The non-igneous genesis of angrites: Support from trace element ... · D Orbigny phases. Trace element data were obtaine d from both the porous and the compact part of this meteorite

Meteoritics amp Planetary Science 40 Nr 3 409ndash430 (2005)Abstract available online at httpmeteoriticsorg

409 copy The Meteoritical Society 2005 Printed in USA

The non-igneous genesis of angrites Support from trace element distribution between phases in DrsquoOrbigny

MarIgravea Eugenia VARELA1 Gero KURAT2 Ernst ZINNER3 Peter HOPPE4 Theodoros NTAFLOS2 and Mikhail A NAZAROV5

1CONICET-UNS Dpto GeologIgravea San Juan 670 (8000) B Blanca Argentina2Institut fcedilr Geologische Wissenschaften Universitpermilt Wien Althanstrasse 14 A-1090 Vienna Austria

3Laboratory for Space Sciences and Physics Department Washington University Saint Louis Missouri 63130 USA4Abteilung Kosmochemie Max-Planck-Institut fcedilr Chemie Postfach 3060 D-55020 Mainz Germany

5Vernadsky Institute RAS 119991 Moscow RussiaCorresponding author E-mail evarelacribaeduar

(Received 18 August 2004 revision accepted 20 December 2004)

AbstractndashDrsquoOrbigny is an exceptional angrite Chemically it resembles other angrites such asAsuka-881371 Sahara 99555 Lewis Cliff (LEW) 87051 and LEW 86010 but its structure andtexture are peculiar It has a compact and porous lithology abundant glasses augite-bearing drusesand chemical and mineralogical properties that are highly unusual for igneous rocks Our previousstudies led us to a new view on angrites they can possibly be considered as CAIs that grew to largersizes than the ones we know from carbonaceous chondrites Thus angrites may bear a record of rareand special conditions in some part of the early solar nebula Here we report trace element contents ofDrsquoOrbigny phases Trace element data were obtained from both the porous and the compact part ofthis meteorite We have confronted our results with the popular igneous genetic model According tothis model if all phases of DrsquoOrbigny crystallized from the same system as an igneous origin impliesa record of this genesis should be expressed in the distribution of trace elements among early and latephases Our results show that the trace element distribution of the two contemporaneous phasesolivine and plagioclase which form the backbone of the rock seem to require liquids of differentcomposition Abundances of highly incompatible elements in all olivines including the megacrystsindicate disequilibrium with the bulk rock and suggest liquids very rich in these elements (gt10000 timesCI) which is much richer than any fractional crystallization could possibly produce In addition traceelement contents of late phases are incompatible with formation from the bulk systemrsquos residual meltThese results add additional severe constraints to the many conflicts that existed previously betweenan igneous model for the origin of angrites and the mineralogical and chemical observations Thisnew trace element content data reported here corroborate our previous results based on the shapestructure mineralogy chemical and isotopic data of the whole meteorite as well as on a petrographicand chemical composition study of all types of glasses and give strength to a new genetic model thatpostulates that DrsquoOrbigny (and possibly all angrites) could have formed in the solar nebula underchanging redox conditions more akin to chondritic constituents (eg CAIs) than to planetarydifferentiated rock

INTRODUCTION

Angrites are a small group of augite-anorthite-olivinerocks with apparent formation ages similar to those ofchondrites the U-Pb Th-Pb and Pb-Pb ages for Angra dosReis LEW 86010 and DrsquoOrbigny are between 454 and45578 Ga (Wasserburg et al 1977 Lugmair and Galer 1992Jagoutz et al 2002) The genesis of these rocks is highly

controversial as shown by their mineralogical compositionpetrology geochemistry and isotopic features (Prinz et al1977 1988 Goodrich 1988 McKay et al 1988 1990 Prinzand Weisberg 1995 Mikouchi et al 1996 Mikouchi andMcKay 2001) Recent petrographic and geochemical studiesof the dense part of DrsquoOrbigny suggest that this rock formedfrom a melt by rapid and complete crystallization(Mittlefehldt et al 2001 2002) However the mineralogical

410 M E Valera et al

mineral and bulk chemical properties of angrites remainpeculiar because all phases are usually out of equilibrium(Prinz and Weisberg 1995 Kurat et al 2001a 2001b 2004)Specifically the high abundances of refractory lithophileelements combined with high abundances of the moderatelyvolatile elements Mn and Fe2+ and low abundances ofsiderophile and volatile elements (eg Mittlefehldt et al1998) pose severe petrogenetic problems In addition theabundances of refractory elements are unfractionated withrespect to solar abundances at the 10 times to 15 times CI level verysimilar to what is observed in eucrites and Ca- and Al-richinclusions from carbonaceous chondrites (Prinz et al 19881990 Prinz and Weisberg 1995) There are many problemswith the distribution of certain trace elements between thephases in DrsquoOrbigny Such discrepancies for DrsquoOrbigny andother angrites have been reported by Floss et al (2003) whosuggested that kinetic effects during fast crystallization couldbe the cause Clearly as has been previously recognized byPrinz et al (1988 1990) Prinz and Weisberg (1995) andLonghi (1999) there is no simple way to create this class ofrocks

The shape structure and texture of DrsquoOrbigny and itsmineral and bulk chemical compositions indicate a complexgenesis under changing redox conditions as do manyconstituents of chondrites (eg Kurat 1988 Kurat et al 2002Varela et al 2002) Our observations on the textural featuresand data of major chemical compositions of all phases (Kuratet al 2004) as well as the petrographic and chemicalcomposition of all types of glasses present in DrsquoOrbigny(Varela et al 2003) are incompatible with a planetary igneousorigin for this rock and support an origin related to that of Ca-and Al-rich inclusions in carbonaceous chondrites Here wereport trace element abundances of the different phases in thecompact and porous part of DrsquoOrbigny The results supportour previous conclusions and strengthen the view thatangrites are rocks that record special conditions in the earlysolar nebula Short preliminary reports were given by Kuratet al (2001a 2001b 2003)

ANALYTICAL TECHNIQUES

Mineral phases were analyzed for their trace elementcontents with the laser ablation inductively coupled plasmamass spectrometry (LA-ICP-MS) facility at MemorialUniversity of Newfoundland The instrument is a VGPlasmaQuad 2S+ ICP-MS coupled to a 266 nm NdYAG laserbuilt in-house The ICP-MS instrument is equipped with afast-switching quadrupole mass filter and a single Galileo-type electron multiplier The laser beam is focused through theobjective of a microscope onto the sample surface A 50 cm3

sample cell is mounted on the computer-driven motorizedstage of the microscope The laser was set up to produce anenergy of 15 mJpulse (measured just before the beam enteredthe objective of the microscope) at a repetition rate of 10 Hzwith the laser beam focused about 200 microm above the surface

in order to produce a spot of about 50 microm on the samplesurface The cell was flushed with He gas during ablation tominimize fallback of ejecta and thus maximize analyticalsensitivity Typical data acquisitions consisted of a 60 secmeasurement of the gas blank before the start of ablationwhich lasted another 60 sec Laser ablation produced a pit inthe sample about 50 microm wide and 60 microm deep Raw ICP-MSdata were corrected for electron multiplier dead time (20 ns)and processed offline using a spreadsheet program(LAMTRACE S Jackson unpublished) to integrate signalssubtract the gas blank and calculate concentrationsMeasurements on meteoritic samples were calibrated againstthe NIST SRM 612 standard using the concentration values ofPearce et al (1997) Silicon determined by EMP analysiswas used as the internal standard

To avoid contamination by surrounding phases the traceelement contents of small phases were measured with theCameca IMS 3F ion microprobes at Washington UniversitySt Louis and the Max-Planck-Institut fcedilr Chemie in Mainzfollowing a modified procedure of Zinner and Crozaz (1986)

RESULTS

The investigated samples were the polished sectionsDrsquoOrbigny C DrsquoOrbigny D DrsquoOrbigny G DrsquoOrbigny XAand mineral separates from rock specimens and rock debrisDrsquoOrbigny B2 (all from the Naturhistorisches Museum inVienna)

The phases analyzed for trace elements were selectedfollowing the detailed petrographic and chemical studyundertaken by Kurat et al (2004) a brief summary of whichis given below This overview will help the reader understandthe structure and textures of this rock its minerals (egolivines augites and anorthite) and their occurrence (eg indruses shells or plates) It will also provide information onthe location of the phases that were analyzed

The Rock and Its Constituents

The DrsquoOrbigny meteorite has a peculiar shaperesembling a loaf of bread Its front and back shields are madeof a compact lithology and the space between these shields isfilled by a highly porous lithology very rich in open drusesand hollow shells

Hollow shells mostly perfectly spherical vugs withdiameters from lt1 mm to sim2 cm are present throughout themeteorite but appear to be more abundant in the porous partthan in the compact shields

The following six sections describe the constituents ofDrsquoOrbigny

Compact Shield RockThis part has a medium-grained micro-gabbroic texture

with little pore space and scattered small open or closeddruses and spherical hollow shells Occasionally some very

Non-igneous genesis of angrites 411

thin (lt1 mm) plates (up to sim10 cm long) consisting ofplagioclase-olivine intergrowths are present The transition tothe porous lithology is gradual with increasing grain sizepore size and abundances of druses and hollow shells Thecompact micro-gabbro-like rock consists mainly of anorthiteolivine and augite The centers of olivines commonly displayeuhedral rhombic shapes with Ca-rich olivine-kirschsteiniteintergrowths filling the intergranular space Trace elementanalyses of phases belonging to the micro-gabbroic texture(either in the compact or porous part of the rock) will bereferred to as anorthite micro-gabbro (mg) olivine mg augitemg spinel mg and kirschsteinite The late phases such askirschsteinite sulfides ulvˆspinel Fe-Ti-Al silicate silicon-phosphate etc only occur in the micro-gabbroic-texture part

Olivine Megacrysts and OlivinitesThese are more common in the porous part of DrsquoOrbigny

than in the rest The olivine megacrysts are large greencrystals they are clear and transparent and are intimatelyintergrown with the host rock Large olivinites(polycrystalline olivine) consist of large clear green olivinegrains of up to 8 mm in diameter or of very fine-grainedolivines forming milky greenish-white olivinites (Fig 1)These olivinites are also intimately intergrown with the hostrock and are mostly accompanied by anorthite-olivineintergrowths Trace element analyses on these phases arereferred to as olivine mega and olivinite respectively

ShellsHollow spherical shells are unevenly distributed

throughout DrsquoOrbigny they are present in all parts but aremost common in the porous inner portion The shell itself is acompact granular intergrowth of fine-grained anorthite andolivine (similar to the large plates see below) andoccasionally has some augite at the outside In some placesolivine is more abundant than anorthite and has a tendency tobe oriented perpendicular to the surface (Fig 2) Traceelement analyses on these phases are referred to as olivineshell and anorthite shell

Anorthite-Olivine Plates The compact and fluffy parts of DrsquoOrbigny contain thin

(sim1 mm) but occasionally large (up to 10 cm long) platesconsisting of anorthite-olivine intergrowths like the onesforming the shells (Fig 3) The center of the plate consists oflarge anorthite grains that are intimately intergrown withmostly anhedral olivines (up to 100 microm) commonly in agraphic way and rare euhedral Cr-bearing Al spinel (Fig 3b)Trace element analyses on these phases are referred to asolivine plate and anorthite plate Two plate olivines arelocated in big plagioclase grains close to nests of ulvˆspinel +sulfides in nearby vugs The trace element compositions ofthese phases as explained below suggest that the Ca-richolivines inside plagioclase are the products of late-stagemetasomatism These phases are referred to as Ca-rich Ol

DrusesThey are omnipresent in the porous portion of

DrsquoOrbigny They are irregular open spaces up to 3 cm orgreater in elongation into which perfectly crystallized augitesof prismatic habit and occasional anorthite plates protrude(Fig 4) Trace element analyses on these phases are referredto as augite druse Ion microprobe analyses undertaken in thecore are referred to as augite core Aluminous hedenbergite isfilling most of the intergranular space (Fig 4b) and is presentonly when augite is in contact with other phases In closeddruses it can be observed overgrowing augite crystalsforming a rim-like texture (see Fig 10 Kurat et al 2004)However it is totally absent on augite crystals protrudinginto open druses (Fig 4b)

Minor PhasesCr-bearing Al spinels are common and typically

associated with olivine and plagioclase (small euhedraloctahedra) in the olivine-plagioclase intergrowthsoccasionally also with augite They occur also as largeanhedral grains in the rock mostly associated with olivineand plagioclase Ulvˆspinels are also common and occurtypically as distorted skeletal crystals (hopper crystals) thatare associated with late aluminous hedenbergitekirschsteinite sulfides and occasionally silico-phosphate Anunknown Fe-Al-Ti-silicate was found in multi-phase pocketsin anorthite This phase forms euhedral crystals of up to

Fig 1 Large olivinite (green) abundant druses with augites (brown)and hollow shells in the porous part of DrsquoOrbigny Some of the openspaces are partly filled by caliche (white) The fusion crust is visibleat the bottom of the image Width of the picture is 4 cm


20 microm diameter is enclosed by augite and associated withmagnetite troilite and kirschsteinite Trace element analyseson these phases are referred to as ulvˆspinel and Fe-Alsilicate

Trace Element Contents of Minerals

Olivines have highly variable trace element contents(Tables 1 2 and 3) Rare earth element (REE) abundancesrange from Yb sim01 times CI (abundance in CI chondrites) inolivine megacrysts (Fig 5) to Yb sim1 times CI in olivines from themicro-gabbroic rock and shells (Fig 6) to Yb sim20 times CI inkirschsteinites (Fig 7) The abundance patterns are allfractionated with LaN ltltYbN (LaN and YbN normalized toCI chondrite abundance) Olivine megacrysts and oliviniteshave the lowest TE contents with La and Yb abundancesranging from lt0001 to sim02 times CI and sim005 to sim02 times CIrespectively (Fig 5) Olivine megacrysts are clearly poorer inall TEs than olivinites except for Li and are particularly poorin highly incompatible elements and in Cr and Mn Traceelement contents of olivines from shells and from the micro-gabbroic rock have La and Yb abundances of sim003ndash03 and07ndash1 times CI respectively (Fig 6) A similar range is alsocovered by olivines from a plate A particular situation is

observed in some Ca-rich olivines located inside bigplagioclase crystals (Ol Ca-rich M and Ol Ca-rich GA1)These olivines form part of a plate but their chemicalcomposition is different from that of the common olivines ofthe plate They are extremely enriched in refractory traceelements (eg La sim2 Yb sim13 times CI Fig 7) Abundances ofother trace elements also vary over wide ranges eg Zr fromsim0002 times CI in olivinites to sim44 times CI in Ol Ca-rich GA1 Crfrom sim0001 times CI in kirschsteinite to sim20 times CI in Cr-bearingAl spinel (mg and plate) and Li from sim015 times CI in olivinitesto sim5 times CI in plagioclase of the micro-gabbroic rock (mg) andshell (Fig 8)

Trace element contents of augites vary within verynarrow boundaries except for the aluminous hedenbergiterims (Ferro-augite HH13 Fig 9) Druse augite cores andaugites from the micro-gabbroic rock (Aug mg) have thesame TE contents (Table 1 Fig 9) They are rich in TEs andhave an almost flat REE abundance pattern at sim10 times CI withonly small negative deviations for LREEs and Eu (Figs 9 and10) Normalized abundances of Zr Ti Sc and V are at thesame or at slightly higher level but abundances of Nb Sr andthe moderately volatile and volatile elements are much lowerthan those of the REEs Aluminous hedenbergite rims haveabundance patterns that approximately follow those of the

