~ e

tlJ L Q tlJ e

tlJ O o E

4

3

L shyo e tlJ x 2

O tlJ 01 01 o gt

O


So Nb C~ P

Rb K La Sr








K = 1-3 Zr = 1-19 Sr = 2-3 P =




Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020




l ltIl Qgt U J


lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti



Ba Nb Ce p Ti


i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525






1










m across)





56deg

24deg

A

bull gt 90 Ma

O 70-90 Na

O lt 70 Na

~~ 3 ~ 4LcJ

5~5X -lt1

7-lt1 B

bull O T

csJ J

~US EZ2l LS

1 1 pe

Figl

509













Eastern Paraguay

2

OVP 65 46

OlM 62 37

OlG 36 34

CpxX 15 05

CpxlM 09 60

CpxlG 46 1 366

MtfM 06 03

MtG 39 50

Nepheline 188 164

Glass 111 225

Apatite 05 05

Biotite

Carbonates

PI

Xenolilhs 03 05


~-

iexclI











Mantle xenoliths



OVP 65 46 23 U~ 07 42 26 050-200 I TE

OJIM 62 37 23 21 07 26 65 47 015-0 50

OllG 36 34 38 55 55 43 30 008-015

CpxX 15 05 01 04 09 02 0 5 028-200

CpxJM 09 60 15 14 09 03 463 06 015-050

CpxJG 461 366 399 440 413 419 39 3 lt0 15

I

MtlM 06 03 07 04 07 06 03 010-023 51

M tlG 39 50 62 68 50 56 50 lt010

Nepheline 188 164 173 153 210 206 214 192

Glass 111 225 248 171 225 187 206 214

Apatite 05 05 07 01 04 04 01 03 laquo 010

Biotite 01 lt001

Carbonates 01 002-010 PI 02 002-010


2 3 4 5 6 7 8 (mm) range


1000

511





Si02 5513 5416 4787 4530 5484 4119 4030 3866 3809 4l94 Ti02 010 012 228 361 000 1892 2099

AI20 3 148 272 620 807 480 647 456 3509 FeO 233 233 627 740 518 859 1114 1912 2221 6625 6722 MnO 016 011 017 010 014 011 020 047 066 086 096 MgO 1766 1700 1415 1233 3292 4964 4778 4109 3837 362 283 CaO 2190 2172 2205 2261 117 002 009 051 059 091

Na20 099 091 050 023 001 1826 K 20 000 000 000 004 000 447 2e Cr203 085 085 029 012 092 137 081 NiO 040 026 016 011

SUM 10060 9992 9978 9981 9998 9995 9990 10001 10003 9749 9737 10067


Ti 0003 0003 0063 0102 0000 0505 0570 AIv 0021 0041 0230 0306 0109 0987 AIY) 0042 0075 0040 0050 0086 Fe3+ 0018 0000 0091 0066 0000 0000 0003 0017 0014 0680 0642 I p


Na 0069 0064 0036 0017 0001 0845








Mt Nephe line

M G M G

S66 3809 41 94

1892 2099

647 4 56 3509

~ 1 2 2221 6625 67 22

)47 066 086 096

109 3837 362 283

051 059 091

1826

447

137 081

U16 011

001 10003 9749 9737 10067

992 0993 1003

0505 0570

0987

017 0014 0680 0642

394 0470 1286 1387

010 0015 0026 0029

571 1490 0193 0154

014 0017 0024

0845

0136

0038 0023

003 0002

0271 0194

000 4000 4000 4000 4000




Ca OUacute

(1

Q

40 I I I

I I

I I JO I

I I I

1 (~-x

20 I

I

I

I 10

I I I I

2(1 30

Mg I P I Fe 2 ++ Mn + fe 3 +2 = 01 = b










513



01 Opx

BF 3192 3269 3192 3269

Si02 Ti02 AI 2O)

FeO

MgO CaO

Na20 K20

Cr20)

4123

930 4994

003

4108

805

5009 003

5686

007 333

580

3377 049

005

024

5660

002 270

519

3394 047

054

BB 3198 3304 3198 3304

Si02 Ti02 AI2O)

FeO

MgO

CaO

Na20 K20

Cr20)

4154

891

4922 004

4026

840

4938

000

5604

005

347

567 3322

057

005

024

5721

002

193

533

3436

042 005

038



AMPH PHLOGCpx Sp

Tertiary ne



11 ~N=6O-s0 e

~~8~ ~~~r ~~ I ~ ~0i~6O~ -

8 ~ ~ ~~8iexcl~ ~ ~ U ~r-j lt26oS e

N S=~~ H ~~ ~ ~sect ~ ~N j= ~~ ~Vl-

DO


lN( 60t - - __


~N 6 S=v

~ i g 8 ~~~8 ~ N S6 ltXi = i

~~ ~

~ iquest

iexcl-1 ~~ 8~ 1 2~~ ~~ ~N=C~~ Vi c

iexcls

3192

5302

031

568 257

1532

2092 147

001

082

3198

5132

045

584

279

1542 2010

137

001

076

ible

3269 3192 3269

5354

005 270

217

1662

006

5653 1063

2070

006 4172

1065

1874

4398

074

1410

390

1799

4101

018 1349 260

2603 2197

096

001

103 1238 2758

1075

348

056

158

3304 3198 3304 BLEBS

5476

003

399 217

1618 2276

094

001

087

012

5767

898

2079

1070

014

4354

1298

1894

24 01

4421

045

783

651

2857 418

130

190 400


001

032

1000

082



Manlle xenolitbs











O-~NJ (1)0 (1)(1)(1)~~]~g- ~~0J T IiexclQ(l 3



Vgt

Jogt

~ r

O r r shyO el

-71 Cl~ ~ Q)

8 5shy3 ~

O (1)

~ y =go Q)gt Vl 5

-00 deg033 tll

~ (0 gtl_ o l _ Vgt _

o 8shy Vgt

~t rgt (O ~



I(n ~ 2) 2(n ~ 2) 3( ~ 1) 4( ~ 2) 5(n ~ 4) 6( ~ 2) 7(n ~ 1) 8( ~ 2) 9(n ~ 6) lO(n ~ 14) 1I(n ~ 6) 12(n ~ 2)





Ne 2161 2570 2264 2A 51 2334 2309 2120 2634 23 48 2616 27 58 2669 Cgt

eCs 112 000 000 000 000 000 000 (100 000 000 000 000 Di 3293 3183 2778 34 01 3041 2937 3140 3242 3056 3099 31 43 2872 J


e iexcliexcl

Mg lt(1) 0687 0646 0619 0655 0653 0664 0674 0665 0662 0648 0636 0638 (2) 0692 0651 0624 0660 0658 0669 Ooacute79 0670 0667 0653 0641 0643

Fe20 621 456 384 439 447 468 399 445 407 417 409 402 FeO 548 666 640 7 06 613 669 613 682 647 654 660 6 19 LO 246 234 199 200 269 211 187 234 206 202 206 207

Sum 9965 9948 9929 99 47 9933 9921 9932 9962 9929 9928 9926 9930


bull bull bull

bull bull bullbull

bull bull

bull bull

bull bull bull


1shy

1shy

FeO

bull bull bull o

o o o o bull

bull bull CaO

bull O O

bull bull bull bull

OO O bull bull

-

-

-

-

1shy

1shy

bull

AI203

O


bull

O O

O O

bull O


-

-shy

-

Ti0 2

bull bullbull-0deg

O O bull O

bull bull N~O

bull deg0

O 0 O


--

-

-

-

bull3

Si02

I

O 0912 10


I I I

bull6

I

bull1

K2 0

bull3

I

12 11

0 0

I

10 9 4 O O bull O

8 smiddot 2f

6bull I I

1bull -

-

8 10 12 8 10 12

MgO



-bull bull Rb

bull

O

bull - O bullO ltfl

bull Sr

bull O O

bull middot o O

Omiddot

bull Ba

bull O O

00 O

bull bull

Ni

9 0 8 1110 0 bull

3 616 0 O 7


Cr

bull 1

110

30

90

1200

30

1000 20

300 1200

200 1000

180

300

140

200

120

600

100

400

bullO

bullO O O bull O Nb



O 00 Zr


Ce

0 0 9 bull1

10

12 0 11 O 8 6

bull O 2

bull bullmiddot4

bull3 S La

8 10 12 8 10 12

MgO MgO


Tertiar) ni


BF Suite 3192 3269




Sr Nd and e isotop


11

10

16 1shy

12

28

24

43

41

12

10

13

09

6

5

2

ll

bull ----l 12 o

) o o J 10

~ 13 J O

O bull

O

bull tO


10 9 4 8 O O bull O 6

O 1 -i 2

S 1bull2 7

~ 10 12


bullO

bull00 O bull O Nb

OOO iexcl bull O Y

bull

O bull bull O

0deg 0 bull Zr

bull00 O 0 0bull

bull bullbull Ce

10 bull1 12deg1 1

0 0 6bull

8 6 O bull

2 4











Ni 2131 2377 2081 2321














LOCALITY AGE (Ma)

CERRO VERDE 570t23

LIMPIO 502t 19


NUEVA TEBLADA

46 3 t 20 NEMBY 457t18

TACUMBUacute 413t16

REMANSO CASTILLO

406t 16


shy(X)

SAMPLE 3080 3082 3097 3103 3209 3213 3283 3068 3083 3399


Sum


4003 258

1198 627 546 023

11 77 1215 4 55 091 119 244

9956

53 480 277

1258 55

1278 130 188 300 27

122

4188 246

1352 460 664 021 951

1052 560 122 094 229

9939

385 223

1050 39

1111 105 157 288 29 96

4105 248

1310 458 680 021

1084 1062 489 125 113 205

9900

57 544 317 991

41 1070

111 176 285

29 108

4148 2 11

1295 448 714 023

10 10 1112 5 18 164 111 185

9939

428 274

1004 56

1066 101 183 282

25 99

4252 205

1341 402 648 020 954

1045 580 146 118 219

9929

58 648 273 980

59 1013

116 176 234

33 101

4191 216

1369 347 722 020 889

10 84 555 1 93 122 212

9920

539 242 990 50

1030 106 180 237

36 101

4247 209

1320 407 678 020 988

1046 462 226 116 207

9926

500 253 968

50 1063

119 186 225 33

105

4184 253

1430 451 617 017 929

10 86 498 138 078 259

9940

50 371 179

1237 70

1082 82

131 218

20 89

4298 217

1555 384 640 018 778

1078 528 143 090 199

9929

48 398 154

1031 56

1102 81

141 200 29 94

4252 232

1440 399 613 017 977

1171 500 067 087 187

9932

46 542 207

1090 22

1016 81

145 165 26 89

j

() o

ordfl n ~ Q) Q)

3 o amp ~

~


14]Ndl l44 Nd 0512729t6 0512624t 12 0512803t6 0512800t20

0512760t 10 0512655 t 8 0512746t6 0512753t7

Mg 0690 0650 0676 0655 0665 0644 0665 0654 0624 0679


0~~3 - iquestoz3~ ~ ~ ~ ~

g ~

o

o w I

o

o w 00

I

o

o w ltDIr I

~ 3 ~ ~ ~ g 1 ~~ a~~~ ~~6- 2 -~0 cn~QQ~ (l Or 1 o


~ tn 3 ~ = __ 2 g ~ w ~ ~ ~ 2shyfr ~ g g g 5 0


= u- lt-ro

l-~

= lt-ro --

p lt-ro

ltLgt

70) gl o-J (l)

iexcliexcl lt J (l)








NO S--N -lt


N S S--N


)(lt)0 S--N



)Za)~ vJ 8Ngt-Z

+1 ~ lt=gt ltshy6

+1 D lt)

lt=gt

+1 v -D

lt=gt lt-

+1 oshy-D lt)

lt=gt

+1 D lt-

+1 D lt) o 6

+1 Oshy-D

=

-+1 lt)

lt=gtltshy6

+1 00 = lt-

+1 c O

o

c

~ ()

iquest rl

+1 v ltshy v

6

D +1

-D

Ntilde v

lt=gt

00 +1 V v -D N

S +1 o -D ~ V

-D O

~~ 0= ~O ~Ssect

V

6

S +1

-D S V

= -D +1 OshyN N V

6

-o Z iexcl iexcl f

oshy 6

~ D

6

-D

v -D

~ -D 6

v -D

V V

D (C 6

~ 6

$ 6

oacute

(143144) ~d

05129

05127

05125


~ I

-Z~~nit


(DBB o BF)

