Sapphirine as a breakdown product of garnet in a Variscan UHP/HT peridotite from the Vosges Mountains (France): an indication of near-isothermal decompression

Abstract. In the Variscan Vosges Mountains (France) small bodies of orogenic garnet peridotite occur within felsic gneisses (former granulites). In most of these peridotite bodies the original garnet is completely transformed to kelyphite surrounded by a relatively thin two-layer corona of orthopyr...

Full description

Saved in:
Bibliographic Details
Main Authors: Altherr, Rainer (Author) , Soder, Christian (Author)
Format: Article (Journal)
Language:English
Published: 24 October 2018
In: Journal of petrology
Year: 2018, Volume: 59, Issue: 11, Pages: 2221-2243
ISSN:1460-2415
DOI:10.1093/petrology/egy096
Online Access:Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1093/petrology/egy096
Verlag, lizenzpflichtig, Volltext: https://academic.oup.com/petrology/article/59/11/2221/5144196
Get full text
Author Notes:Rainer Altherr and Christian G. Soder

MARC

LEADER 00000caa a2200000 c 4500
001 169770459X
003 DE-627
005 20220818075737.0
007 cr uuu---uuuuu
008 200507s2018 xx |||||o 00| ||eng c
024 7 |a 10.1093/petrology/egy096  |2 doi 
035 |a (DE-627)169770459X 
035 |a (DE-599)KXP169770459X 
035 |a (OCoLC)1341319424 
040 |a DE-627  |b ger  |c DE-627  |e rda 
041 |a eng 
084 |a 31  |2 sdnb 
100 1 |a Altherr, Rainer  |d 1947-  |e VerfasserIn  |0 (DE-588)1019804831  |0 (DE-627)691022925  |0 (DE-576)358794722  |4 aut 
245 1 0 |a Sapphirine as a breakdown product of garnet in a Variscan UHP/HT peridotite from the Vosges Mountains (France)  |b an indication of near-isothermal decompression  |c Rainer Altherr and Christian G. Soder 
264 1 |c 24 October 2018 
300 |a 23 
336 |a Text  |b txt  |2 rdacontent 
337 |a Computermedien  |b c  |2 rdamedia 
338 |a Online-Ressource  |b cr  |2 rdacarrier 
500 |a Gesehen am 07.05.2020 
520 |a Abstract. In the Variscan Vosges Mountains (France) small bodies of orogenic garnet peridotite occur within felsic gneisses (former granulites). In most of these peridotite bodies the original garnet is completely transformed to kelyphite surrounded by a relatively thin two-layer corona of orthopyroxene ± clinopyroxene and orthopyroxene + clinopyroxene + spinel, which was formed during decompression and reflects the transition from garnet peridotite to spinel peridotite. The porphyroblastic garnet peridotite of Laveline-du-Houx originally formed at 4·1± 0·2 GPa and 1000 ± 20°C, as shown by geothermobarometry on relics of pyroxene and garnet. Geochemically, the rock is only moderately depleted relative to primitive mantle. It contains mineralogically zoned pseudomorphs after garnet, which formed during exhumation and allow for reconstruction of the retrograde pressure-temperature (P–T) path. Inside the commonly present, marginal, two-layer corona of these pseudomorphs, there follow two additional spherical shells: a relatively thick shell consisting of Al-rich pyroxenes (with small inclusions of chemically modified garnet relics) and spinel followed by an inner shell containing the assemblage sapphirine + Al-rich orthopyroxene + Al-rich clinopyroxene ± spinel. Both shells were generated by metasomatic reactions (introduction of Na and Ca) between garnet and olivine at pressures between about 2·3 and 1·0 GPa and temperatures of 950–1000°C. Increasing infiltration of water during exhumation is documented by inclusions of aspidolite in spinel and by formation of amphibole in the sapphirine-bearing zone. Locally, spaces between Al-rich orthopyroxene and clinopyroxene reacted to olivine, plagioclase and minor amounts of Al-poor pyroxenes, indicating pressures below ∼0·7 GPa. Moreover, sapphirine became partially or completely