Granitoids and dykes of the Pine Island Bay region, West Antarctica
We present geochronological and geochemical data for eight plutonic rocks from five locations in the Pine Island Bay area of West Antarctica, collected during RV Polarstern expedition ANT-XXIII/4. Ar-Ar laser method dating yielded closure temperatures ages of c. 147–98 Ma for dioritic and granitic p...
Published in: | Antarctic Science |
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Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Cambridge Univ. Press
2012
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Subjects: | |
Online Access: | https://oceanrep.geomar.de/id/eprint/14393/ https://oceanrep.geomar.de/id/eprint/14393/1/Kipf.pdf https://oceanrep.geomar.de/id/eprint/14393/2/Kopie%20von%20S0954102012000259sup001.xls https://doi.org/10.1017/S0954102012000259 |
Summary: | We present geochronological and geochemical data for eight plutonic rocks from five locations in the Pine Island Bay area of West Antarctica, collected during RV Polarstern expedition ANT-XXIII/4. Ar-Ar laser method dating yielded closure temperatures ages of c. 147–98 Ma for dioritic and granitic plutonic rocks and an age range of c. 97–95 Ma for granitoid and trachyandesitic dykes. Major and trace element compositions indicate that all rocks have an I-type subduction-related chemistry. There are no A-type granitic rocks in our dataset, and none are yet reported from the Pine Island Bay area. Our results confirm earlier models of post 100 Ma subduction on this part of the Gondwana margin. |
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