0704

Ro +CPce 070391shy

070381shy tcv

f +LA

070371shy -ff- RC

-f--I Ma

I





3199 3213

3252

3260

-687 - 707

-764

- 792

3263

3313A 3222

3288

-522

-739

-687

-734


13 14 15 16

Si02 4159 4231 4366 4296

Ti02 261 241 228 199 Al20 3 1212 1275 1410 1270

FeO 1141 11 59 1007 1113 MnO 024 022 018 022 MgO 13U 1331 U72 1285

CaO 1228 1033 1154 1026

Na20 460 476 493 543 K20 092 122 066 139

P20S 121 110 086 106

Co 57 67 51 61

Cr 515 612 587 676

Ni 358 546 309 492

Ba 1257 943 1043 983

Rb 54 39 21 57

Sr 1246 1019 972 1002 La 130 106 78 106

Ce 188 168 139 163

Zr 300 272 159 245

Y 26 27 25 26

Nb 122 103 85 90










Tertiary n

Table 9 SoliciI

01 Opl



U1 tlJ U shy

o ~

Vl

O tlJ

9 ~

~ o u

~ e

tlJ L Q tlJ e

tlJ O o E

4

3

L shyo e tlJ x 2

O tlJ 01 01 o gt

O


So Nb C~ P

Rb K La Sr








K = 1-3 Zr = 1-19 Sr = 2-3 P =




Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020




l ltIl Qgt U J


lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti



Ba Nb Ce p Ti


i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525













Eastern Paraguay

2

OVP 65 46

OlM 62 37

OlG 36 34

CpxX 15 05

CpxlM 09 60

CpxlG 46 1 366

MtfM 06 03

MtG 39 50

Nepheline 188 164

Glass 111 225

Apatite 05 05

Biotite

Carbonates

PI

Xenolilhs 03 05


~-

iexclI











Mantle xenoliths



OVP 65 46 23 U~ 07 42 26 050-200 I TE

OJIM 62 37 23 21 07 26 65 47 015-0 50

OllG 36 34 38 55 55 43 30 008-015

CpxX 15 05 01 04 09 02 0 5 028-200

CpxJM 09 60 15 14 09 03 463 06 015-050

CpxJG 461 366 399 440 413 419 39 3 lt0 15

I

MtlM 06 03 07 04 07 06 03 010-023 51

M tlG 39 50 62 68 50 56 50 lt010

Nepheline 188 164 173 153 210 206 214 192

Glass 111 225 248 171 225 187 206 214

Apatite 05 05 07 01 04 04 01 03 laquo 010

Biotite 01 lt001

Carbonates 01 002-010 PI 02 002-010


2 3 4 5 6 7 8 (mm) range


1000

511





Si02 5513 5416 4787 4530 5484 4119 4030 3866 3809 4l94 Ti02 010 012 228 361 000 1892 2099

AI20 3 148 272 620 807 480 647 456 3509 FeO 233 233 627 740 518 859 1114 1912 2221 6625 6722 MnO 016 011 017 010 014 011 020 047 066 086 096 MgO 1766 1700 1415 1233 3292 4964 4778 4109 3837 362 283 CaO 2190 2172 2205 2261 117 002 009 051 059 091

Na20 099 091 050 023 001 1826 K 20 000 000 000 004 000 447 2e Cr203 085 085 029 012 092 137 081 NiO 040 026 016 011

SUM 10060 9992 9978 9981 9998 9995 9990 10001 10003 9749 9737 10067


Ti 0003 0003 0063 0102 0000 0505 0570 AIv 0021 0041 0230 0306 0109 0987 AIY) 0042 0075 0040 0050 0086 Fe3+ 0018 0000 0091 0066 0000 0000 0003 0017 0014 0680 0642 I p


Na 0069 0064 0036 0017 0001 0845








Mt Nephe line

M G M G

S66 3809 41 94

1892 2099

647 4 56 3509

~ 1 2 2221 6625 67 22

)47 066 086 096

109 3837 362 283

051 059 091

1826

447

137 081

U16 011

001 10003 9749 9737 10067

992 0993 1003

0505 0570

0987

017 0014 0680 0642

394 0470 1286 1387

010 0015 0026 0029

571 1490 0193 0154

014 0017 0024

0845

0136

0038 0023

003 0002

0271 0194

000 4000 4000 4000 4000




Ca OUacute

(1

Q

40 I I I

I I

I I JO I

I I I

1 (~-x

20 I

I

I

I 10

I I I I

2(1 30

Mg I P I Fe 2 ++ Mn + fe 3 +2 = 01 = b










513



01 Opx

BF 3192 3269 3192 3269

Si02 Ti02 AI 2O)

FeO

MgO CaO

Na20 K20

Cr20)

4123

930 4994

003

4108

805

5009 003

5686

007 333

580

3377 049

005

024

5660

002 270

519

3394 047

054

BB 3198 3304 3198 3304

Si02 Ti02 AI2O)

FeO

MgO

CaO

Na20 K20

Cr20)

4154

891

4922 004

4026

840

4938

000

5604

005

347

567 3322

057

005

024

5721

002

193

533

3436

042 005

038



AMPH PHLOGCpx Sp

Tertiary ne



11 ~N=6O-s0 e

~~8~ ~~~r ~~ I ~ ~0i~6O~ -

8 ~ ~ ~~8iexcl~ ~ ~ U ~r-j lt26oS e

N S=~~ H ~~ ~ ~sect ~ ~N j= ~~ ~Vl-

DO


lN( 60t - - __


~N 6 S=v

~ i g 8 ~~~8 ~ N S6 ltXi = i

~~ ~

~ iquest

iexcl-1 ~~ 8~ 1 2~~ ~~ ~N=C~~ Vi c

iexcls

3192

5302

031

568 257

1532

2092 147

001

082

3198

5132

045

584

279

1542 2010

137

001

076

ible

3269 3192 3269

5354

005 270

217

1662

006

5653 1063

2070

006 4172

1065

1874

4398

074

1410

390

1799

4101

018 1349 260

2603 2197

096

001

103 1238 2758

1075

348

056

158

3304 3198 3304 BLEBS

5476

003

399 217

1618 2276

094

001

087

012

5767

898

2079

1070

014

4354

1298

1894

24 01

4421

045

783

651

2857 418

130

190 400


001

032

1000

082



Manlle xenolitbs











O-~NJ (1)0 (1)(1)(1)~~]~g- ~~0J T IiexclQ(l 3



Vgt

Jogt

~ r

O r r shyO el

-71 Cl~ ~ Q)

8 5shy3 ~

O (1)

~ y =go Q)gt Vl 5

-00 deg033 tll

~ (0 gtl_ o l _ Vgt _

o 8shy Vgt

~t rgt (O ~



I(n ~ 2) 2(n ~ 2) 3( ~ 1) 4( ~ 2) 5(n ~ 4) 6( ~ 2) 7(n ~ 1) 8( ~ 2) 9(n ~ 6) lO(n ~ 14) 1I(n ~ 6) 12(n ~ 2)





Ne 2161 2570 2264 2A 51 2334 2309 2120 2634 23 48 2616 27 58 2669 Cgt

eCs 112 000 000 000 000 000 000 (100 000 000 000 000 Di 3293 3183 2778 34 01 3041 2937 3140 3242 3056 3099 31 43 2872 J


e iexcliexcl

Mg lt(1) 0687 0646 0619 0655 0653 0664 0674 0665 0662 0648 0636 0638 (2) 0692 0651 0624 0660 0658 0669 Ooacute79 0670 0667 0653 0641 0643

Fe20 621 456 384 439 447 468 399 445 407 417 409 402 FeO 548 666 640 7 06 613 669 613 682 647 654 660 6 19 LO 246 234 199 200 269 211 187 234 206 202 206 207

Sum 9965 9948 9929 99 47 9933 9921 9932 9962 9929 9928 9926 9930


bull bull bull

bull bull bullbull

bull bull

bull bull

bull bull bull


1shy

1shy

FeO

bull bull bull o

o o o o bull

bull bull CaO

bull O O

bull bull bull bull

OO O bull bull

-

-

-

-

1shy

1shy

bull

AI203

O


bull

O O

O O

bull O


-

-shy

-

Ti0 2

bull bullbull-0deg

O O bull O

bull bull N~O

bull deg0

O 0 O


--

-

-

-

bull3

Si02

I

O 0912 10


I I I

bull6

I

bull1

K2 0

bull3

I

12 11

0 0

I

10 9 4 O O bull O

8 smiddot 2f

6bull I I

1bull -

-

8 10 12 8 10 12

MgO



-bull bull Rb

bull

O

bull - O bullO ltfl

bull Sr

bull O O

bull middot o O

Omiddot

bull Ba

bull O O

00 O

bull bull

Ni

9 0 8 1110 0 bull

3 616 0 O 7


Cr

bull 1

110

30

90

1200

30

1000 20

300 1200

200 1000

180

300

140

200

120

600

100

400

bullO

bullO O O bull O Nb



O 00 Zr


Ce

0 0 9 bull1

10

12 0 11 O 8 6

bull O 2

bull bullmiddot4

bull3 S La

8 10 12 8 10 12

MgO MgO


Tertiar) ni


BF Suite 3192 3269




Sr Nd and e isotop


11

10

16 1shy

12

28

24

43

41

12

10

13

09

6

5

2

ll

bull ----l 12 o

) o o J 10

~ 13 J O

O bull

O

bull tO


10 9 4 8 O O bull O 6

O 1 -i 2

S 1bull2 7

~ 10 12


bullO

bull00 O bull O Nb

OOO iexcl bull O Y

bull

O bull bull O

0deg 0 bull Zr

bull00 O 0 0bull

bull bullbull Ce

10 bull1 12deg1 1

0 0 6bull

8 6 O bull

2 4











Ni 2131 2377 2081 2321














LOCALITY AGE (Ma)

CERRO VERDE 570t23

LIMPIO 502t 19


NUEVA TEBLADA

46 3 t 20 NEMBY 457t18

TACUMBUacute 413t16

REMANSO CASTILLO

406t 16


shy(X)

SAMPLE 3080 3082 3097 3103 3209 3213 3283 3068 3083 3399


Sum


4003 258

1198 627 546 023

11 77 1215 4 55 091 119 244

9956

53 480 277

1258 55

1278 130 188 300 27

122

4188 246

1352 460 664 021 951

1052 560 122 094 229

9939

385 223

1050 39

1111 105 157 288 29 96

4105 248

1310 458 680 021

1084 1062 489 125 113 205

9900

57 544 317 991

41 1070

111 176 285

29 108

4148 2 11

1295 448 714 023

10 10 1112 5 18 164 111 185

9939

428 274

1004 56

1066 101 183 282

25 99

4252 205

1341 402 648 020 954

1045 580 146 118 219

9929

58 648 273 980

59 1013

116 176 234

33 101

4191 216

1369 347 722 020 889

10 84 555 1 93 122 212

9920

539 242 990 50

1030 106 180 237

36 101

4247 209

1320 407 678 020 988

1046 462 226 116 207

9926

500 253 968

50 1063

119 186 225 33

105

4184 253

1430 451 617 017 929

10 86 498 138 078 259

9940

50 371 179

1237 70

1082 82

131 218

20 89

4298 217

1555 384 640 018 778

1078 528 143 090 199

9929

48 398 154

1031 56

1102 81

141 200 29 94

4252 232

1440 399 613 017 977

1171 500 067 087 187

9932

46 542 207

1090 22

1016 81

145 165 26 89

j

() o

ordfl n ~ Q) Q)

3 o amp ~

~


14]Ndl l44 Nd 0512729t6 0512624t 12 0512803t6 0512800t20

0512760t 10 0512655 t 8 0512746t6 0512753t7

Mg 0690 0650 0676 0655 0665 0644 0665 0654 0624 0679


0~~3 - iquestoz3~ ~ ~ ~ ~

g ~

o

o w I

o

o w 00

I

o

o w ltDIr I

~ 3 ~ ~ ~ g 1 ~~ a~~~ ~~6- 2 -~0 cn~QQ~ (l Or 1 o


~ tn 3 ~ = __ 2 g ~ w ~ ~ ~ 2shyfr ~ g g g 5 0


= u- lt-ro

l-~

= lt-ro --

p lt-ro

ltLgt

70) gl o-J (l)

iexcliexcl lt J (l)








NO S--N -lt


N S S--N


)(lt)0 S--N



)Za)~ vJ 8Ngt-Z

+1 ~ lt=gt ltshy6

+1 D lt)

lt=gt

+1 v -D

lt=gt lt-

+1 oshy-D lt)

lt=gt

+1 D lt-

+1 D lt) o 6

+1 Oshy-D

=

-+1 lt)

lt=gtltshy6

+1 00 = lt-

+1 c O

o

c

~ ()

iquest rl

+1 v ltshy v

6

D +1

-D

Ntilde v

lt=gt

00 +1 V v -D N

S +1 o -D ~ V

-D O

~~ 0= ~O ~Ssect

V

6

S +1

-D S V

= -D +1 OshyN N V

6

-o Z iexcl iexcl f

oshy 6

~ D

6

-D

v -D

~ -D 6

v -D

V V

D (C 6

~ 6

$ 6

oacute

(143144) ~d

05129

05127

05125


~ I

-Z~~nit


(DBB o BF)

