Tectono-metamorphic evolution and significance of shear-zone lithologies in Akebono Rock, Lützow-Holm Complex, East Antarctica
Abstract We describe a major shear zone exposed at Akebono Rock and discuss its deformation and metamorphic history, with a view to providing a better understanding of the geological history of the Lützow-Holm Complex. Three deformation episodes are recognized: D1 produced open folds (F1), boudinage...
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crcambridgeupr:10.1017/s0954102020000450 2024-03-03T08:38:51+00:00 Tectono-metamorphic evolution and significance of shear-zone lithologies in Akebono Rock, Lützow-Holm Complex, East Antarctica Baba, Sotaro Hokada, Tomokazu Kamei, Atsushi Kitano, Ippei Motoyoshi, Yoichi Nantasin, Prayath Setiawan, Nugroho Imam Dashbaatar, Davaa-Ochir 2020 http://dx.doi.org/10.1017/s0954102020000450 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102020000450 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Antarctic Science volume 33, issue 1, page 52-72 ISSN 0954-1020 1365-2079 Geology Ecology, Evolution, Behavior and Systematics Oceanography journal-article 2020 crcambridgeupr https://doi.org/10.1017/s0954102020000450 2024-02-08T08:34:01Z Abstract We describe a major shear zone exposed at Akebono Rock and discuss its deformation and metamorphic history, with a view to providing a better understanding of the geological history of the Lützow-Holm Complex. Three deformation episodes are recognized: D1 produced open folds (F1), boudinage and a regional ductile foliation, whilst the related metamorphic facies is characterized by stable garnet. F1 folding is dominantly preserved in the eastern part of the study area. During D2, an isoclinal to tight asymmetric F2 folds developed mainly in the west part of the region, accompanied by an S2 shear, under biotite facies retrograde metamorphism. The D3 episode involved the formation of the major shear zone, characterized by mylonite and L-tectonite fabrics, which took place at ~610–660°C and 4–5 kbar. Large, sigmoidal garnet core domains have S-shaped inclusion trails, suggesting that syntectonic garnet growth occurred before the formation of the shear zone. Estimated P-T conditions suggest that the sigmoidal garnet-bearing amphibolite was recrystallized at a deeper crustal level and was brought to a higher level during the formation of the shear zone. Crustal-scale deformation involving syntectonic recrystallization and shearing of Akebono Rock is a key issue for reconsidering the evolution of the Lützow-Holm Complex. Article in Journal/Newspaper Antarc* Antarctic Science Antarctica East Antarctica Cambridge University Press East Antarctica Akebono Rock ENVELOPE(42.950,42.950,-68.083,-68.083) Antarctic Science 33 1 52 72 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Geology Ecology, Evolution, Behavior and Systematics Oceanography |
spellingShingle |
Geology Ecology, Evolution, Behavior and Systematics Oceanography Baba, Sotaro Hokada, Tomokazu Kamei, Atsushi Kitano, Ippei Motoyoshi, Yoichi Nantasin, Prayath Setiawan, Nugroho Imam Dashbaatar, Davaa-Ochir Tectono-metamorphic evolution and significance of shear-zone lithologies in Akebono Rock, Lützow-Holm Complex, East Antarctica |
topic_facet |
Geology Ecology, Evolution, Behavior and Systematics Oceanography |
description |
Abstract We describe a major shear zone exposed at Akebono Rock and discuss its deformation and metamorphic history, with a view to providing a better understanding of the geological history of the Lützow-Holm Complex. Three deformation episodes are recognized: D1 produced open folds (F1), boudinage and a regional ductile foliation, whilst the related metamorphic facies is characterized by stable garnet. F1 folding is dominantly preserved in the eastern part of the study area. During D2, an isoclinal to tight asymmetric F2 folds developed mainly in the west part of the region, accompanied by an S2 shear, under biotite facies retrograde metamorphism. The D3 episode involved the formation of the major shear zone, characterized by mylonite and L-tectonite fabrics, which took place at ~610–660°C and 4–5 kbar. Large, sigmoidal garnet core domains have S-shaped inclusion trails, suggesting that syntectonic garnet growth occurred before the formation of the shear zone. Estimated P-T conditions suggest that the sigmoidal garnet-bearing amphibolite was recrystallized at a deeper crustal level and was brought to a higher level during the formation of the shear zone. Crustal-scale deformation involving syntectonic recrystallization and shearing of Akebono Rock is a key issue for reconsidering the evolution of the Lützow-Holm Complex. |
format |
Article in Journal/Newspaper |
author |
Baba, Sotaro Hokada, Tomokazu Kamei, Atsushi Kitano, Ippei Motoyoshi, Yoichi Nantasin, Prayath Setiawan, Nugroho Imam Dashbaatar, Davaa-Ochir |
author_facet |
Baba, Sotaro Hokada, Tomokazu Kamei, Atsushi Kitano, Ippei Motoyoshi, Yoichi Nantasin, Prayath Setiawan, Nugroho Imam Dashbaatar, Davaa-Ochir |
author_sort |
Baba, Sotaro |
title |
Tectono-metamorphic evolution and significance of shear-zone lithologies in Akebono Rock, Lützow-Holm Complex, East Antarctica |
title_short |
Tectono-metamorphic evolution and significance of shear-zone lithologies in Akebono Rock, Lützow-Holm Complex, East Antarctica |
title_full |
Tectono-metamorphic evolution and significance of shear-zone lithologies in Akebono Rock, Lützow-Holm Complex, East Antarctica |
title_fullStr |
Tectono-metamorphic evolution and significance of shear-zone lithologies in Akebono Rock, Lützow-Holm Complex, East Antarctica |
title_full_unstemmed |
Tectono-metamorphic evolution and significance of shear-zone lithologies in Akebono Rock, Lützow-Holm Complex, East Antarctica |
title_sort |
tectono-metamorphic evolution and significance of shear-zone lithologies in akebono rock, lützow-holm complex, east antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
2020 |
url |
http://dx.doi.org/10.1017/s0954102020000450 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102020000450 |
long_lat |
ENVELOPE(42.950,42.950,-68.083,-68.083) |
geographic |
East Antarctica Akebono Rock |
geographic_facet |
East Antarctica Akebono Rock |
genre |
Antarc* Antarctic Science Antarctica East Antarctica |
genre_facet |
Antarc* Antarctic Science Antarctica East Antarctica |
op_source |
Antarctic Science volume 33, issue 1, page 52-72 ISSN 0954-1020 1365-2079 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0954102020000450 |
container_title |
Antarctic Science |
container_volume |
33 |
container_issue |
1 |
container_start_page |
52 |
op_container_end_page |
72 |
_version_ |
1792507312659759104 |