Partial melting during tectonic exhumation of a granulite terrane: an example from the Larsemann Hills, East Antarctica
Anatectic migmatites in medium‐ to low‐pressure granulite facies metasediments exposed in the Larsemann Hills, East Antarctica, contain leucosomes with abundant quartz and plagioclase and minor interstitial K‐feldspar, and assemblages of garnet–cordierite–spinel–ilmenite–sillimanite. Qualitative mod...
Published in: | Journal of Metamorphic Geology |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
1997
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1111/j.1525-1314.1997.00059.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1525-1314.1997.00059.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1525-1314.1997.00059.x |
id |
crwiley:10.1111/j.1525-1314.1997.00059.x |
---|---|
record_format |
openpolar |
spelling |
crwiley:10.1111/j.1525-1314.1997.00059.x 2024-09-30T14:24:53+00:00 Partial melting during tectonic exhumation of a granulite terrane: an example from the Larsemann Hills, East Antarctica CARSON, C. J. POWELL, * R. WILSON, C. J. L. DIRKS, P. H. G. M. 1997 http://dx.doi.org/10.1111/j.1525-1314.1997.00059.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1525-1314.1997.00059.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1525-1314.1997.00059.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Journal of Metamorphic Geology volume 15, issue 1, page 105-126 ISSN 0263-4929 1525-1314 journal-article 1997 crwiley https://doi.org/10.1111/j.1525-1314.1997.00059.x 2024-09-05T05:07:07Z Anatectic migmatites in medium‐ to low‐pressure granulite facies metasediments exposed in the Larsemann Hills, East Antarctica, contain leucosomes with abundant quartz and plagioclase and minor interstitial K‐feldspar, and assemblages of garnet–cordierite–spinel–ilmenite–sillimanite. Qualitative modelling in the system K 2 O–FeO–MgO–Al 2 O 3 –SiO 2 –H 2 O–TiO 2 –O 2 , in conjunction with various P – T calculations indicate that the high‐grade retrograde evolution of the terrane was dominated by decompression from peak conditions of c. 7 kbar at c. 800 °C to 4–5 kbar at c. 750 °C. Extensive partial melting during decompression involved the replacement of biotite by the assemblage cordierite–garnet–spinel within the leucosomes. These leucosomes represent the site of partial melt generation, the cordierite–garnet–spinel–ilmenite assemblage representing the solid products and excess reactants from the melting reaction. The extraction and accumulation of this decompression‐generated melt led to the formation of syntectonic pegmatites and extensive granitic plutons. Leucosome development and terrane decompression proceeded during crustal transpression, synchronous with upper crustal extension, during a progressive Early Palaeozoic collisional event. Subsequent retrograde evolution was characterized by cooling, as indicated by the growth of biotite replacing spinel and garnet, thin mantles of cordierite replacing spinel and quartz within metapelites, and garnet replacing orthopyroxene and hornblende within metabasites. P–T calculations on late mylonites indicate lower grade conditions of formation of c. 3.5 kbar at c. 650 °C, consistent with the development of late cooling textures. Article in Journal/Newspaper Antarc* Antarctica East Antarctica Wiley Online Library East Antarctica Larsemann Hills ENVELOPE(76.217,76.217,-69.400,-69.400) Journal of Metamorphic Geology 15 1 105 126 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Anatectic migmatites in medium‐ to low‐pressure granulite facies metasediments exposed in the Larsemann Hills, East Antarctica, contain leucosomes with abundant quartz and plagioclase and minor interstitial K‐feldspar, and assemblages of garnet–cordierite–spinel–ilmenite–sillimanite. Qualitative modelling in the system K 2 O–FeO–MgO–Al 2 O 3 –SiO 2 –H 2 O–TiO 2 –O 2 , in conjunction with various P – T calculations indicate that the high‐grade retrograde evolution of the terrane was dominated by decompression from peak conditions of c. 7 kbar at c. 800 °C to 4–5 kbar at c. 750 °C. Extensive partial melting during decompression involved the replacement of biotite by the assemblage cordierite–garnet–spinel within the leucosomes. These leucosomes represent the site of partial melt generation, the cordierite–garnet–spinel–ilmenite assemblage representing the solid products and excess reactants from the melting reaction. The extraction and accumulation of this decompression‐generated melt led to the formation of syntectonic pegmatites and extensive granitic plutons. Leucosome development and terrane decompression proceeded during crustal transpression, synchronous with upper crustal extension, during a progressive Early Palaeozoic collisional event. Subsequent retrograde evolution was characterized by cooling, as indicated by the growth of biotite replacing spinel and garnet, thin mantles of cordierite replacing spinel and quartz within metapelites, and garnet replacing orthopyroxene and hornblende within metabasites. P–T calculations on late mylonites indicate lower grade conditions of formation of c. 3.5 kbar at c. 650 °C, consistent with the development of late cooling textures. |
format |
Article in Journal/Newspaper |
author |
CARSON, C. J. POWELL, * R. WILSON, C. J. L. DIRKS, P. H. G. M. |
spellingShingle |
CARSON, C. J. POWELL, * R. WILSON, C. J. L. DIRKS, P. H. G. M. Partial melting during tectonic exhumation of a granulite terrane: an example from the Larsemann Hills, East Antarctica |
author_facet |
CARSON, C. J. POWELL, * R. WILSON, C. J. L. DIRKS, P. H. G. M. |
author_sort |
CARSON, C. J. |
title |
Partial melting during tectonic exhumation of a granulite terrane: an example from the Larsemann Hills, East Antarctica |
title_short |
Partial melting during tectonic exhumation of a granulite terrane: an example from the Larsemann Hills, East Antarctica |
title_full |
Partial melting during tectonic exhumation of a granulite terrane: an example from the Larsemann Hills, East Antarctica |
title_fullStr |
Partial melting during tectonic exhumation of a granulite terrane: an example from the Larsemann Hills, East Antarctica |
title_full_unstemmed |
Partial melting during tectonic exhumation of a granulite terrane: an example from the Larsemann Hills, East Antarctica |
title_sort |
partial melting during tectonic exhumation of a granulite terrane: an example from the larsemann hills, east antarctica |
publisher |
Wiley |
publishDate |
1997 |
url |
http://dx.doi.org/10.1111/j.1525-1314.1997.00059.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1525-1314.1997.00059.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1525-1314.1997.00059.x |
long_lat |
ENVELOPE(76.217,76.217,-69.400,-69.400) |
geographic |
East Antarctica Larsemann Hills |
geographic_facet |
East Antarctica Larsemann Hills |
genre |
Antarc* Antarctica East Antarctica |
genre_facet |
Antarc* Antarctica East Antarctica |
op_source |
Journal of Metamorphic Geology volume 15, issue 1, page 105-126 ISSN 0263-4929 1525-1314 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1525-1314.1997.00059.x |
container_title |
Journal of Metamorphic Geology |
container_volume |
15 |
container_issue |
1 |
container_start_page |
105 |
op_container_end_page |
126 |
_version_ |
1811642645730033664 |