0704

Ro +CPce 070391shy

070381shy tcv

f +LA

070371shy -ff- RC

-f--I Ma

I





3199 3213

3252

3260

-687 - 707

-764

- 792

3263

3313A 3222

3288

-522

-739

-687

-734


13 14 15 16

Si02 4159 4231 4366 4296

Ti02 261 241 228 199 Al20 3 1212 1275 1410 1270

FeO 1141 11 59 1007 1113 MnO 024 022 018 022 MgO 13U 1331 U72 1285

CaO 1228 1033 1154 1026

Na20 460 476 493 543 K20 092 122 066 139

P20S 121 110 086 106

Co 57 67 51 61

Cr 515 612 587 676

Ni 358 546 309 492

Ba 1257 943 1043 983

Rb 54 39 21 57

Sr 1246 1019 972 1002 La 130 106 78 106

Ce 188 168 139 163

Zr 300 272 159 245

Y 26 27 25 26

Nb 122 103 85 90










Tertiary n

Table 9 SoliciI

01 Opl



U1 tlJ U shy

o ~

Vl

O tlJ

9 ~

~ o u

~ e

tlJ L Q tlJ e

tlJ O o E

4

3

L shyo e tlJ x 2

O tlJ 01 01 o gt

O


So Nb C~ P

Rb K La Sr








K = 1-3 Zr = 1-19 Sr = 2-3 P =




Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020




l ltIl Qgt U J


lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti



Ba Nb Ce p Ti


i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525

~-

iexclI











Mantle xenoliths



OVP 65 46 23 U~ 07 42 26 050-200 I TE

OJIM 62 37 23 21 07 26 65 47 015-0 50

OllG 36 34 38 55 55 43 30 008-015

CpxX 15 05 01 04 09 02 0 5 028-200

CpxJM 09 60 15 14 09 03 463 06 015-050

CpxJG 461 366 399 440 413 419 39 3 lt0 15

I

MtlM 06 03 07 04 07 06 03 010-023 51

M tlG 39 50 62 68 50 56 50 lt010

Nepheline 188 164 173 153 210 206 214 192

Glass 111 225 248 171 225 187 206 214

Apatite 05 05 07 01 04 04 01 03 laquo 010

Biotite 01 lt001

Carbonates 01 002-010 PI 02 002-010


2 3 4 5 6 7 8 (mm) range


1000

511





Si02 5513 5416 4787 4530 5484 4119 4030 3866 3809 4l94 Ti02 010 012 228 361 000 1892 2099

AI20 3 148 272 620 807 480 647 456 3509 FeO 233 233 627 740 518 859 1114 1912 2221 6625 6722 MnO 016 011 017 010 014 011 020 047 066 086 096 MgO 1766 1700 1415 1233 3292 4964 4778 4109 3837 362 283 CaO 2190 2172 2205 2261 117 002 009 051 059 091

Na20 099 091 050 023 001 1826 K 20 000 000 000 004 000 447 2e Cr203 085 085 029 012 092 137 081 NiO 040 026 016 011

SUM 10060 9992 9978 9981 9998 9995 9990 10001 10003 9749 9737 10067


Ti 0003 0003 0063 0102 0000 0505 0570 AIv 0021 0041 0230 0306 0109 0987 AIY) 0042 0075 0040 0050 0086 Fe3+ 0018 0000 0091 0066 0000 0000 0003 0017 0014 0680 0642 I p


Na 0069 0064 0036 0017 0001 0845








Mt Nephe line

M G M G

S66 3809 41 94

1892 2099

647 4 56 3509

~ 1 2 2221 6625 67 22

)47 066 086 096

109 3837 362 283

051 059 091

1826

447

137 081

U16 011

001 10003 9749 9737 10067

992 0993 1003

0505 0570

0987

017 0014 0680 0642

394 0470 1286 1387

010 0015 0026 0029

571 1490 0193 0154

014 0017 0024

0845

0136

0038 0023

003 0002

0271 0194

000 4000 4000 4000 4000




Ca OUacute

(1

Q

40 I I I

I I

I I JO I

I I I

1 (~-x

20 I

I

I

I 10

I I I I

2(1 30

Mg I P I Fe 2 ++ Mn + fe 3 +2 = 01 = b










513



01 Opx

BF 3192 3269 3192 3269

Si02 Ti02 AI 2O)

FeO

MgO CaO

Na20 K20

Cr20)

4123

930 4994

003

4108

805

5009 003

5686

007 333

580

3377 049

005

024

5660

002 270

519

3394 047

054

BB 3198 3304 3198 3304

Si02 Ti02 AI2O)

FeO

MgO

CaO

Na20 K20

Cr20)

4154

891

4922 004

4026

840

4938

000

5604

005

347

567 3322

057

005

024

5721

002

193

533

3436

042 005

038



AMPH PHLOGCpx Sp

Tertiary ne



11 ~N=6O-s0 e

~~8~ ~~~r ~~ I ~ ~0i~6O~ -

8 ~ ~ ~~8iexcl~ ~ ~ U ~r-j lt26oS e

N S=~~ H ~~ ~ ~sect ~ ~N j= ~~ ~Vl-

DO


lN( 60t - - __


~N 6 S=v

~ i g 8 ~~~8 ~ N S6 ltXi = i

~~ ~

~ iquest

iexcl-1 ~~ 8~ 1 2~~ ~~ ~N=C~~ Vi c

iexcls

3192

5302

031

568 257

1532

2092 147

001

082

3198

5132

045

584

279

1542 2010

137

001

076

ible

3269 3192 3269

5354

005 270

217

1662

006

5653 1063

2070

006 4172

1065

1874

4398

074

1410

390

1799

4101

018 1349 260

2603 2197

096

001

103 1238 2758

1075

348

056

158

3304 3198 3304 BLEBS

5476

003

399 217

1618 2276

094

001

087

012

5767

898

2079

1070

014

4354

1298

1894

24 01

4421

045

783

651

2857 418

130

190 400


001

032

1000

082



Manlle xenolitbs











O-~NJ (1)0 (1)(1)(1)~~]~g- ~~0J T IiexclQ(l 3



Vgt

Jogt

~ r

O r r shyO el

-71 Cl~ ~ Q)

8 5shy3 ~

O (1)

~ y =go Q)gt Vl 5

-00 deg033 tll

~ (0 gtl_ o l _ Vgt _

o 8shy Vgt

~t rgt (O ~



I(n ~ 2) 2(n ~ 2) 3( ~ 1) 4( ~ 2) 5(n ~ 4) 6( ~ 2) 7(n ~ 1) 8( ~ 2) 9(n ~ 6) lO(n ~ 14) 1I(n ~ 6) 12(n ~ 2)





Ne 2161 2570 2264 2A 51 2334 2309 2120 2634 23 48 2616 27 58 2669 Cgt

eCs 112 000 000 000 000 000 000 (100 000 000 000 000 Di 3293 3183 2778 34 01 3041 2937 3140 3242 3056 3099 31 43 2872 J


e iexcliexcl

Mg lt(1) 0687 0646 0619 0655 0653 0664 0674 0665 0662 0648 0636 0638 (2) 0692 0651 0624 0660 0658 0669 Ooacute79 0670 0667 0653 0641 0643

Fe20 621 456 384 439 447 468 399 445 407 417 409 402 FeO 548 666 640 7 06 613 669 613 682 647 654 660 6 19 LO 246 234 199 200 269 211 187 234 206 202 206 207

Sum 9965 9948 9929 99 47 9933 9921 9932 9962 9929 9928 9926 9930


bull bull bull

bull bull bullbull

bull bull

bull bull

bull bull bull


1shy

1shy

FeO

bull bull bull o

o o o o bull

bull bull CaO

bull O O

bull bull bull bull

OO O bull bull

-

-

-

-

1shy

1shy

bull

AI203

O


bull

O O

O O

bull O


-

-shy

-

Ti0 2

bull bullbull-0deg

O O bull O

bull bull N~O

bull deg0

O 0 O


--

-

-

-

bull3

Si02

I

O 0912 10


I I I

bull6

I

bull1

K2 0

bull3

I

12 11

0 0

I

10 9 4 O O bull O

8 smiddot 2f

6bull I I

1bull -

-

8 10 12 8 10 12

MgO



-bull bull Rb

bull

O

bull - O bullO ltfl

bull Sr

bull O O

bull middot o O

Omiddot

bull Ba

bull O O

00 O

bull bull

Ni

9 0 8 1110 0 bull

3 616 0 O 7


Cr

bull 1

110

30

90

1200

30

1000 20

300 1200

200 1000

180

300

140

200

120

600

100

400

bullO

bullO O O bull O Nb



O 00 Zr


Ce

0 0 9 bull1

10

12 0 11 O 8 6

bull O 2

bull bullmiddot4

bull3 S La

8 10 12 8 10 12

MgO MgO


Tertiar) ni


BF Suite 3192 3269




Sr Nd and e isotop


11

10

16 1shy

12

28

24

43

41

12

10

13

09

6

5

2

ll

bull ----l 12 o

) o o J 10

~ 13 J O

O bull

O

bull tO


10 9 4 8 O O bull O 6

O 1 -i 2

S 1bull2 7

~ 10 12


bullO

bull00 O bull O Nb

OOO iexcl bull O Y

bull

O bull bull O

0deg 0 bull Zr

bull00 O 0 0bull

bull bullbull Ce

10 bull1 12deg1 1

0 0 6bull

8 6 O bull

2 4











Ni 2131 2377 2081 2321














LOCALITY AGE (Ma)

CERRO VERDE 570t23

LIMPIO 502t 19


NUEVA TEBLADA

46 3 t 20 NEMBY 457t18

TACUMBUacute 413t16

REMANSO CASTILLO

406t 16


shy(X)

SAMPLE 3080 3082 3097 3103 3209 3213 3283 3068 3083 3399


Sum


4003 258

1198 627 546 023

11 77 1215 4 55 091 119 244

9956

53 480 277

1258 55

1278 130 188 300 27

122

4188 246

1352 460 664 021 951

1052 560 122 094 229

9939

385 223

1050 39

1111 105 157 288 29 96

4105 248

1310 458 680 021

1084 1062 489 125 113 205

9900

57 544 317 991

41 1070

111 176 285

29 108

4148 2 11

1295 448 714 023

10 10 1112 5 18 164 111 185

9939

428 274

1004 56

1066 101 183 282

25 99

4252 205

1341 402 648 020 954

1045 580 146 118 219

9929

58 648 273 980

59 1013

116 176 234

33 101

4191 216

1369 347 722 020 889

10 84 555 1 93 122 212

9920

539 242 990 50

1030 106 180 237

36 101

4247 209

1320 407 678 020 988

1046 462 226 116 207

9926

500 253 968

50 1063

119 186 225 33

105

4184 253

1430 451 617 017 929

10 86 498 138 078 259

9940

50 371 179

1237 70

1082 82

131 218

20 89

4298 217

1555 384 640 018 778

1078 528 143 090 199

9929

48 398 154

1031 56

1102 81

141 200 29 94

4252 232

1440 399 613 017 977

1171 500 067 087 187

9932

46 542 207

1090 22

1016 81

145 165 26 89

j

() o

ordfl n ~ Q) Q)

3 o amp ~

~


14]Ndl l44 Nd 0512729t6 0512624t 12 0512803t6 0512800t20

0512760t 10 0512655 t 8 0512746t6 0512753t7

Mg 0690 0650 0676 0655 0665 0644 0665 0654 0624 0679


0~~3 - iquestoz3~ ~ ~ ~ ~

g ~

o

o w I

o

o w 00

I

o

o w ltDIr I

~ 3 ~ ~ ~ g 1 ~~ a~~~ ~~6- 2 -~0 cn~QQ~ (l Or 1 o


~ tn 3 ~ = __ 2 g ~ w ~ ~ ~ 2shyfr ~ g g g 5 0


= u- lt-ro

l-~

= lt-ro --

p lt-ro

ltLgt

70) gl o-J (l)

iexcliexcl lt J (l)








NO S--N -lt


N S S--N


)(lt)0 S--N



)Za)~ vJ 8Ngt-Z

+1 ~ lt=gt ltshy6

+1 D lt)

lt=gt

+1 v -D

lt=gt lt-

+1 oshy-D lt)

lt=gt

+1 D lt-

+1 D lt) o 6

+1 Oshy-D

=

-+1 lt)

lt=gtltshy6

+1 00 = lt-

+1 c O

o

c

~ ()

iquest rl

+1 v ltshy v

6

D +1

-D

Ntilde v

lt=gt

00 +1 V v -D N

S +1 o -D ~ V

-D O

~~ 0= ~O ~Ssect

V

6

S +1

-D S V

= -D +1 OshyN N V

6

-o Z iexcl iexcl f

oshy 6

~ D

6

-D

v -D

~ -D 6

v -D

V V

D (C 6

~ 6

$ 6

oacute

(143144) ~d

05129

05127

05125


~ I

-Z~~nit


(DBB o BF)