Fig 2 Detail of a hollow shell consisting of anorthite-olivine intergrowths Note the replicate of a former surface by the void surface andgrowth perpendicular to that surface Reflected light picture


Fig 3 a) Plate of anorthite-olivine intergrowth The anorthite and the anorthite + olivine intergrowths form the clear brilliant plate with darkareas corresponding to augite Both images are in reflected light but the upper image was taken with crossed polarizers Also indicated is theplace of the olivine GA2 The square inset corresponds to Fig 3b Width of the sample is 11 mm b) Detail of the anorthite + olivine plateOlivine and Cr-bearing Al spinel (light gray) augite (gray) anorthite (dark gray) Also indicated are the olivines GA1 (center) GA5 (centerdown) and Ca-Ol (upper right) Vertical scale bar 200 microm


Fig 4 a) Polished section of a hollow shell (bottom) and a druse with euhedral augites and anorthites protruding into the open space Dotsare ablation holes from LA-ICP-MS analyses Backscattered electron (BSE) picture Width of the picture is 10 mm b) Augites in a open drusein DrsquoOrbigny Note the filling of the wedges by aluminous hedenbergite (black) Transmitted light picture


augite cores but at levels between sim30 and 90 times CI A fewelements do not follow the general pattern Sc is much lessabundant in the rims (sim5 times CI) than in the cores (sim30 times CI) asare V (sim01ndash1 times CI versus sim10 times CI) and Cr (sim0001ndash003 timesCI versus 008ndash1 times CI) (Figs 9 and 10)

Anorthite is generally poor in trace elements with REEssim01 times CI except for Eu (sim8 times CI) and has a slight LaN gtYbN fractionation (Fig 11) Abundances of other traceelements are very low (lt01 times CI) except for Sr (sim30 times CI) Li(5 times CI) and Ti (sim03 times CI)

Cr-bearing Al spinel is also poor in trace elements with aflat REE pattern at sim01 times CI (also Zr) but with high contentsof Sc (sim1 times CI) V and Cr (sim40 times CI) (Fig 12) We analyzeda small spinel from a plate and a large one in the micro-gabbroic rock Both showed the same trace element contentsbut the analysis of the small grain showed some contributionfrom the surrounding anorthite so we took the analysis of thebig grain (see Fig 12a of Kurat et al 2004) to represent thespinel composition

Ulvˆspinel has fractionated REEs with La sim01 times CI andYb sim8 times CI high contents of Zr (sim100 times CI) and V (sim8 times CI)and very low Cr content (sim00004 times CI) The unnamed Fe-Ti-Ca-Al silicate (Mikouchi and McKay 2001 Kurat et al 2004)is very rich in trace elements with the REEs and Zr forming aflat pattern at sim100 times CI and with Sr being slightly depleted(sim40 times CI) Sc depleted (sim2 times CI) and V and Cr stronglydepleted (sim009 and 00002 times CI respectively) with respect tothe refractory trace elements (Fig 12)

DISCUSSION

DrsquoOrbigny is an angrite with chemical isotopic texturaland mineralogical properties resembling those of angritespreviously described such as Asuka-881371 and Sahara99555 (Yanai 1994 Prinz and Weisberg 1995 Warren andDavis 1995 Bischoff et al 2000 Mittlefehldt et al 2002)Compositionally DrsquoOrbigny is almost identical to Sahara99555 (Mittlefehldt et al 2002) showing very similar REEabundances and distributions between phases (Floss et al2003) However as mentioned before the structure sometextural features and the presence of augite druses and glassmake DrsquoOrbigny unique in this group The shape ofDrsquoOrbigny is a consequence of its internal structure with theporous lithology situated between two shields made ofcompact micro-gabbroic rock In our view when all of thefeatures present in DrsquoOrbigny are taken into considerationboth data and observations are in conflict with an igneousmodel for angrite genesis (Kurat et al 2001a 2001b 20032004 Varela et al 2003) Here we discuss the trace elementcontents of all major and some minor phases in DrsquoOrbignyand confront the results with the existing genetic models forangritic rocks

The Igneous Model Evidence For and Against

Angrites are widely believed to be igneous rocks ofbasaltic composition originating from a differentiated

Table 1 LA-ICP-MS analyses (in ppm) of olivines augites and plagioclase from DrsquoOrbigny

Element

Olivine mega(2)

Olivinite(14)

Olivine mg(4)

Olivine shell(4)

Plag shell(4)

Plag mg(7)

Augite druse(10)

Augite mg(22)

Ferro-augite(1)

Li 039 042 210 176 613 578 102 112 123Ca 2190 8090 7480 2190 153580 152920 162080 161980 160570Sc 486 642 17 17 889 661 154 152 33Ti 21 51 1645 1471 189 155 10000 9920 16450V 12 16 31 34 10 630 562 616 58Cr 192 1556 199 229 94 67 945 1085Mn 466 710 2912 2408 180 68 1280 1280 1320Sr 124 343 228 240 19 18 37Y 006 021 044 039 021 013 17 15 34Zr 025 042 033 024 79 70 200Nb 005 006 002 005 002 040 032 105La 003 004 002 020 015 100 093 287Ce 004 018 007 039 033 380 386 830Nd 004 006 003 025 018 448 422 11Sm 001 002 002 006 002 183 170 390Eu 001 001 058 059 052 050 100Tb 043 040 090Gd 001 004 002 005 004 250 233 516Dy 002 005 005 004 002 300 272 628Ho 001 001 063 057 129Tm 001 001 026 023 055Yb 002 004 012 012 001 002 190 170 454Lu 002 002 005 004 011References Plag = plagioclase mg = micro-gabbroic (4) = number of minerals analyzed


Tabl

e 2

Ion

mic

ropr

obe

anal

yses

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny p

late

El

emen

tO

l pl

ate

GB

1Er

ror

Ol

plat

e G

A2

Erro

rO

l Pl

ate

GA

5Er

ror

Ol

Ca-

rich

MEr

ror

Li11

80

18

02

60

13B

elt0

000

80

0032

000

07B

002

000

40

022

000

70

010

004

Mg

2078

1414

019

5570

253

1993

7521

8Si

1868

0012

018

6800

230

1868

0020

0P

454

322

04

138

25

K3

50

12

70

20

860

0918

03

3C

a93

6873

1157

015

095

0011

6Sc

256

02

245

04

210

330

084

Ti18

31

170

214

62

588

157

V49

04

420

631

60

526

1C

r54

31

551

53

482

52

514

92

8M

n52

556

5238

1152

849

Fe45

7990

350

4573

2866

946

1875

570

Co

256

224

23

232

52

512

34

5R

b0

770

15lt0

77

058

024

Sr0

310

023

50

20

060

012

181

2Y

059

003

08

005

059

005

135

077

Zr0

220

020

190

020

110

01N

b0

030

005

002

10

007

000

750

0025

034

017

Ba

028

003

046

005

004

10

008

270

78La

000

50

001

005

60

008

042

008

3C

e0

035

000

60

044

000

70

010

0025

127

016

Pr0

002

000

090

012

000

3lt0

004

40

140

05N

d0

020

003

006

50

01lt0

004

60

840

13Sm

001

000

4lt0

022

001

000

50

780

18Eu

lt00

027

001

50

004

035

01

Gd

001

20

004

lt00

20

011

000

41

080

27Tb

000

50

001

lt00

068

000

70

002

027

008

Dy

004

90

004

008

001

005

90

008

243

022

Ho

001

90

003

001

60

005

001

40

003

057

01

Er0

077

000

60

106

001

30

090

011

730

2Tm

001

20

002

001

50

004

001

250

003

034

008

Yb

017

60

012

019

50

025

017

50

025

283

027

Lu0

031

000

40

036

000

80

030

0075

036

01


Tabl

e 2

Con

tinue

d Io

n m

icro

prob

e an

alys

es (i

n pp

m) o

f min

eral

pha

ses

in D

rsquoOrb

igny

pla

te

Elem

ent

Ol

Ca-

rich

GA

1Er

ror

Plag

pla

te G

B1

Erro

rPl

ag p

late

GA

1Er

ror

Sp

meg

acry

stEr

ror

Li12

02

63

014

150

20

870

055

Be

005

50

005

006

20

007

006

50

005

004

80

004

B0

160

020

0165

000

50

0062

000

240

0136

000

37M

g18

7600

200

880

410

084

7188

082

0Si

1868

0018

320

4300

194

2043

0017

516

1118

P38

74

622

351

69

06

K14

60

32

70

153

014

047

007

Ca

1852

017

095

762

156

9456

014

286

0Sc

350

42

60

22

20

24

50

3Ti

1475

451

154

09

1417

17V

680

65

50

24

70

1118

6722

Cr

542

21

50

11

60

1159

840

690

Mn

5200

85

981

106

09

1166

14Fe

4560

8053

027

4239

2606

3417

8000

2060

Co

225

26

30

46

90

415

23

Rb

20

60

660

11Sr

90

2613

51

128

10

570

07Y

48

017

012

001

009

001

018

002

Zr17

05

lt00

280

026

000

90

680

07N

b1

070

090

090

015

Ba

44

025

63

03

59

03

015

50

03La

08

006

50

097

001

50

061

000

90

028

000

7C

e2

20

140

175

001

80

168

002

20

072

001

5Pr

037

003

002

10

004

001

50

003

000

880

0025

Nd

163

008

008

30

010

0755

000

90

046

000

9Sm

042

005

001

70

008

lt00

120

018

000

8Eu

014

001

40

390

030

340

02lt0

004

6G

d0

50

080

026

000

8lt0

015

lt00

22Tb

008

50

010

0063

000

190

005

000

2lt0

005

5D

y0

90

055

001

60

004

001

750

0044

002

50

006

Ho

018

002

lt00

033

000

330

001

000

520

0024

Er0

630

040

0097

000

4lt0

008

001

60

005

Tm0

095

001

lt00

03Y

b0

630

06lt0

015

lt00

14lt0

017

Lu0

117

001

6lt0

003


Tabl

e 3

Ion

mic

ropr

obe

anal

ysis

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny

Elem

ent

Aug

cor

e G

A4

Erro

rA

ug c

ore

Erro

rA

ug r

imEr

ror

Ulvˆs

pine

lEr

ror

Kirs

ch

Erro

rTi

-Fe

silic

ate

Erro

r

Li2

90

06B

e0

053

000

45B

011

60

012

P15

72

K3

40

10

440

079

750

361

70

3618

30

5796

2Sc

190

05

252

101

200

326

70

4411

027

93

038

5Ti

9042

869

3022

727

770

502

1250

000

819

1410

1332

400

97V

368

144

31

717

420

2429

83

760

480

073

70

31C

r41

01

366

12

532

990

190

830

242

90

220

50

137

Mn

1572

3

C

o56

08

230

8244

51

2515

15

5993

21

331

93R

b1

50

6

Sr

220

3521

053

881

191

50

378

66

038

271

37

Y22

02

180

3860

077

18

032

519

05

102

18

Zr13

50

967

118

344

295

426

796

14

021

686

58

4N

b0

630

040

180

062

207

023

212

571

lt01

619

74

Ba

16

01

006

001

91

060

070

80

161

680

107

300

7La

12

006

077

004

85

090

136

0

070

018

174

045

Ce

43

02

032

010

817

70

274

028

009

037

004

756

087

Pr0

90

050

850

052

349

011

50

190

070

060

019

99

035

Nd

49

02

483

012

819

80

289

035

01

059

006

500

84Sm

19

012

218

012

778

025

068

017

027

005

717

40

69Eu

047

003

062

004

52

440

1lt0

10

140

036

140

28G

d2

50

22

320

258

690

486

lt06

10

90

1719

51

13Tb

048

005

051

005

162

009

024

004

349

026

4D

y3

40

12

320

1111

024

024

009

257

013

240

637

Ho

07

005

066

004

82

360

090

160

070

720

065

026

Er2

20

11

680

097

310

202

05

013

62

70

1414

051

Tm0

340

030

240

031

290

080

170

070

590

062

230

186

Yb

22

01

021

011

106

026

057

015

64

40

199

60

5Lu

04

004

03

004

61

560

1

0

620

076

111

019


planetesimal (eg Treiman 1989 Mittlefehldt and Lindstrom1990 Longhi 1999 Mittlefehldt et al 2002) Four of theangrites (LEW 87051 Asuka-881371 Sahara 99555DrsquoOrbigny) seem to be closely related as the trace elementcontents of clinopyroxenes and olivines suggest that they allcrystallized from similar magmas (Floss et al 2003) Thelarge variations in incompatible trace element concentrationsin phases of LEW 87051 Asuka-881371 Sahara 99555 andDrsquoOrbigny are believed to indicate rapid crystallization undernear-closed-system conditions (Floss et al 2003) This is alsoin agreement with the petrographic observations as textures

of all these meteorites seem to be the result of rapidcrystallization process (McKay et al 1990 Mikouchi et al1996 2000 Mikouchi and McKay 2001 Mittlefehldt et al2002) However this is not the case for DrsquoOrbigny Anigneous rapid crystallization model fails when all features ofDrsquoOrbigny are taken into consideration (Kurat et al 2004)The variety of glasses contained in this rock and theiroccurrence are also inconsistent with the igneous modelChemical data as well as petrographic observations excludeformation of DrsquoOrbigny glasses by shock or a partial meltingprocess (Varela et al 2003) Bulk REE abundances and the

Fig 5 CI-normalized (Lodders and Fegley 1998) abundances of major and trace elements in olivine megacryst and olivinites In this and thefollowing figures elements are arranged in order of increasing volatility except the REE which are arranged in order of increasing Z Notethe high content of Cr in olivinites compared to that in olivine megacrysts

Fig 6 CI-normalized abundances of major and trace elements in olivine from a hollow shell (Ol shell) and from the rock with micro-gabbroictexture (Ol mg)


compositions of the melt calculated to be in equilibrium withthe major phases present another conflict with the igneousformation model (Kurat et al 2001b 2003 Floss et al 2003)The partition coefficient (D) for clinopyroxenes andanorthite calculated with the assumption that the angritescrystallized from a melt with the REE abundances of theirbulk composition turn out to be 15 to 45 times higher thanthe experimental D values of McKay et al (1994) Floss et al(2003) attributed these misfits to kinetic effects due to rapidcrystallization which according to Kennedy et al (1993) canresult in non-equilibrium partitioning of REEs

Chromium and V are present in olivines in highlyvariable amounts as for example in olivinites withnormalized abundances from 03 to 08 times CI Ascrystallization proceeds in an igneous setting we expectolivines to become richer in incompatible elements (eg Tiand Y) and poorer in compatible elements (eg Cr and V)This is indeed what has been observed by Floss et al (2003)in several angrites where Ti and Y contents increase and Crand V decrease with increasing Fe of olivines Howeverwhat we see in our data is quite different Abundances inolivines of all four elements Ti Y Cr and V increase with

Fig 7 CI-normalized abundances of major and trace elements in olivine from a plate (GA1-GA2 and GA5) Ca-rich olivines andkirschsteinite Note the increase in trace element contents (sim20ndash100times) from the early (olivines from the plate) and late (Ca-rich olivine andkirschsteinite) olivines and the deficits in V and Cr in kirschsteinite

