New constraints on metamorphism in the Rauer Group, Prydz Bay, east Antarctica
Granulite facies metapelites of the Mather and Filla Paragneisses within the Rauer Group, east Antarctica, possess markedly different compositions. The metamorphic evolution of the two metapelite types has been interpreted as temporally distinct, with the Rauer Group preserving at least two distinct...
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ftunivadelaidedl:oai:digital.library.adelaide.edu.au:2440/34315 2023-12-17T10:19:56+01:00 New constraints on metamorphism in the Rauer Group, Prydz Bay, east Antarctica Kelsey, D. White, R. Powell, R. Wilson, C. Quinn, C. 2003 http://hdl.handle.net/2440/34315 https://doi.org/10.1046/j.1525-1314.2003.00476.x en eng Blackwell Publishing Ltd Journal of Metamorphic Geology, 2003; 21(8):739-759 0263-4929 1525-1314 http://hdl.handle.net/2440/34315 doi:10.1046/j.1525-1314.2003.00476.x http://dx.doi.org/10.1046/j.1525-1314.2003.00476.x Journal article 2003 ftunivadelaidedl https://doi.org/10.1046/j.1525-1314.2003.00476.x 2023-11-20T23:32:46Z Granulite facies metapelites of the Mather and Filla Paragneisses within the Rauer Group, east Antarctica, possess markedly different compositions. The metamorphic evolution of the two metapelite types has been interpreted as temporally distinct, with the Rauer Group preserving at least two distinct granulite facies tectonothermal episodes. Calculated P–T pseudosections and orthopyroxene Al content indicate the revised maximum-preserved P–T conditions within the Mather Paragneiss to lie in the vicinity of 950–975 °C and 10–10.6 kbar, less extreme than previous estimates. The range of possible P–T paths for the Mather Paragneiss consistent with mineral textural relationships and pseudosections contoured for mineral proportion are significantly shallower (dP/dT) than previous estimates. A near-isothermal decompression P–T path, and extreme peak metamorphic conditions, are not necessary to explain the development of preserved mineral reaction textures. The Filla Paragneiss contains pelitic assemblages less amenable to rigorous quantitative analysis. Nevertheless, possibilities for the shared or otherwise metamorphic evolution of the Mather and Filla Paragneisses may be postulated on the basis of calculated pseudosections in the context of existing geochronology for the Rauer Group and preserved microstructures. A shared evolution, most likely during Pan-African granulite facies metamorphism, is plausible and consistent with mineral assemblage development, geochronology and microstructures. A revised interpretation of the Rauer Group's preserved metamorphic evolution may warrant the revision of existing tectonic models, applicable also to the remainder of Prydz Bay. More generally, the employed approach may incite a revision of peak P–T and P–T paths in other granulite facies terranes. D. E. Kelsey, R. W. White, R. Powell, C. J. L. Wilson and C. D. Quinn Article in Journal/Newspaper Antarc* Antarctica East Antarctica Prydz Bay The University of Adelaide: Digital Library East Antarctica Kelsey ENVELOPE(-22.306,-22.306,-80.448,-80.448) Prydz Bay Rauer Group ENVELOPE(77.833,77.833,-68.850,-68.850) Journal of Metamorphic Geology 21 8 739 759 |
institution |
Open Polar |
collection |
The University of Adelaide: Digital Library |
op_collection_id |
ftunivadelaidedl |
language |
English |
description |
Granulite facies metapelites of the Mather and Filla Paragneisses within the Rauer Group, east Antarctica, possess markedly different compositions. The metamorphic evolution of the two metapelite types has been interpreted as temporally distinct, with the Rauer Group preserving at least two distinct granulite facies tectonothermal episodes. Calculated P–T pseudosections and orthopyroxene Al content indicate the revised maximum-preserved P–T conditions within the Mather Paragneiss to lie in the vicinity of 950–975 °C and 10–10.6 kbar, less extreme than previous estimates. The range of possible P–T paths for the Mather Paragneiss consistent with mineral textural relationships and pseudosections contoured for mineral proportion are significantly shallower (dP/dT) than previous estimates. A near-isothermal decompression P–T path, and extreme peak metamorphic conditions, are not necessary to explain the development of preserved mineral reaction textures. The Filla Paragneiss contains pelitic assemblages less amenable to rigorous quantitative analysis. Nevertheless, possibilities for the shared or otherwise metamorphic evolution of the Mather and Filla Paragneisses may be postulated on the basis of calculated pseudosections in the context of existing geochronology for the Rauer Group and preserved microstructures. A shared evolution, most likely during Pan-African granulite facies metamorphism, is plausible and consistent with mineral assemblage development, geochronology and microstructures. A revised interpretation of the Rauer Group's preserved metamorphic evolution may warrant the revision of existing tectonic models, applicable also to the remainder of Prydz Bay. More generally, the employed approach may incite a revision of peak P–T and P–T paths in other granulite facies terranes. D. E. Kelsey, R. W. White, R. Powell, C. J. L. Wilson and C. D. Quinn |
format |
Article in Journal/Newspaper |
author |
Kelsey, D. White, R. Powell, R. Wilson, C. Quinn, C. |
spellingShingle |
Kelsey, D. White, R. Powell, R. Wilson, C. Quinn, C. New constraints on metamorphism in the Rauer Group, Prydz Bay, east Antarctica |
author_facet |
Kelsey, D. White, R. Powell, R. Wilson, C. Quinn, C. |
author_sort |
Kelsey, D. |
title |
New constraints on metamorphism in the Rauer Group, Prydz Bay, east Antarctica |
title_short |
New constraints on metamorphism in the Rauer Group, Prydz Bay, east Antarctica |
title_full |
New constraints on metamorphism in the Rauer Group, Prydz Bay, east Antarctica |
title_fullStr |
New constraints on metamorphism in the Rauer Group, Prydz Bay, east Antarctica |
title_full_unstemmed |
New constraints on metamorphism in the Rauer Group, Prydz Bay, east Antarctica |
title_sort |
new constraints on metamorphism in the rauer group, prydz bay, east antarctica |
publisher |
Blackwell Publishing Ltd |
publishDate |
2003 |
url |
http://hdl.handle.net/2440/34315 https://doi.org/10.1046/j.1525-1314.2003.00476.x |
long_lat |
ENVELOPE(-22.306,-22.306,-80.448,-80.448) ENVELOPE(77.833,77.833,-68.850,-68.850) |
geographic |
East Antarctica Kelsey Prydz Bay Rauer Group |
geographic_facet |
East Antarctica Kelsey Prydz Bay Rauer Group |
genre |
Antarc* Antarctica East Antarctica Prydz Bay |
genre_facet |
Antarc* Antarctica East Antarctica Prydz Bay |
op_source |
http://dx.doi.org/10.1046/j.1525-1314.2003.00476.x |
op_relation |
Journal of Metamorphic Geology, 2003; 21(8):739-759 0263-4929 1525-1314 http://hdl.handle.net/2440/34315 doi:10.1046/j.1525-1314.2003.00476.x |
op_doi |
https://doi.org/10.1046/j.1525-1314.2003.00476.x |
container_title |
Journal of Metamorphic Geology |
container_volume |
21 |
container_issue |
8 |
container_start_page |
739 |
op_container_end_page |
759 |
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1785587472951934976 |