0704

Ro +CPce 070391shy

070381shy tcv

f +LA

070371shy -ff- RC

-f--I Ma

I





3199 3213

3252

3260

-687 - 707

-764

- 792

3263

3313A 3222

3288

-522

-739

-687

-734


13 14 15 16

Si02 4159 4231 4366 4296

Ti02 261 241 228 199 Al20 3 1212 1275 1410 1270

FeO 1141 11 59 1007 1113 MnO 024 022 018 022 MgO 13U 1331 U72 1285

CaO 1228 1033 1154 1026

Na20 460 476 493 543 K20 092 122 066 139

P20S 121 110 086 106

Co 57 67 51 61

Cr 515 612 587 676

Ni 358 546 309 492

Ba 1257 943 1043 983

Rb 54 39 21 57

Sr 1246 1019 972 1002 La 130 106 78 106

Ce 188 168 139 163

Zr 300 272 159 245

Y 26 27 25 26

Nb 122 103 85 90










Tertiary n

Table 9 SoliciI

01 Opl



U1 tlJ U shy

o ~

Vl

O tlJ

9 ~

~ o u

~ e

tlJ L Q tlJ e

tlJ O o E

4

3

L shyo e tlJ x 2

O tlJ 01 01 o gt

O


So Nb C~ P

Rb K La Sr








K = 1-3 Zr = 1-19 Sr = 2-3 P =




Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020




l ltIl Qgt U J


lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti



Ba Nb Ce p Ti


i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525





Si02 5513 5416 4787 4530 5484 4119 4030 3866 3809 4l94 Ti02 010 012 228 361 000 1892 2099

AI20 3 148 272 620 807 480 647 456 3509 FeO 233 233 627 740 518 859 1114 1912 2221 6625 6722 MnO 016 011 017 010 014 011 020 047 066 086 096 MgO 1766 1700 1415 1233 3292 4964 4778 4109 3837 362 283 CaO 2190 2172 2205 2261 117 002 009 051 059 091

Na20 099 091 050 023 001 1826 K 20 000 000 000 004 000 447 2e Cr203 085 085 029 012 092 137 081 NiO 040 026 016 011

SUM 10060 9992 9978 9981 9998 9995 9990 10001 10003 9749 9737 10067


Ti 0003 0003 0063 0102 0000 0505 0570 AIv 0021 0041 0230 0306 0109 0987 AIY) 0042 0075 0040 0050 0086 Fe3+ 0018 0000 0091 0066 0000 0000 0003 0017 0014 0680 0642 I p


Na 0069 0064 0036 0017 0001 0845








Mt Nephe line

M G M G

S66 3809 41 94

1892 2099

647 4 56 3509

~ 1 2 2221 6625 67 22

)47 066 086 096

109 3837 362 283

051 059 091

1826

447

137 081

U16 011

001 10003 9749 9737 10067

992 0993 1003

0505 0570

0987

017 0014 0680 0642

394 0470 1286 1387

010 0015 0026 0029

571 1490 0193 0154

014 0017 0024

0845

0136

0038 0023

003 0002

0271 0194

000 4000 4000 4000 4000




Ca OUacute

(1

Q

40 I I I

I I

I I JO I

I I I

1 (~-x

20 I

I

I

I 10

I I I I

2(1 30

Mg I P I Fe 2 ++ Mn + fe 3 +2 = 01 = b










513



01 Opx

BF 3192 3269 3192 3269

Si02 Ti02 AI 2O)

FeO

MgO CaO

Na20 K20

Cr20)

4123

930 4994

003

4108

805

5009 003

5686

007 333

580

3377 049

005

024

5660

002 270

519

3394 047

054

BB 3198 3304 3198 3304

Si02 Ti02 AI2O)

FeO

MgO

CaO

Na20 K20

Cr20)

4154

891

4922 004

4026

840

4938

000

5604

005

347

567 3322

057

005

024

5721

002

193

533

3436

042 005

038



AMPH PHLOGCpx Sp

Tertiary ne



11 ~N=6O-s0 e

~~8~ ~~~r ~~ I ~ ~0i~6O~ -

8 ~ ~ ~~8iexcl~ ~ ~ U ~r-j lt26oS e

N S=~~ H ~~ ~ ~sect ~ ~N j= ~~ ~Vl-

DO


lN( 60t - - __


~N 6 S=v

~ i g 8 ~~~8 ~ N S6 ltXi = i

~~ ~

~ iquest

iexcl-1 ~~ 8~ 1 2~~ ~~ ~N=C~~ Vi c

iexcls

3192

5302

031

568 257

1532

2092 147

001

082

3198

5132

045

584

279

1542 2010

137

001

076

ible

3269 3192 3269

5354

005 270

217

1662

006

5653 1063

2070

006 4172

1065

1874

4398

074

1410

390

1799

4101

018 1349 260

2603 2197

096

001

103 1238 2758

1075

348

056

158

3304 3198 3304 BLEBS

5476

003

399 217

1618 2276

094

001

087

012

5767

898

2079

1070

014

4354

1298

1894

24 01

4421

045

783

651

2857 418

130

190 400


001

032

1000

082



Manlle xenolitbs











O-~NJ (1)0 (1)(1)(1)~~]~g- ~~0J T IiexclQ(l 3



Vgt

Jogt

~ r

O r r shyO el

-71 Cl~ ~ Q)

8 5shy3 ~

O (1)

~ y =go Q)gt Vl 5

-00 deg033 tll

~ (0 gtl_ o l _ Vgt _

o 8shy Vgt

~t rgt (O ~



I(n ~ 2) 2(n ~ 2) 3( ~ 1) 4( ~ 2) 5(n ~ 4) 6( ~ 2) 7(n ~ 1) 8( ~ 2) 9(n ~ 6) lO(n ~ 14) 1I(n ~ 6) 12(n ~ 2)





Ne 2161 2570 2264 2A 51 2334 2309 2120 2634 23 48 2616 27 58 2669 Cgt

eCs 112 000 000 000 000 000 000 (100 000 000 000 000 Di 3293 3183 2778 34 01 3041 2937 3140 3242 3056 3099 31 43 2872 J


e iexcliexcl

Mg lt(1) 0687 0646 0619 0655 0653 0664 0674 0665 0662 0648 0636 0638 (2) 0692 0651 0624 0660 0658 0669 Ooacute79 0670 0667 0653 0641 0643

Fe20 621 456 384 439 447 468 399 445 407 417 409 402 FeO 548 666 640 7 06 613 669 613 682 647 654 660 6 19 LO 246 234 199 200 269 211 187 234 206 202 206 207

Sum 9965 9948 9929 99 47 9933 9921 9932 9962 9929 9928 9926 9930


bull bull bull

bull bull bullbull

bull bull

bull bull

bull bull bull


1shy

1shy

FeO

bull bull bull o

o o o o bull

bull bull CaO

bull O O

bull bull bull bull

OO O bull bull

-

-

-

-

1shy

1shy

bull

AI203

O


bull

O O

O O

bull O


-

-shy

-

Ti0 2

bull bullbull-0deg

O O bull O

bull bull N~O

bull deg0

O 0 O


--

-

-

-

bull3

Si02

I

O 0912 10


I I I

bull6

I

bull1

K2 0

bull3

I

12 11

0 0

I

10 9 4 O O bull O

8 smiddot 2f

6bull I I

1bull -

-

8 10 12 8 10 12

MgO



-bull bull Rb

bull

O

bull - O bullO ltfl

bull Sr

bull O O

bull middot o O

Omiddot

bull Ba

bull O O

00 O

bull bull

Ni

9 0 8 1110 0 bull

3 616 0 O 7


Cr

bull 1

110

30

90

1200

30

1000 20

300 1200

200 1000

180

300

140

200

120

600

100

400

bullO

bullO O O bull O Nb



O 00 Zr


Ce

0 0 9 bull1

10

12 0 11 O 8 6

bull O 2

bull bullmiddot4

bull3 S La

8 10 12 8 10 12

MgO MgO


Tertiar) ni


BF Suite 3192 3269




Sr Nd and e isotop


11

10

16 1shy

12

28

24

43

41

12

10

13

09

6

5

2

ll

bull ----l 12 o

) o o J 10

~ 13 J O

O bull

O

bull tO


10 9 4 8 O O bull O 6

O 1 -i 2

S 1bull2 7

~ 10 12


bullO

bull00 O bull O Nb

OOO iexcl bull O Y

bull

O bull bull O

0deg 0 bull Zr

bull00 O 0 0bull

bull bullbull Ce

10 bull1 12deg1 1

0 0 6bull

8 6 O bull

2 4











Ni 2131 2377 2081 2321














LOCALITY AGE (Ma)

CERRO VERDE 570t23

LIMPIO 502t 19


NUEVA TEBLADA

46 3 t 20 NEMBY 457t18

TACUMBUacute 413t16

REMANSO CASTILLO

406t 16


shy(X)

SAMPLE 3080 3082 3097 3103 3209 3213 3283 3068 3083 3399


Sum


4003 258

1198 627 546 023

11 77 1215 4 55 091 119 244

9956

53 480 277

1258 55

1278 130 188 300 27

122

4188 246

1352 460 664 021 951

1052 560 122 094 229

9939

385 223

1050 39

1111 105 157 288 29 96

4105 248

1310 458 680 021

1084 1062 489 125 113 205

9900

57 544 317 991

41 1070

111 176 285

29 108

4148 2 11

1295 448 714 023

10 10 1112 5 18 164 111 185

9939

428 274

1004 56

1066 101 183 282

25 99

4252 205

1341 402 648 020 954

1045 580 146 118 219

9929

58 648 273 980

59 1013

116 176 234

33 101

4191 216

1369 347 722 020 889

10 84 555 1 93 122 212

9920

539 242 990 50

1030 106 180 237

36 101

4247 209

1320 407 678 020 988

1046 462 226 116 207

9926

500 253 968

50 1063

119 186 225 33

105

4184 253

1430 451 617 017 929

10 86 498 138 078 259

9940

50 371 179

1237 70

1082 82

131 218

20 89

4298 217

1555 384 640 018 778

1078 528 143 090 199

9929

48 398 154

1031 56

1102 81

141 200 29 94

4252 232

1440 399 613 017 977

1171 500 067 087 187

9932

46 542 207

1090 22

1016 81

145 165 26 89

j

() o

ordfl n ~ Q) Q)

3 o amp ~

~


14]Ndl l44 Nd 0512729t6 0512624t 12 0512803t6 0512800t20

0512760t 10 0512655 t 8 0512746t6 0512753t7

Mg 0690 0650 0676 0655 0665 0644 0665 0654 0624 0679


0~~3 - iquestoz3~ ~ ~ ~ ~

g ~

o

o w I

o

o w 00

I

o

o w ltDIr I

~ 3 ~ ~ ~ g 1 ~~ a~~~ ~~6- 2 -~0 cn~QQ~ (l Or 1 o


~ tn 3 ~ = __ 2 g ~ w ~ ~ ~ 2shyfr ~ g g g 5 0


= u- lt-ro

l-~

= lt-ro --

p lt-ro

ltLgt

70) gl o-J (l)

iexcliexcl lt J (l)








NO S--N -lt


N S S--N


)(lt)0 S--N



)Za)~ vJ 8Ngt-Z

+1 ~ lt=gt ltshy6

+1 D lt)

lt=gt

+1 v -D

lt=gt lt-

+1 oshy-D lt)

lt=gt

+1 D lt-

+1 D lt) o 6

+1 Oshy-D

=

-+1 lt)

lt=gtltshy6

+1 00 = lt-

+1 c O

o

c

~ ()

iquest rl

+1 v ltshy v

6

D +1

-D

Ntilde v

lt=gt

00 +1 V v -D N

S +1 o -D ~ V

-D O

~~ 0= ~O ~Ssect

V

6

S +1

-D S V

= -D +1 OshyN N V

6

-o Z iexcl iexcl f

oshy 6

~ D

6

-D

v -D

~ -D 6

v -D

V V

D (C 6

~ 6

$ 6

oacute

(143144) ~d

05129

05127

05125


~ I

-Z~~nit


(DBB o BF)

0704

Ro +CPce 070391shy

070381shy tcv

f +LA

070371shy -ff- RC

-f--I Ma

I





3199 3213

3252

3260

-687 - 707

-764

- 792

3263

3313A 3222

3288

-522

-739

-687

-734


13 14 15 16

Si02 4159 4231 4366 4296

Ti02 261 241 228 199 Al20 3 1212 1275 1410 1270

FeO 1141 11 59 1007 1113 MnO 024 022 018 022 MgO 13U 1331 U72 1285

CaO 1228 1033 1154 1026

Na20 460 476 493 543 K20 092 122 066 139

P20S 121 110 086 106

Co 57 67 51 61

Cr 515 612 587 676

Ni 358 546 309 492

Ba 1257 943 1043 983

Rb 54 39 21 57

Sr 1246 1019 972 1002 La 130 106 78 106

Ce 188 168 139 163

Zr 300 272 159 245

Y 26 27 25 26

Nb 122 103 85 90










Tertiary n

Table 9 SoliciI

01 Opl



U1 tlJ U shy

o ~

Vl

O tlJ

9 ~

~ o u

~ e

tlJ L Q tlJ e

tlJ O o E

4

3

L shyo e tlJ x 2

O tlJ 01 01 o gt

O


So Nb C~ P

Rb K La Sr








K = 1-3 Zr = 1-19 Sr = 2-3 P =




Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020




l ltIl Qgt U J


lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti



Ba Nb Ce p Ti


i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525


Mt Nephe line

M G M G

S66 3809 41 94

1892 2099

647 4 56 3509

~ 1 2 2221 6625 67 22

)47 066 086 096

109 3837 362 283

051 059 091

1826

447

137 081

U16 011

001 10003 9749 9737 10067

992 0993 1003

0505 0570

0987

017 0014 0680 0642

394 0470 1286 1387

010 0015 0026 0029

571 1490 0193 0154

014 0017 0024

0845

0136

0038 0023

003 0002

0271 0194

000 4000 4000 4000 4000




Ca OUacute

(1

Q

40 I I I

I I

I I JO I

I I I

1 (~-x

20 I

I

I

I 10

I I I I

2(1 30

Mg I P I Fe 2 ++ Mn + fe 3 +2 = 01 = b










513



01 Opx

BF 3192 3269 3192 3269

Si02 Ti02 AI 2O)