Fig 8 CI-normalized abundances of major and trace elements in selected olivines from DrsquoOrbigny Note the variation in trace elements formearly olivines (gray symbols) olivines from the shells and mega-gabbroic textured rock (black symbols) and late olivines (open symbols)


the Ca content (Figs 13a 13b and 13c) except for Cr inolivinites The Ca content in olivines can also be taken as aproxy for the time of formation as the system becomes rich inCa late in its evolution (eg all late phases are extremely Ca-rich like kirschsteinite) These results clearly precludecrystallization of all olivines from a common melt andsuggest instead that Cr and V must have been added to thesystem during the late stage of rock formation

Modeling the Crystallization of DrsquoOrbigny

We model the crystallization of DrsquoOrbigny from a melthaving the composition of the bulk rock following theprocedure of Ariskin et al (1997) and using the experimentaldata on crystallization of angrite melts obtained by McKayet al (1988) Model calculations were carried out for 1 atm

pressure and an oxygen fugacity of 1 log unit above the iron-wuumlstite buffer in agreement with McKay et al (1994) Underthese conditions we found a crystallization sequence whereanorthite is the liquidus phase and crystallization proceeds(after 7 of the melt crystallized) with anorthite + olivinefollowed (after gt50 of the melt crystallized) by anorthite +olivine + augite This crystallization sequence differs fromthat deduced from experimental and petrographic studies ofall basaltic angrites which indicate a sequence of olivinefollowed by plagioclase and finally pyroxene (McKay et al1991 Longhi 1999 Mittlefehldt et al 2002) Textures of allbasaltic angrites commonly suggest olivine to be the liquidusphase Eliminating these olivines by classifying them asxenocrysts puts anorthite onto the liquidus As indicated byKurat et al (2004) the crystallization sequences for angritescan be deduced from their textures but are model-dependent

Fig 9 CI-normalized abundances of major and trace elements in augite from the druses from the rock with micro-gabbroic texture and inaluminous hedenbergite (ferro-augite) Trace element contents of both augites overlap The pattern of the late aluminous hedenbergite followsthose of augites but with higher abundances except for the negative anomalies in Sc and V

Fig 10 CI-normalized abundances of major and trace elements in augite cores (aug core) from druses a mean value from the augites of therock with micro-gabbroic texture (mean aug mg) aluminous hedenbergite (ferro-augite) and the calculated early and late augite composition(calc early augite calc late augite) obtained from modeling DrsquoOrbigny crystallization The aluminous hedenbergite is enriched in TEs about10 times with respect to the augite core Note the relatively low abundances of Sc V and Cr


ie if the olivine and spinel megacrysts are indeed xenocrysts(Prinz and Weisberg 1995 Prinz et al 1990 Mikouchi et al1996 Mittlefehldt et al 1998 2001) then the crystallizationsequence shown by the texture is anorthite + olivine followedby anorthite + olivine + augite followed by anorthite +olivine + augite + ulvˆspinel The sequence obtained frommodeling crystallization of DrsquoOrbigny from its bulk chemicalcomposition (Kurat et al 2001c) is only shown byLEW 86010 which has abundant large anorthite grains setinto a granular matrix but has no igneous texture (egDelaney and Sutton 1988 Mittlefehldt et al 1998 Mikouchiet al 2000 Kurat et al 2004)

If all phases of DrsquoOrbigny crystallized from the same

system as the igneous model implies then this relationshipshould be visible in the distribution of trace elements betweenthe phases For example because anorthite one of the earliestphases to form takes up large quantities of Eu and Sr (egMcKay et al 1994) and augite did not form before most of theanorthite and olivine had crystallized (sim50 crystallizationbefore the appearance of augite see above) augite shouldhave pronounced negative Eu and Sr abundance anomaliesThe olivines from the plate and Al spinel both of which arecontemporaneous with the anorthite of the plate as well as theearly augite (augite cores) do indeed show an abundancedeficit in Sr (also probably due to low mineralmelt partitioncoefficients) and a very small one in Eu (Fig 14) However

Fig 11 CI-normalized abundances of major and trace elements in plagioclase from the hollow shell and from the rock with micro-gabbroictexture

Fig 12 CI-normalized abundances of trace elements in minor phases ulvˆspinel a large Cr-bearing Al spinel from the compact micro-gabbroic rock and the Fe-Al-Ca-Ti silicate


none of the late phases such as aluminous hedenbergite Ca-rich olivine kirschsteinite and Fe-Ti-Ca-Al silicate show anysign of an underabundance of Eu with respect to the otherREEs (Fig 15) Consequently they cannot have formed fromthe bulk systemrsquos residual melt

A serious problem is also posed by Sc which is mainlycarried by pyroxene and olivine Early olivines and the augitecores are enriched in Sc compared to other trace elements a

fact that fits the predictions of igneous models Modeling oftrace element evolution as outlined above shows that theresidual liquid after crystallization of most of the anorthiteolivine and augite should be slightly enriched in Sc (157 timesCI) over the initial liquid (Sc = 77 times CI) (Fig 16 Table 4)Consequently all late phases should be slightly richer in Scthan the early ones or at least have comparable contents Thecalculated augite composition after crystallization of 50 and

Fig 13 Compositional variation diagrams of CI-normalized trace and major element abundances in olivines from DrsquoOrbigny a) YCI versusTiCI b) CaCI versus VCI c) CaCI versus CrCI


93 of the system (Cal Early augite and Cal Late augite inFig 10) clearly shows that Sc should have an abundancecomparable to that found in the early phases What we see inDrsquoOrbigny however is that the late aluminous hedenbergiteis very poor in Sc (sim5 times CI compared to sim50 times CI for HREEsFigs 10 and 15) indicating that either its mineralmeltpartition coefficient for Sc is much smaller than that of augiteor it crystallized from a system poor in Sc

A comparison of elemental abundances and phasemeltdistribution coefficients (Green et al 1994 McKay 1986McKay et al 1994 Bindeman et al 1998) reveals that thecontents of highly incompatible elements in all phases are farout of equilibrium with a melt of the composition of bulkDrsquoOrbigny and also of an evolved liquid (Table 4) Theabundances of the compatible elements in olivine megacrystsolivinites olivines from the plate and the Ca-rich olivines arein reasonable agreement with the predictions of thecrystallization model (Fig 17) Abundances of highly

incompatible elements in all olivines including themegacrysts however indicate non-equilibrium with the bulkrock and suggest liquids very rich in these elements (gt10000times CI) much richer than any fractional crystallization couldpossibly produce Plagioclase from the plate however showsvery good agreement for the incompatible elements butsuggests equilibrium with liquids poor in Ti Lu Sc Mn andCr and richer in V as compared to the bulk rock (Fig 17Table 4) Furthermore the calculated augite composition inequilibrium with an evolved melt is about 03 times poorer inREE and up to 010 times poorer in HFSE than the augite inthe rock (Kurat et al 2001) Evidently not only the earlyphases document an environment very different from thatrecorded by the late phases but the two contemporaneousphases (eg olivine and plagioclase that form the plate) seemto require liquids of different composition These data clearlyadd another serious problem to the many conflicts that havebeen noticed previously (eg Prinz et al 1977 1988 McKay

Fig 14 CI-normalized abundances of trace elements in early phases plagioclase Cr-bearing Al spinel and olivines (GB1 GA2 and GA5)and the augite core

Fig 15 CI-normalized abundances of trace elements in late phases ulvˆspinel olivine-Ca-rich (GA1 and M) kirschsteinite aluminoushedenbergite (ferro-augite) and the Fe-Al-Ca-Ti silicate


et al 1988 Treiman 1989 Jurewicz et al 1993 Prinz andWeisberg 1995 Longhi 1999 Mittlefehldt et al 2002)between an igneous model for the origin of angrites and themineralogical and chemical observations

The New Genetic Model

According to the new genetic model (Kurat et el 2004)DrsquoOrbigny provides us with a record of changing conditionsranging from extremely reducing to highly oxidizing andwith a record of the formation of an achondritic rock from achondritic source In the course of changing redox conditions

early minerals became unstable and were replaced by stableassemblages Consequently the early phases havedisappeared but later ones did compositionally adapt to thechanging conditions The earliest phases still preserved inDrsquoOrbigny are olivine megacrysts olivinites and anorthite-olivine (+sp) intergrowths The now hollow shells are verylikely morphological copies of solid spheres of an unknowncompound maybe CaS possibly the earliest phase presentduring formation of the rock These spheres were covered byanorthite-olivine intergrowths at the earliest stage of rockformation The growth of the earliest phases forming thespheres must have taken place under reducing conditions The

Fig 16 CI-normalized abundances of trace elements in the bulk DrsquoOrbigny the glass and the liquids (100 = initial liquid 80 = after 20crystallization 50 = after 50 crystallization 20 = after 80 crystallization 63 = residual melt) obtained by modeling the crystallization ofDrsquoOrbigny following the procedure of Ariskin et al (1997)

Table 4 Equilibrium liquid compositionLa Ce Eu Gd Yb Sc Mn

Glassa 102 107 116 97 89 57 09Initial liquidb 89 97 99 90 87 77 08Liquid 50 crystallizationb 178 194 165 183 175 140 10Plag plate (abundanceCI)Kdc 119 170 117 114 155 13 03Augite core (abundanceCI)Kdc 402 380 321 223 306Olivine plate (abundanceCI)Kdd 4255 11161 400 569 567 164 49Olivine megacryst (abundanceCI)Kdd 100 33 04Residual liquid (94 crystallization)b 1076 1073 389 641 538 157 14Ca-rich olivine (abundanceCI)Kdd 685800 709970 16012 24436 2024 222 49Kirschsteinite (abundanceCI)Kdd 58300 119680 16959 46275 14175 68 Augite rim (abundanceCI)Kdc 2640 2040 1384 849 1512

aVarela et al (2003)bAriskin et al (1997)cMcKay et al (1994)dMcKay (1986) and Green (1994)


olivine megacrysts could be relics of these early conditionsthat because of their size survive and were subsequentlyweakly metasomatized from Fo100 to Fo90 The olivine-anorthite intergrowths covering the spheres must have formedunder somewhat less reducing conditions because Cr3+ andFe2+ were available for the formation of spinel Similar redoxconditions are also indicated by the spinel-liquid Vpartitioning DV(spinelmelt) (Canil 2002) Taking intoaccount the V content of the Cr-bearing Al spinel (1867 ppmTable 2) and the mean V content of all glasses in DrsquoOrbigny(106 ppm see Table 2 Varela et al 2003) the DV(spinelmelt)of 176 indicates oxygen fugacity of 05 log units above theiron-wuumlstite buffer (simIW + 05 Canil 2002) Withincreasingly oxidizing conditions the reduced phase(s)constituting the solid spheres became unstable and vanishedin the course of the evolution of the rock During this eventlarge quantities of oxidized Fe (plus Mn Cr V and most traceelements) became available in the vapor phase Olivine beganto exchange Mg for Fe Mn and Cr and augites started togrow into open voids and by reaction with olivine Pigeonitea phase that should be formed by reaction with olivine isabsent however suggesting that the physico-chemicalconditions prevailing (eg low pressure very high Caabundance and temperatures sim1000 degC) could prevent itsformation and force augite to become stable A late highlyoxidizing event created the titaniferous aluminoushedenbergite Ca-rich olivine and kirschsteinite rims onaugites and olivines respectively

In the following paragraphs we explain how the traceelement contents of all phases strengthen this genetic model

The bulk trace element abundances indicate formation ofDrsquoOrbigny as a refractory precipitate from a source withchondritic abundances of refractory lithophile elements Theunfractionated abundances of the refractory lithophileelements in the bulk rock (at about 10 times CI abundances)indicate derivation from a primitive chondritic source withoutthe need for geochemical processes like partial melting (Kuratet al 2001 2004) The relative abundances of all refractorylithophile elements in the glasses are also chondritic whichsuggests that the source for the glass had also chondriticrelative abundances of the refractory elements In additionthe abundances of FeO and MnO in the bulk rock and theglasses are similar to those in CI chondrites (Varela et al2003 Kurat et al 2004) The fact that refractory lithophiletrace element abundances in olivines are similar to those inolivines from carbonaceous chondrites also points in the samedirection In particular the unfractionated trace elementabundance pattern of the Ca-rich olivine is similar to those ofsome olivines from carbonaceous chondrites (Kurat et al1989 Weinbruch et al 2000) suggesting that the latemetasomatic event likely has been fed by a chondritic source(Fig 18a)

Olivines from the plate indicate an origin from a melt thatwas enriched to about 10 times CI in Sc Sr Nd and Eu about 20ndash50 times CI in the HREE and gt100 times CI in La Ce and NbBecause there are no indications that such a melt ever existedin angrite systems (Varela et al 2003) the REE and Nb areclearly out of equilibrium with the bulk rock compositionInterestingly the primary trace elements are out ofequilibrium while the secondarily introduced elements Mn

Fig 17 Comparison of CI-normalized DrsquoOrbigny bulk composition (Bulk) and the calculated liquids (after 50 and sim93 crystallization 50and 63 respectively) with (CI-normalized abundance)(phase-melt distribution coefficients) ratios (Kds from Green 1994 McKay 1986McKay et al 1994 Bindeman et al 1998)


and Cr are not This is similar to what has been observed forglasses (Varela et al 2003) Because the FeMn ratios of theglasses and the rock are close to chondritic the rock seems tohave kept a memory of the source of this metasomatic eventThis memory of an unfractionated chondritic source wasapparently preserved until the very late phases crystallized(eg Ca-rich olivines ferro-augite and Fig 18a)

Formation of plagioclase of the plate (one of the earlierphases) must have taken place under reducing conditions(eg Eu contents are compatible with a KdEu for redoxconditions log IW-1 Fig 18b) Trace element abundancesindicate equilibrium with a source of sim10 times CI abundancesbut with large deficits in Cr Fe B and Mn Obviously onlylate phases are rich in Cr V Fe and Mn This is similar towhat can be observed in glass that fills open spaces and thatkept its connection with the vapor phase (Varela et al 2003)Interestingly the early anorthite also indicates a low supply ofTi Zr and Sc This could indicate that these elements werealready deposited into the very early phase(s) forming thespheres Very late in the history of the rock Ti and Zr will be

available again (from the breakdown of the early phase[s]) toform ulvˆspinel and the Fe-Ca-Ti-Al silicate Because Sc wasseparated from Ti and Zr during the subsequent processing ofDrsquoOrbigny the breakdown of the early phase forming thespheres must have resulted in the formation of two phases asolid able to keep Ti and Zr until the very late stage and avapor rich in Sc and REE from which the augites wereformed Olivine data show that Cr and V must have beenadded to the system during the late stage of rock formation aswas explained above

Up to this point of the discussion we have seen a possiblerelationship between DrsquoOrbigny and chondrites and havegiven evidence suggesting that moderately volatile elements(eg V Cr Mn Fe) were added by a late metasomatic eventAs it is suggested by the new genetic model for angrites(Kurat et al 2004) large amounts of trace elements couldbecame available in the vapor phase during the late stage ofrock formation If this hypothesis is correct we must observesubstantial trace element abundance variations between theearly and late phases

Fig 18 CI-normalized abundances of trace elements a) in an early olivine from the plate in a late Ca-rich olivine in an olivine from anAllende dark inclusion and the olivineliquid distribution coefficient (Kd) from Green (1994) b) in two early plagioclase grains and theplagioclaseliquid distribution coefficient (Kd) from McKay et al (1994) and Bindeman et al (1998) The elements are arranged in order ofincreasing Kd


