Archaean crust in the Rayner Complex of east Antarctica: Oygarden Group of islands, Kemp Land
ABSTRACT 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 ∼36...
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crcambridgeupr:10.1017/s0263593300001176 2024-03-03T08:38:02+00:00 Archaean crust in the Rayner Complex of east Antarctica: Oygarden Group of islands, Kemp Land Kelly, N. M. Clarke, G. L. Fanning, C. M. 2004 http://dx.doi.org/10.1017/s0263593300001176 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0263593300001176 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Earth and Environmental Science Transactions of the Royal Society of Edinburgh volume 95, issue 3-4, page 491-510 ISSN 1755-6910 1755-6929 General Earth and Planetary Sciences General Environmental Science journal-article 2004 crcambridgeupr https://doi.org/10.1017/s0263593300001176 2024-02-08T08:31:27Z ABSTRACT 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 S 1 , but contains an intense S 2 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* Antarctica East Antarctica Kemp Land Cambridge University Press East Antarctica Rayner ENVELOPE(-45.166,-45.166,-60.650,-60.650) 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) Earth and Environmental Science Transactions of the Royal Society of Edinburgh 95 3-4 491 510 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
General Earth and Planetary Sciences General Environmental Science |
spellingShingle |
General Earth and Planetary Sciences General Environmental Science Kelly, N. M. Clarke, G. L. Fanning, C. M. Archaean crust in the Rayner Complex of east Antarctica: Oygarden Group of islands, Kemp Land |
topic_facet |
General Earth and Planetary Sciences General Environmental Science |
description |
ABSTRACT 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 S 1 , but contains an intense S 2 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, C. M. |
author_facet |
Kelly, N. M. Clarke, G. L. Fanning, C. M. |
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 |
Cambridge University Press (CUP) |
publishDate |
2004 |
url |
http://dx.doi.org/10.1017/s0263593300001176 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0263593300001176 |
long_lat |
ENVELOPE(-45.166,-45.166,-60.650,-60.650) 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) |
geographic |
East Antarctica Rayner Kemp Land Oygarden Oygarden Group |
geographic_facet |
East Antarctica Rayner Kemp Land Oygarden Oygarden Group |
genre |
Antarc* Antarctica East Antarctica Kemp Land |
genre_facet |
Antarc* Antarctica East Antarctica Kemp Land |
op_source |
Earth and Environmental Science Transactions of the Royal Society of Edinburgh volume 95, issue 3-4, page 491-510 ISSN 1755-6910 1755-6929 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0263593300001176 |
container_title |
Earth and Environmental Science Transactions of the Royal Society of Edinburgh |
container_volume |
95 |
container_issue |
3-4 |
container_start_page |
491 |
op_container_end_page |
510 |
_version_ |
1792503885261176832 |