FeO

MgO CaO

Na20 K20

Cr20)

4123

930 4994

003

4108

805

5009 003

5686

007 333

580

3377 049

005

024

5660

002 270

519

3394 047

054

BB 3198 3304 3198 3304

Si02 Ti02 AI2O)

FeO

MgO

CaO

Na20 K20

Cr20)

4154

891

4922 004

4026

840

4938

000

5604

005

347

567 3322

057

005

024

5721

002

193

533

3436

042 005

038



AMPH PHLOGCpx Sp

Tertiary ne



11 ~N=6O-s0 e

~~8~ ~~~r ~~ I ~ ~0i~6O~ -

8 ~ ~ ~~8iexcl~ ~ ~ U ~r-j lt26oS e

N S=~~ H ~~ ~ ~sect ~ ~N j= ~~ ~Vl-

DO


lN( 60t - - __


~N 6 S=v

~ i g 8 ~~~8 ~ N S6 ltXi = i

~~ ~

~ iquest

iexcl-1 ~~ 8~ 1 2~~ ~~ ~N=C~~ Vi c

iexcls

3192

5302

031

568 257

1532

2092 147

001

082

3198

5132

045

584

279

1542 2010

137

001

076

ible

3269 3192 3269

5354

005 270

217

1662

006

5653 1063

2070

006 4172

1065

1874

4398

074

1410

390

1799

4101

018 1349 260

2603 2197

096

001

103 1238 2758

1075

348

056

158

3304 3198 3304 BLEBS

5476

003

399 217

1618 2276

094

001

087

012

5767

898

2079

1070

014

4354

1298

1894

24 01

4421

045

783

651

2857 418

130

190 400


001

032

1000

082



Manlle xenolitbs











O-~NJ (1)0 (1)(1)(1)~~]~g- ~~0J T IiexclQ(l 3



Vgt

Jogt

~ r

O r r shyO el

-71 Cl~ ~ Q)

8 5shy3 ~

O (1)

~ y =go Q)gt Vl 5

-00 deg033 tll

~ (0 gtl_ o l _ Vgt _

o 8shy Vgt

~t rgt (O ~



I(n ~ 2) 2(n ~ 2) 3( ~ 1) 4( ~ 2) 5(n ~ 4) 6( ~ 2) 7(n ~ 1) 8( ~ 2) 9(n ~ 6) lO(n ~ 14) 1I(n ~ 6) 12(n ~ 2)





Ne 2161 2570 2264 2A 51 2334 2309 2120 2634 23 48 2616 27 58 2669 Cgt

eCs 112 000 000 000 000 000 000 (100 000 000 000 000 Di 3293 3183 2778 34 01 3041 2937 3140 3242 3056 3099 31 43 2872 J


e iexcliexcl

Mg lt(1) 0687 0646 0619 0655 0653 0664 0674 0665 0662 0648 0636 0638 (2) 0692 0651 0624 0660 0658 0669 Ooacute79 0670 0667 0653 0641 0643

Fe20 621 456 384 439 447 468 399 445 407 417 409 402 FeO 548 666 640 7 06 613 669 613 682 647 654 660 6 19 LO 246 234 199 200 269 211 187 234 206 202 206 207

Sum 9965 9948 9929 99 47 9933 9921 9932 9962 9929 9928 9926 9930


bull bull bull

bull bull bullbull

bull bull

bull bull

bull bull bull


1shy

1shy

FeO

bull bull bull o

o o o o bull

bull bull CaO

bull O O

bull bull bull bull

OO O bull bull

-

-

-

-

1shy

1shy

bull

AI203

O


bull

O O

O O

bull O


-

-shy

-

Ti0 2

bull bullbull-0deg

O O bull O

bull bull N~O

bull deg0

O 0 O


--

-

-

-

bull3

Si02

I

O 0912 10


I I I

bull6

I

bull1

K2 0

bull3

I

12 11

0 0

I

10 9 4 O O bull O

8 smiddot 2f

6bull I I

1bull -

-

8 10 12 8 10 12

MgO



-bull bull Rb

bull

O

bull - O bullO ltfl

bull Sr

bull O O

bull middot o O

Omiddot

bull Ba

bull O O

00 O

bull bull

Ni

9 0 8 1110 0 bull

3 616 0 O 7


Cr

bull 1

110

30

90

1200

30

1000 20

300 1200

200 1000

180

300

140

200

120

600

100

400

bullO

bullO O O bull O Nb



O 00 Zr


Ce

0 0 9 bull1

10

12 0 11 O 8 6

bull O 2

bull bullmiddot4

bull3 S La

8 10 12 8 10 12

MgO MgO


Tertiar) ni


BF Suite 3192 3269




Sr Nd and e isotop


11

10

16 1shy

12

28

24

43

41

12

10

13

09

6

5

2

ll

bull ----l 12 o

) o o J 10

~ 13 J O

O bull

O

bull tO


10 9 4 8 O O bull O 6

O 1 -i 2

S 1bull2 7

~ 10 12


bullO

bull00 O bull O Nb

OOO iexcl bull O Y

bull

O bull bull O

0deg 0 bull Zr

bull00 O 0 0bull

bull bullbull Ce

10 bull1 12deg1 1

0 0 6bull

8 6 O bull

2 4











Ni 2131 2377 2081 2321














LOCALITY AGE (Ma)

CERRO VERDE 570t23

LIMPIO 502t 19


NUEVA TEBLADA

46 3 t 20 NEMBY 457t18

TACUMBUacute 413t16

REMANSO CASTILLO

406t 16


shy(X)

SAMPLE 3080 3082 3097 3103 3209 3213 3283 3068 3083 3399


Sum


4003 258

1198 627 546 023

11 77 1215 4 55 091 119 244

9956

53 480 277

1258 55

1278 130 188 300 27

122

4188 246

1352 460 664 021 951

1052 560 122 094 229

9939

385 223

1050 39

1111 105 157 288 29 96

4105 248

1310 458 680 021

1084 1062 489 125 113 205

9900

57 544 317 991

41 1070

111 176 285

29 108

4148 2 11

1295 448 714 023

10 10 1112 5 18 164 111 185

9939

428 274

1004 56

1066 101 183 282

25 99

4252 205

1341 402 648 020 954

1045 580 146 118 219

9929

58 648 273 980

59 1013

116 176 234

33 101

4191 216

1369 347 722 020 889

10 84 555 1 93 122 212

9920

539 242 990 50

1030 106 180 237

36 101

4247 209

1320 407 678 020 988

1046 462 226 116 207

9926

500 253 968

50 1063

119 186 225 33

105

4184 253

1430 451 617 017 929

10 86 498 138 078 259

9940

50 371 179

1237 70

1082 82

131 218

20 89

4298 217

1555 384 640 018 778

1078 528 143 090 199

9929

48 398 154

1031 56

1102 81

141 200 29 94

4252 232

1440 399 613 017 977

1171 500 067 087 187

9932

46 542 207

1090 22

1016 81

145 165 26 89

j

() o

ordfl n ~ Q) Q)

3 o amp ~

~


14]Ndl l44 Nd 0512729t6 0512624t 12 0512803t6 0512800t20

0512760t 10 0512655 t 8 0512746t6 0512753t7

Mg 0690 0650 0676 0655 0665 0644 0665 0654 0624 0679


0~~3 - iquestoz3~ ~ ~ ~ ~

g ~

o

o w I

o

o w 00

I

o

o w ltDIr I

~ 3 ~ ~ ~ g 1 ~~ a~~~ ~~6- 2 -~0 cn~QQ~ (l Or 1 o


~ tn 3 ~ = __ 2 g ~ w ~ ~ ~ 2shyfr ~ g g g 5 0


= u- lt-ro

l-~

= lt-ro --

p lt-ro

ltLgt

70) gl o-J (l)

iexcliexcl lt J (l)








NO S--N -lt


N S S--N


)(lt)0 S--N



)Za)~ vJ 8Ngt-Z

+1 ~ lt=gt ltshy6

+1 D lt)

lt=gt

+1 v -D

lt=gt lt-

+1 oshy-D lt)

lt=gt

+1 D lt-

+1 D lt) o 6

+1 Oshy-D

=

-+1 lt)

lt=gtltshy6

+1 00 = lt-

+1 c O

o

c

~ ()

iquest rl

+1 v ltshy v

6

D +1

-D

Ntilde v

lt=gt

00 +1 V v -D N

S +1 o -D ~ V

-D O

~~ 0= ~O ~Ssect

V

6

S +1

-D S V

= -D +1 OshyN N V

6

-o Z iexcl iexcl f

oshy 6

~ D

6

-D

v -D

~ -D 6

v -D

V V

D (C 6

~ 6

$ 6

oacute

(143144) ~d

05129

05127

05125


~ I

-Z~~nit


(DBB o BF)

0704

Ro +CPce 070391shy

070381shy tcv

f +LA

070371shy -ff- RC

-f--I Ma

I





3199 3213

3252

3260

-687 - 707

-764

- 792

3263

3313A 3222

3288

-522

-739

-687

-734


13 14 15 16

Si02 4159 4231 4366 4296

Ti02 261 241 228 199 Al20 3 1212 1275 1410 1270

FeO 1141 11 59 1007 1113 MnO 024 022 018 022 MgO 13U 1331 U72 1285

CaO 1228 1033 1154 1026

Na20 460 476 493 543 K20 092 122 066 139

P20S 121 110 086 106

Co 57 67 51 61

Cr 515 612 587 676

Ni 358 546 309 492

Ba 1257 943 1043 983

Rb 54 39 21 57

Sr 1246 1019 972 1002 La 130 106 78 106

Ce 188 168 139 163

Zr 300 272 159 245

Y 26 27 25 26

Nb 122 103 85 90










Tertiary n

Table 9 SoliciI

01 Opl



U1 tlJ U shy

o ~

Vl

O tlJ

9 ~

~ o u

~ e

tlJ L Q tlJ e

tlJ O o E

4

3

L shyo e tlJ x 2

O tlJ 01 01 o gt

O


So Nb C~ P

Rb K La Sr








K = 1-3 Zr = 1-19 Sr = 2-3 P =




Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020




l ltIl Qgt U J


lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti



Ba Nb Ce p Ti


i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525



01 Opx

BF 3192 3269 3192 3269

Si02 Ti02 AI 2O)

FeO

MgO CaO

Na20 K20

Cr20)

4123

930 4994

003

4108

805

5009 003

5686

007 333

580

3377 049

005

024

5660

002 270

519

3394 047

054

BB 3198 3304 3198 3304

Si02 Ti02 AI2O)

FeO

MgO

CaO

Na20 K20

Cr20)

4154

891

4922 004

4026

840

4938

000

5604

005

347

567 3322

057

005

024

5721

002

193

533

3436

042 005

038



AMPH PHLOGCpx Sp

Tertiary ne



11 ~N=6O-s0 e

~~8~ ~~~r ~~ I ~ ~0i~6O~ -

8 ~ ~ ~~8iexcl~ ~ ~ U ~r-j lt26oS e

N S=~~ H ~~ ~ ~sect ~ ~N j= ~~ ~Vl-

DO


lN( 60t - - __


~N 6 S=v

~ i g 8 ~~~8 ~ N S6 ltXi = i

~~ ~

~ iquest

iexcl-1 ~~ 8~ 1 2~~ ~~ ~N=C~~ Vi c

iexcls

3192

5302

031

568 257

1532

2092 147

001

082

3198

5132

045

584

279

1542 2010

137

001

076

ible

3269 3192 3269

5354

005 270

217

1662

006

5653 1063

2070

006 4172

1065

1874

4398

074

1410

390

1799

4101

018 1349 260

2603 2197

096

001

103 1238 2758

1075

348

056

158

3304 3198 3304 BLEBS

5476

003

399 217

1618 2276

094

001

087

012

5767

898

2079

1070

014

4354

1298

1894

24 01

4421

045

783

651

2857 418

130

190 400


001

032

1000

082



Manlle xenolitbs











O-~NJ (1)0 (1)(1)(1)~~]~g- ~~0J T IiexclQ(l 3



Vgt

Jogt

~ r

O r r shyO el

-71 Cl~ ~ Q)

8 5shy3 ~

O (1)