Late phases are not only enriched in moderately volatileelements with respect to the early phases suggestive of ametasomatic event but they also seem to have grown in adifferent environment The rock-forming anorthite and theearly olivine and Al spinel must have tapped a source that wasdifferent from the source of the late phases Due to theformation of plagioclase the depletion in Eu and Sr isobserved only in the contemporaneous phases such asolivines from the plate the Al-spinel and the augite cores(Fig 14) This feature is absent in the latest phases None ofthem show any depletion in Eu with respect to the otherREEs Evidently the late phases grew in an environment thatwas rich in trace elements with unfractionated relativeabundances According to Kurat et al (2004) the traceelements were originally locked up in the earliest phase(s)constituting the spheres Consequently early silicate phasesindicate normal TE availability (sim10 times CI) except for thehighly refractory Zr Sc and Ti The subsequent oxidizingconditions destabilized the TE-rich early phase(s) and TEswere probably liberated by the decomposition of this earlyphase Not even the nature of this phase is unknown what isclearly observed from our data is that there was a sink of TEsand Ca during early rock formation that were afterwardavailable during growth of the late phases A good candidatethat can produce such TE content variations in the system isCaS (Kurat et al 2004) This phase is not only a major hostphase for trace elements under reducing conditions but also itcan form spheres (eg oldhamite globules in the Busteeaubrite) With changing redox conditions CaS becameunstable and vanished leaving behind the hollow shells thatare very likely morphological copies of solid spheres (Kuratet al 2004) However no evidence of the reducing conditionsneeded to form oldhamite (Lodders and Fegley 1993) seemsto have been preserved in the rock as compared to thoseindicated by the Eu content of the early plagioclase (egredox conditions log IW-1) Breakdown of CaS underoxidizing conditions can produce perovskite SO2 and someother mobile chemical species one of which likely wasCa(OH)2 In this way large amounts of trace elements and Cabecame available in the vapor during growth of the latephases mainly augite

One possible way this breakdown could have occurred is

(1)

Re-precipitation of Ca into pyroxene could have taken placeaccording to

(2)

(s = solid g = gas)

Not even the main part of S was lost to the vapor as SO2(g)we can find some traces of S as sulfides associated with the

very late phases The liberated S could have re-precipitatedforming pyrrhotite

(3)

and

(4)

In addition small amounts of calcite (CaCO3) arecommonly present inside the hollow spheres which carry aprimitive Pb and Sr isotope signature comparable to that ofthe DrsquoOrbigny bulk rock and the glass (Jotter et al 2002)These could be remnants of the Ca-rich phase constituting thespheres Furthermore the calcite also testifies for a stronglyoxidizing event that was capable of producing CO2

It appears that large quantities of Ti and Zr were retaineduntil the very late phases aluminous hedenbergiteulvˆspinel and the Fe-Ti-Ca-Al silicate formed Thissuggests that the complete destabilization of perovskite couldhave happened in the late stage of formation of the rock

This model inherently incomplete and imprecise offerssimple and natural explanations for features that are eithertotally incompatible with or create severe problems for anigneous genetic model of angrites

CONCLUSIONS

Given that angrites are widely believed to be igneousrocks distributions of trace elements were modeled under theassumption that all phases of DrsquoOrbigny crystallized from thesame system with the initial composition of bulk DrsquoOrbignyas the igneous model implies In such a system anorthite isthe liquidus phase and crystallization proceeds (after 7 ofmelt crystallized) with anorthite + olivine followed (aftergt50 of melt crystallized) by anorthite + olivine + augiteBecause anorthite is one of the earliest phases (and takes upmost of Eu and Sr) and because augite is formed only after50 of the melt crystallized we might expect augite to showa negative anomaly of Eu and Sr Early augites indeed showsmall deficits in Eu and Sr as compared to other refractoryTEs but none of the latest phases show any Eu depletion withrespect to the other REEs Obviously they could not haveformed from a melt that had crystallized the major phases ofthe rock

Another severe problem is posed by the behavior of ScModeling of DrsquoOrbigny crystallization shows that thiselement should be present in comparable amounts in earlyand late phases The underabundance of Sc observed in latephases suggests that either late aluminous hedenbergite has amineralmelt partition coefficient for Sc that is much smallerthan that of augite or that it crystallized from a system poor inSc Furthermore the results of modeling the crystallization ofDrsquoOrbigny do not match those that are expected from anigneous model as olivines and anorthite that form platesmdash

CaS s( ) 4H2O g( )+ Ca OH( )2 g( )H2SO3g 2H2 g( )

++

=

Ca OH( )2 g( ) Si OH( )4 g( )+ CaSiO3 g( ) 3H2O g( )+=

SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=


two contemporaneous phasesmdashand also the early augites areapparently in equilibrium with different liquids In additionthe increment in the contents of Cr and V in late olivines aswell as the abundances of highly incompatible elements in allolivines indicate disequilibrium with the bulk rock and areinconsistent with an igneous origin of DrsquoOrbigny

The genesis of DrsquoOrbigny rather appears to be more akinto that of chondritic constituents like CAIs than to that ofplanetary differentiated rocks The unfractionated abundancesof the refractory lithophile elements in the bulk rock (at about10 times CI abundances) indicate formation from a primitivechondritic source without any geochemical processes likepartial melting Only the anorthite from the plates retainedsome memory of the early conditions which were reducing(simlog IW-1) During metasomatic introduction of themoderately volatile elements conditions were somewhatmore oxidizing (simlog IW + 05) and became stronglyoxidizing in the end (presence of magnetite and ulvˆspinel)The oxidizing conditions could have led to a breakdown ofthe early phase(s) (possibly CaS) This breakdown must havebeen an incongruent one giving rise to the formation of twophases a vapor rich in Sc and REEs (from which the augitesgrew) and a solid phase which retained Ti and Zr until thelate stage The addition of these elements to the reservoir(from which the late Ti-Zr-rich phases grew) could have beenprovided by the destabilization of its host phase triggered byfurther increasing oxidizing conditions that characterized thelate stage of angrite formation

Thus distributions of trace elements documentsuccessive events taking place under changing redoxconditions that were responsible for the variable distributionof refractory incompatible elements The unfractionated traceelement abundance pattern of late phases (eg Ca-richolivine with abundances similar to those observed in olivinesfrom carbonaceous chondrites) as well as the highconcentration of moderately volatile elements (eg Mn Feand Cr) in late phases in chondritic ratios suggest the presenceof a late metasomatic event that conferred to the whole rockthe elemental signature of its chondritic source

In conclusion DrsquoOrbigny records changing redoxconditions very similar to those recorded by chondriticconstituents but with initial and final conditions (reducing andoxidizing respectively) being more extreme

One of the questions that arises is whether we can extendthe conclusions drawn for DrsquoOrbigny to all other angritesThis is unknown Because DrsquoOrbigny is particular andunique it could turn out to be an exception among all otherangrites or it could turn out to be the first that was able toretain a memory of a large variety of conditions prevailingduring formation of angrites Only the study of more angriticmeteorites can give us the correct answer

AcknowledgmentsndashWe thank Mike Tubrett and GaborDobosi Memorial University St Johnrsquos for help with the

LA-ICP-MS We are grateful to Elmar Grˆner for hisassistance with the ion microprobe analyses at MPI fcedilrChemie Mainz Constructive reviews by Christine Floss andthe associated editor Urs Krpermilhenbcedilhl helped to improve thismanuscript Financial support was received from FWF (P-13975-GEO) and the Friederike und Oskar ErmannndashFondsAustria NASA grant NAG 5-9801 and CONICET andSECYT (PICT 07- 08176) Argentina

Editorial HandlingmdashDr Urs Krpermilhenbcedilhl

REFERENCES

Ariskin A A Petaev M Borisov A and Barmina G S 1997METEOMOD A numerical model for the calculation of melting-crystallization relationships in meteoritic igneous systemsMeteoritics amp Planetary Science 32123ndash133

Bindeman I N Davis A and Drake M 1998 Ion microprobe studyof plagioclase-basalt partition experiments at naturalconcentration levels of trace elements Geochimica etCosmochimica Acta 621175ndash1193

Bischoff A Clayton R N Markl G Mayeda T K Palme HSchultz L Srinivasan G Weber H W Weckwerth G andWolf D 2000 Mineralogy chemistry noble gases and oxygen-and magnesium-isotopic compositions of the angrite Sahara99555 (abstract) Meteoritics amp Planetary Science 35A27

Canil D 2002 Vanadium in peridotites mantle redox and tectonicenvironments Archean to present Earth and Planetary ScienceLetters 19575ndash90

Delaney J S and Sutton S R 1988 Lewis Cliff 86010 anADORable Antarctican (abstract) 19th Lunar and PlanetaryScience Conference pp 265ndash266

Floss C Crozaz G and Mikouchi T 2000 Sahara 99555 Traceelement composition and relationship to Antarctic angrites(abstract) Meteoritics amp Planetary Science 35A53

Floss C Crozaz G McKay G Mikouchi T and Killgore M 2003Petrogenesis of angrites Geochimica et Cosmochimica Acta 674775ndash4789

Goodrich C A 1988 Petrology of the unique achondrite LEW 86010(abstract) 19th Lunar and Planetary Science Conferencepp 399ndash400

Green T H 1994 Experimental studies of trace element partitioningapplicable to igneous petrogenesismdashSedona 16 years laterChemical Geology 1171ndash36

Jagoutz E Jotter R Varela M E Zartman R Kurat G andLugmair G W 2002 Pb-U-Th isotopic evolution of theDrsquoOrbigny angrite (abstract 1043) 32nd Lunar and PlanetaryScience Conference CD-ROM

Jotter R Jagoutz E Varela M E Zartmann R and Kurat G 2002Pb isotopes in glass and carbonate of the DrsquoOrbigny angrite(abstract) Meteoritics amp Planetary Science 37A73

Jurewicz A J G Mittlefehldt D W and Jones J H 1993Experimental partial melting of the Allende (CV) and Murchison(CM) chondrites and the origin of asteroidal basalts Geochimicaet Cosmochimica Acta 572123ndash2139

Kennedy A K Lofgren G E and Wasserburg G J 1993 Anexperimental study of trace element partitioning between olivineorthopyroxene and melt in chondrules Equilibrium values andkinetics effects Earth and Planetary Science Letters 115177ndash195

Kurat G 1988 Primitive meteorites An attempt towards unificationPhilosophical Transactions of the Royal Society A 325459ndash482


Kurat G Zinner E and Palme H 1989 Primitive olivines with hightrace element contents in Allende-AF aggregates (abstract)Meteoritics 24290

Kurat G Brandstpermiltter F Clayton R Nazarov M A Palme HSchultz L Varela M E Waesch E Weber H W andWeckwerth G 2001a DrsquoOrbigny A new and unusual angrite(abstract 1753) 32nd Lunar and Planetary Science ConferenceCD-ROM

Kurat G Ntaflos T Brandstpermiltter F Varela M E Sylvester P J andNazarov M A 2001b Trace element contents of major phases ofthe DrsquoOrbigny angrite (abstract) Meteoritics amp PlanetaryScience 36A108

Kurat G Zinner E and Brandstpermiltter F 2002 A plagioclase-olivine-spinel-magnetite inclusion from Maralinga (CK) Evidence forsequential condensation and solid-gas exchange Geochimica etCosmochimica Acta 662959ndash2979

Kurat G Varela M E Zinner E and Brandstpermiltter F 2003 Largeplates of anorthite-olivine intergrowths in the DrsquoOrbigny angrite(abstract) Meteoritics amp Planetary Science 38A57

Kurat G Varela M E Brandstpermiltter F Weckwerth G Clayton R NWeber H W Schultz L Wpermilsch E and Nazarov M A 2004DrsquoOrbigny A non-igneous angritic achondrite Geochimica etCosmochimica Acta 681901ndash1921

Longhi J 1999 Phase equilibrium constraints on angritepetrogenesis Geochimica et Cosmochimica Acta 63573ndash585

Lodders K and Fegley B Jr 1998 The planetary scientistrsquoscompanion Oxford Oxford University Press 371 p

Lugmair G W and Galer S J C 1992 Age and isotopic relationshipsamong the angrites Lewis Cliff 86010 and Angra dos ReisGeochimica et Cosmochimica Acta 561673ndash1694

McKay G Lindstrom D Le L and Yang S R 1988 Experimentalstudies on synthetic LEW 86010 analogs Petrogenesis of aunique achondrite (abstract) 19th Lunar and Planetary ScienceConference pp 760ndash761

McKay G Crozaz G Wagstaff J Yang S-R and Lundberg L 1990A petrographic electron microprobe and ion probe study of mini-angrite Lewis Cliff 887051 (abstract) 21th Lunar and PlanetaryScience Conference pp 771ndash772

McKay G Le L Wagstaff J and Crozaz G 1994 Experimentalpartitioning of rare earth elements and strontium Constraints onpetrogenesis and redox conditions during crystallization ofAntarctic angrite Lewis Cliff 86010 Geochimica etCosmochimica Acta 582911ndash2919

McKay G 1986 Crystalliquid partitioning of REE in basalticsystems Extreme fractionations of REE in olivine Geochimicaet Cosmochimica Acta 5069ndash79

McKay G Le L and Wagstaff J 1991 Olivines in angrites LEW87051 Pheno or xenos (abstract) Meteoritics 26370

Mikouchi T Miyamoto M and McKay G 1996 Mineralogy studyof angrite Asuka-881371 Its possible relation to angrite LEW87051 Proceedings of the NIPR Symposium on AntarcticMeteorites 9174ndash188

Mikouchi T McKay G and Le L 2000 A new angrite Sahara99555 Mineralogical comparison with Angra dos Reis LewisCliff 86010 Lewis Cliff 87051 and Asuka-881371 angrites(abstract) Antarctic Meteorites 2574ndash76

Mikouchi T and McKay G 2001 Mineralogical investigation ofDrsquoOrbigny A new angrite showing close affinities to Asuka-881371 Sahara 99555 and Lewis Cliff 87051 (abstract 1876)32nd Lunar and Planetary Science Conference CD-ROM

Mittlefehldt D W and Lindstrom M M 1990 Geochemistry and

genesis of angrites Geochimica et Cosmochimica Acta 543209ndash3218

Mittlefehldt D W McCoy T J Goodrich C A and Kracher A1998 Non-chondritic meteorites from asteroidal bodies InPlanetary materials edited by Papike J J Washington D CMineralogical Society of America pp 1ndash195

Mittlefehldt D W Killgore M and Lee M T 2001 Petrology andgeochemistry of the new angrite DrsquoOrbigny (abstract 2057)32nd Lunar and Planetary Science Conference CD-ROM

Mittlefehldt D W Killgore M and Lee M T 2002 Petrology andgeochemistry of DrsquoOrbigny geochemistry of Sahara 99555 andthe origins of angrites Meteoritics amp Planetary Science 37345ndash369

Pearce N J G Perkins W T Westgate J A Gorton M P JacksonS E Neal C R and Chenery S P 1997 A compilation of newand published major and trace element data for NIST SRM 610and NIST SRM 612 glass reference materials GeostandardsNewsletter 21115ndash144

Prinz M Keil K Hlava P F Berkley J L Gomes C B andCurvello W S 1977 Studies of Brazilian meteorites III Originand history of the Angra dos Reis achondrite Earth andPlanetary Science Letters 35317ndash330

