Geochronological study of post-metamorphic granite from Kasumi Rock, Lutzow-Holm Complex, East Antarctica
Kasumi Rock is situated in the amphibolite-facies metamorphic zone in the Lutzow-Holm Complex, East Antarctica. In this area, granitic rocks occur as steeply dipping linear dykes with sharp intrusive contacts, and cross-cut the foliation of layered metamorphic rocks. A geochronological study of this...
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Graduate School of Education, Saga University/Faculty of Culture and Education, Saga University/Faculty of Education, Okayama University/Department of Earth and Planetary Sciences, Graduate School of Science, Kyushu University
2004
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ftnipr:oai:nipr.repo.nii.ac.jp:00003135 2023-05-15T13:49:00+02:00 Geochronological study of post-metamorphic granite from Kasumi Rock, Lutzow-Holm Complex, East Antarctica Ajishi,Hideaki Kawano,Yoshinobu Kawakami,Tetsuo Ikeda,Takeshi 2004-10 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3135 http://id.nii.ac.jp/1291/00003135/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3135&item_no=1&attribute_id=18&file_no=1 en eng Graduate School of Education, Saga University/Faculty of Culture and Education, Saga University/Faculty of Education, Okayama University/Department of Earth and Planetary Sciences, Graduate School of Science, Kyushu University National Institute of Polar Research https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3135 http://id.nii.ac.jp/1291/00003135/ AA1130866X Polar geoscience, 17, 35-44(2004-10) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3135&item_no=1&attribute_id=18&file_no=1 Rb-Sr whole rock isochron Sm-Nd whole rock isochron post-metamorphic granite Kasumi Rock Lutzow-Holm Complex Departmental Bulletin Paper P(論文) 2004 ftnipr 2022-12-03T19:43:04Z Kasumi Rock is situated in the amphibolite-facies metamorphic zone in the Lutzow-Holm Complex, East Antarctica. In this area, granitic rocks occur as steeply dipping linear dykes with sharp intrusive contacts, and cross-cut the foliation of layered metamorphic rocks. A geochronological study of this post-metamorphic granite (PMG) has been performed. An Rb-Sr whole rock isochron for five granitic rocks defines an age of 492.1+-23.4 Ma with an initial ^87Sr/^86Sr ratio of 0.70535+-0.00027 (MSWD=0.08). In the Sm-Nd isochron diagram, four rock samples yield an age of 498.4+-90.6 Ma with an initial ^143Nd/^144Nd ratio of 0.511782+-0.000101 (MSWD=0.05). The whole rock isochron ages and mode of occurrence suggest that the Kasumi PMGs were intruded after regional cooling of the area, and probably affected local reequilibrium for isotopic systems of surrounding metamorphic rocks. The PMGs might have been slowly cooled and crystallized after the intrusion. The Kasumi PMGs have no genetic relation to the Oku-iwa PMGs as regards Rb-Sr and Sm-Nd isotopic systems, because the initial ratios of both PMGs are quite different from each other. This is interpreted to mean that the PMGs in the Lutzow-Holm Complex were originated from different source materials or had different chemical reaction processes with crustal materials. Report Antarc* Antarctica East Antarctica Polar geoscience National Institute of Polar Research Repository, Japan East Antarctica Kasumi Rock ENVELOPE(42.250,42.250,-68.383,-68.383) Oku-iwa ENVELOPE(40.833,40.833,-68.717,-68.717) |
institution |
Open Polar |
collection |
National Institute of Polar Research Repository, Japan |
op_collection_id |
ftnipr |
language |
English |
topic |
Rb-Sr whole rock isochron Sm-Nd whole rock isochron post-metamorphic granite Kasumi Rock Lutzow-Holm Complex |
spellingShingle |