converted to fine-grained symplectitic aggregates of spinel and plagioclase, and Al-rich clinopyroxene partially reacted to a very fine-grained symplectite of amphibole, plagioclase, and minor spinel. Relic garnet in the central parts of the pseudomorphs was almost completely transformed to kelyphite. The near-isothermal exhumation path of this small ultramafic body indicates rapid exhumation that seems only possible within a larger mass of less dense, more felsic rocks, which also underwent ultrahigh-pressure metamorphism, but reequilibrated much faster and more efficiently than its ultramafic passenger during uplift. 
700 1 |a Soder, Christian  |e VerfasserIn  |0 (DE-588)1100382216  |0 (DE-627)859333647  |0 (DE-576)469669217  |4 aut 
773 0 8 |i Enthalten in  |t Journal of petrology  |d Oxford : Oxford Univ. Press, 1960  |g 59(2018), 11, Seite 2221-2243  |h Online-Ressource  |w (DE-627)266016286  |w (DE-600)1466724-1  |w (DE-576)074960105  |x 1460-2415  |7 nnas  |a Sapphirine as a breakdown product of garnet in a Variscan UHP/HT peridotite from the Vosges Mountains (France) an indication of near-isothermal decompression 
773 1 8 |g volume:59  |g year:2018  |g number:11  |g pages:2221-2243  |g extent:23  |a Sapphirine as a breakdown product of garnet in a Variscan UHP/HT peridotite from the Vosges Mountains (France) an indication of near-isothermal decompression 
856 4 0 |u https://doi.org/10.1093/petrology/egy096  |x Verlag  |x Resolving-System  |z lizenzpflichtig  |3 Volltext 
856 4 0 |u https://academic.oup.com/petrology/article/59/11/2221/5144196  |x Verlag  |z lizenzpflichtig  |3 Volltext 
951 |a AR 
992 |a 20200507 
993 |a Article 
994 |a 2018 
998 |g 1100382216  |a Soder, Christian  |m 1100382216:Soder, Christian  |p 2  |y j 
998 |g 1019804831  |a Altherr, Rainer  |m 1019804831:Altherr, Rainer  |d 120000  |d 121000  |e 120000PA1019804831  |e 121000PA1019804831  |k 0/120000/  |k 1/120000/121000/  |p 1  |x j 
999 |a KXP-PPN169770459X  |e 3662567385 
BIB |a Y 
SER |a journal 
JSO |a {"name":{"displayForm":["Rainer Altherr and Christian G. Soder"]},"id":{"eki":["169770459X"],"doi":["10.1093/petrology/egy096"]},"origin":[{"dateIssuedKey":"2018","dateIssuedDisp":"24 October 2018"}],"relHost":[{"physDesc":[{"extent":"Online-Ressource"}],"id":{"zdb":["1466724-1"],"eki":["266016286"],"issn":["1460-2415"]},"origin":[{"publisherPlace":"Oxford","dateIssuedKey":"1960","publisher":"Oxford Univ. Press","dateIssuedDisp":"1960-"}],"recId":"266016286","language":["eng"],"type":{"media":"Online-Ressource","bibl":"periodical"},"note":["Gesehen am 16.03.23"],"disp":"Sapphirine as a breakdown product of garnet in a Variscan UHP/HT peridotite from the Vosges Mountains (France) an indication of near-isothermal decompressionJournal of petrology","part":{"text":"59(2018), 11, Seite 2221-2243","volume":"59","extent":"23","year":"2018","pages":"2221-2243","issue":"11"},"pubHistory":["1.1960 -"],"title":[{"title":"Journal of petrology","title_sort":"Journal of petrology"}]}],"physDesc":[{"extent":"23 S."}],"person":[{"given":"Rainer","family":"Altherr","role":"aut","roleDisplay":"VerfasserIn","display":"Altherr, Rainer"},{"role":"aut","display":"Soder, Christian","roleDisplay":"VerfasserIn","given":"Christian","family":"Soder"}],"title":[{"subtitle":"an indication of near-isothermal decompression","title":"Sapphirine as a breakdown product of garnet in a Variscan UHP/HT peridotite from the Vosges Mountains (France)","title_sort":"Sapphirine as a breakdown product of garnet in a Variscan UHP/HT peridotite from the Vosges Mountains (France)"}],"language":["eng"],"recId":"169770459X","note":["Gesehen am 07.05.2020"],"type":{"bibl":"article-journal","media":"Online-Ressource"}} 
SRT |a ALTHERRRAISAPPHIRINE2420