Prinz M Weisberg M K and Nehru C E 1988 LEW 86010 asecond angrite Relationship to CAIs and opaque matrix(abstract) 19th Lunar and Planetary Science Conference pp949ndash950

Prinz M Weisberg M K and Nehru C E 1990 LEW 87051 a newangrite Origin in a Ca-Al-enriched planetesimal (abstract) 21stLunar and Planetary Science Conference pp 979ndash980

Prinz M and Weisberg M K 1995 Asuka-881371 and the angritesOrigin in a heterogeneous CAI-enriched differentiated volatile-depleted body (abstract) Antarctic Meteorites 20207ndash210

Treiman A H 1989 An alternate hypothesis for the origin of Angrados Reis Porphyry not cumulate 19th Lunar and PlanetaryScience Conference pp 443ndash450

Varela M E Kurat G Hoppe P and Brandstpermiltter F 2002Chemistry of glass inclusions in olivines of the CR chondritesRenazzo Acfer 182 and El Djouf 001 Geochimica etCosmochimica Acta 661663ndash1679

Varela M E Kurat G Zinner E MEgravetrich N Brandstpermiltter FNtaflos T and Sylvester P 2003 Glasses in DrsquoOrbigny angriteGeochimica et Cosmochimica Acta 675027ndash5046

Warren P H and Davis A M 1995 Consortium investigation of theAsuka-881371 angrite Petrographic electron microprobe andion probe observations (abstract) Antarctic Meteorites 20257ndash260

Wasserburg G J Tera F Papanastassiou D A and Huneke J C1977 Isotopic and chemical investigation of Angra dos ReisEarth and Planetary Science Letters 35294ndash316

Weinbruch S Palme H and Spettel B 2000 Refractory forsterite inprimitive meteorites Condensates from the solar nebularMeteoritics amp Planetary Science 35161ndash171

Yanai K 1994 Angrite Asuka-881371 Preliminary examination ofa unique meteorite in the Japanese collection of Antarcticmeteorites Proceedings of the NIPR Symposium on AntarcticMeteorites 730ndash41

Zinner E and Crozaz G 1986 A method for the quantitativemeasurement of rare earth elements in the ion probeInternational Journal of Mass Spectrometry and Ion Processes6917ndash38


mineral and bulk chemical properties of angrites remainpeculiar because all phases are usually out of equilibrium(Prinz and Weisberg 1995 Kurat et al 2001a 2001b 2004)Specifically the high abundances of refractory lithophileelements combined with high abundances of the moderatelyvolatile elements Mn and Fe2+ and low abundances ofsiderophile and volatile elements (eg Mittlefehldt et al1998) pose severe petrogenetic problems In addition theabundances of refractory elements are unfractionated withrespect to solar abundances at the 10 times to 15 times CI level verysimilar to what is observed in eucrites and Ca- and Al-richinclusions from carbonaceous chondrites (Prinz et al 19881990 Prinz and Weisberg 1995) There are many problemswith the distribution of certain trace elements between thephases in DrsquoOrbigny Such discrepancies for DrsquoOrbigny andother angrites have been reported by Floss et al (2003) whosuggested that kinetic effects during fast crystallization couldbe the cause Clearly as has been previously recognized byPrinz et al (1988 1990) Prinz and Weisberg (1995) andLonghi (1999) there is no simple way to create this class ofrocks

The shape structure and texture of DrsquoOrbigny and itsmineral and bulk chemical compositions indicate a complexgenesis under changing redox conditions as do manyconstituents of chondrites (eg Kurat 1988 Kurat et al 2002Varela et al 2002) Our observations on the textural featuresand data of major chemical compositions of all phases (Kuratet al 2004) as well as the petrographic and chemicalcomposition of all types of glasses present in DrsquoOrbigny(Varela et al 2003) are incompatible with a planetary igneousorigin for this rock and support an origin related to that of Ca-and Al-rich inclusions in carbonaceous chondrites Here wereport trace element abundances of the different phases in thecompact and porous part of DrsquoOrbigny The results supportour previous conclusions and strengthen the view thatangrites are rocks that record special conditions in the earlysolar nebula Short preliminary reports were given by Kuratet al (2001a 2001b 2003)

ANALYTICAL TECHNIQUES

Mineral phases were analyzed for their trace elementcontents with the laser ablation inductively coupled plasmamass spectrometry (LA-ICP-MS) facility at MemorialUniversity of Newfoundland The instrument is a VGPlasmaQuad 2S+ ICP-MS coupled to a 266 nm NdYAG laserbuilt in-house The ICP-MS instrument is equipped with afast-switching quadrupole mass filter and a single Galileo-type electron multiplier The laser beam is focused through theobjective of a microscope onto the sample surface A 50 cm3

sample cell is mounted on the computer-driven motorizedstage of the microscope The laser was set up to produce anenergy of 15 mJpulse (measured just before the beam enteredthe objective of the microscope) at a repetition rate of 10 Hzwith the laser beam focused about 200 microm above the surface

in order to produce a spot of about 50 microm on the samplesurface The cell was flushed with He gas during ablation tominimize fallback of ejecta and thus maximize analyticalsensitivity Typical data acquisitions consisted of a 60 secmeasurement of the gas blank before the start of ablationwhich lasted another 60 sec Laser ablation produced a pit inthe sample about 50 microm wide and 60 microm deep Raw ICP-MSdata were corrected for electron multiplier dead time (20 ns)and processed offline using a spreadsheet program(LAMTRACE S Jackson unpublished) to integrate signalssubtract the gas blank and calculate concentrationsMeasurements on meteoritic samples were calibrated againstthe NIST SRM 612 standard using the concentration values ofPearce et al (1997) Silicon determined by EMP analysiswas used as the internal standard

To avoid contamination by surrounding phases the traceelement contents of small phases were measured with theCameca IMS 3F ion microprobes at Washington UniversitySt Louis and the Max-Planck-Institut fcedilr Chemie in Mainzfollowing a modified procedure of Zinner and Crozaz (1986)

RESULTS

The investigated samples were the polished sectionsDrsquoOrbigny C DrsquoOrbigny D DrsquoOrbigny G DrsquoOrbigny XAand mineral separates from rock specimens and rock debrisDrsquoOrbigny B2 (all from the Naturhistorisches Museum inVienna)

The phases analyzed for trace elements were selectedfollowing the detailed petrographic and chemical studyundertaken by Kurat et al (2004) a brief summary of whichis given below This overview will help the reader understandthe structure and textures of this rock its minerals (egolivines augites and anorthite) and their occurrence (eg indruses shells or plates) It will also provide information onthe location of the phases that were analyzed

The Rock and Its Constituents

The DrsquoOrbigny meteorite has a peculiar shaperesembling a loaf of bread Its front and back shields are madeof a compact lithology and the space between these shields isfilled by a highly porous lithology very rich in open drusesand hollow shells

Hollow shells mostly perfectly spherical vugs withdiameters from lt1 mm to sim2 cm are present throughout themeteorite but appear to be more abundant in the porous partthan in the compact shields

The following six sections describe the constituents ofDrsquoOrbigny

Compact Shield RockThis part has a medium-grained micro-gabbroic texture

with little pore space and scattered small open or closeddruses and spherical hollow shells Occasionally some very






























DISCUSSION





Element

Olivine mega(2)

Olivinite(14)

Olivine mg(4)

Olivine shell(4)

Plag shell(4)

Plag mg(7)

Augite druse(10)

Augite mg(22)

Ferro-augite(1)



Tabl

e 2

Ion

mic

ropr

obe

anal

yses

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny p

late

El

emen

tO

l pl

ate

GB

1Er

ror

Ol

plat

e G

A2

Erro

rO

l Pl

ate

GA

5Er

ror

Ol

Ca-

rich

MEr

ror

Li11

80

18

02

60

13B

elt0

000

80

0032

000

07B

002

000

40

022

000

70

010

004

Mg

2078

1414

019

5570

253

1993

7521

8Si

1868

0012

018

6800

230

1868

0020

0P

454

322

04

138

25

K3

50

12

70

20

860

0918

03

3C

a93

6873

1157

015

095

0011

6Sc

256

02

245

04

210

330

084

Ti18

31

170

214

62

588

157

V49

04

420

631

60

526

1C

r54

31

551

53

482

52

514

92

8M

n52

556

5238

1152

849

Fe45

7990

350

4573

2866

946

1875

570

Co

256

224

23

232

52

512

34

5R

b0

770

15lt0

77

058

024

Sr0

310

023

50

20

060

012

181

2Y

059

003

08

005

059

005

135

077

Zr0

220

020

190

020

110

01N

b0

030

005

002

10

007

000

750

0025

034

017

Ba

028

003

046

005

004

10

008

270

78La

000

50

001

005

60

008

042

008

3C

e0

035

000

60

044

000

70

010

0025

127

016

Pr0

002

000

090

012

000

3lt0

004

40

140

05N

d0

020

003

006

50

01lt0

004

60

840

13Sm

001

000

4lt0

022

001

000

50

780

18Eu

lt00

027

001

50

004

035

01

Gd

001

20

004

lt00

20

011

000

41

080

27Tb

000

50

001

lt00

068

000

70

002

027

008

Dy

004

90

004

008

001

005

90

008

243

022

Ho

001

90

003

001

60

005

001

40

003

057

01

Er0

077

000

60

106

001

30

090

011

730

2Tm

001

20

002

001

50

004

001

250

003

034

008

Yb

017

60

012

019

50

025

017

50

025

283

027

Lu0

031

000

40

036

000

80

030

0075

036

01


Tabl

e 2

Con

tinue

d Io

n m

icro

prob

e an

alys

es (i

n pp

m) o

f min

eral

pha

ses

in D

rsquoOrb

igny

pla

te

Elem

ent

Ol

Ca-

rich

GA

1Er

ror

Plag

pla

te G

B1

Erro

rPl

ag p

late

GA

1Er

ror

Sp

meg

acry

stEr

ror

Li12

02

63

014

150

20

870

055

Be

005

50

005

006

20

007

006

50

005

004

80

004

B0

160

020

0165

000

50

0062

000

240

0136

000

37M

g18

7600

200

880

410

084

7188

082

0Si

1868

0018

320

4300

194

2043

0017

516

1118

P38

74

622

351

69

06

K14

60

32

70

153

014

047

007

Ca

1852

017

095

762

156

9456

014

286

0Sc

350

42

60

22

20

24

50

3Ti

1475

451

154

09

1417

17V

680

65

50

24

70

1118

6722

Cr

542

21

50

11

60

1159

840

690

Mn

5200

85

981

106

09

1166

14Fe

4560

8053

027

4239

2606

3417

8000

2060

Co

225

26

30

46

90

415

23

Rb

20

60

660

11Sr

90

2613

51

128

10

570

07Y

48

017

012

001

009

001

018

002

Zr17

05

lt00

280

026

000

90

680

07N

b1

070

090

090

015

Ba

44

025

63

03

59

03

015

50

03La

08

006

50

097

001

50

061

000

90

028

000

7C

e2

20

140

175

001

80

168

002

20

072

001

5Pr

037

003

002

10

004

001

50

003

000

880

0025

Nd

163

008

008

30

010

0755

000

90

046

000

9Sm

042

005

001

70

008

lt00

120

018

000

8Eu

014

001

40

390

030

340

02lt0

004

6G

d0

50

080

026

000

8lt0

015

lt00

22Tb

008

50

010

0063

000

190

005

000

2lt0

005

5D

y0

90

055

001

60

004

001

750

0044

002

50

006

Ho

018

002

lt00

033

000

330

001

000

520

0024

Er0

630

040

0097

000

4lt0

008

001

60

005

Tm0

095

001

lt00

03Y

b0

630

06lt0

015

lt00

14lt0

017

Lu0

117

001

6lt0

003


Tabl

e 3

Ion

mic

ropr

obe

anal

ysis

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny

Elem

ent

Aug

cor

e G

A4

Erro

rA

ug c

ore

Erro

rA

ug r

imEr

ror

Ulvˆs

pine

lEr

ror

Kirs

ch

Erro

rTi

-Fe

silic

ate

Erro

r

Li2

90

06B

e0

053

000

45B

011

60

012

P15

72

K3

40

10

440

079

750

361

70

3618

30

5796

2Sc

190

05

252

101

200

326

70

4411

027

93

038

5Ti

9042

869

3022

727

770

502

1250

000

819

1410

1332

400

97V

368

144

31

717

420

2429

83

760

480

073

70

31C

r41

01

366

12

532

990

190

830

242

90

220

50

137

Mn

1572

3

C

o56

08

230

8244

51

2515

15

5993

21

331

93R

b1

50

6

Sr

220

3521

053

881

191

50

378

66

038

271

37

Y22

02

180

3860

077

18

032

519

05

102

18

Zr13

50

967

118

344

295

426

796

14

021

686

58

4N

b0

630

040

180

062

207

023

212

571

lt01

619

74

Ba

16

01

006

001

91

060

070

80

161

680

107

300

7La

12

006

077

004

85

090

136

0

070

018

174

045

Ce

43

02

032

010

817

70

274

028

009

037

004

756

087

Pr0

90

050

850

052

349

011

50

190

070

060

019

99

035

Nd

49

02

483

012

819

80

289

035

01

059

006

500

84Sm

19

012

218

012

778

025

068

017

027

005

717

40

69Eu

047

003

062

004

52

440

1lt0

10

140

036

140

28G

d2

50

22

320

258

690

486

lt06

10

90

1719

51

13Tb

048

005

051

005

162

009

024

004

349

026

4D

y3

40

12

320

1111

024

024

009

257

013

240

637

Ho

07

005

066

004

82

360

090

160

070

720

065

026

Er2

20

11

680

097

310

202

05

013

62

70

1414

051

Tm0

340

030

240

031

290

080

170

070

590

062

230

186

Yb

22

01

021

011

106

026

057

015

64

40

199

60

5Lu

04

004

03

004

61

560

1

0

620

076

111

019



























































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES
















































































DISCUSSION





Element

Olivine mega(2)

Olivinite(14)

Olivine mg(4)

Olivine shell(4)

Plag shell(4)

Plag mg(7)

Augite druse(10)

Augite mg(22)

Ferro-augite(1)



