Ultramafic to mafic granulites from the Larsemann Hills, East Antarctica: Geochemistry and tectonic implications
International audience The Larsemann Hills area is part of a reworked early Neoproterozoic metamorphic terrain in southwestern Prydz Bay, East Antarctica. Ultramafic and mafic granulites, whose origins remain controversial, occur as lenses, boudins or layered bodies within the para- and ortho-gneiss...
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ftccsdartic:oai:HAL:hal-01622589v1 2023-05-15T13:32:58+02:00 Ultramafic to mafic granulites from the Larsemann Hills, East Antarctica: Geochemistry and tectonic implications Tong, Laixi Jahn, Bor-Ming Liu, Xiaohan Liang, Xirong Xu, Yi-gang IONOV, Dmitri Guangzhou Institute of Geochemistry National Taiwan University Institute of Tibetan Plateau, Beijing Géosciences Montpellier Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS) 2017-09-01 https://hal.archives-ouvertes.fr/hal-01622589 https://doi.org/10.1016/j.jseaes.2017.06.012 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jseaes.2017.06.012 hal-01622589 https://hal.archives-ouvertes.fr/hal-01622589 doi:10.1016/j.jseaes.2017.06.012 ISSN: 0743-9547 Journal of Southeast Asian earth sciences https://hal.archives-ouvertes.fr/hal-01622589 Journal of Southeast Asian earth sciences, Elsevier, 2017, 145, pp.679-690. ⟨10.1016/j.jseaes.2017.06.012⟩ Ultramafic to mafic granulites Geochemistry Rayner orogeny Larsemann Hills East Antarctica [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry info:eu-repo/semantics/article Journal articles 2017 ftccsdartic https://doi.org/10.1016/j.jseaes.2017.06.012 2021-11-07T03:36:34Z International audience The Larsemann Hills area is part of a reworked early Neoproterozoic metamorphic terrain in southwestern Prydz Bay, East Antarctica. Ultramafic and mafic granulites, whose origins remain controversial, occur as lenses, boudins or layered bodies within the para- and ortho-gneiss in the region. The ultramafic and mafic granulites show spinel-olivine-bearing and two-pyroxene-bearing mineral assemblages recrystallized at 860–900 °C. Their bulk rock analyses indicate an origin as igneous cumulates, with high Mg# (molar MgO/(MgO + FeO)) from 0.73 to 0.84 for ultramafic granulite and from 0.46 to 0.78 for mostly mafic granulite as well as high Cr and Ni contents ([Cr] and [Ni] up to 1826 ppm and 1400 ppm respectively for ultramafic granulite and [Cr] of 1460 ppm for mafic granulite). Trace element patterns show pronounced negative Nb anomalies, suggesting a subduction-related tectonic setting for their precursors, consistent with derivation from arc basalts, also suggested by low TiO2 and K-enrichment in mafic granulites. The ultramafic to mafic granulites may have been formed in a subduction-related continental back-arc basin environment simultaneously with peak metamorphism associated with arc-continent collision during the early Neoproterozoic (990–900 Ma) Rayner orogeny. Article in Journal/Newspaper Antarc* Antarctica East Antarctica Prydz Bay Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) East Antarctica Larsemann Hills ENVELOPE(76.217,76.217,-69.400,-69.400) Prydz Bay Rayner ENVELOPE(-45.166,-45.166,-60.650,-60.650) Journal of Asian Earth Sciences 145 679 690 |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
Ultramafic to mafic granulites Geochemistry Rayner orogeny Larsemann Hills East Antarctica [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry |
spellingShingle |
Ultramafic to mafic granulites Geochemistry Rayner orogeny Larsemann Hills East Antarctica [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry Tong, Laixi Jahn, Bor-Ming Liu, Xiaohan Liang, Xirong Xu, Yi-gang IONOV, Dmitri Ultramafic to mafic granulites from the Larsemann Hills, East Antarctica: Geochemistry and tectonic implications |
