Poly-phase metamorphism of garnet-bearing mafic granulite from the Larsemann Hills, East Antarctica: P-T path, U-Pb ages and tectonic implications
A rare garnet-bearing mafic granulite boulder has recently been identified from the Larsemann Hills, East Antarctica, with the development of two-stage decompression textures. Detailed petrographic study and P-T estimates suggest three distinct metamorphic stages: (1) peak ultrahigh-temperature (UHT...
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Online Access: | http://ir.gig.ac.cn/handle/344008/50481 https://doi.org/10.1016/j.precamres.2017.12.045 |
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ftchacadscgigcas:oai:ir.gig.ac.cn:344008/50481 2023-05-15T13:30:35+02:00 Poly-phase metamorphism of garnet-bearing mafic granulite from the Larsemann Hills, East Antarctica: P-T path, U-Pb ages and tectonic implications Tong, Laixi Liu, Zhao Li, Zheng-Xiang Liu, Xiaohan Zhou, Xin 2019-06-15 http://ir.gig.ac.cn/handle/344008/50481 https://doi.org/10.1016/j.precamres.2017.12.045 英语 eng ELSEVIER SCIENCE BV PRECAMBRIAN RESEARCH http://ir.gig.ac.cn/handle/344008/50481 doi:10.1016/j.precamres.2017.12.045 Geology Garnet-bearing mafic granulite Poly-phase metamorphism P-T path Zircon U-Pb ages Larsemann Hills East Antarctica Geosciences Multidisciplinary PRINCE-CHARLES MOUNTAINS PRYDZ-BAY FACIES METAMORPHISM BRATTSTRAND BLUFFS RAUER GROUP CONSTRAINTS EVOLUTION TEMPERATURE AREA GEOCHEMISTRY 期刊论文 2019 ftchacadscgigcas https://doi.org/10.1016/j.precamres.2017.12.045 2020-12-22T07:22:33Z A rare garnet-bearing mafic granulite boulder has recently been identified from the Larsemann Hills, East Antarctica, with the development of two-stage decompression textures. Detailed petrographic study and P-T estimates suggest three distinct metamorphic stages: (1) peak ultrahigh-temperature (UHT) stage (M1) represented by coarse-grained garnet-orthopyroxene-bearing porphyroblastic assemblage, with P-T conditions of similar to 9.3 kbar and 900-950 degrees C; (2) post-peak decompression stage I (M2) represented by relatively coarse-grained orthopyroxene-plagioclase-ilmenite-bearing corona assemblage, with P-T conditions of 7.2-7.6 kbar and 810-830 degrees C; and (3) post-peak decompression stage II (M3) represented by fine-grained orthopyroxene-plagioclase-ilmenite-bearing symplectite assemblage on garnets and along garnet cracks, with P-T conditions of 6.2-6.9 kbar and 730-770 degrees C. Combined with P-T pseudosection calculation in the NCKFMASHTO system, these P-T data define a clockwise P-T path with post-peak two-stage decompression accompanied by important cooling. LA-ICP-MS zircon U-Pb age dating results show two weighted mean ages of 927 +/- 13 Ma and 547 +/- 30 Ma, suggesting that M1 UHT stage occurred in the early Neoproterozoic Rayner orogeny (990-900 Ma), whereas M2-M3 stages occurred during the early Palaeozoic Pan-African tectonic event (550-500 Ma). The peak P-T conditions, post-peak two-stage decompression P-T path and age data resemble those of the early Neoproterozoic garnet-bearing mafic granulite on Sostrene Island. It is inferred that the mafic granulite boulder may have been derived from the bedrock under inland ice sheet of the Larsemann Hills. Thus, the early Neoproterozoic metamorphism (M1) may reflect crustal thickening followed by post-orogenic extension likely associated with the assembly of Rodinia continent, while the overprinting of early Palaeozoic metamorphism (M2-M3) may reflect an extensive intra-continental reworking. Report Antarc* Antarctica East Antarctica Ice Sheet Prince Charles Mountains Prydz Bay Guangzhou Institute of Geochemistry: GIG OpenIR (Chinese Academy of Sciences) Brattstrand Bluffs ENVELOPE(77.020,77.020,-69.208,-69.208) East Antarctica Larsemann Hills ENVELOPE(76.217,76.217,-69.400,-69.400) Prince Charles Mountains ENVELOPE(67.246,67.246,-71.427,-71.427) Prydz Bay Rauer Group ENVELOPE(77.833,77.833,-68.850,-68.850) Rayner ENVELOPE(-45.166,-45.166,-60.650,-60.650) Sostrene ENVELOPE(75.503,75.503,-69.588,-69.588) Precambrian Research 326 385 398 |
institution |
Open Polar |
collection |
Guangzhou Institute of Geochemistry: GIG OpenIR (Chinese Academy of Sciences) |
op_collection_id |
ftchacadscgigcas |
language |
English |
topic |
Geology Garnet-bearing mafic granulite Poly-phase metamorphism P-T path Zircon U-Pb ages Larsemann Hills East Antarctica Geosciences Multidisciplinary PRINCE-CHARLES MOUNTAINS PRYDZ-BAY FACIES METAMORPHISM BRATTSTRAND BLUFFS RAUER GROUP CONSTRAINTS EVOLUTION TEMPERATURE AREA GEOCHEMISTRY |
spellingShingle |
Geology Garnet-bearing mafic granulite Poly-phase metamorphism P-T path Zircon U-Pb ages Larsemann Hills East Antarctica Geosciences Multidisciplinary PRINCE-CHARLES MOUNTAINS PRYDZ-BAY FACIES METAMORPHISM BRATTSTRAND BLUFFS RAUER GROUP CONSTRAINTS EVOLUTION TEMPERATURE AREA GEOCHEMISTRY Tong, Laixi Liu, Zhao Li, Zheng-Xiang Liu, Xiaohan Zhou, Xin Poly-phase metamorphism of garnet-bearing mafic granulite from the Larsemann Hills, East Antarctica: P-T path, U-Pb ages and tectonic implications |