~ y =go Q)gt Vl 5

-00 deg033 tll

~ (0 gtl_ o l _ Vgt _

o 8shy Vgt

~t rgt (O ~



I(n ~ 2) 2(n ~ 2) 3( ~ 1) 4( ~ 2) 5(n ~ 4) 6( ~ 2) 7(n ~ 1) 8( ~ 2) 9(n ~ 6) lO(n ~ 14) 1I(n ~ 6) 12(n ~ 2)





Ne 2161 2570 2264 2A 51 2334 2309 2120 2634 23 48 2616 27 58 2669 Cgt

eCs 112 000 000 000 000 000 000 (100 000 000 000 000 Di 3293 3183 2778 34 01 3041 2937 3140 3242 3056 3099 31 43 2872 J


e iexcliexcl

Mg lt(1) 0687 0646 0619 0655 0653 0664 0674 0665 0662 0648 0636 0638 (2) 0692 0651 0624 0660 0658 0669 Ooacute79 0670 0667 0653 0641 0643

Fe20 621 456 384 439 447 468 399 445 407 417 409 402 FeO 548 666 640 7 06 613 669 613 682 647 654 660 6 19 LO 246 234 199 200 269 211 187 234 206 202 206 207

Sum 9965 9948 9929 99 47 9933 9921 9932 9962 9929 9928 9926 9930


bull bull bull

bull bull bullbull

bull bull

bull bull

bull bull bull


1shy

1shy

FeO

bull bull bull o

o o o o bull

bull bull CaO

bull O O

bull bull bull bull

OO O bull bull

-

-

-

-

1shy

1shy

bull

AI203

O


bull

O O

O O

bull O


-

-shy

-

Ti0 2

bull bullbull-0deg

O O bull O

bull bull N~O

bull deg0

O 0 O


--

-

-

-

bull3

Si02

I

O 0912 10


I I I

bull6

I

bull1

K2 0

bull3

I

12 11

0 0

I

10 9 4 O O bull O

8 smiddot 2f

6bull I I

1bull -

-

8 10 12 8 10 12

MgO



-bull bull Rb

bull

O

bull - O bullO ltfl

bull Sr

bull O O

bull middot o O

Omiddot

bull Ba

bull O O

00 O

bull bull

Ni

9 0 8 1110 0 bull

3 616 0 O 7


Cr

bull 1

110

30

90

1200

30

1000 20

300 1200

200 1000

180

300

140

200

120

600

100

400

bullO

bullO O O bull O Nb



O 00 Zr


Ce

0 0 9 bull1

10

12 0 11 O 8 6

bull O 2

bull bullmiddot4

bull3 S La

8 10 12 8 10 12

MgO MgO


Tertiar) ni


BF Suite 3192 3269




Sr Nd and e isotop


11

10

16 1shy

12

28

24

43

41

12

10

13

09

6

5

2

ll

bull ----l 12 o

) o o J 10

~ 13 J O

O bull

O

bull tO


10 9 4 8 O O bull O 6

O 1 -i 2

S 1bull2 7

~ 10 12


bullO

bull00 O bull O Nb

OOO iexcl bull O Y

bull

O bull bull O

0deg 0 bull Zr

bull00 O 0 0bull

bull bullbull Ce

10 bull1 12deg1 1

0 0 6bull

8 6 O bull

2 4











Ni 2131 2377 2081 2321














LOCALITY AGE (Ma)

CERRO VERDE 570t23

LIMPIO 502t 19


NUEVA TEBLADA

46 3 t 20 NEMBY 457t18

TACUMBUacute 413t16

REMANSO CASTILLO

406t 16


shy(X)

SAMPLE 3080 3082 3097 3103 3209 3213 3283 3068 3083 3399


Sum


4003 258

1198 627 546 023

11 77 1215 4 55 091 119 244

9956

53 480 277

1258 55

1278 130 188 300 27

122

4188 246

1352 460 664 021 951

1052 560 122 094 229

9939

385 223

1050 39

1111 105 157 288 29 96

4105 248

1310 458 680 021

1084 1062 489 125 113 205

9900

57 544 317 991

41 1070

111 176 285

29 108

4148 2 11

1295 448 714 023

10 10 1112 5 18 164 111 185

9939

428 274

1004 56

1066 101 183 282

25 99

4252 205

1341 402 648 020 954

1045 580 146 118 219

9929

58 648 273 980

59 1013

116 176 234

33 101

4191 216

1369 347 722 020 889

10 84 555 1 93 122 212

9920

539 242 990 50

1030 106 180 237

36 101

4247 209

1320 407 678 020 988

1046 462 226 116 207

9926

500 253 968

50 1063

119 186 225 33

105

4184 253

1430 451 617 017 929

10 86 498 138 078 259

9940

50 371 179

1237 70

1082 82

131 218

20 89

4298 217

1555 384 640 018 778

1078 528 143 090 199

9929

48 398 154

1031 56

1102 81

141 200 29 94

4252 232

1440 399 613 017 977

1171 500 067 087 187

9932

46 542 207

1090 22

1016 81

145 165 26 89

j

() o

ordfl n ~ Q) Q)

3 o amp ~

~


14]Ndl l44 Nd 0512729t6 0512624t 12 0512803t6 0512800t20

0512760t 10 0512655 t 8 0512746t6 0512753t7

Mg 0690 0650 0676 0655 0665 0644 0665 0654 0624 0679


0~~3 - iquestoz3~ ~ ~ ~ ~

g ~

o

o w I

o

o w 00

I

o

o w ltDIr I

~ 3 ~ ~ ~ g 1 ~~ a~~~ ~~6- 2 -~0 cn~QQ~ (l Or 1 o


~ tn 3 ~ = __ 2 g ~ w ~ ~ ~ 2shyfr ~ g g g 5 0


= u- lt-ro

l-~

= lt-ro --

p lt-ro

ltLgt

70) gl o-J (l)

iexcliexcl lt J (l)








NO S--N -lt


N S S--N


)(lt)0 S--N



)Za)~ vJ 8Ngt-Z

+1 ~ lt=gt ltshy6

+1 D lt)

lt=gt

+1 v -D

lt=gt lt-

+1 oshy-D lt)

lt=gt

+1 D lt-

+1 D lt) o 6

+1 Oshy-D

=

-+1 lt)

lt=gtltshy6

+1 00 = lt-

+1 c O

o

c

~ ()

iquest rl

+1 v ltshy v

6

D +1

-D

Ntilde v

lt=gt

00 +1 V v -D N

S +1 o -D ~ V

-D O

~~ 0= ~O ~Ssect

V

6

S +1

-D S V

= -D +1 OshyN N V

6

-o Z iexcl iexcl f

oshy 6

~ D

6

-D

v -D

~ -D 6

v -D

V V

D (C 6

~ 6

$ 6

oacute

(143144) ~d

05129

05127

05125


~ I

-Z~~nit


(DBB o BF)

0704

Ro +CPce 070391shy

070381shy tcv

f +LA

070371shy -ff- RC

-f--I Ma

I





3199 3213

3252

3260

-687 - 707

-764

- 792

3263

3313A 3222

3288

-522

-739

-687

-734


13 14 15 16

Si02 4159 4231 4366 4296

Ti02 261 241 228 199 Al20 3 1212 1275 1410 1270

FeO 1141 11 59 1007 1113 MnO 024 022 018 022 MgO 13U 1331 U72 1285

CaO 1228 1033 1154 1026

Na20 460 476 493 543 K20 092 122 066 139

P20S 121 110 086 106

Co 57 67 51 61

Cr 515 612 587 676

Ni 358 546 309 492

Ba 1257 943 1043 983

Rb 54 39 21 57

Sr 1246 1019 972 1002 La 130 106 78 106

Ce 188 168 139 163

Zr 300 272 159 245

Y 26 27 25 26

Nb 122 103 85 90










Tertiary n

Table 9 SoliciI

01 Opl



U1 tlJ U shy

o ~

Vl

O tlJ

9 ~

~ o u

~ e

tlJ L Q tlJ e

tlJ O o E

4

3

L shyo e tlJ x 2

O tlJ 01 01 o gt

O


So Nb C~ P

Rb K La Sr








K = 1-3 Zr = 1-19 Sr = 2-3 P =




Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020




l ltIl Qgt U J


lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti



Ba Nb Ce p Ti


i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525










O-~NJ (1)0 (1)(1)(1)~~]~g- ~~0J T IiexclQ(l 3



Vgt

Jogt

~ r

O r r shyO el

-71 Cl~ ~ Q)

8 5shy3 ~

O (1)

~ y =go Q)gt Vl 5

-00 deg033 tll

~ (0 gtl_ o l _ Vgt _

o 8shy Vgt

~t rgt (O ~



I(n ~ 2) 2(n ~ 2) 3( ~ 1) 4( ~ 2) 5(n ~ 4) 6( ~ 2) 7(n ~ 1) 8( ~ 2) 9(n ~ 6) lO(n ~ 14) 1I(n ~ 6) 12(n ~ 2)





Ne 2161 2570 2264 2A 51 2334 2309 2120 2634 23 48 2616 27 58 2669 Cgt

eCs 112 000 000 000 000 000 000 (100 000 000 000 000 Di 3293 3183 2778 34 01 3041 2937 3140 3242 3056 3099 31 43 2872 J


e iexcliexcl

Mg lt(1) 0687 0646 0619 0655 0653 0664 0674 0665 0662 0648 0636 0638 (2) 0692 0651 0624 0660 0658 0669 Ooacute79 0670 0667 0653 0641 0643

Fe20 621 456 384 439 447 468 399 445 407 417 409 402 FeO 548 666 640 7 06 613 669 613 682 647 654 660 6 19 LO 246 234 199 200 269 211 187 234 206 202 206 207

Sum 9965 9948 9929 99 47 9933 9921 9932 9962 9929 9928 9926 9930


bull bull bull

bull bull bullbull

bull bull

bull bull

bull bull bull


1shy

1shy

FeO

bull bull bull o

o o o o bull

bull bull CaO

bull O O

bull bull bull bull

OO O bull bull

-

-

-

-

1shy

1shy

bull

AI203

O


bull

O O

O O

bull O


-

-shy

-

Ti0 2

bull bullbull-0deg

O O bull O

bull bull N~O

bull deg0

O 0 O


--

-

-

-

bull3

Si02

I

O 0912 10


I I I

bull6

I

bull1

K2 0

bull3

I

12 11

0 0

I

10 9 4 O O bull O

8 smiddot 2f

6bull I I

1bull -

-

8 10 12 8 10 12

MgO



-bull bull Rb

bull

O

bull - O bullO ltfl

bull Sr

bull O O

bull middot o O

Omiddot

bull Ba

bull O O

00 O

bull bull

Ni

9 0 8 1110 0 bull

3 616 0 O 7


Cr

bull 1

110

30

90

1200

30

1000 20

300 1200

200 1000

180

300

140

200

120

600

100

400

bullO

bullO O O bull O Nb



O 00 Zr


Ce

0 0 9 bull1

10

12 0 11 O 8 6

bull O 2

bull bullmiddot4

bull3 S La

8 10 12 8 10 12

MgO MgO


Tertiar) ni


BF Suite 3192 3269




Sr Nd and e isotop


11

10

16 1shy

12

28

24

43

41

12

10

13

09

6

5

2

ll

bull ----l 12 o

) o o J 10

~ 13 J O

O bull

O

bull tO


10 9 4 8 O O bull O 6

O 1 -i 2

S 1bull2 7

~ 10 12


bullO

bull00 O bull O Nb

OOO iexcl bull O Y

bull

O bull bull O

0deg 0 bull Zr

bull00 O 0 0bull

bull bullbull Ce

10 bull1 12deg1 1

0 0 6bull

8 6 O bull

2 4











Ni 2131 2377 2081 2321














LOCALITY AGE (Ma)

CERRO VERDE 570t23

LIMPIO 502t 19


NUEVA TEBLADA

46 3 t 20 NEMBY 457t18

TACUMBUacute 413t16

REMANSO CASTILLO

406t 16


shy(X)

SAMPLE 3080 3082 3097 3103 3209 3213 3283 3068 3083 3399


Sum


4003 258

1198 627 546 023

11 77 1215 4 55 091 119 244

9956

53 480 277

1258 55

1278 130 188 300 27

122

4188 246

1352 460 664 021 951

1052 560 122 094 229

9939

385 223

1050 39

1111 105 157 288 29 96

4105 248

1310 458 680 021

1084 1062 489 125 113 205

9900

57 544 317 991

41 1070

111 176 285

29 108

4148 2 11

1295 448 714 023

10 10 1112 5 18 164 111 185

9939

428 274

1004 56

1066 101 183 282

25 99

4252 205

1341 402 648 020 954

1045 580 146 118 219

9929

58 648 273 980

59 1013

116 176 234

33 101

4191 216

1369 347 722 020 889

10 84 555 1 93 122 212

9920

539 242 990 50

1030 106 180 237

36 101

4247 209

1320 407 678 020 988

1046 462 226 116 207

9926

500 253 968

50 1063

119 186 225 33

105

4184 253

1430 451 617 017 929

10 86 498 138 078 259

9940

50 371 179

1237 70

1082 82

131 218

20 89

4298 217

1555 384 640 018 778

1078 528 143 090 199

9929

48 398 154

1031 56

1102 81

141 200 29 94

4252 232

1440 399 613 017 977

1171 500 067 087 187

9932

46 542 207

1090 22

1016 81

145 165 26 89

j

() o

ordfl n ~ Q) Q)

