Reconnaissance thermochronology of southern Zealandia
We report new fission-track, (U–Th)/He and 40 Ar/ 39 Ar ages for minerals in surface, dredge and borehole cuttings samples from the southern South Island, Campbell Plateau and Chatham Rise regions of the Zealandia continent. Our results indicate that much of southern Zealandia underwent rapid coolin...
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Geological Society of London
2016
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ftdatacite:10.6084/m9.figshare.3454127 2023-05-15T13:34:28+02:00 Reconnaissance thermochronology of southern Zealandia Mortimer, Nick Kohn, Barry Seward, Diane Spell, Terry Tulloch, Andy 2016 https://dx.doi.org/10.6084/m9.figshare.3454127 https://geolsoc.figshare.com/articles/dataset/Reconnaissance_thermochronology_of_southern_Zealandia/3454127 unknown Geological Society of London https://dx.doi.org/10.1144/jgs2015-021 Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 CC-BY Geology FOS Earth and related environmental sciences dataset Dataset 2016 ftdatacite https://doi.org/10.6084/m9.figshare.3454127 https://doi.org/10.1144/jgs2015-021 2021-11-05T12:55:41Z We report new fission-track, (U–Th)/He and 40 Ar/ 39 Ar ages for minerals in surface, dredge and borehole cuttings samples from the southern South Island, Campbell Plateau and Chatham Rise regions of the Zealandia continent. Our results indicate that much of southern Zealandia underwent rapid cooling in the interval 105–80 Ma, probably during widespread intracontinental rifting before Zealandia split from Gondwana. The 108 ± 11 Ma rapid exhumation of a zircon He retention zone in the Chatham Schist, however, may record cessation of long-lived subduction at the Gondwana margin owing to Hikurangi Plateau collision and/or the onset of the extensional rifting episode. Locally, basement rocks have been appreciably heated, and thermochronological systems reset, in response to deepening of the Great South Basin and by local Miocene intraplate volcanism. An apatite fission-track age of 179 ± 17 Ma from a dredge sample of Precambrian granite at the southern tip of the Campbell Plateau indicates that it is probably ice-rafted, thus in situ Precambrian crust in Zealandia is still unconfirmed. In contrast, a zircon (U–Th)/He age of 99 ± 9 Ma from a Precambrian metarhyolite from Iselin Bank at the conjugate Antarctic continental margin plausibly indicates an in situ position. Dataset Antarc* Antarctic DataCite Metadata Store (German National Library of Science and Technology) Antarctic Campbell Plateau ENVELOPE(171.000,171.000,-50.667,-50.667) Iselin Bank ENVELOPE(-179.000,-179.000,-72.500,-72.500) |
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Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
unknown |
topic |
Geology FOS Earth and related environmental sciences |
spellingShingle |
Geology FOS Earth and related environmental sciences Mortimer, Nick Kohn, Barry Seward, Diane Spell, Terry Tulloch, Andy Reconnaissance thermochronology of southern Zealandia |
topic_facet |
Geology FOS Earth and related environmental sciences |
description |
We report new fission-track, (U–Th)/He and 40 Ar/ 39 Ar ages for minerals in surface, dredge and borehole cuttings samples from the southern South Island, Campbell Plateau and Chatham Rise regions of the Zealandia continent. Our results indicate that much of southern Zealandia underwent rapid cooling in the interval 105–80 Ma, probably during widespread intracontinental rifting before Zealandia split from Gondwana. The 108 ± 11 Ma rapid exhumation of a zircon He retention zone in the Chatham Schist, however, may record cessation of long-lived subduction at the Gondwana margin owing to Hikurangi Plateau collision and/or the onset of the extensional rifting episode. Locally, basement rocks have been appreciably heated, and thermochronological systems reset, in response to deepening of the Great South Basin and by local Miocene intraplate volcanism. An apatite fission-track age of 179 ± 17 Ma from a dredge sample of Precambrian granite at the southern tip of the Campbell Plateau indicates that it is probably ice-rafted, thus in situ Precambrian crust in Zealandia is still unconfirmed. In contrast, a zircon (U–Th)/He age of 99 ± 9 Ma from a Precambrian metarhyolite from Iselin Bank at the conjugate Antarctic continental margin plausibly indicates an in situ position. |
format |
Dataset |
author |
Mortimer, Nick Kohn, Barry Seward, Diane Spell, Terry Tulloch, Andy |
author_facet |
Mortimer, Nick Kohn, Barry Seward, Diane Spell, Terry Tulloch, Andy |
author_sort |
Mortimer, Nick |
title |
Reconnaissance thermochronology of southern Zealandia |
title_short |
Reconnaissance thermochronology of southern Zealandia |
title_full |
Reconnaissance thermochronology of southern Zealandia |
title_fullStr |
Reconnaissance thermochronology of southern Zealandia |
title_full_unstemmed |
Reconnaissance thermochronology of southern Zealandia |
title_sort |
reconnaissance thermochronology of southern zealandia |
publisher |
Geological Society of London |
publishDate |
2016 |
url |
https://dx.doi.org/10.6084/m9.figshare.3454127 https://geolsoc.figshare.com/articles/dataset/Reconnaissance_thermochronology_of_southern_Zealandia/3454127 |
long_lat |
ENVELOPE(171.000,171.000,-50.667,-50.667) ENVELOPE(-179.000,-179.000,-72.500,-72.500) |
geographic |
Antarctic Campbell Plateau Iselin Bank |
geographic_facet |
Antarctic Campbell Plateau Iselin Bank |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
https://dx.doi.org/10.1144/jgs2015-021 |
op_rights |
Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.6084/m9.figshare.3454127 https://doi.org/10.1144/jgs2015-021 |
_version_ |
1766053171141017600 |