topic_facet |
Geology Garnet-bearing mafic granulite Poly-phase metamorphism P-T path Zircon U-Pb ages Larsemann Hills East Antarctica Geosciences Multidisciplinary PRINCE-CHARLES MOUNTAINS PRYDZ-BAY FACIES METAMORPHISM BRATTSTRAND BLUFFS RAUER GROUP CONSTRAINTS EVOLUTION TEMPERATURE AREA GEOCHEMISTRY |
description |
A rare garnet-bearing mafic granulite boulder has recently been identified from the Larsemann Hills, East Antarctica, with the development of two-stage decompression textures. Detailed petrographic study and P-T estimates suggest three distinct metamorphic stages: (1) peak ultrahigh-temperature (UHT) stage (M1) represented by coarse-grained garnet-orthopyroxene-bearing porphyroblastic assemblage, with P-T conditions of similar to 9.3 kbar and 900-950 degrees C; (2) post-peak decompression stage I (M2) represented by relatively coarse-grained orthopyroxene-plagioclase-ilmenite-bearing corona assemblage, with P-T conditions of 7.2-7.6 kbar and 810-830 degrees C; and (3) post-peak decompression stage II (M3) represented by fine-grained orthopyroxene-plagioclase-ilmenite-bearing symplectite assemblage on garnets and along garnet cracks, with P-T conditions of 6.2-6.9 kbar and 730-770 degrees C. Combined with P-T pseudosection calculation in the NCKFMASHTO system, these P-T data define a clockwise P-T path with post-peak two-stage decompression accompanied by important cooling. LA-ICP-MS zircon U-Pb age dating results show two weighted mean ages of 927 +/- 13 Ma and 547 +/- 30 Ma, suggesting that M1 UHT stage occurred in the early Neoproterozoic Rayner orogeny (990-900 Ma), whereas M2-M3 stages occurred during the early Palaeozoic Pan-African tectonic event (550-500 Ma). The peak P-T conditions, post-peak two-stage decompression P-T path and age data resemble those of the early Neoproterozoic garnet-bearing mafic granulite on Sostrene Island. It is inferred that the mafic granulite boulder may have been derived from the bedrock under inland ice sheet of the Larsemann Hills. Thus, the early Neoproterozoic metamorphism (M1) may reflect crustal thickening followed by post-orogenic extension likely associated with the assembly of Rodinia continent, while the overprinting of early Palaeozoic metamorphism (M2-M3) may reflect an extensive intra-continental reworking. |
format |
Report |
author |
Tong, Laixi Liu, Zhao Li, Zheng-Xiang Liu, Xiaohan Zhou, Xin |
author_facet |
Tong, Laixi Liu, Zhao Li, Zheng-Xiang Liu, Xiaohan Zhou, Xin |
author_sort |
Tong, Laixi |
title |
Poly-phase metamorphism of garnet-bearing mafic granulite from the Larsemann Hills, East Antarctica: P-T path, U-Pb ages and tectonic implications |
title_short |
Poly-phase metamorphism of garnet-bearing mafic granulite from the Larsemann Hills, East Antarctica: P-T path, U-Pb ages and tectonic implications |
title_full |
Poly-phase metamorphism of garnet-bearing mafic granulite from the Larsemann Hills, East Antarctica: P-T path, U-Pb ages and tectonic implications |
title_fullStr |
Poly-phase metamorphism of garnet-bearing mafic granulite from the Larsemann Hills, East Antarctica: P-T path, U-Pb ages and tectonic implications |
title_full_unstemmed |
Poly-phase metamorphism of garnet-bearing mafic granulite from the Larsemann Hills, East Antarctica: P-T path, U-Pb ages and tectonic implications |
title_sort |
poly-phase metamorphism of garnet-bearing mafic granulite from the larsemann hills, east antarctica: p-t path, u-pb ages and tectonic implications |
publisher |
ELSEVIER SCIENCE BV |
publishDate |
2019 |
url |
http://ir.gig.ac.cn/handle/344008/50481 https://doi.org/10.1016/j.precamres.2017.12.045 |
long_lat |
ENVELOPE(77.020,77.020,-69.208,-69.208) ENVELOPE(76.217,76.217,-69.400,-69.400) ENVELOPE(67.246,67.246,-71.427,-71.427) ENVELOPE(77.833,77.833,-68.850,-68.850) ENVELOPE(-45.166,-45.166,-60.650,-60.650) ENVELOPE(75.503,75.503,-69.588,-69.588) |
geographic |
Brattstrand Bluffs East Antarctica Larsemann Hills Prince Charles Mountains Prydz Bay Rauer Group Rayner Sostrene |
geographic_facet |
Brattstrand Bluffs East Antarctica Larsemann Hills Prince Charles Mountains Prydz Bay Rauer Group Rayner Sostrene |
genre |
Antarc* Antarctica East Antarctica Ice Sheet Prince Charles Mountains Prydz Bay |
genre_facet |
Antarc* Antarctica East Antarctica Ice Sheet Prince Charles Mountains Prydz Bay |
op_relation |
PRECAMBRIAN RESEARCH http://ir.gig.ac.cn/handle/344008/50481 doi:10.1016/j.precamres.2017.12.045 |
op_doi |
https://doi.org/10.1016/j.precamres.2017.12.045 |
container_title |
Precambrian Research |
container_volume |
326 |
container_start_page |
385 |
op_container_end_page |
398 |
_version_ |
1766010506201530368 |