topic_facet |
Ultramafic to mafic granulites Geochemistry Rayner orogeny Larsemann Hills East Antarctica [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry |
description |
International audience The Larsemann Hills area is part of a reworked early Neoproterozoic metamorphic terrain in southwestern Prydz Bay, East Antarctica. Ultramafic and mafic granulites, whose origins remain controversial, occur as lenses, boudins or layered bodies within the para- and ortho-gneiss in the region. The ultramafic and mafic granulites show spinel-olivine-bearing and two-pyroxene-bearing mineral assemblages recrystallized at 860–900 °C. Their bulk rock analyses indicate an origin as igneous cumulates, with high Mg# (molar MgO/(MgO + FeO)) from 0.73 to 0.84 for ultramafic granulite and from 0.46 to 0.78 for mostly mafic granulite as well as high Cr and Ni contents ([Cr] and [Ni] up to 1826 ppm and 1400 ppm respectively for ultramafic granulite and [Cr] of 1460 ppm for mafic granulite). Trace element patterns show pronounced negative Nb anomalies, suggesting a subduction-related tectonic setting for their precursors, consistent with derivation from arc basalts, also suggested by low TiO2 and K-enrichment in mafic granulites. The ultramafic to mafic granulites may have been formed in a subduction-related continental back-arc basin environment simultaneously with peak metamorphism associated with arc-continent collision during the early Neoproterozoic (990–900 Ma) Rayner orogeny. |
author2 |
Guangzhou Institute of Geochemistry National Taiwan University Institute of Tibetan Plateau, Beijing Géosciences Montpellier Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Tong, Laixi Jahn, Bor-Ming Liu, Xiaohan Liang, Xirong Xu, Yi-gang IONOV, Dmitri |
author_facet |
Tong, Laixi Jahn, Bor-Ming Liu, Xiaohan Liang, Xirong Xu, Yi-gang IONOV, Dmitri |
author_sort |
Tong, Laixi |
title |
Ultramafic to mafic granulites from the Larsemann Hills, East Antarctica: Geochemistry and tectonic implications |
title_short |
Ultramafic to mafic granulites from the Larsemann Hills, East Antarctica: Geochemistry and tectonic implications |
title_full |
Ultramafic to mafic granulites from the Larsemann Hills, East Antarctica: Geochemistry and tectonic implications |
title_fullStr |
Ultramafic to mafic granulites from the Larsemann Hills, East Antarctica: Geochemistry and tectonic implications |
title_full_unstemmed |
Ultramafic to mafic granulites from the Larsemann Hills, East Antarctica: Geochemistry and tectonic implications |
title_sort |
ultramafic to mafic granulites from the larsemann hills, east antarctica: geochemistry and tectonic implications |
publisher |
HAL CCSD |
publishDate |
2017 |
url |
https://hal.archives-ouvertes.fr/hal-01622589 https://doi.org/10.1016/j.jseaes.2017.06.012 |
long_lat |
ENVELOPE(76.217,76.217,-69.400,-69.400) ENVELOPE(-45.166,-45.166,-60.650,-60.650) |
geographic |
East Antarctica Larsemann Hills Prydz Bay Rayner |
geographic_facet |
East Antarctica Larsemann Hills Prydz Bay Rayner |
genre |
Antarc* Antarctica East Antarctica Prydz Bay |
genre_facet |
Antarc* Antarctica East Antarctica Prydz Bay |
op_source |
ISSN: 0743-9547 Journal of Southeast Asian earth sciences https://hal.archives-ouvertes.fr/hal-01622589 Journal of Southeast Asian earth sciences, Elsevier, 2017, 145, pp.679-690. ⟨10.1016/j.jseaes.2017.06.012⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jseaes.2017.06.012 hal-01622589 https://hal.archives-ouvertes.fr/hal-01622589 doi:10.1016/j.jseaes.2017.06.012 |
op_doi |
https://doi.org/10.1016/j.jseaes.2017.06.012 |
container_title |
Journal of Asian Earth Sciences |
container_volume |
145 |
container_start_page |
679 |
op_container_end_page |
690 |
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1766037278748049408 |