A two-stage evolution of the Neoproterozoic Rayner Structural Episode: new U-Pb sensitive high resolution ion microprobe constraints from the Oygarden Group, Kemp Land, East Antarctica
U-Pb sensitive high resolution ion microprobe (SHRIMP) zircon analyses have been used to place time constraints on the Proterozoic reworking of Archaean rocks during the Rayner Structural Episode in the Oygarden Group of islands, Kemp Land, East Antarctica. Felsic orthogneiss that preserves evidence...
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ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/94239 2024-01-14T09:59:33+01:00 A two-stage evolution of the Neoproterozoic Rayner Structural Episode: new U-Pb sensitive high resolution ion microprobe constraints from the Oygarden Group, Kemp Land, East Antarctica Kelly, N M Clarke, G L Fanning, Christopher http://hdl.handle.net/1885/94239 https://doi.org/10.1016/S0301-9268(02)00028-1 https://openresearch-repository.anu.edu.au/bitstream/1885/94239/5/MigratedxPub23775_RSD_2002.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/94239/7/01_Kelly_A_two-stage_evolution_of_the_2002.pdf.jpg unknown Elsevier 0301-9268 http://hdl.handle.net/1885/94239 doi:10.1016/S0301-9268(02)00028-1 https://openresearch-repository.anu.edu.au/bitstream/1885/94239/5/MigratedxPub23775_RSD_2002.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/94239/7/01_Kelly_A_two-stage_evolution_of_the_2002.pdf.jpg Precambrian Research Keywords: lead uranium granulite facies ion microprobe metamorphism Proterozoic SHRIMP dating zircon analytic method Antarctica article evolution geology granite metamorphosis rock sampling Antarctica Eastern Ghats Rayner complex U-Pb geochronology Journal article ftanucanberra https://doi.org/10.1016/S0301-9268(02)00028-1 2023-12-15T09:37:58Z U-Pb sensitive high resolution ion microprobe (SHRIMP) zircon analyses have been used to place time constraints on the Proterozoic reworking of Archaean rocks during the Rayner Structural Episode in the Oygarden Group of islands, Kemp Land, East Antarctica. Felsic orthogneiss that preserves evidence for foliations that pre-date the Rayner Structural Episode, was deformed by two events during the Rayner Structural Episode: the first characterised by east-directed sub-horizontal thrusting, and the second by a regional scale south-dipping extensional shear zone. Metamorphic overgrowths on zircon grains from felsic orthogneiss, which have 929 ± 12 and 924 ± 17 Ma ages, are interpreted to have formed during granulite facies metamorphism that accompanied the thrusting event. Crystallisation of zircon in migmatite that also formed during this event, occurred in two stages: 904 ± 16 and 884 ± 24 Ma. Overgrowths on zircon in a pegmatite that intruded during the second event formed at 931 ± 14 Ma. Charnockite that was emplaced in the Stillwell Hills prior to a regional thrusting event, was metamorphosed at 913 ± 8 Ma. However, the distribution of isotopic data suggest the charnockite may have intruded at ca. 960 Ma. The ages for regional thrusting in the Oygarden Group and the Stillwell Hills correlate, suggesting that the Rayner Structural Episode did not affect Kemp Land until ca. 930 Ma. This age for peak metamorphism in Kemp Land is therefore 50 Myr younger than the age inferred for the Rayner Structural Episode further to the east on the Mawson Coast and south in the northern Prince Charles Mountains. The ages from the Oygarden rocks correlate with the second half of the orogenic episode seen on the Mawson Coast and northern Prince Charles Mountains, consistent with the possibility of two phases of collision in a transition from an Andean-style margin to continent-continent collision between 1000 and 900 Ma. Previously unreported ca. 1600-1650 Ma ages were also discovered in orthogneiss and pegmatite samples, ... Article in Journal/Newspaper Antarc* Antarctica East Antarctica Kemp Land Prince Charles Mountains Australian National University: ANU Digital Collections East Antarctica Prince Charles Mountains ENVELOPE(67.246,67.246,-71.427,-71.427) Rayner ENVELOPE(-45.166,-45.166,-60.650,-60.650) Kemp Land ENVELOPE(57.500,57.500,-67.500,-67.500) Mawson Coast ENVELOPE(63.000,63.000,-68.000,-68.000) Stillwell Hills ENVELOPE(59.467,59.467,-67.417,-67.417) Oygarden ENVELOPE(57.500,57.500,-66.900,-66.900) Oygarden Group ENVELOPE(57.500,57.500,-66.900,-66.900) Precambrian Research 116 3-4 307 330 |
institution |
Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
unknown |
topic |
Keywords: lead uranium granulite facies ion microprobe metamorphism Proterozoic SHRIMP dating zircon analytic method Antarctica article evolution geology granite metamorphosis rock sampling Antarctica Eastern Ghats Rayner complex U-Pb geochronology |
spellingShingle |
Keywords: lead uranium granulite facies ion microprobe metamorphism Proterozoic SHRIMP dating zircon analytic method Antarctica article evolution geology granite metamorphosis rock sampling Antarctica Eastern Ghats Rayner complex U-Pb geochronology Kelly, N M Clarke, G L Fanning, Christopher A two-stage evolution of the Neoproterozoic Rayner Structural Episode: new U-Pb sensitive high resolution ion microprobe constraints from the Oygarden Group, Kemp Land, East Antarctica |
topic_facet |
