THE PETROGENESIS OF MESOZOIC GONDWANA LOW-TI FLOOD BASALTS
New major, trace element and isotopic data for Jurassic basalts from SE Australia indicate that they are strikingly similar to the Jurassic tholeiitic rocks of Tasmania and the Transantarctic Mountains. These rocks are all characterised by low TiO2, P2O5, Na2O, Fe2O3, Ti/Zr, Ti/Y and epsilon-Nd, and...
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ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/b49408a2-c330-4af9-96b6-9775f1065c51 2023-05-15T13:35:46+02:00 THE PETROGENESIS OF MESOZOIC GONDWANA LOW-TI FLOOD BASALTS HERGT, J M PEATE, D W Hawkesworth, Chris 1991-07 https://risweb.st-andrews.ac.uk/portal/en/researchoutput/the-petrogenesis-of-mesozoic-gondwana-lowti-flood-basalts(b49408a2-c330-4af9-96b6-9775f1065c51).html http://www.scopus.com/inward/record.url?scp=0026289631&partnerID=8YFLogxK eng eng info:eu-repo/semantics/restrictedAccess HERGT , J M , PEATE , D W & Hawkesworth , C 1991 , ' THE PETROGENESIS OF MESOZOIC GONDWANA LOW-TI FLOOD BASALTS ' , Earth and Planetary Science Letters , vol. 105 , no. 1-3 , pp. 134-148 . DRONNING-MAUD-LAND FRACTIONAL CRYSTALLIZATION CONTINENTAL LITHOSPHERE JURASSIC DOLERITES KIRKPATRICK BASALT ANTARCTICA GEOCHEMISTRY MANTLE RIDGE ASSIMILATION article 1991 ftunstandrewcris 2021-12-26T14:18:03Z New major, trace element and isotopic data for Jurassic basalts from SE Australia indicate that they are strikingly similar to the Jurassic tholeiitic rocks of Tasmania and the Transantarctic Mountains. These rocks are all characterised by low TiO2, P2O5, Na2O, Fe2O3, Ti/Zr, Ti/Y and epsilon-Nd, and high SiO2, Rb/Ba, Rb/Sr, Sr-87/Sr-86 and Pb-207/Pb-204, relative to oceanic basalts. They therefore comprise a major province, termed the Ferrar magmatic province, which extended for 3000-4000 km across the Gondwana supercontinent. A review of the other Mesozoic low-Ti CFB's suggests that the Ferrar rocks are an extreme example of these magma types. It is striking that both the major and trace element compositions are different from oceanic basalts, which suggests that these features are linked, and it is argued that they were derived from distinctive source regions in the sub-continental mantle. Such source regions were variably depleted in major and minor elements, and then relatively enriched in highly incompatible elements and Sr and Pb isotopes, which is best explained by the introduction of a small amount of subducted sediment. The tectonic setting of the Ferrar magmatism is poorly constrained, but at present there is no clear geochemical evidence for the involvement of asthenospheric plume material in the petrogenesis of these low-Ti CFB's. Article in Journal/Newspaper Antarc* Antarctica Dronning Maud Land University of St Andrews: Research Portal Dronning Maud Land Transantarctic Mountains |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
DRONNING-MAUD-LAND FRACTIONAL CRYSTALLIZATION CONTINENTAL LITHOSPHERE JURASSIC DOLERITES KIRKPATRICK BASALT ANTARCTICA GEOCHEMISTRY MANTLE RIDGE ASSIMILATION |
spellingShingle |
DRONNING-MAUD-LAND FRACTIONAL CRYSTALLIZATION CONTINENTAL LITHOSPHERE JURASSIC DOLERITES KIRKPATRICK BASALT ANTARCTICA GEOCHEMISTRY MANTLE RIDGE ASSIMILATION HERGT, J M PEATE, D W Hawkesworth, Chris THE PETROGENESIS OF MESOZOIC GONDWANA LOW-TI FLOOD BASALTS |
topic_facet |
DRONNING-MAUD-LAND FRACTIONAL CRYSTALLIZATION CONTINENTAL LITHOSPHERE JURASSIC DOLERITES KIRKPATRICK BASALT ANTARCTICA GEOCHEMISTRY MANTLE RIDGE ASSIMILATION |
description |
New major, trace element and isotopic data for Jurassic basalts from SE Australia indicate that they are strikingly similar to the Jurassic tholeiitic rocks of Tasmania and the Transantarctic Mountains. These rocks are all characterised by low TiO2, P2O5, Na2O, Fe2O3, Ti/Zr, Ti/Y and epsilon-Nd, and high SiO2, Rb/Ba, Rb/Sr, Sr-87/Sr-86 and Pb-207/Pb-204, relative to oceanic basalts. They therefore comprise a major province, termed the Ferrar magmatic province, which extended for 3000-4000 km across the Gondwana supercontinent. A review of the other Mesozoic low-Ti CFB's suggests that the Ferrar rocks are an extreme example of these magma types. It is striking that both the major and trace element compositions are different from oceanic basalts, which suggests that these features are linked, and it is argued that they were derived from distinctive source regions in the sub-continental mantle. Such source regions were variably depleted in major and minor elements, and then relatively enriched in highly incompatible elements and Sr and Pb isotopes, which is best explained by the introduction of a small amount of subducted sediment. The tectonic setting of the Ferrar magmatism is poorly constrained, but at present there is no clear geochemical evidence for the involvement of asthenospheric plume material in the petrogenesis of these low-Ti CFB's. |
format |
Article in Journal/Newspaper |
author |
HERGT, J M PEATE, D W Hawkesworth, Chris |
author_facet |
HERGT, J M PEATE, D W Hawkesworth, Chris |
author_sort |
HERGT, J M |
title |
THE PETROGENESIS OF MESOZOIC GONDWANA LOW-TI FLOOD BASALTS |
title_short |
THE PETROGENESIS OF MESOZOIC GONDWANA LOW-TI FLOOD BASALTS |
title_full |
THE PETROGENESIS OF MESOZOIC GONDWANA LOW-TI FLOOD BASALTS |
title_fullStr |
THE PETROGENESIS OF MESOZOIC GONDWANA LOW-TI FLOOD BASALTS |
title_full_unstemmed |
THE PETROGENESIS OF MESOZOIC GONDWANA LOW-TI FLOOD BASALTS |
title_sort |
petrogenesis of mesozoic gondwana low-ti flood basalts |
publishDate |
1991 |
url |
https://risweb.st-andrews.ac.uk/portal/en/researchoutput/the-petrogenesis-of-mesozoic-gondwana-lowti-flood-basalts(b49408a2-c330-4af9-96b6-9775f1065c51).html http://www.scopus.com/inward/record.url?scp=0026289631&partnerID=8YFLogxK |
geographic |
Dronning Maud Land Transantarctic Mountains |
geographic_facet |
Dronning Maud Land Transantarctic Mountains |
genre |
Antarc* Antarctica Dronning Maud Land |
genre_facet |
Antarc* Antarctica Dronning Maud Land |
op_source |
HERGT , J M , PEATE , D W & Hawkesworth , C 1991 , ' THE PETROGENESIS OF MESOZOIC GONDWANA LOW-TI FLOOD BASALTS ' , Earth and Planetary Science Letters , vol. 105 , no. 1-3 , pp. 134-148 . |
op_rights |
info:eu-repo/semantics/restrictedAccess |
_version_ |
1766069992042790912 |