3 o amp ~

~


14]Ndl l44 Nd 0512729t6 0512624t 12 0512803t6 0512800t20

0512760t 10 0512655 t 8 0512746t6 0512753t7

Mg 0690 0650 0676 0655 0665 0644 0665 0654 0624 0679


0~~3 - iquestoz3~ ~ ~ ~ ~

g ~

o

o w I

o

o w 00

I

o

o w ltDIr I

~ 3 ~ ~ ~ g 1 ~~ a~~~ ~~6- 2 -~0 cn~QQ~ (l Or 1 o


~ tn 3 ~ = __ 2 g ~ w ~ ~ ~ 2shyfr ~ g g g 5 0


= u- lt-ro

l-~

= lt-ro --

p lt-ro

ltLgt

70) gl o-J (l)

iexcliexcl lt J (l)








NO S--N -lt


N S S--N


)(lt)0 S--N



)Za)~ vJ 8Ngt-Z

+1 ~ lt=gt ltshy6

+1 D lt)

lt=gt

+1 v -D

lt=gt lt-

+1 oshy-D lt)

lt=gt

+1 D lt-

+1 D lt) o 6

+1 Oshy-D

=

-+1 lt)

lt=gtltshy6

+1 00 = lt-

+1 c O

o

c

~ ()

iquest rl

+1 v ltshy v

6

D +1

-D

Ntilde v

lt=gt

00 +1 V v -D N

S +1 o -D ~ V

-D O

~~ 0= ~O ~Ssect

V

6

S +1

-D S V

= -D +1 OshyN N V

6

-o Z iexcl iexcl f

oshy 6

~ D

6

-D

v -D

~ -D 6

v -D

V V

D (C 6

~ 6

$ 6

oacute

(143144) ~d

05129

05127

05125


~ I

-Z~~nit


(DBB o BF)

0704

Ro +CPce 070391shy

070381shy tcv

f +LA

070371shy -ff- RC

-f--I Ma

I





3199 3213

3252

3260

-687 - 707

-764

- 792

3263

3313A 3222

3288

-522

-739

-687

-734


13 14 15 16

Si02 4159 4231 4366 4296

Ti02 261 241 228 199 Al20 3 1212 1275 1410 1270

FeO 1141 11 59 1007 1113 MnO 024 022 018 022 MgO 13U 1331 U72 1285

CaO 1228 1033 1154 1026

Na20 460 476 493 543 K20 092 122 066 139

P20S 121 110 086 106

Co 57 67 51 61

Cr 515 612 587 676

Ni 358 546 309 492

Ba 1257 943 1043 983

Rb 54 39 21 57

Sr 1246 1019 972 1002 La 130 106 78 106

Ce 188 168 139 163

Zr 300 272 159 245

Y 26 27 25 26

Nb 122 103 85 90










Tertiary n

Table 9 SoliciI

01 Opl



U1 tlJ U shy

o ~

Vl

O tlJ

9 ~

~ o u

~ e

tlJ L Q tlJ e

tlJ O o E

4

3

L shyo e tlJ x 2

O tlJ 01 01 o gt

O


So Nb C~ P

Rb K La Sr








K = 1-3 Zr = 1-19 Sr = 2-3 P =




Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020




l ltIl Qgt U J


lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti



Ba Nb Ce p Ti


i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525

bull bull bull

bull bull bullbull

bull bull

bull bull

bull bull bull


1shy

1shy

FeO

bull bull bull o

o o o o bull

bull bull CaO

bull O O

bull bull bull bull

OO O bull bull

-

-

-

-

1shy

1shy

bull

AI203

O


bull

O O

O O

bull O


-

-shy

-

Ti0 2

bull bullbull-0deg

O O bull O

bull bull N~O

bull deg0

O 0 O


--

-

-

-

bull3

Si02

I

O 0912 10


I I I

bull6

I

bull1

K2 0

bull3

I

12 11

0 0

I

10 9 4 O O bull O

8 smiddot 2f

6bull I I

1bull -

-

8 10 12 8 10 12

MgO



-bull bull Rb

bull

O

bull - O bullO ltfl

bull Sr

bull O O

bull middot o O

Omiddot

bull Ba

bull O O

00 O

bull bull

Ni

9 0 8 1110 0 bull

3 616 0 O 7


Cr

bull 1

110

30

90

1200

30

1000 20

300 1200

200 1000

180

300

140

200

120

600

100

400

bullO

bullO O O bull O Nb



O 00 Zr


Ce

0 0 9 bull1

10

12 0 11 O 8 6

bull O 2

bull bullmiddot4

bull3 S La

8 10 12 8 10 12

MgO MgO


Tertiar) ni


BF Suite 3192 3269




Sr Nd and e isotop


11

10

16 1shy

12

28

24

43

41

12

10

13

09

6

5

2

ll

bull ----l 12 o

) o o J 10

~ 13 J O

O bull

O

bull tO


10 9 4 8 O O bull O 6

O 1 -i 2

S 1bull2 7

~ 10 12


bullO

bull00 O bull O Nb

OOO iexcl bull O Y

bull

O bull bull O

0deg 0 bull Zr

bull00 O 0 0bull

bull bullbull Ce

10 bull1 12deg1 1

0 0 6bull

8 6 O bull

2 4











Ni 2131 2377 2081 2321














LOCALITY AGE (Ma)

CERRO VERDE 570t23

LIMPIO 502t 19


NUEVA TEBLADA

46 3 t 20 NEMBY 457t18

TACUMBUacute 413t16

REMANSO CASTILLO

406t 16


shy(X)

SAMPLE 3080 3082 3097 3103 3209 3213 3283 3068 3083 3399


Sum


4003 258

1198 627 546 023

11 77 1215 4 55 091 119 244

9956

53 480 277

1258 55

1278 130 188 300 27

122

4188 246

1352 460 664 021 951

1052 560 122 094 229

9939

385 223

1050 39

1111 105 157 288 29 96

4105 248

1310 458 680 021

1084 1062 489 125 113 205

9900

57 544 317 991

41 1070

111 176 285

29 108

4148 2 11

1295 448 714 023

10 10 1112 5 18 164 111 185

9939

428 274

1004 56

1066 101 183 282

25 99

4252 205

1341 402 648 020 954

1045 580 146 118 219

9929

58 648 273 980

59 1013

116 176 234

33 101

4191 216

1369 347 722 020 889

10 84 555 1 93 122 212

9920

539 242 990 50

1030 106 180 237

36 101

4247 209

1320 407 678 020 988

1046 462 226 116 207

9926

500 253 968

50 1063

119 186 225 33

105

4184 253

1430 451 617 017 929

10 86 498 138 078 259

9940

50 371 179

1237 70

1082 82

131 218

20 89

4298 217

1555 384 640 018 778

1078 528 143 090 199

9929

48 398 154

1031 56

1102 81

141 200 29 94

4252 232

1440 399 613 017 977

1171 500 067 087 187

9932

46 542 207

1090 22

1016 81

145 165 26 89

j

() o

ordfl n ~ Q) Q)

3 o amp ~

~


14]Ndl l44 Nd 0512729t6 0512624t 12 0512803t6 0512800t20

0512760t 10 0512655 t 8 0512746t6 0512753t7

Mg 0690 0650 0676 0655 0665 0644 0665 0654 0624 0679


0~~3 - iquestoz3~ ~ ~ ~ ~

g ~

o

o w I

o

o w 00

I

o

o w ltDIr I

~ 3 ~ ~ ~ g 1 ~~ a~~~ ~~6- 2 -~0 cn~QQ~ (l Or 1 o


~ tn 3 ~ = __ 2 g ~ w ~ ~ ~ 2shyfr ~ g g g 5 0


= u- lt-ro

l-~

= lt-ro --

p lt-ro

ltLgt

70) gl o-J (l)

iexcliexcl lt J (l)








NO S--N -lt


N S S--N


)(lt)0 S--N



)Za)~ vJ 8Ngt-Z

+1 ~ lt=gt ltshy6

+1 D lt)

lt=gt

+1 v -D

lt=gt lt-

+1 oshy-D lt)

lt=gt

+1 D lt-

+1 D lt) o 6

+1 Oshy-D

=

-+1 lt)

lt=gtltshy6

+1 00 = lt-

+1 c O

o

c

~ ()

iquest rl

+1 v ltshy v

6

D +1

-D

Ntilde v

lt=gt

00 +1 V v -D N

S +1 o -D ~ V

-D O

~~ 0= ~O ~Ssect

V

6

S +1

-D S V

= -D +1 OshyN N V

6

-o Z iexcl iexcl f

oshy 6

~ D

6

-D

v -D

~ -D 6

v -D

V V

D (C 6

~ 6

$ 6

oacute

(143144) ~d

05129

05127

05125


~ I

-Z~~nit


(DBB o BF)

0704

Ro +CPce 070391shy

070381shy tcv

f +LA

070371shy -ff- RC

-f--I Ma

I





3199 3213

3252

3260

-687 - 707

-764

- 792

3263

3313A 3222

3288

-522

-739

-687

-734


13 14 15 16

Si02 4159 4231 4366 4296

Ti02 261 241 228 199 Al20 3 1212 1275 1410 1270

FeO 1141 11 59 1007 1113 MnO 024 022 018 022 MgO 13U 1331 U72 1285

CaO 1228 1033 1154 1026

Na20 460 476 493 543 K20 092 122 066 139

P20S 121 110 086 106

Co 57 67 51 61

Cr 515 612 587 676

Ni 358 546 309 492

Ba 1257 943 1043 983

Rb 54 39 21 57

Sr 1246 1019 972 1002 La 130 106 78 106

Ce 188 168 139 163

Zr 300 272 159 245

Y 26 27 25 26

Nb 122 103 85 90










Tertiary n

Table 9 SoliciI

01 Opl



U1 tlJ U shy

o ~

Vl

O tlJ

9 ~

~ o u

~ e

tlJ L Q tlJ e

tlJ O o E

4

3

L shyo e tlJ x 2

O tlJ 01 01 o gt

O


So Nb C~ P

Rb K La Sr








K = 1-3 Zr = 1-19 Sr = 2-3 P =




Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020




l ltIl Qgt U J


lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti



Ba Nb Ce p Ti


i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525

ll

bull ----l 12 o

) o o J 10

~ 13 J O

O bull

O

bull tO


10 9 4 8 O O bull O 6

O 1 -i 2

S 1bull2 7

~ 10 12


bullO

bull00 O bull O Nb

OOO iexcl bull O Y

bull

O bull bull O

0deg 0 bull Zr

bull00 O 0 0bull

bull bullbull Ce

10 bull1 12deg1 1

0 0 6bull

8 6 O bull

2 4











Ni 2131 2377 2081 2321














LOCALITY AGE (Ma)

CERRO VERDE 570t23

LIMPIO 502t 19


NUEVA TEBLADA

46 3 t 20 NEMBY 457t18

TACUMBUacute 413t16

REMANSO CASTILLO

406t 16


shy(X)

SAMPLE 3080 3082 3097 3103 3209 3213 3283 3068 3083 3399


Sum


4003 258

1198 627 546 023

11 77 1215 4 55 091 119 244

9956

53 480 277

1258 55

1278 130 188 300 27

122

4188 246

1352 460 664 021 951

1052 560 122 094 229

9939

385 223

1050 39

1111 105 157 288 29 96

4105 248

1310 458 680 021

1084 1062 489 125 113 205

9900

57 544 317 991

41 1070

111 176 285

29 108

4148 2 11

1295 448 714 023

10 10 1112 5 18 164 111 185

9939

428 274

1004 56

1066 101 183 282

25 99

4252 205

1341 402 648 020 954

1045 580 146 118 219

9929

58 648 273 980

59 1013

116 176 234

33 101

4191 216

1369 347 722 020 889

10 84 555 1 93 122 212

9920

539 242 990 50

1030 106 180 237

36 101

4247 209

1320 407 678 020 988

1046 462 226 116 207

9926

500 253 968

50 1063

119 186 225 33

105

4184 253

1430 451 617 017 929

10 86 498 138 078 259

9940

50 371 179

1237 70

1082 82

131 218

20 89

4298 217

1555 384 640 018 778

1078 528 143 090 199

9929

48 398 154

1031 56

1102 81

141 200 29 94

4252 232

1440 399 613 017 977

1171 500 067 087 187

9932

46 542 207

1090 22

1016 81

145 165 26 89

j

() o

ordfl n ~ Q) Q)

3 o amp ~

~


14]Ndl l44 Nd 0512729t6 0512624t 12 0512803t6 0512800t20

0512760t 10 0512655 t 8 0512746t6 0512753t7

Mg 0690 0650 0676 0655 0665 0644 0665 0654 0624 0679


0~~3 - iquestoz3~ ~ ~ ~ ~

g ~

o

o w I

o

o w 00

I

o

o w ltDIr I

~ 3 ~ ~ ~ g 1 ~~ a~~~ ~~6- 2 -~0 cn~QQ~ (l Or 1 o


~ tn 3 ~ = __ 2 g ~ w ~ ~ ~ 2shyfr ~ g g g 5 0


= u- lt-ro

l-~

= lt-ro --

p lt-ro

ltLgt

70) gl o-J (l)

iexcliexcl lt J (l)








