Extreme persistence of cratonic lithosphere in the southwest Pacific: Paleoproterozoic Os isotopic signatures in Zealandia
Zealandia is a largely submerged, continental fragment in the southwest Pacific, generally considered to be derived from East Gondwana, but whose origins, age, structure, and relationships with other continental masses are poorly known. To explore the development of this microcontinent, a suite of m...
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ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/70823 2024-01-14T10:00:32+01:00 Extreme persistence of cratonic lithosphere in the southwest Pacific: Paleoproterozoic Os isotopic signatures in Zealandia McCoy-West, Alexander Bennett, Victoria Puchtel, Igor S Walker, Richard J http://hdl.handle.net/1885/70823 https://doi.org/10.1130/G33626.1 https://openresearch-repository.anu.edu.au/bitstream/1885/70823/5/f5625xPUB2430_2013.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/70823/7/01_McCoy-West_Extreme_persistence_of_2013.pdf.jpg unknown Geological Society of America Inc 0091-7613 http://hdl.handle.net/1885/70823 doi:10.1130/G33626.1 https://openresearch-repository.anu.edu.au/bitstream/1885/70823/5/f5625xPUB2430_2013.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/70823/7/01_McCoy-West_Extreme_persistence_of_2013.pdf.jpg Geology Keywords: Age structures Antarctica Crustal rocks Isochron age Isotopic signatures Isotopic systematics Lithospheric mantle Mantle lithosphere Mantle xenoliths Marie Byrd Land New zealand Paleoproterozoic South Island Southeastern australia Sub-contin Journal article ftanucanberra https://doi.org/10.1130/G33626.1 2023-12-15T09:35:30Z Zealandia is a largely submerged, continental fragment in the southwest Pacific, generally considered to be derived from East Gondwana, but whose origins, age, structure, and relationships with other continental masses are poorly known. To explore the development of this microcontinent, a suite of mantle xenoliths was assembled from 12 localities throughout New Zealand, an emergent part of Zealandia. The 187Re-188Os isotopic systematics of the xenoliths yield model ages (TRD2) between 0 and 2.3 Ga. Six samples from the newly defined Waitaha domain, South Island, have a narrow range of TRD2 ages from 1.6 to 1.9 Ga, in agreement with an aluminochron model age for this mantle domain of ca. 1.95 Ga, and with a three-point Re-Os isochron age of 2.26 ± 0.10 Ga. These ages are >500 m.y. older than TRD2 ages preserved in other regions of mantle lithosphere from the eastern margin of Gondwana (e.g., southeastern Australia and Marie Byrd Land, Antarctica) and >1 b.y. older than the oldest crustal rocks exposed in New Zealand. Thus, the lithospheric mantle of Zealandia has a complex age structure, including a region of Paleoproterozoic cratonic mantle with a minimum extent of ~45,000 km2. This ancient mantle resided at the margins of several supercontinents during the past ~2 b.y., attesting to the durability of subcontinental lithospheric mantle domains, even when decoupled from overlying contemporaneous crust and in an oceanic setting distanced from stable cratonic nuclei. Article in Journal/Newspaper Antarc* Antarctica Marie Byrd Land Australian National University: ANU Digital Collections Pacific New Zealand Byrd Marie Byrd Land ENVELOPE(-130.000,-130.000,-78.000,-78.000) Geology 41 2 231 234 |
institution |
Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
unknown |
topic |
Keywords: Age structures Antarctica Crustal rocks Isochron age Isotopic signatures Isotopic systematics Lithospheric mantle Mantle lithosphere Mantle xenoliths Marie Byrd Land New zealand Paleoproterozoic South Island Southeastern australia Sub-contin |
spellingShingle |
Keywords: Age structures Antarctica Crustal rocks Isochron age Isotopic signatures Isotopic systematics Lithospheric mantle Mantle lithosphere Mantle xenoliths Marie Byrd Land New zealand Paleoproterozoic South Island Southeastern australia Sub-contin McCoy-West, Alexander Bennett, Victoria Puchtel, Igor S Walker, Richard J Extreme persistence of cratonic lithosphere in the southwest Pacific: Paleoproterozoic Os isotopic signatures in Zealandia |
