Archaean crust in the Rayner Complex of east Antarctica: Oygarden Group of islands, Kemp Land
Archaean zircon grains from the Oygarden Group of islands in Kemp Land, east Antarctica, record evidence for multiple episodes of recrystallisation, dissolution and growth from the Early to Middle Archaean to the Neoproterozoic. Zircon grains in layered felsic orthogneiss have an age of ∼ 3650 Ma, a...
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ftanucanberra:oai:digitalcollections.anu.edu.au:1885/84048 2023-05-15T13:56:14+02:00 Archaean crust in the Rayner Complex of east Antarctica: Oygarden Group of islands, Kemp Land Kelly, N M Clarke, G L Fanning, Christopher 2015-12-13T23:00:16Z http://hdl.handle.net/1885/84048 unknown Royal Society of Edinburgh 0263-5933 http://hdl.handle.net/1885/84048 Transactions of the Royal Society of Edinburgh: Earth Sciences Keywords: Archean granulite uranium-lead dating Antarctica Arctic and Antarctic East Antarctica World Granulite facies Pb-loss Recrystallisation U-Pb geochronology Zircon Journal article 2015 ftanucanberra 2015-12-21T23:54:40Z Archaean zircon grains from the Oygarden Group of islands in Kemp Land, east Antarctica, record evidence for multiple episodes of recrystallisation, dissolution and growth from the Early to Middle Archaean to the Neoproterozoic. Zircon grains in layered felsic orthogneiss have an age of ∼ 3650 Ma, a minimum protolith age for this rock. These zircon grains were subsequently affected by a ∼ 3470 Ma Pb-loss event. Homogeneous felsic orthogneiss that cuts S1, but contains an intense S2, foliation, has disturbed ∼ 2780 Ma metamorphic zircon cores and rims that suggest a minimum age of ∼ 2780 Ma for the protolith to the orthogneiss. All zircon U-Pb data display considerable disturbance with further Pb-loss at ∼ 2400 Ma and ∼ 1600 Ma, and a major episode of isotopic resetting at ∼ 930 Ma. The highly disturbed data are related to complexly zoned zircon grains that developed through growth and modification during successive metamorphic events. Zircon cores with relic growth zoning patterns are inferred to have resulted from partial annealing or recrystallisation of older magmatic zircon. Highly luminescent zircon rims that embay cores along curved boundaries are interpreted to have formed through recrystallisation of zircon cores, and not new growth. The ages reported here confirm that central Kemp Land is composed of Archaean crust reworked during the Neoproterozoic Rayner Structural Episode. Article in Journal/Newspaper Antarc* Antarctic Antarctica Arctic East Antarctica Kemp Land Australian National University: ANU Digital Collections Antarctic Arctic East Antarctica Kemp Land ENVELOPE(57.500,57.500,-67.500,-67.500) Oygarden ENVELOPE(57.500,57.500,-66.900,-66.900) Oygarden Group ENVELOPE(57.500,57.500,-66.900,-66.900) Rayner ENVELOPE(-45.166,-45.166,-60.650,-60.650) |
institution |
Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
unknown |
topic |
Keywords: Archean granulite uranium-lead dating Antarctica Arctic and Antarctic East Antarctica World Granulite facies Pb-loss Recrystallisation U-Pb geochronology Zircon |
spellingShingle |
Keywords: Archean granulite uranium-lead dating Antarctica Arctic and Antarctic East Antarctica World Granulite facies Pb-loss Recrystallisation U-Pb geochronology Zircon Kelly, N M Clarke, G L Fanning, Christopher Archaean crust in the Rayner Complex of east Antarctica: Oygarden Group of islands, Kemp Land |
topic_facet |
Keywords: Archean granulite uranium-lead dating Antarctica Arctic and Antarctic East Antarctica World Granulite facies Pb-loss Recrystallisation U-Pb geochronology Zircon |
description |
Archaean zircon grains from the Oygarden Group of islands in Kemp Land, east Antarctica, record evidence for multiple episodes of recrystallisation, dissolution and growth from the Early to Middle Archaean to the Neoproterozoic. Zircon grains in layered felsic orthogneiss have an age of ∼ 3650 Ma, a minimum protolith age for this rock. These zircon grains were subsequently affected by a ∼ 3470 Ma Pb-loss event. Homogeneous felsic orthogneiss that cuts S1, but contains an intense S2, foliation, has disturbed ∼ 2780 Ma metamorphic zircon cores and rims that suggest a minimum age of ∼ 2780 Ma for the protolith to the orthogneiss. All zircon U-Pb data display considerable disturbance with further Pb-loss at ∼ 2400 Ma and ∼ 1600 Ma, and a major episode of isotopic resetting at ∼ 930 Ma. The highly disturbed data are related to complexly zoned zircon grains that developed through growth and modification during successive metamorphic events. Zircon cores with relic growth zoning patterns are inferred to have resulted from partial annealing or recrystallisation of older magmatic zircon. Highly luminescent zircon rims that embay cores along curved boundaries are interpreted to have formed through recrystallisation of zircon cores, and not new growth. The ages reported here confirm that central Kemp Land is composed of Archaean crust reworked during the Neoproterozoic Rayner Structural Episode. |
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 |
Archaean crust in the Rayner Complex of east Antarctica: Oygarden Group of islands, Kemp Land |
title_short |
Archaean crust in the Rayner Complex of east Antarctica: Oygarden Group of islands, Kemp Land |
title_full |
Archaean crust in the Rayner Complex of east Antarctica: Oygarden Group of islands, Kemp Land |
title_fullStr |
Archaean crust in the Rayner Complex of east Antarctica: Oygarden Group of islands, Kemp Land |
title_full_unstemmed |
Archaean crust in the Rayner Complex of east Antarctica: Oygarden Group of islands, Kemp Land |
title_sort |
archaean crust in the rayner complex of east antarctica: oygarden group of islands, kemp land |
publisher |
Royal Society of Edinburgh |
publishDate |
2015 |
url |
http://hdl.handle.net/1885/84048 |
long_lat |
ENVELOPE(57.500,57.500,-67.500,-67.500) ENVELOPE(57.500,57.500,-66.900,-66.900) ENVELOPE(57.500,57.500,-66.900,-66.900) ENVELOPE(-45.166,-45.166,-60.650,-60.650) |
geographic |
Antarctic Arctic East Antarctica Kemp Land Oygarden Oygarden Group Rayner |
geographic_facet |
Antarctic Arctic East Antarctica Kemp Land Oygarden Oygarden Group Rayner |
genre |
Antarc* Antarctic Antarctica Arctic East Antarctica Kemp Land |
genre_facet |
Antarc* Antarctic Antarctica Arctic East Antarctica Kemp Land |
op_source |
Transactions of the Royal Society of Edinburgh: Earth Sciences |
op_relation |
0263-5933 http://hdl.handle.net/1885/84048 |
_version_ |
1766263598476165120 |