Tabl

e 2

Ion

mic

ropr

obe

anal

yses

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny p

late

El

emen

tO

l pl

ate

GB

1Er

ror

Ol

plat

e G

A2

Erro

rO

l Pl

ate

GA

5Er

ror

Ol

Ca-

rich

MEr

ror

Li11

80

18

02

60

13B

elt0

000

80

0032

000

07B

002

000

40

022

000

70

010

004

Mg

2078

1414

019

5570

253

1993

7521

8Si

1868

0012

018

6800

230

1868

0020

0P

454

322

04

138

25

K3

50

12

70

20

860

0918

03

3C

a93

6873

1157

015

095

0011

6Sc

256

02

245

04

210

330

084

Ti18

31

170

214

62

588

157

V49

04

420

631

60

526

1C

r54

31

551

53

482

52

514

92

8M

n52

556

5238

1152

849

Fe45

7990

350

4573

2866

946

1875

570

Co

256

224

23

232

52

512

34

5R

b0

770

15lt0

77

058

024

Sr0

310

023

50

20

060

012

181

2Y

059

003

08

005

059

005

135

077

Zr0

220

020

190

020

110

01N

b0

030

005

002

10

007

000

750

0025

034

017

Ba

028

003

046

005

004

10

008

270

78La

000

50

001

005

60

008

042

008

3C

e0

035

000

60

044

000

70

010

0025

127

016

Pr0

002

000

090

012

000

3lt0

004

40

140

05N

d0

020

003

006

50

01lt0

004

60

840

13Sm

001

000

4lt0

022

001

000

50

780

18Eu

lt00

027

001

50

004

035

01

Gd

001

20

004

lt00

20

011

000

41

080

27Tb

000

50

001

lt00

068

000

70

002

027

008

Dy

004

90

004

008

001

005

90

008

243

022

Ho

001

90

003

001

60

005

001

40

003

057

01

Er0

077

000

60

106

001

30

090

011

730

2Tm

001

20

002

001

50

004

001

250

003

034

008

Yb

017

60

012

019

50

025

017

50

025

283

027

Lu0

031

000

40

036

000

80

030

0075

036

01


Tabl

e 2

Con

tinue

d Io

n m

icro

prob

e an

alys

es (i

n pp

m) o

f min

eral

pha

ses

in D

rsquoOrb

igny

pla

te

Elem

ent

Ol

Ca-

rich

GA

1Er

ror

Plag

pla

te G

B1

Erro

rPl

ag p

late

GA

1Er

ror

Sp

meg

acry

stEr

ror

Li12

02

63

014

150

20

870

055

Be

005

50

005

006

20

007

006

50

005

004

80

004

B0

160

020

0165

000

50

0062

000

240

0136

000

37M

g18

7600

200

880

410

084

7188

082

0Si

1868

0018

320

4300

194

2043

0017

516

1118

P38

74

622

351

69

06

K14

60

32

70

153

014

047

007

Ca

1852

017

095

762

156

9456

014

286

0Sc

350

42

60

22

20

24

50

3Ti

1475

451

154

09

1417

17V

680

65

50

24

70

1118

6722

Cr

542

21

50

11

60

1159

840

690

Mn

5200

85

981

106

09

1166

14Fe

4560

8053

027

4239

2606

3417

8000

2060

Co

225

26

30

46

90

415

23

Rb

20

60

660

11Sr

90

2613

51

128

10

570

07Y

48

017

012

001

009

001

018

002

Zr17

05

lt00

280

026

000

90

680

07N

b1

070

090

090

015

Ba

44

025

63

03

59

03

015

50

03La

08

006

50

097

001

50

061

000

90

028

000

7C

e2

20

140

175

001

80

168

002

20

072

001

5Pr

037

003

002

10

004

001

50

003

000

880

0025

Nd

163

008

008

30

010

0755

000

90

046

000

9Sm

042

005

001

70

008

lt00

120

018

000

8Eu

014

001

40

390

030

340

02lt0

004

6G

d0

50

080

026

000

8lt0

015

lt00

22Tb

008

50

010

0063

000

190

005

000

2lt0

005

5D

y0

90

055

001

60

004

001

750

0044

002

50

006

Ho

018

002

lt00

033

000

330

001

000

520

0024

Er0

630

040

0097

000

4lt0

008

001

60

005

Tm0

095

001

lt00

03Y

b0

630

06lt0

015

lt00

14lt0

017

Lu0

117

001

6lt0

003


Tabl

e 3

Ion

mic

ropr

obe

anal

ysis

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny

Elem

ent

Aug

cor

e G

A4

Erro

rA

ug c

ore

Erro

rA

ug r

imEr

ror

Ulvˆs

pine

lEr

ror

Kirs

ch

Erro

rTi

-Fe

silic

ate

Erro

r

Li2

90

06B

e0

053

000

45B

011

60

012

P15

72

K3

40

10

440

079

750

361

70

3618

30

5796

2Sc

190

05

252

101

200

326

70

4411

027

93

038

5Ti

9042

869

3022

727

770

502

1250

000

819

1410

1332

400

97V

368

144

31

717

420

2429

83

760

480

073

70

31C

r41

01

366

12

532

990

190

830

242

90

220

50

137

Mn

1572

3

C

o56

08

230

8244

51

2515

15

5993

21

331

93R

b1

50

6

Sr

220

3521

053

881

191

50

378

66

038

271

37

Y22

02

180

3860

077

18

032

519

05

102

18

Zr13

50

967

118

344

295

426

796

14

021

686

58

4N

b0

630

040

180

062

207

023

212

571

lt01

619

74

Ba

16

01

006

001

91

060

070

80

161

680

107

300

7La

12

006

077

004

85

090

136

0

070

018

174

045

Ce

43

02

032

010

817

70

274

028

009

037

004

756

087

Pr0

90

050

850

052

349

011

50

190

070

060

019

99

035

Nd

49

02

483

012

819

80

289

035

01

059

006

500

84Sm

19

012

218

012

778

025

068

017

027

005

717

40

69Eu

047

003

062

004

52

440

1lt0

10

140

036

140

28G

d2

50

22

320

258

690

486

lt06

10

90

1719

51

13Tb

048

005

051

005

162

009

024

004

349

026

4D

y3

40

12

320

1111

024

024

009

257

013

240

637

Ho

07

005

066

004

82

360

090

160

070

720

065

026

Er2

20

11

680

097

310

202

05

013

62

70

1414

051

Tm0

340

030

240

031

290

080

170

070

590

062

230

186

Yb

22

01

021

011

106

026

057

015

64

40

199

60

5Lu

04

004

03

004

61

560

1

0

620

076

111

019



























































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES



































































DISCUSSION





Element

Olivine mega(2)

Olivinite(14)

Olivine mg(4)

Olivine shell(4)

Plag shell(4)

Plag mg(7)

Augite druse(10)

Augite mg(22)

Ferro-augite(1)



Tabl

e 2

Ion

mic

ropr

obe

anal

yses

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny p

late

El

emen

tO

l pl

ate

GB

1Er

ror

Ol

plat

e G

A2

Erro

rO

l Pl

ate

GA

5Er

ror

Ol

Ca-

rich

MEr

ror

Li11

80

18

02

60

13B

elt0

000

80

0032

000

07B

002

000

40

022

000

70

010

004

Mg

2078

1414

019

5570

253

1993

7521

8Si

1868

0012

018

6800

230

1868

0020

0P

454

322

04

138

25

K3

50

12

70

20

860

0918

03

3C

a93

6873

1157

015

095

0011

6Sc

256

02

245

04

210

330

084

Ti18

31

170

214

62

588

157

V49

04

420

631

60

526

1C

r54

31

551

53

482

52

514

92

8M

n52

556

5238

1152

849

Fe45

7990

350

4573

2866

946

1875

570

Co

256

224

23

232

52

512

34

5R

b0

770

15lt0

77

058

024

Sr0

310

023

50

20

060

012

181

2Y

059

003

08

005

059

005

135

077

Zr0

220

020

190

020

110

01N

b0

030

005

002

10

007

000

750

0025

034

017

Ba

028

003

046

005

004

10

008

270

78La

000

50

001

005

60

008

042

008

3C

e0

035

000

60

044

000

70

010

0025

127

016

Pr0

002

000

090

012

000

3lt0

004

40

140

05N

d0

020

003

006

50

01lt0

004

60

840

13Sm

001

000

4lt0

022

001

000

50

780

18Eu

lt00

027

001

50

004

035

01

Gd

001

20

004

lt00

20

011

000

41

080

27Tb

000

50

001

lt00

068

000

70

002

027

008

Dy

004

90

004

008

001

005

90

008

243

022

Ho

001

90

003

001

60

005

001

40

003

057

01

Er0

077

000

60

106

001

30

090

011

730

2Tm

001

20

002

001

50

004

001

250

003

034

008

Yb

017

60

012

019

50

025

017

50

025

283

027

Lu0

031

000

40

036

000

80

030

0075

036

01


Tabl

e 2

Con

tinue

d Io

n m

icro

prob

e an

alys

es (i

n pp

m) o

f min

eral

pha

ses

in D

rsquoOrb

igny

pla

te

Elem

ent

Ol

Ca-

rich

GA

1Er

ror

Plag

pla

te G

B1

Erro

rPl

ag p

late

GA

1Er

ror

Sp

meg

acry

stEr

ror

Li12

02

63

014

150

20

870

055

Be

005

50

005

006

20

007

006

50

005

004

80

004

B0

160

020

0165

000

50

0062

000

240

0136

000

37M

g18

7600

200

880

410

084

7188

082

0Si

1868

0018

320

4300

194

2043

0017

516

1118

P38

74

622

351

69

06

K14

60

32

70

153

014

047

007

Ca

1852

017

095

762

156

9456

014

286

0Sc

350

42

60

22

20

24

50

3Ti

1475

451

154

09

1417

17V

680

65

50

24

70

1118

6722

Cr

542

21

50

11

60

1159

840

690

Mn

5200

85

981

106

09

1166

14Fe

4560

8053

027

4239

2606

3417

8000

2060

Co

225

26

30

46

90

415

23

Rb

20

60

660

11Sr

90

2613

51

128

10

570

07Y

48

017

012

001

009

001

018

002

Zr17

05

lt00

280

026

000

90

680

07N

b1

070

090

090

015

Ba

44

025

63

03

59

03

015

50

03La

08

006

50

097

001

50

061

000

90

028

000

7C

e2

20

140

175

001

80

168

002

20

072

001

5Pr

037

003

002

10

004

001

50

003

000

880

0025

Nd

163

008

008

30

010

0755

000

90

046

000

9Sm

042

005

001

70

008

lt00

120

018

000

8Eu

014

001

40

390

030

340

02lt0

004

6G

d0

50

080

026

000

8lt0

015

lt00

22Tb

008

50

010

0063

000

190

005

000

2lt0

005

5D

y0

90

055

001

60

004

001

750

0044

002

50

006

Ho

018

002

lt00

033

000

330

001

000

520

0024

Er0

630

040

0097

000

4lt0

008

001

60

005

Tm0

095

001

lt00

03Y

b0

630

06lt0

015

lt00

14lt0

017

Lu0

117

001

6lt0

003


Tabl

e 3

Ion

mic

ropr

obe

anal

ysis

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny

Elem

ent

Aug

cor

e G

A4

Erro

rA

ug c

ore

Erro

rA

ug r

imEr

ror

Ulvˆs

pine

lEr

ror

Kirs

ch

Erro

rTi

-Fe

silic

ate

Erro

r

Li2

90

06B

e0

053

000

45B

011

60

012

P15

72

K3

40

10

440

079

750

361

70

3618

30

5796

2Sc

190

05

252

101

200

326

70

4411

027

93

038

5Ti

9042

869

3022

727

770

502

1250

000

819

1410

1332

400

97V

368

144

31

717

420

2429

83

760

480

073

70

31C

r41

01

366

12

532

990

190

830

242

90

220

50

137

Mn

1572

3

C

o56

08

230

8244

51

2515

15

5993

21

331

93R

b1

50

6

Sr

220

3521

053

881

191

50

378

66

038

271

37

Y22

02

180

3860

077

18

032

519

05

102

18

Zr13

50

967

118

344

295

426

796

14

021

686

58

4N

b0

630

040

180

062

207

023

212

571

lt01

619

74

Ba

16

01

006

001

91

060

070

80

161

680

107

300

7La

12

006

077

004

85

090

136

0

070

018

174

045

Ce

43

02

032

010

817

70

274

028

009

037

004

756

087

Pr0

90

050

850

052

349

011

50

190

070

060

019

99

035

Nd

49

02

483

012

819

80

289

035

01

059

006

500

84Sm

19

012

218

012

778

025

068

017

027

005

717

40

69Eu

047

003

062

004

52

440

1lt0

10

140

036

140

28G

d2

50

22

320

258

690

486

lt06

10

90

1719

51

13Tb

048

005

051

005

162

009

024

004

349

026

4D

y3

40

12

320

1111

024

024

009

257

013

240

637

Ho

07

005

066

004

82

360

090

160

070

720

065

026

Er2

20

11

680

097

310

202

05

013

62

70

1414

051

Tm0

340

030

240

031

290

080

170

070

590

062

230

186

Yb

22

01

021

011

106

026

057

015

64

40

199

60

5Lu

04

004

03

004

61

560

1

0

620

076

111

019



























































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES




























































DISCUSSION





Element

Olivine mega(2)

Olivinite(14)

Olivine mg(4)

Olivine shell(4)

Plag shell(4)

Plag mg(7)

Augite druse(10)

Augite mg(22)

Ferro-augite(1)