Rb-Sr whole rock isochron Sm-Nd whole rock isochron post-metamorphic granite Kasumi Rock Lutzow-Holm Complex Ajishi,Hideaki Kawano,Yoshinobu Kawakami,Tetsuo Ikeda,Takeshi Geochronological study of post-metamorphic granite from Kasumi Rock, Lutzow-Holm Complex, East Antarctica |
topic_facet |
Rb-Sr whole rock isochron Sm-Nd whole rock isochron post-metamorphic granite Kasumi Rock Lutzow-Holm Complex |
description |
Kasumi Rock is situated in the amphibolite-facies metamorphic zone in the Lutzow-Holm Complex, East Antarctica. In this area, granitic rocks occur as steeply dipping linear dykes with sharp intrusive contacts, and cross-cut the foliation of layered metamorphic rocks. A geochronological study of this post-metamorphic granite (PMG) has been performed. An Rb-Sr whole rock isochron for five granitic rocks defines an age of 492.1+-23.4 Ma with an initial ^87Sr/^86Sr ratio of 0.70535+-0.00027 (MSWD=0.08). In the Sm-Nd isochron diagram, four rock samples yield an age of 498.4+-90.6 Ma with an initial ^143Nd/^144Nd ratio of 0.511782+-0.000101 (MSWD=0.05). The whole rock isochron ages and mode of occurrence suggest that the Kasumi PMGs were intruded after regional cooling of the area, and probably affected local reequilibrium for isotopic systems of surrounding metamorphic rocks. The PMGs might have been slowly cooled and crystallized after the intrusion. The Kasumi PMGs have no genetic relation to the Oku-iwa PMGs as regards Rb-Sr and Sm-Nd isotopic systems, because the initial ratios of both PMGs are quite different from each other. This is interpreted to mean that the PMGs in the Lutzow-Holm Complex were originated from different source materials or had different chemical reaction processes with crustal materials. |
format |
Report |
author |
Ajishi,Hideaki Kawano,Yoshinobu Kawakami,Tetsuo Ikeda,Takeshi |
author_facet |
Ajishi,Hideaki Kawano,Yoshinobu Kawakami,Tetsuo Ikeda,Takeshi |
author_sort |
Ajishi,Hideaki |
title |
Geochronological study of post-metamorphic granite from Kasumi Rock, Lutzow-Holm Complex, East Antarctica |
title_short |
Geochronological study of post-metamorphic granite from Kasumi Rock, Lutzow-Holm Complex, East Antarctica |
title_full |
Geochronological study of post-metamorphic granite from Kasumi Rock, Lutzow-Holm Complex, East Antarctica |
title_fullStr |
Geochronological study of post-metamorphic granite from Kasumi Rock, Lutzow-Holm Complex, East Antarctica |
title_full_unstemmed |
Geochronological study of post-metamorphic granite from Kasumi Rock, Lutzow-Holm Complex, East Antarctica |
title_sort |
geochronological study of post-metamorphic granite from kasumi rock, lutzow-holm complex, east antarctica |
publisher |
Graduate School of Education, Saga University/Faculty of Culture and Education, Saga University/Faculty of Education, Okayama University/Department of Earth and Planetary Sciences, Graduate School of Science, Kyushu University |
publishDate |
2004 |
url |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3135 http://id.nii.ac.jp/1291/00003135/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3135&item_no=1&attribute_id=18&file_no=1 |
long_lat |
ENVELOPE(42.250,42.250,-68.383,-68.383) ENVELOPE(40.833,40.833,-68.717,-68.717) |
geographic |
East Antarctica Kasumi Rock Oku-iwa |
geographic_facet |
East Antarctica Kasumi Rock Oku-iwa |
genre |
Antarc* Antarctica East Antarctica Polar geoscience |
genre_facet |
Antarc* Antarctica East Antarctica Polar geoscience |
op_relation |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3135 http://id.nii.ac.jp/1291/00003135/ AA1130866X Polar geoscience, 17, 35-44(2004-10) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3135&item_no=1&attribute_id=18&file_no=1 |
_version_ |
1766250365324361728 |