Occurrences of metamorphosed ultramafic rock and associating rocks in Howard Hills, Enderby Land, East Antarctica: Evidence of partial melting from geochemical and isotopic characteristics
Large blocks of metamorphic rocks with mafic to ultramafic compositions were discovered in felsic gneiss at the central part of northern Howard Hills in Enderby Land. The ultramafic core is separated from the felsic gneiss by a mantle of pyroxene granulite. We can recognize from mineral assemblages...
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ftnipr:oai:nipr.repo.nii.ac.jp:00003138 2023-05-15T13:49:00+02:00 Occurrences of metamorphosed ultramafic rock and associating rocks in Howard Hills, Enderby Land, East Antarctica: Evidence of partial melting from geochemical and isotopic characteristics Tomoharu Miyamoto Yasutaka Yoshimura Kei Sato Yoichi Motoyoshi Daniel J. Dunkley Christopher J. Carson 2004-10 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3138 http://id.nii.ac.jp/1291/00003138/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3138&item_no=1&attribute_id=18&file_no=1 en eng Department of Earth and Planetary Sciences, Kyushu University/Department of Natural Environmental Science, Kochi University/Division of Earth Sciences, Department of Biosphere-Geosphere Sciences, Ehime University/National Institute of Polar Research/National Institute of Polar Research/Geological Survey of Canada National Institute of Polar Research https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3138 http://id.nii.ac.jp/1291/00003138/ AA1130866X Polar geoscience, 17, 88-111(2004-10) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3138&item_no=1&attribute_id=18&file_no=1 Howard Hills Napier Complex Sr-Nd isotope chemistry partial melting Departmental Bulletin Paper P(論文) 2004 ftnipr 2022-12-03T19:43:04Z Large blocks of metamorphic rocks with mafic to ultramafic compositions were discovered in felsic gneiss at the central part of northern Howard Hills in Enderby Land. The ultramafic core is separated from the felsic gneiss by a mantle of pyroxene granulite. We can recognize from mineral assemblages and chemical compositions that the metamorphic rocks experienced ultrahigh temperature (UHT) metamorphism. Rubidium-strontium and samarium neodymium analytical data from the metamorphic rocks yield apparent ages of about 2.65 Ga within analytical error on isochron diagrams. Metamorphic rocks with mafic to ultramafic compositions are enriched in incompatible elements and have high Sr isotope ratios, resulting in some samples in improbable Nd model ages. This is attributed to enrichment of compatible elements and/or depletion of incompatible elements during metamorphism. We conclude that these metamorphic rocks experienced partial melting during UHT metamorphism. Pyroxene granulite was produced as a residual material after partial melting of LILE-enriched protoliths with high Sr isotope ratios. Report Antarc* Antarctica East Antarctica Enderby Land Polar geoscience National Institute of Polar Research Repository, Japan East Antarctica Napier ENVELOPE(-58.440,-58.440,-62.167,-62.167) Howard Hills ENVELOPE(51.167,51.167,-67.117,-67.117) |
institution |
Open Polar |
collection |
National Institute of Polar Research Repository, Japan |
op_collection_id |
ftnipr |
language |
English |
topic |
Howard Hills Napier Complex Sr-Nd isotope chemistry partial melting |
spellingShingle |
Howard Hills Napier Complex Sr-Nd isotope chemistry partial melting Tomoharu Miyamoto Yasutaka Yoshimura Kei Sato Yoichi Motoyoshi Daniel J. Dunkley Christopher J. Carson Occurrences of metamorphosed ultramafic rock and associating rocks in Howard Hills, Enderby Land, East Antarctica: Evidence of partial melting from geochemical and isotopic characteristics |
topic_facet |
Howard Hills Napier Complex Sr-Nd isotope chemistry partial melting |
description |
Large blocks of metamorphic rocks with mafic to ultramafic compositions were discovered in felsic gneiss at the central part of northern Howard Hills in Enderby Land. The ultramafic core is separated from the felsic gneiss by a mantle of pyroxene granulite. We can recognize from mineral assemblages and chemical compositions that the metamorphic rocks experienced ultrahigh temperature (UHT) metamorphism. Rubidium-strontium and samarium neodymium analytical data from the metamorphic rocks yield apparent ages of about 2.65 Ga within analytical error on isochron diagrams. Metamorphic rocks with mafic to ultramafic compositions are enriched in incompatible elements and have high Sr isotope ratios, resulting in some samples in improbable Nd model ages. This is attributed to enrichment of compatible elements and/or depletion of incompatible elements during metamorphism. We conclude that these metamorphic rocks experienced partial melting during UHT metamorphism. Pyroxene granulite was produced as a residual material after partial melting of LILE-enriched protoliths with high Sr isotope ratios. |
format |
Report |
author |
Tomoharu Miyamoto Yasutaka Yoshimura Kei Sato Yoichi Motoyoshi Daniel J. Dunkley Christopher J. Carson |
author_facet |
Tomoharu Miyamoto Yasutaka Yoshimura Kei Sato Yoichi Motoyoshi Daniel J. Dunkley Christopher J. Carson |
author_sort |
Tomoharu Miyamoto |
title |
Occurrences of metamorphosed ultramafic rock and associating rocks in Howard Hills, Enderby Land, East Antarctica: Evidence of partial melting from geochemical and isotopic characteristics |
title_short |
Occurrences of metamorphosed ultramafic rock and associating rocks in Howard Hills, Enderby Land, East Antarctica: Evidence of partial melting from geochemical and isotopic characteristics |
title_full |
Occurrences of metamorphosed ultramafic rock and associating rocks in Howard Hills, Enderby Land, East Antarctica: Evidence of partial melting from geochemical and isotopic characteristics |
title_fullStr |
Occurrences of metamorphosed ultramafic rock and associating rocks in Howard Hills, Enderby Land, East Antarctica: Evidence of partial melting from geochemical and isotopic characteristics |
title_full_unstemmed |
Occurrences of metamorphosed ultramafic rock and associating rocks in Howard Hills, Enderby Land, East Antarctica: Evidence of partial melting from geochemical and isotopic characteristics |
title_sort |
occurrences of metamorphosed ultramafic rock and associating rocks in howard hills, enderby land, east antarctica: evidence of partial melting from geochemical and isotopic characteristics |
publisher |
Department of Earth and Planetary Sciences, Kyushu University/Department of Natural Environmental Science, Kochi University/Division of Earth Sciences, Department of Biosphere-Geosphere Sciences, Ehime University/National Institute of Polar Research/National Institute of Polar Research/Geological Survey of Canada |
publishDate |
2004 |
url |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3138 http://id.nii.ac.jp/1291/00003138/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3138&item_no=1&attribute_id=18&file_no=1 |
long_lat |
ENVELOPE(-58.440,-58.440,-62.167,-62.167) ENVELOPE(51.167,51.167,-67.117,-67.117) |
geographic |
East Antarctica Napier Howard Hills |
geographic_facet |
East Antarctica Napier Howard Hills |
genre |
Antarc* Antarctica East Antarctica Enderby Land Polar geoscience |
genre_facet |
Antarc* Antarctica East Antarctica Enderby Land Polar geoscience |
op_relation |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3138 http://id.nii.ac.jp/1291/00003138/ AA1130866X Polar geoscience, 17, 88-111(2004-10) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3138&item_no=1&attribute_id=18&file_no=1 |
_version_ |
1766250366070947840 |