Tabl

e 2

Ion

mic

ropr

obe

anal

yses

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny p

late

El

emen

tO

l pl

ate

GB

1Er

ror

Ol

plat

e G

A2

Erro

rO

l Pl

ate

GA

5Er

ror

Ol

Ca-

rich

MEr

ror

Li11

80

18

02

60

13B

elt0

000

80

0032

000

07B

002

000

40

022

000

70

010

004

Mg

2078

1414

019

5570

253

1993

7521

8Si

1868

0012

018

6800

230

1868

0020

0P

454

322

04

138

25

K3

50

12

70

20

860

0918

03

3C

a93

6873

1157

015

095

0011

6Sc

256

02

245

04

210

330

084

Ti18

31

170

214

62

588

157

V49

04

420

631

60

526

1C

r54

31

551

53

482

52

514

92

8M

n52

556

5238

1152

849

Fe45

7990

350

4573

2866

946

1875

570

Co

256

224

23

232

52

512

34

5R

b0

770

15lt0

77

058

024

Sr0

310

023

50

20

060

012

181

2Y

059

003

08

005

059

005

135

077

Zr0

220

020

190

020

110

01N

b0

030

005

002

10

007

000

750

0025

034

017

Ba

028

003

046

005

004

10

008

270

78La

000

50

001

005

60

008

042

008

3C

e0

035

000

60

044

000

70

010

0025

127

016

Pr0

002

000

090

012

000

3lt0

004

40

140

05N

d0

020

003

006

50

01lt0

004

60

840

13Sm

001

000

4lt0

022

001

000

50

780

18Eu

lt00

027

001

50

004

035

01

Gd

001

20

004

lt00

20

011

000

41

080

27Tb

000

50

001

lt00

068

000

70

002

027

008

Dy

004

90

004

008

001

005

90

008

243

022

Ho

001

90

003

001

60

005

001

40

003

057

01

Er0

077

000

60

106

001

30

090

011

730

2Tm

001

20

002

001

50

004

001

250

003

034

008

Yb

017

60

012

019

50

025

017

50

025

283

027

Lu0

031

000

40

036

000

80

030

0075

036

01


Tabl

e 2

Con

tinue

d Io

n m

icro

prob

e an

alys

es (i

n pp

m) o

f min

eral

pha

ses

in D

rsquoOrb

igny

pla

te

Elem

ent

Ol

Ca-

rich

GA

1Er

ror

Plag

pla

te G

B1

Erro

rPl

ag p

late

GA

1Er

ror

Sp

meg

acry

stEr

ror

Li12

02

63

014

150

20

870

055

Be

005

50

005

006

20

007

006

50

005

004

80

004

B0

160

020

0165

000

50

0062

000

240

0136

000

37M

g18

7600

200

880

410

084

7188

082

0Si

1868

0018

320

4300

194

2043

0017

516

1118

P38

74

622

351

69

06

K14

60

32

70

153

014

047

007

Ca

1852

017

095

762

156

9456

014

286

0Sc

350

42

60

22

20

24

50

3Ti

1475

451

154

09

1417

17V

680

65

50

24

70

1118

6722

Cr

542

21

50

11

60

1159

840

690

Mn

5200

85

981

106

09

1166

14Fe

4560

8053

027

4239

2606

3417

8000

2060

Co

225

26

30

46

90

415

23

Rb

20

60

660

11Sr

90

2613

51

128

10

570

07Y

48

017

012

001

009

001

018

002

Zr17

05

lt00

280

026

000

90

680

07N

b1

070

090

090

015

Ba

44

025

63

03

59

03

015

50

03La

08

006

50

097

001

50

061

000

90

028

000

7C

e2

20

140

175

001

80

168

002

20

072

001

5Pr

037

003

002

10

004

001

50

003

000

880

0025

Nd

163

008

008

30

010

0755

000

90

046

000

9Sm

042

005

001

70

008

lt00

120

018

000

8Eu

014

001

40

390

030

340

02lt0

004

6G

d0

50

080

026

000

8lt0

015

lt00

22Tb

008

50

010

0063

000

190

005

000

2lt0

005

5D

y0

90

055

001

60

004

001

750

0044

002

50

006

Ho

018

002

lt00

033

000

330

001

000

520

0024

Er0

630

040

0097

000

4lt0

008

001

60

005

Tm0

095

001

lt00

03Y

b0

630

06lt0

015

lt00

14lt0

017

Lu0

117

001

6lt0

003


Tabl

e 3

Ion

mic

ropr

obe

anal

ysis

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny

Elem

ent

Aug

cor

e G

A4

Erro

rA

ug c

ore

Erro

rA

ug r

imEr

ror

Ulvˆs

pine

lEr

ror

Kirs

ch

Erro

rTi

-Fe

silic

ate

Erro

r

Li2

90

06B

e0

053

000

45B

011

60

012

P15

72

K3

40

10

440

079

750

361

70

3618

30

5796

2Sc

190

05

252

101

200

326

70

4411

027

93

038

5Ti

9042

869

3022

727

770

502

1250

000

819

1410

1332

400

97V

368

144

31

717

420

2429

83

760

480

073

70

31C

r41

01

366

12

532

990

190

830

242

90

220

50

137

Mn

1572

3

C

o56

08

230

8244

51

2515

15

5993

21

331

93R

b1

50

6

Sr

220

3521

053

881

191

50

378

66

038

271

37

Y22

02

180

3860

077

18

032

519

05

102

18

Zr13

50

967

118

344

295

426

796

14

021

686

58

4N

b0

630

040

180

062

207

023

212

571

lt01

619

74

Ba

16

01

006

001

91

060

070

80

161

680

107

300

7La

12

006

077

004

85

090

136

0

070

018

174

045

Ce

43

02

032

010

817

70

274

028

009

037

004

756

087

Pr0

90

050

850

052

349

011

50

190

070

060

019

99

035

Nd

49

02

483

012

819

80

289

035

01

059

006

500

84Sm

19

012

218

012

778

025

068

017

027

005

717

40

69Eu

047

003

062

004

52

440

1lt0

10

140

036

140

28G

d2

50

22

320

258

690

486

lt06

10

90

1719

51

13Tb

048

005

051

005

162

009

024

004

349

026

4D

y3

40

12

320

1111

024

024

009

257

013

240

637

Ho

07

005

066

004

82

360

090

160

070

720

065

026

Er2

20

11

680

097

310

202

05

013

62

70

1414

051

Tm0

340

030

240

031

290

080

170

070

590

062

230

186

Yb

22

01

021

011

106

026

057

015

64

40

199

60

5Lu

04

004

03

004

61

560

1

0

620

076

111

019



























































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES


























































DISCUSSION





Element

Olivine mega(2)

Olivinite(14)

Olivine mg(4)

Olivine shell(4)

Plag shell(4)

Plag mg(7)

Augite druse(10)

Augite mg(22)

Ferro-augite(1)



Tabl

e 2

Ion

mic

ropr

obe

anal

yses

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny p

late

El

emen

tO

l pl

ate

GB

1Er

ror

Ol

plat

e G

A2

Erro

rO

l Pl

ate

GA

5Er

ror

Ol

Ca-

rich

MEr

ror

Li11

80

18

02

60

13B

elt0

000

80

0032

000

07B

002

000

40

022

000

70

010

004

Mg

2078

1414

019

5570

253

1993

7521

8Si

1868

0012

018

6800

230

1868

0020

0P

454

322

04

138

25

K3

50

12

70

20

860

0918

03

3C

a93

6873

1157

015

095

0011

6Sc

256

02

245

04

210

330

084

Ti18

31

170

214

62

588

157

V49

04

420

631

60

526

1C

r54

31

551

53

482

52

514

92

8M

n52

556

5238

1152

849

Fe45

7990

350

4573

2866

946

1875

570

Co

256

224

23

232

52

512

34

5R

b0

770

15lt0

77

058

024

Sr0

310

023

50

20

060

012

181

2Y

059

003

08

005

059

005

135

077

Zr0

220

020

190

020

110

01N

b0

030

005

002

10

007

000

750

0025

034

017

Ba

028

003

046

005

004

10

008

270

78La

000

50

001

005

60

008

042

008

3C

e0

035

000

60

044

000

70

010

0025

127

016

Pr0

002

000

090

012

000

3lt0

004

40

140

05N

d0

020

003

006

50

01lt0

004

60

840

13Sm

001

000

4lt0

022

001

000

50

780

18Eu

lt00

027

001

50

004

035

01

Gd

001

20

004

lt00

20

011

000

41

080

27Tb

000

50

001

lt00

068

000

70

002

027

008

Dy

004

90

004

008

001

005

90

008

243

022

Ho

001

90

003

001

60

005

001

40

003

057

01

Er0

077

000

60

106

001

30

090

011

730

2Tm

001

20

002

001

50

004

001

250

003

034

008

Yb

017

60

012

019

50

025

017

50

025

283

027

Lu0

031

000

40

036

000

80

030

0075

036

01


Tabl

e 2

Con

tinue

d Io

n m

icro

prob

e an

alys

es (i

n pp

m) o

f min

eral

pha

ses

in D

rsquoOrb

igny

pla

te

Elem

ent

Ol

Ca-

rich

GA

1Er

ror

Plag

pla

te G

B1

Erro

rPl

ag p

late

GA

1Er

ror

Sp

meg

acry

stEr

ror

Li12

02

63

014

150

20

870

055

Be

005

50

005

006

20

007

006

50

005

004

80

004

B0

160

020

0165

000

50

0062

000

240

0136

000

37M

g18

7600

200

880

410

084

7188

082

0Si

1868

0018

320

4300

194

2043

0017

516

1118

P38

74

622

351

69

06

K14

60

32

70

153

014

047

007

Ca

1852

017

095

762

156

9456

014

286

0Sc

350

42

60

22

20

24

50

3Ti

1475

451

154

09

1417

17V

680

65

50

24

70

1118

6722

Cr

542

21

50

11

60

1159

840

690

Mn

5200

85

981

106

09

1166

14Fe

4560

8053

027

4239

2606

3417

8000

2060

Co

225

26

30

46

90

415

23

Rb

20

60

660

11Sr

90

2613

51

128

10

570

07Y

48

017

012

001

009

001

018

002

Zr17

05

lt00

280

026

000

90

680

07N

b1

070

090

090

015

Ba

44

025

63

03

59

03

015

50

03La

08

006

50

097

001

50

061

000

90

028

000

7C

e2

20

140

175

001

80

168

002

20

072

001

5Pr

037

003

002

10

004

001

50

003

000

880

0025

Nd

163

008

008

30

010

0755

000

90

046

000

9Sm

042

005

001

70

008

lt00

120

018

000

8Eu

014

001

40

390

030

340

02lt0

004

6G

d0

50

080

026

000

8lt0

015

lt00

22Tb

008

50

010

0063

000

190

005

000

2lt0

005

5D

y0

90

055

001

60

004

001

750

0044

002

50

006

Ho

018

002

lt00

033

000

330

001

000

520

0024

Er0

630

040

0097

000

4lt0

008

001

60

005

Tm0

095

001

lt00

03Y

b0

630

06lt0

015

lt00

14lt0

017

Lu0

117

001

6lt0

003


Tabl

e 3

Ion

mic

ropr

obe

anal

ysis

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny

Elem

ent

Aug

cor

e G

A4

Erro

rA

ug c

ore

Erro

rA

ug r

imEr

ror

Ulvˆs

pine

lEr

ror

Kirs

ch

Erro

rTi

-Fe

silic

ate

Erro

r

Li2

90

06B

e0

053

000

45B

011

60

012

P15

72

K3

40

10

440

079

750

361

70

3618

30

5796

2Sc

190

05

252

101

200

326

70

4411

027

93

038

5Ti

9042

869

3022

727

770

502

1250

000

819

1410

1332

400

97V

368

144

31

717

420

2429

83

760

480

073

70

31C

r41

01

366

12

532

990

190

830

242

90

220

50

137

Mn

1572

3

C

o56

08

230

8244

51

2515

15

5993

21

331

93R

b1

50

6

Sr

220

3521

053

881

191

50

378

66

038

271

37

Y22

02

180

3860

077

18

032

519

05

102

18

Zr13

50

967

118

344

295

426

796

14

021

686

58

4N

b0

630

040

180

062

207

023

212

571

lt01

619

74

Ba

16

01

006

001

91

060

070

80

161

680

107

300

7La

12

006

077

004

85

090

136

0

070

018

174

045

Ce

43

02

032

010

817

70

274

028

009

037

004

756

087

Pr0

90

050

850

052

349

011

50

190

070

060

019

99

035

Nd

49

02

483

012

819

80

289

035

01

059

006

500

84Sm

19

012

218

012

778

025

068

017

027

005

717

40

69Eu

047

003

062

004

52

440

1lt0

10

140

036

140

28G

d2

50

22

320

258

690

486

lt06

10

90

1719

51

13Tb

048

005

051

005

162

009

024

004

349

026

4D

y3

40

12

320

1111

024

024

009

257

013

240

637

Ho

07

005

066

004

82

360

090

160

070

720

065

026

Er2

20

11

680

097

310

202

05

013

62

70

1414

051

Tm0

340

030

240

031

290

080

170

070

590

062

230

186

Yb

22

01

021

011

106

026

057

015

64

40

199

60

5Lu

04

004

03

004

61

560

1

0

620

076

111

019



























































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES
























































DISCUSSION





Element

Olivine mega(2)

Olivinite(14)

Olivine mg(4)

Olivine shell(4)

Plag shell(4)

Plag mg(7)

Augite druse(10)

Augite mg(22)

Ferro-augite(1)



