Age of pre-break-up Gondwana magmatism
Extensive outpourings of basalt, and to a lesser extent rhyolite, are closely associated with continental break-up and plume-lithosphere interactions. The Gondwana supercontinent began to fiagment during Early-Middle Jurassic times and was associated with the eruption of over three millionkm’ of dom...
Published in: | Antarctic Science |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
Cambridge University Press
2001
|
Subjects: | |
Online Access: | http://nora.nerc.ac.uk/id/eprint/20233/ http://journals.cambridge.org/abstract_S0954102001000177 |
id |
ftnerc:oai:nora.nerc.ac.uk:20233 |
---|---|
record_format |
openpolar |
spelling |
ftnerc:oai:nora.nerc.ac.uk:20233 2023-05-15T13:45:12+02:00 Age of pre-break-up Gondwana magmatism Riley, Teal R. Knight, Kim B. 2001 http://nora.nerc.ac.uk/id/eprint/20233/ http://journals.cambridge.org/abstract_S0954102001000177 unknown Cambridge University Press Riley, Teal R. orcid:0000-0002-3333-5021 Knight, Kim B. 2001 Age of pre-break-up Gondwana magmatism. Antarctic Science, 13 (2). 99-110. https://doi.org/10.1017/S0954102001000177 <https://doi.org/10.1017/S0954102001000177> Publication - Article PeerReviewed 2001 ftnerc https://doi.org/10.1017/S0954102001000177 2023-02-04T19:32:47Z Extensive outpourings of basalt, and to a lesser extent rhyolite, are closely associated with continental break-up and plume-lithosphere interactions. The Gondwana supercontinent began to fiagment during Early-Middle Jurassic times and was associated with the eruption of over three millionkm’ of dominantly basaltic magma. This intense magmatic episode is recorded in volcanic rocks of the Karoo (Africa), Ferrar (Antarctica) and Chon Aike (South America). K-Ar and Rb-Sr whole rock geochronology has consistently failed to produce reliable ages for these volcanic rocks, but in the last four years, the wider application of single grain 40Ar/39Aarn dor U-Pb geochronology has produced more robust and precise dating of the magmatism. This paper reviews the recent advances in high precision geochronology and provides a full recalibrated 40ArPgAr dataset. Application of these methods across the majority of the volcanic provinces indicates that approximately 80% of the volcanic rocks were erupted within a short, 3-4 Myr period at c. 182 Ma. This burst of magmatism occurred in the Karoo province at c. 183 Ma and in the Ferrar provinces at c. 180 Ma, and was dominated by mafk volcanism. Ths peak in volcanism is coincident with a second order mass extinction event at the end of the Pliensbachian when c. 5% of marine families were wiped out coinciding with widespread oceanic anoxia in the early Toarcian. A prolonged period of silicic volcanism occurred along the protoPacific margin, prior to, and during the main phase of break-up. Silicic volcanism was initially coincident with the plume related Karoo-Ferrar provinces, but continued over c. 40 Myr, associated with lithospheric extension and subduction along the proto-Pacific continental margin. Article in Journal/Newspaper Antarc* Antarctic Science Antarctica Natural Environment Research Council: NERC Open Research Archive Pacific Antarctic Science 13 2 99 110 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
description |
Extensive outpourings of basalt, and to a lesser extent rhyolite, are closely associated with continental break-up and plume-lithosphere interactions. The Gondwana supercontinent began to fiagment during Early-Middle Jurassic times and was associated with the eruption of over three millionkm’ of dominantly basaltic magma. This intense magmatic episode is recorded in volcanic rocks of the Karoo (Africa), Ferrar (Antarctica) and Chon Aike (South America). K-Ar and Rb-Sr whole rock geochronology has consistently failed to produce reliable ages for these volcanic rocks, but in the last four years, the wider application of single grain 40Ar/39Aarn dor U-Pb geochronology has produced more robust and precise dating of the magmatism. This paper reviews the recent advances in high precision geochronology and provides a full recalibrated 40ArPgAr dataset. Application of these methods across the majority of the volcanic provinces indicates that approximately 80% of the volcanic rocks were erupted within a short, 3-4 Myr period at c. 182 Ma. This burst of magmatism occurred in the Karoo province at c. 183 Ma and in the Ferrar provinces at c. 180 Ma, and was dominated by mafk volcanism. Ths peak in volcanism is coincident with a second order mass extinction event at the end of the Pliensbachian when c. 5% of marine families were wiped out coinciding with widespread oceanic anoxia in the early Toarcian. A prolonged period of silicic volcanism occurred along the protoPacific margin, prior to, and during the main phase of break-up. Silicic volcanism was initially coincident with the plume related Karoo-Ferrar provinces, but continued over c. 40 Myr, associated with lithospheric extension and subduction along the proto-Pacific continental margin. |
format |
Article in Journal/Newspaper |
author |
Riley, Teal R. Knight, Kim B. |
spellingShingle |
Riley, Teal R. Knight, Kim B. Age of pre-break-up Gondwana magmatism |
author_facet |
Riley, Teal R. Knight, Kim B. |
author_sort |
Riley, Teal R. |
title |
Age of pre-break-up Gondwana magmatism |
title_short |
Age of pre-break-up Gondwana magmatism |
title_full |
Age of pre-break-up Gondwana magmatism |
title_fullStr |
Age of pre-break-up Gondwana magmatism |
title_full_unstemmed |
Age of pre-break-up Gondwana magmatism |
title_sort |
age of pre-break-up gondwana magmatism |
publisher |
Cambridge University Press |
publishDate |
2001 |
url |
http://nora.nerc.ac.uk/id/eprint/20233/ http://journals.cambridge.org/abstract_S0954102001000177 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Antarc* Antarctic Science Antarctica |
genre_facet |
Antarc* Antarctic Science Antarctica |
op_relation |
Riley, Teal R. orcid:0000-0002-3333-5021 Knight, Kim B. 2001 Age of pre-break-up Gondwana magmatism. Antarctic Science, 13 (2). 99-110. https://doi.org/10.1017/S0954102001000177 <https://doi.org/10.1017/S0954102001000177> |
op_doi |
https://doi.org/10.1017/S0954102001000177 |
container_title |
Antarctic Science |
container_volume |
13 |
container_issue |
2 |
container_start_page |
99 |
op_container_end_page |
110 |
_version_ |
1766217004724781056 |