NO S--N -lt


N S S--N


)(lt)0 S--N



)Za)~ vJ 8Ngt-Z

+1 ~ lt=gt ltshy6

+1 D lt)

lt=gt

+1 v -D

lt=gt lt-

+1 oshy-D lt)

lt=gt

+1 D lt-

+1 D lt) o 6

+1 Oshy-D

=

-+1 lt)

lt=gtltshy6

+1 00 = lt-

+1 c O

o

c

~ ()

iquest rl

+1 v ltshy v

6

D +1

-D

Ntilde v

lt=gt

00 +1 V v -D N

S +1 o -D ~ V

-D O

~~ 0= ~O ~Ssect

V

6

S +1

-D S V

= -D +1 OshyN N V

6

-o Z iexcl iexcl f

oshy 6

~ D

6

-D

v -D

~ -D 6

v -D

V V

D (C 6

~ 6

$ 6

oacute

(143144) ~d

05129

05127

05125


~ I

-Z~~nit


(DBB o BF)

0704

Ro +CPce 070391shy

070381shy tcv

f +LA

070371shy -ff- RC

-f--I Ma

I





3199 3213

3252

3260

-687 - 707

-764

- 792

3263

3313A 3222

3288

-522

-739

-687

-734


13 14 15 16

Si02 4159 4231 4366 4296

Ti02 261 241 228 199 Al20 3 1212 1275 1410 1270

FeO 1141 11 59 1007 1113 MnO 024 022 018 022 MgO 13U 1331 U72 1285

CaO 1228 1033 1154 1026

Na20 460 476 493 543 K20 092 122 066 139

P20S 121 110 086 106

Co 57 67 51 61

Cr 515 612 587 676

Ni 358 546 309 492

Ba 1257 943 1043 983

Rb 54 39 21 57

Sr 1246 1019 972 1002 La 130 106 78 106

Ce 188 168 139 163

Zr 300 272 159 245

Y 26 27 25 26

Nb 122 103 85 90










Tertiary n

Table 9 SoliciI

01 Opl



U1 tlJ U shy

o ~

Vl

O tlJ

9 ~

~ o u

~ e

tlJ L Q tlJ e

tlJ O o E

4

3

L shyo e tlJ x 2

O tlJ 01 01 o gt

O


So Nb C~ P

Rb K La Sr








K = 1-3 Zr = 1-19 Sr = 2-3 P =




Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020




l ltIl Qgt U J


lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti



Ba Nb Ce p Ti


i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525


LOCALITY AGE (Ma)

CERRO VERDE 570t23

LIMPIO 502t 19


NUEVA TEBLADA

46 3 t 20 NEMBY 457t18

TACUMBUacute 413t16

REMANSO CASTILLO

406t 16


shy(X)

SAMPLE 3080 3082 3097 3103 3209 3213 3283 3068 3083 3399


Sum


4003 258

1198 627 546 023

11 77 1215 4 55 091 119 244

9956

53 480 277

1258 55

1278 130 188 300 27

122

4188 246

1352 460 664 021 951

1052 560 122 094 229

9939

385 223

1050 39

1111 105 157 288 29 96

4105 248

1310 458 680 021

1084 1062 489 125 113 205

9900

57 544 317 991

41 1070

111 176 285

29 108

4148 2 11

1295 448 714 023

10 10 1112 5 18 164 111 185

9939

428 274

1004 56

1066 101 183 282

25 99

4252 205

1341 402 648 020 954

1045 580 146 118 219

9929

58 648 273 980

59 1013

116 176 234

33 101

4191 216

1369 347 722 020 889

10 84 555 1 93 122 212

9920

539 242 990 50

1030 106 180 237

36 101

4247 209

1320 407 678 020 988

1046 462 226 116 207

9926

500 253 968

50 1063

119 186 225 33

105

4184 253

1430 451 617 017 929

10 86 498 138 078 259

9940

50 371 179

1237 70

1082 82

131 218

20 89

4298 217

1555 384 640 018 778

1078 528 143 090 199

9929

48 398 154

1031 56

1102 81

141 200 29 94

4252 232

1440 399 613 017 977

1171 500 067 087 187

9932

46 542 207

1090 22

1016 81

145 165 26 89

j

() o

ordfl n ~ Q) Q)

3 o amp ~

~


14]Ndl l44 Nd 0512729t6 0512624t 12 0512803t6 0512800t20

0512760t 10 0512655 t 8 0512746t6 0512753t7

Mg 0690 0650 0676 0655 0665 0644 0665 0654 0624 0679


0~~3 - iquestoz3~ ~ ~ ~ ~

g ~

o

o w I

o

o w 00

I

o

o w ltDIr I

~ 3 ~ ~ ~ g 1 ~~ a~~~ ~~6- 2 -~0 cn~QQ~ (l Or 1 o


~ tn 3 ~ = __ 2 g ~ w ~ ~ ~ 2shyfr ~ g g g 5 0


= u- lt-ro

l-~

= lt-ro --

p lt-ro

ltLgt

70) gl o-J (l)

iexcliexcl lt J (l)








NO S--N -lt


N S S--N


)(lt)0 S--N



)Za)~ vJ 8Ngt-Z

+1 ~ lt=gt ltshy6

+1 D lt)

lt=gt

+1 v -D

lt=gt lt-

+1 oshy-D lt)

lt=gt

+1 D lt-

+1 D lt) o 6

+1 Oshy-D

=

-+1 lt)

lt=gtltshy6

+1 00 = lt-

+1 c O

o

c

~ ()

iquest rl

+1 v ltshy v

6

D +1

-D

Ntilde v

lt=gt

00 +1 V v -D N

S +1 o -D ~ V

-D O

~~ 0= ~O ~Ssect

V

6

S +1

-D S V

= -D +1 OshyN N V

6

-o Z iexcl iexcl f

oshy 6

~ D

6

-D

v -D

~ -D 6

v -D

V V

D (C 6

~ 6

$ 6

oacute

(143144) ~d

05129

05127

05125


~ I

-Z~~nit


(DBB o BF)

0704

Ro +CPce 070391shy

070381shy tcv

f +LA

070371shy -ff- RC

-f--I Ma

I





3199 3213

3252

3260

-687 - 707

-764

- 792

3263

3313A 3222

3288

-522

-739

-687

-734


13 14 15 16

Si02 4159 4231 4366 4296

Ti02 261 241 228 199 Al20 3 1212 1275 1410 1270

FeO 1141 11 59 1007 1113 MnO 024 022 018 022 MgO 13U 1331 U72 1285

CaO 1228 1033 1154 1026

Na20 460 476 493 543 K20 092 122 066 139

P20S 121 110 086 106

Co 57 67 51 61

Cr 515 612 587 676

Ni 358 546 309 492

Ba 1257 943 1043 983

Rb 54 39 21 57

Sr 1246 1019 972 1002 La 130 106 78 106

Ce 188 168 139 163

Zr 300 272 159 245

Y 26 27 25 26

Nb 122 103 85 90










Tertiary n

Table 9 SoliciI

01 Opl



U1 tlJ U shy

o ~

Vl

O tlJ

9 ~

~ o u

~ e

tlJ L Q tlJ e

tlJ O o E

4

3

L shyo e tlJ x 2

O tlJ 01 01 o gt

O


So Nb C~ P

Rb K La Sr








K = 1-3 Zr = 1-19 Sr = 2-3 P =




Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020




l ltIl Qgt U J


lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti



Ba Nb Ce p Ti


i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525








NO S--N -lt


N S S--N


)(lt)0 S--N



)Za)~ vJ 8Ngt-Z

+1 ~ lt=gt ltshy6

+1 D lt)

lt=gt

+1 v -D

lt=gt lt-

+1 oshy-D lt)

lt=gt

+1 D lt-

+1 D lt) o 6

+1 Oshy-D

=

-+1 lt)

lt=gtltshy6

+1 00 = lt-

+1 c O

o

c

~ ()

iquest rl

+1 v ltshy v

6

D +1

-D

Ntilde v

lt=gt

00 +1 V v -D N

S +1 o -D ~ V

-D O

~~ 0= ~O ~Ssect

V

6

S +1

-D S V

= -D +1 OshyN N V

6

-o Z iexcl iexcl f

oshy 6

~ D

6

-D

v -D

~ -D 6

v -D

V V

D (C 6

~ 6

$ 6

oacute

(143144) ~d

05129

05127

05125


~ I

-Z~~nit


(DBB o BF)

0704

Ro +CPce 070391shy

070381shy tcv

f +LA

070371shy -ff- RC

-f--I Ma

I





3199 3213

3252

3260

-687 - 707

-764

- 792

3263

3313A 3222

3288

-522

-739

-687

-734


13 14 15 16

Si02 4159 4231 4366 4296

Ti02 261 241 228 199 Al20 3 1212 1275 1410 1270

FeO 1141 11 59 1007 1113 MnO 024 022 018 022 MgO 13U 1331 U72 1285

CaO 1228 1033 1154 1026

Na20 460 476 493 543 K20 092 122 066 139

P20S 121 110 086 106

Co 57 67 51 61

Cr 515 612 587 676

Ni 358 546 309 492

Ba 1257 943 1043 983

Rb 54 39 21 57

Sr 1246 1019 972 1002 La 130 106 78 106

Ce 188 168 139 163

Zr 300 272 159 245

Y 26 27 25 26

Nb 122 103 85 90










Tertiary n

Table 9 SoliciI

01 Opl



U1 tlJ U shy

o ~

Vl

O tlJ

9 ~

~ o u

~ e

tlJ L Q tlJ e

tlJ O o E

4

3

L shyo e tlJ x 2

O tlJ 01 01 o gt

O


So Nb C~ P

Rb K La Sr








K = 1-3 Zr = 1-19 Sr = 2-3 P =




Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020




l ltIl Qgt U J


lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti



Ba Nb Ce p Ti


i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525




3199 3213

3252

3260

-687 - 707

-764

- 792

3263

3313A 3222

3288

-522

-739

-687

-734


13 14 15 16

Si02 4159 4231 4366 4296

Ti02 261 241 228 199 Al20 3 1212 1275 1410 1270

FeO 1141 11 59 1007 1113 MnO 024 022 018 022 MgO 13U 1331 U72 1285

CaO 1228 1033 1154 1026

Na20 460 476 493 543 K20 092 122 066 139

P20S 121 110 086 106

Co 57 67 51 61

Cr 515 612 587 676

Ni 358 546 309 492

Ba 1257 943 1043 983

Rb 54 39 21 57

Sr 1246 1019 972 1002 La 130 106 78 106

Ce 188 168 139 163

Zr 300 272 159 245

Y 26 27 25 26

Nb 122 103 85 90










Tertiary n

Table 9 SoliciI

01 Opl



U1 tlJ U shy

o ~

Vl

O tlJ

9 ~

~ o u

~ e

tlJ L Q tlJ e

tlJ O o E

4

3

L shyo e tlJ x 2

O tlJ 01 01 o gt

O


So Nb C~ P

Rb K La Sr








K = 1-3 Zr = 1-19 Sr = 2-3 P =




Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020




l ltIl Qgt U J


lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti



Ba Nb Ce p Ti


i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525







K = 1-3 Zr = 1-19 Sr = 2-3 P =




Rb 00001 0001 0025 0010 00001 300 03 Ba 00001 0010 0007 0010 00001 100 04 K 00002 0001 00028 0001 00001 1000 10 Nb 00010 015 010 010 005 100 05

La 000044 00005 002 001 0029 003 012

Ce 000030 00009 004 0021 0032 003 0 20

Sr 00010 0010 0086 0010 00001 010 05

P 0043 0014 0009 019 005 020 020 Zr 001 0030 010 0155 002 060 035 Ti 0 010 0100 0uuml30 030 010 090 07

Y 00010 0080 0367 l 85 0048 003 020




l ltIl Qgt U J


lfl (1)0

o u

o c

C J CT

~ 2 2 Qiexcl

2 c O

Q) -O)

Qiexcl O)

-30 coQiexclI

Qiexcl

I o O (1)1Qgtc o

O Ua 1 JoaE u

O o E

V

Ba Nb Ce P Ti



Ba Nb Ce p Ti


i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525

i






~














Tertiary m









1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525

1 I


1

I I j

~

t 1

~ pBa Nb Ce TI

ylb K La Sr Zr



Sr = 237 P = 92 Nd = 137 Ti = 1300 Y = 469)



W 50deg 20deg E

10 deg B RAZrL

10deg

-shyUK







References



















































al





































525













































al





































525

al





































525

Documents

I PIERO COMIN-CHIARAMONTI(I, '), LUCIA CIVETTA(2 ... · 510 P. Comin-Chiaramonti el al. Tertiary n 400°C and reacting with 100 % H3P04 by a Finningan Mat Delta E mass spectrometer