Tabl

e 2

Ion

mic

ropr

obe

anal

yses

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny p

late

El

emen

tO

l pl

ate

GB

1Er

ror

Ol

plat

e G

A2

Erro

rO

l Pl

ate

GA

5Er

ror

Ol

Ca-

rich

MEr

ror

Li11

80

18

02

60

13B

elt0

000

80

0032

000

07B

002

000

40

022

000

70

010

004

Mg

2078

1414

019

5570

253

1993

7521

8Si

1868

0012

018

6800

230

1868

0020

0P

454

322

04

138

25

K3

50

12

70

20

860

0918

03

3C

a93

6873

1157

015

095

0011

6Sc

256

02

245

04

210

330

084

Ti18

31

170

214

62

588

157

V49

04

420

631

60

526

1C

r54

31

551

53

482

52

514

92

8M

n52

556

5238

1152

849

Fe45

7990

350

4573

2866

946

1875

570

Co

256

224

23

232

52

512

34

5R

b0

770

15lt0

77

058

024

Sr0

310

023

50

20

060

012

181

2Y

059

003

08

005

059

005

135

077

Zr0

220

020

190

020

110

01N

b0

030

005

002

10

007

000

750

0025

034

017

Ba

028

003

046

005

004

10

008

270

78La

000

50

001

005

60

008

042

008

3C

e0

035

000

60

044

000

70

010

0025

127

016

Pr0

002

000

090

012

000

3lt0

004

40

140

05N

d0

020

003

006

50

01lt0

004

60

840

13Sm

001

000

4lt0

022

001

000

50

780

18Eu

lt00

027

001

50

004

035

01

Gd

001

20

004

lt00

20

011

000

41

080

27Tb

000

50

001

lt00

068

000

70

002

027

008

Dy

004

90

004

008

001

005

90

008

243

022

Ho

001

90

003

001

60

005

001

40

003

057

01

Er0

077

000

60

106

001

30

090

011

730

2Tm

001

20

002

001

50

004

001

250

003

034

008

Yb

017

60

012

019

50

025

017

50

025

283

027

Lu0

031

000

40

036

000

80

030

0075

036

01


Tabl

e 2

Con

tinue

d Io

n m

icro

prob

e an

alys

es (i

n pp

m) o

f min

eral

pha

ses

in D

rsquoOrb

igny

pla

te

Elem

ent

Ol

Ca-

rich

GA

1Er

ror

Plag

pla

te G

B1

Erro

rPl

ag p

late

GA

1Er

ror

Sp

meg

acry

stEr

ror

Li12

02

63

014

150

20

870

055

Be

005

50

005

006

20

007

006

50

005

004

80

004

B0

160

020

0165

000

50

0062

000

240

0136

000

37M

g18

7600

200

880

410

084

7188

082

0Si

1868

0018

320

4300

194

2043

0017

516

1118

P38

74

622

351

69

06

K14

60

32

70

153

014

047

007

Ca

1852

017

095

762

156

9456

014

286

0Sc

350

42

60

22

20

24

50

3Ti

1475

451

154

09

1417

17V

680

65

50

24

70

1118

6722

Cr

542

21

50

11

60

1159

840

690

Mn

5200

85

981

106

09

1166

14Fe

4560

8053

027

4239

2606

3417

8000

2060

Co

225

26

30

46

90

415

23

Rb

20

60

660

11Sr

90

2613

51

128

10

570

07Y

48

017

012

001

009

001

018

002

Zr17

05

lt00

280

026

000

90

680

07N

b1

070

090

090

015

Ba

44

025

63

03

59

03

015

50

03La

08

006

50

097

001

50

061

000

90

028

000

7C

e2

20

140

175

001

80

168

002

20

072

001

5Pr

037

003

002

10

004

001

50

003

000

880

0025

Nd

163

008

008

30

010

0755

000

90

046

000

9Sm

042

005

001

70

008

lt00

120

018

000

8Eu

014

001

40

390

030

340

02lt0

004

6G

d0

50

080

026

000

8lt0

015

lt00

22Tb

008

50

010

0063

000

190

005

000

2lt0

005

5D

y0

90

055

001

60

004

001

750

0044

002

50

006

Ho

018

002

lt00

033

000

330

001

000

520

0024

Er0

630

040

0097

000

4lt0

008

001

60

005

Tm0

095

001

lt00

03Y

b0

630

06lt0

015

lt00

14lt0

017

Lu0

117

001

6lt0

003


Tabl

e 3

Ion

mic

ropr

obe

anal

ysis

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny

Elem

ent

Aug

cor

e G

A4

Erro

rA

ug c

ore

Erro

rA

ug r

imEr

ror

Ulvˆs

pine

lEr

ror

Kirs

ch

Erro

rTi

-Fe

silic

ate

Erro

r

Li2

90

06B

e0

053

000

45B

011

60

012

P15

72

K3

40

10

440

079

750

361

70

3618

30

5796

2Sc

190

05

252

101

200

326

70

4411

027

93

038

5Ti

9042

869

3022

727

770

502

1250

000

819

1410

1332

400

97V

368

144

31

717

420

2429

83

760

480

073

70

31C

r41

01

366

12

532

990

190

830

242

90

220

50

137

Mn

1572

3

C

o56

08

230

8244

51

2515

15

5993

21

331

93R

b1

50

6

Sr

220

3521

053

881

191

50

378

66

038

271

37

Y22

02

180

3860

077

18

032

519

05

102

18

Zr13

50

967

118

344

295

426

796

14

021

686

58

4N

b0

630

040

180

062

207

023

212

571

lt01

619

74

Ba

16

01

006

001

91

060

070

80

161

680

107

300

7La

12

006

077

004

85

090

136

0

070

018

174

045

Ce

43

02

032

010

817

70

274

028

009

037

004

756

087

Pr0

90

050

850

052

349

011

50

190

070

060

019

99

035

Nd

49

02

483

012

819

80

289

035

01

059

006

500

84Sm

19

012

218

012

778

025

068

017

027

005

717

40

69Eu

047

003

062

004

52

440

1lt0

10

140

036

140

28G

d2

50

22

320

258

690

486

lt06

10

90

1719

51

13Tb

048

005

051

005

162

009

024

004

349

026

4D

y3

40

12

320

1111

024

024

009

257

013

240

637

Ho

07

005

066

004

82

360

090

160

070

720

065

026

Er2

20

11

680

097

310

202

05

013

62

70

1414

051

Tm0

340

030

240

031

290

080

170

070

590

062

230

186

Yb

22

01

021

011

106

026

057

015

64

40

199

60

5Lu

04

004

03

004

61

560

1

0

620

076

111

019



























































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES




















































Tabl

e 2

Ion

mic

ropr

obe

anal

yses

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny p

late

El

emen

tO

l pl

ate

GB

1Er

ror

Ol

plat

e G

A2

Erro

rO

l Pl

ate

GA

5Er

ror

Ol

Ca-

rich

MEr

ror

Li11

80

18

02

60

13B

elt0

000

80

0032

000

07B

002

000

40

022

000

70

010

004

Mg

2078

1414

019

5570

253

1993

7521

8Si

1868

0012

018

6800

230

1868

0020

0P

454

322

04

138

25

K3

50

12

70

20

860

0918

03

3C

a93

6873

1157

015

095

0011

6Sc

256

02

245

04

210

330

084

Ti18

31

170

214

62

588

157

V49

04

420

631

60

526

1C

r54

31

551

53

482

52

514

92

8M

n52

556

5238

1152

849

Fe45

7990

350

4573

2866

946

1875

570

Co

256

224

23

232

52

512

34

5R

b0

770

15lt0

77

058

024

Sr0

310

023

50

20

060

012

181

2Y

059

003

08

005

059

005

135

077

Zr0

220

020

190

020

110

01N

b0

030

005

002

10

007

000

750

0025

034

017

Ba

028

003

046

005

004

10

008

270

78La

000

50

001

005

60

008

042

008

3C

e0

035

000

60

044

000

70

010

0025

127

016

Pr0

002

000

090

012

000

3lt0

004

40

140

05N

d0

020

003

006

50

01lt0

004

60

840

13Sm

001

000

4lt0

022

001

000

50

780

18Eu

lt00

027

001

50

004

035

01

Gd

001

20

004

lt00

20

011

000

41

080

27Tb

000

50

001

lt00

068

000

70

002

027

008

Dy

004

90

004

008

001

005

90

008

243

022

Ho

001

90

003

001

60

005

001

40

003

057

01

Er0

077

000

60

106

001

30

090

011

730

2Tm

001

20

002

001

50

004

001

250

003

034

008

Yb

017

60

012

019

50

025

017

50

025

283

027

Lu0

031

000

40

036

000

80

030

0075

036

01


Tabl

e 2

Con

tinue

d Io

n m

icro

prob

e an

alys

es (i

n pp

m) o

f min

eral

pha

ses

in D

rsquoOrb

igny

pla

te

Elem

ent

Ol

Ca-

rich

GA

1Er

ror

Plag

pla

te G

B1

Erro

rPl

ag p

late

GA

1Er

ror

Sp

meg

acry

stEr

ror

Li12

02

63

014

150

20

870

055

Be

005

50

005

006

20

007

006

50

005

004

80

004

B0

160

020

0165

000

50

0062

000

240

0136

000

37M

g18

7600

200

880

410

084

7188

082

0Si

1868

0018

320

4300

194

2043

0017

516

1118

P38

74

622

351

69

06

K14

60

32

70

153

014

047

007

Ca

1852

017

095

762

156

9456

014

286

0Sc

350

42

60

22

20

24

50

3Ti

1475

451

154

09

1417

17V

680

65

50

24

70

1118

6722

Cr

542

21

50

11

60

1159

840

690

Mn

5200

85

981

106

09

1166

14Fe

4560

8053

027

4239

2606

3417

8000

2060

Co

225

26

30

46

90

415

23

Rb

20

60

660

11Sr

90

2613

51

128

10

570

07Y

48

017

012

001

009

001

018

002

Zr17

05

lt00

280

026

000

90

680

07N

b1

070

090

090

015

Ba

44

025

63

03

59

03

015

50

03La

08

006

50

097

001

50

061

000

90

028

000

7C

e2

20

140

175

001

80

168

002

20

072

001

5Pr

037

003

002

10

004

001

50

003

000

880

0025

Nd

163

008

008

30

010

0755

000

90

046

000

9Sm

042

005

001

70

008

lt00

120

018

000

8Eu

014

001

40

390

030

340

02lt0

004

6G

d0

50

080

026

000

8lt0

015

lt00

22Tb

008

50

010

0063

000

190

005

000

2lt0

005

5D

y0

90

055

001

60

004

001

750

0044

002

50

006

Ho

018

002

lt00

033

000

330

001

000

520

0024

Er0

630

040

0097

000

4lt0

008

001

60

005

Tm0

095

001

lt00

03Y

b0

630

06lt0

015

lt00

14lt0

017

Lu0

117

001

6lt0

003


Tabl

e 3

Ion

mic

ropr

obe

anal

ysis

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny

Elem

ent

Aug

cor

e G

A4

Erro

rA

ug c

ore

Erro

rA

ug r

imEr

ror

Ulvˆs

pine

lEr

ror

Kirs

ch

Erro

rTi

-Fe

silic

ate

Erro

r

Li2

90

06B

e0

053

000

45B

011

60

012

P15

72

K3

40

10

440

079

750

361

70

3618

30

5796

2Sc

190

05

252

101

200

326

70

4411

027

93

038

5Ti

9042

869

3022

727

770

502

1250

000

819

1410

1332

400

97V

368

144

31

717

420

2429

83

760

480

073

70

31C

r41

01

366

12

532

990

190

830

242

90

220

50

137

Mn

1572

3

C

o56

08

230

8244

51

2515

15

5993

21

331

93R

b1

50

6

Sr

220

3521

053

881

191

50

378

66

038

271

37

Y22

02

180

3860

077

18

032

519

05

102

18

Zr13

50

967

118

344

295

426

796

14

021

686

58

4N

b0

630

040

180

062

207

023

212

571

lt01

619

74

Ba

16

01

006

001

91

060

070

80

161

680

107

300

7La

12

006

077

004

85

090

136

0

070

018

174

045

Ce

43

02

032

010

817

70

274

028

009

037

004

756

087

Pr0

90

050

850

052

349

011

50

190

070

060

019

99

035

Nd

49

02

483

012

819

80

289

035

01

059

006

500

84Sm

19

012

218

012

778

025

068

017

027

005

717

40

69Eu

047

003

062

004

52

440

1lt0

10

140

036

140

28G

d2

50

22

320

258

690

486

lt06

10

90

1719

51

13Tb

048

005

051

005

162

009

024

004

349

026

4D

y3

40

12

320

1111

024

024

009

257

013

240

637

Ho

07

005

066

004

82

360

090

160

070

720

065

026

Er2

20

11

680

097

310

202

05

013

62

70

1414

051

Tm0

340

030

240

031

290

080

170

070

590

062

230

186

Yb

22

01

021

011

106

026

057

015

64

40

199

60

5Lu

04

004

03

004

61

560

1

0

620

076

111

019



























































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES




















































Tabl

e 2

Con

tinue

d Io

n m

icro

prob

e an

alys

es (i

n pp

m) o

f min

eral

pha

ses

in D

rsquoOrb

igny

pla

te

Elem

ent

Ol

Ca-

rich

GA

1Er

ror

Plag

pla

te G

B1

Erro

rPl

ag p

late

GA

1Er

ror

Sp

meg

acry

stEr

ror

Li12

02

63

014

150

20

870

055

Be

005

50

005

006

20

007

006

50

005

004

80

004

B0

160

020

0165

000

50

0062

000

240

0136

000

37M

g18

7600

200

880

410

084

7188

082

0Si

1868

0018

320

4300

194

2043

0017

516

1118

P38

74

622

351

69

06

K14

60

32

70

153

014

047

007

Ca

1852

017

095

762

156

9456

014

286

0Sc

350

42

60

22

20

24

50

3Ti

1475

451

154

09

1417

17V

680

65

50

24

70

1118

6722

Cr

542

21

50

11

60

1159

840

690

Mn

5200

85

981

106

09

1166

14Fe

4560

8053

027

4239

2606

3417

8000

2060

Co

225

26

30

46

90

415

23

Rb

20

60

660

11Sr

90

2613

51

128

10

570

07Y

48

017

012

001

009

001

018

002

Zr17

05

lt00

280

026

000

90

680

07N

b1

070

090

090

015

Ba

44

025

63

03

59

03

015

50

03La

08

006

50

097

001

50

061

000

90

028

000

7C

e2

20

140

175

001

80

168

002

20

072

001

5Pr

037

003

002

10

004

001

50

003

000

880

0025

Nd

163

008

008

30

010

0755

000

90

046

000

9Sm

042

005

001

70

008

lt00

120

018

000

8Eu

014

001

40

390

030

340

02lt0

004

6G

d0

50

080

026

000

8lt0

015

lt00

22Tb

008

50

010

0063

000

190

005

000

2lt0

005

5D

y0

90

055

001

60

004

001

750

0044

002

50

006

Ho

018

002

lt00

033

000

330

001

000

520

0024

Er0

630

040

0097

000

4lt0

008

001

60

005

Tm0

095

001

lt00

03Y

b0

630

06lt0

015

lt00

14lt0

017

Lu0

117

001

6lt0

003


Tabl

e 3

Ion

mic

ropr

obe

anal

ysis

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny

Elem

ent

Aug

cor

e G

A4

Erro

rA

ug c

ore

Erro

rA

ug r

imEr

ror

Ulvˆs

pine

lEr

ror

Kirs

ch

Erro

rTi

-Fe

silic

ate

Erro

r

Li2

90

06B

e0

053

000

45B

011

60

012

P15

72

K3

40

10

440

079

750

361

70

3618

30

5796

2Sc

190

05

252

101

200

326

70

4411

027

93

038

5Ti

9042

869

3022

727

770

502

1250

000

819

1410

1332

400

97V

368

144

31

717

420

2429

83

760

480

073

70

31C

r41

01

366

12

532

990

190

830

242

90

220

50

137

Mn

1572

3

C

o56

08

230

8244

51

2515

15

5993

21

331

93R

b1

50

6

Sr

220

3521

053

881

191

50

378

66

038

271

37

Y22

02

180

3860

077

18

032

519

05

102

18

Zr13

50

967

118

344

295

426

796

14

021

686

58

4N

b0

630

040

180

062

207

023

212

571

lt01

619

74

Ba

16

01

006

001

91

060

070

80

161

680

107

300

7La

12

006

077

004

85

090

136

0

070

018

174

045

Ce

43

02

032

010

817

70

274

028

009

037

004

756

087

Pr0

90

050

850

052

349

011

50

190

070

060

019

99

035

Nd

49

02

483

012

819

80

289

035

01

059

006

500

84Sm

19

012

218

012

778

025

068

017

027

005

717

40

69Eu

047

003

062

004

52

440

1lt0

10

140

036

140

28G

d2

50

22

320

258

690

486

lt06

10

90

1719

51

13Tb

048

005

051

005

162

009

024

004

349

026

4D

y3

40

12

320

1111

024

024

009

257

013

240

637

Ho

07

005

066

004

82

360

090

160

070

720

065

026

Er2

20

11

680

097

310

202

05

013

62

70

1414

051

Tm0

340

030

240

031

290

080

170

070

590

062

230

186

Yb

22

01

021

011

106

026

057

015

64

40

199

60

5Lu

04

004

03

004

61

560

1

0

620

076

111

019



























































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES




















































Tabl

e 3

Ion

mic

ropr

obe

anal

ysis

(in

ppm

) of m

iner

al p

hase

s in

DrsquoO

rbig

ny

Elem

ent

Aug

cor

e G

A4

Erro

rA

ug c

ore

Erro

rA

ug r

imEr

ror

Ulvˆs

pine

lEr

ror

Kirs

ch

Erro

rTi

-Fe

silic

ate

Erro

r

Li2

90

06B

e0

053

000

45B

011

60

012

P15

72

K3

40

10

440

079

750

361

70

3618

30

5796

2Sc

190

05

252

101

200

326

70

4411

027

93

038

5Ti

9042

869

3022

727

770

502

1250

000

819

1410

1332

400

97V

368

144

31

717

420

2429

83

760

480

073

70

31C

r41

01

366

12

532

990

190

830

242

90

220

50

137

Mn

1572

3

C

o56

08

230

8244

51

2515

15

5993

21

331

93R

b1

50

6

Sr

220

3521

053

881

191

50

378

66

038

271

37

Y22

02

180

3860

077

18

032

519

05

102

18

Zr13

50

967

118

344

295

426

796

14

021

686

58

4N

b0

630

040

180

062

207

023

212

571

lt01

619

74

Ba

16

01

006

001

91

060

070

80

161

680

107

300

7La

12

006

077

004

85

090

136

0

070

018

174

045

Ce

43

02

032

010

817

70

274

028

009

037

004

756

087

Pr0

90

050

850

052

349

011

50

190

070

060

019

99

035

Nd

49

02

483

012

819

80

289

035

01

059

006

500

84Sm

19

012

218

012

778

025

068

017

027

005

717

40

69Eu

047

003

062

004

52

440

1lt0

10

140

036

140

28G

d2

50

22

320

258

690

486

lt06

10

90

1719

51

13Tb

048

005

051

005

162

009

024

004

349

026

4D

y3

40

12

320

1111

024

024

009

257

013

240

637

Ho

07

005

066

004

82

360

090

160

070

720

065

026

Er2

20

11

680

097

310

202

05

013

62

70

1414

051

Tm0

340

030

240

031

290

080

170

070

590

062

230

186

Yb

22

01

021

011

106

026

057

015

64

40

199

60

5Lu

04

004

03

004

61

560

1

0

620

076

111

019



























































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES













































































































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES








































































































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES



































































































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES




























































































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES






















































































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES

















































































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES











































































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES


































































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES




























































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES






















































(1)


(2)

(s = solid g = gas)



(3)

and

(4)




CONCLUSIONS




++

=


SO2 g( ) 4H2 g( )+ H2S g( ) 2H2O g( )+=

H2S g( ) Fe g( )+ FeS s( ) H2 g( )+=










REFERENCES




























































REFERENCES























































































Documents

The non-igneous genesis of angrites: Support from trace element ... · D Orbigny phases. Trace element data were obtaine d from both the porous and the compact part of this meteorite