topic_facet |
Keywords: Age structures Antarctica Crustal rocks Isochron age Isotopic signatures Isotopic systematics Lithospheric mantle Mantle lithosphere Mantle xenoliths Marie Byrd Land New zealand Paleoproterozoic South Island Southeastern australia Sub-contin |
description |
Zealandia is a largely submerged, continental fragment in the southwest Pacific, generally considered to be derived from East Gondwana, but whose origins, age, structure, and relationships with other continental masses are poorly known. To explore the development of this microcontinent, a suite of mantle xenoliths was assembled from 12 localities throughout New Zealand, an emergent part of Zealandia. The 187Re-188Os isotopic systematics of the xenoliths yield model ages (TRD2) between 0 and 2.3 Ga. Six samples from the newly defined Waitaha domain, South Island, have a narrow range of TRD2 ages from 1.6 to 1.9 Ga, in agreement with an aluminochron model age for this mantle domain of ca. 1.95 Ga, and with a three-point Re-Os isochron age of 2.26 ± 0.10 Ga. These ages are >500 m.y. older than TRD2 ages preserved in other regions of mantle lithosphere from the eastern margin of Gondwana (e.g., southeastern Australia and Marie Byrd Land, Antarctica) and >1 b.y. older than the oldest crustal rocks exposed in New Zealand. Thus, the lithospheric mantle of Zealandia has a complex age structure, including a region of Paleoproterozoic cratonic mantle with a minimum extent of ~45,000 km2. This ancient mantle resided at the margins of several supercontinents during the past ~2 b.y., attesting to the durability of subcontinental lithospheric mantle domains, even when decoupled from overlying contemporaneous crust and in an oceanic setting distanced from stable cratonic nuclei. |
format |
Article in Journal/Newspaper |
author |
McCoy-West, Alexander Bennett, Victoria Puchtel, Igor S Walker, Richard J |
author_facet |
McCoy-West, Alexander Bennett, Victoria Puchtel, Igor S Walker, Richard J |
author_sort |
McCoy-West, Alexander |
title |
Extreme persistence of cratonic lithosphere in the southwest Pacific: Paleoproterozoic Os isotopic signatures in Zealandia |
title_short |
Extreme persistence of cratonic lithosphere in the southwest Pacific: Paleoproterozoic Os isotopic signatures in Zealandia |
title_full |
Extreme persistence of cratonic lithosphere in the southwest Pacific: Paleoproterozoic Os isotopic signatures in Zealandia |
title_fullStr |
Extreme persistence of cratonic lithosphere in the southwest Pacific: Paleoproterozoic Os isotopic signatures in Zealandia |
title_full_unstemmed |
Extreme persistence of cratonic lithosphere in the southwest Pacific: Paleoproterozoic Os isotopic signatures in Zealandia |
title_sort |
extreme persistence of cratonic lithosphere in the southwest pacific: paleoproterozoic os isotopic signatures in zealandia |
publisher |
Geological Society of America Inc |
url |
http://hdl.handle.net/1885/70823 https://doi.org/10.1130/G33626.1 https://openresearch-repository.anu.edu.au/bitstream/1885/70823/5/f5625xPUB2430_2013.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/70823/7/01_McCoy-West_Extreme_persistence_of_2013.pdf.jpg |
long_lat |
ENVELOPE(-130.000,-130.000,-78.000,-78.000) |
geographic |
Pacific New Zealand Byrd Marie Byrd Land |
geographic_facet |
Pacific New Zealand Byrd Marie Byrd Land |
genre |
Antarc* Antarctica Marie Byrd Land |
genre_facet |
Antarc* Antarctica Marie Byrd Land |
op_source |
Geology |
op_relation |
0091-7613 http://hdl.handle.net/1885/70823 doi:10.1130/G33626.1 https://openresearch-repository.anu.edu.au/bitstream/1885/70823/5/f5625xPUB2430_2013.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/70823/7/01_McCoy-West_Extreme_persistence_of_2013.pdf.jpg |
op_doi |
https://doi.org/10.1130/G33626.1 |
container_title |
Geology |
container_volume |
41 |
container_issue |
2 |
container_start_page |
231 |
op_container_end_page |
234 |
_version_ |
1788066431296864256 |