Keywords: lead uranium granulite facies ion microprobe metamorphism Proterozoic SHRIMP dating zircon analytic method Antarctica article evolution geology granite metamorphosis rock sampling Antarctica Eastern Ghats Rayner complex U-Pb geochronology |
description |
U-Pb sensitive high resolution ion microprobe (SHRIMP) zircon analyses have been used to place time constraints on the Proterozoic reworking of Archaean rocks during the Rayner Structural Episode in the Oygarden Group of islands, Kemp Land, East Antarctica. Felsic orthogneiss that preserves evidence for foliations that pre-date the Rayner Structural Episode, was deformed by two events during the Rayner Structural Episode: the first characterised by east-directed sub-horizontal thrusting, and the second by a regional scale south-dipping extensional shear zone. Metamorphic overgrowths on zircon grains from felsic orthogneiss, which have 929 ± 12 and 924 ± 17 Ma ages, are interpreted to have formed during granulite facies metamorphism that accompanied the thrusting event. Crystallisation of zircon in migmatite that also formed during this event, occurred in two stages: 904 ± 16 and 884 ± 24 Ma. Overgrowths on zircon in a pegmatite that intruded during the second event formed at 931 ± 14 Ma. Charnockite that was emplaced in the Stillwell Hills prior to a regional thrusting event, was metamorphosed at 913 ± 8 Ma. However, the distribution of isotopic data suggest the charnockite may have intruded at ca. 960 Ma. The ages for regional thrusting in the Oygarden Group and the Stillwell Hills correlate, suggesting that the Rayner Structural Episode did not affect Kemp Land until ca. 930 Ma. This age for peak metamorphism in Kemp Land is therefore 50 Myr younger than the age inferred for the Rayner Structural Episode further to the east on the Mawson Coast and south in the northern Prince Charles Mountains. The ages from the Oygarden rocks correlate with the second half of the orogenic episode seen on the Mawson Coast and northern Prince Charles Mountains, consistent with the possibility of two phases of collision in a transition from an Andean-style margin to continent-continent collision between 1000 and 900 Ma. Previously unreported ca. 1600-1650 Ma ages were also discovered in orthogneiss and pegmatite samples, ... |
format |
Article in Journal/Newspaper |
author |
Kelly, N M Clarke, G L Fanning, Christopher |
author_facet |
Kelly, N M Clarke, G L Fanning, Christopher |
author_sort |
Kelly, N M |
title |
A two-stage evolution of the Neoproterozoic Rayner Structural Episode: new U-Pb sensitive high resolution ion microprobe constraints from the Oygarden Group, Kemp Land, East Antarctica |
title_short |
A two-stage evolution of the Neoproterozoic Rayner Structural Episode: new U-Pb sensitive high resolution ion microprobe constraints from the Oygarden Group, Kemp Land, East Antarctica |
title_full |
A two-stage evolution of the Neoproterozoic Rayner Structural Episode: new U-Pb sensitive high resolution ion microprobe constraints from the Oygarden Group, Kemp Land, East Antarctica |
title_fullStr |
A two-stage evolution of the Neoproterozoic Rayner Structural Episode: new U-Pb sensitive high resolution ion microprobe constraints from the Oygarden Group, Kemp Land, East Antarctica |
title_full_unstemmed |
A two-stage evolution of the Neoproterozoic Rayner Structural Episode: new U-Pb sensitive high resolution ion microprobe constraints from the Oygarden Group, Kemp Land, East Antarctica |
title_sort |
two-stage evolution of the neoproterozoic rayner structural episode: new u-pb sensitive high resolution ion microprobe constraints from the oygarden group, kemp land, east antarctica |
publisher |
Elsevier |
url |
http://hdl.handle.net/1885/94239 https://doi.org/10.1016/S0301-9268(02)00028-1 https://openresearch-repository.anu.edu.au/bitstream/1885/94239/5/MigratedxPub23775_RSD_2002.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/94239/7/01_Kelly_A_two-stage_evolution_of_the_2002.pdf.jpg |
long_lat |
ENVELOPE(67.246,67.246,-71.427,-71.427) ENVELOPE(-45.166,-45.166,-60.650,-60.650) ENVELOPE(57.500,57.500,-67.500,-67.500) ENVELOPE(63.000,63.000,-68.000,-68.000) ENVELOPE(59.467,59.467,-67.417,-67.417) ENVELOPE(57.500,57.500,-66.900,-66.900) ENVELOPE(57.500,57.500,-66.900,-66.900) |
geographic |
East Antarctica Prince Charles Mountains Rayner Kemp Land Mawson Coast Stillwell Hills Oygarden Oygarden Group |
geographic_facet |
East Antarctica Prince Charles Mountains Rayner Kemp Land Mawson Coast Stillwell Hills Oygarden Oygarden Group |
genre |
Antarc* Antarctica East Antarctica Kemp Land Prince Charles Mountains |
genre_facet |
Antarc* Antarctica East Antarctica Kemp Land Prince Charles Mountains |
op_source |
Precambrian Research |
op_relation |
0301-9268 http://hdl.handle.net/1885/94239 doi:10.1016/S0301-9268(02)00028-1 https://openresearch-repository.anu.edu.au/bitstream/1885/94239/5/MigratedxPub23775_RSD_2002.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/94239/7/01_Kelly_A_two-stage_evolution_of_the_2002.pdf.jpg |
op_doi |
https://doi.org/10.1016/S0301-9268(02)00028-1 |
container_title |
Precambrian Research |
container_volume |
116 |
container_issue |
3-4 |
container_start_page |
307 |
op_container_end_page |
330 |
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1788059660030312448 |