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Petrology of the Anorthosite-Gabbro Mass at Kadavur, Madras, India1

Published online by Cambridge University Press:  01 May 2009

A. P. Subramaniam
A. P. Subramaniam
Affiliation:
Geological Survey of India, Southern Circle, Mylapore, Madras, 4, India.
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Abstract

A small body of anorthosite with related gabbroic facies from the Archaean of Southern India is described. The mass is inferred to be a funnel shaped phacolithic pluton, emplaced in the crest of a steeply plunging major anticline of metasedimentary quartzite and quartz schists. The marginal rocks of the mass are gabbroic and foliated, while the core is largely made of massive anortho-sites occasionally showing flow structures. The chemistry and petrography of the rocks of this mass suggest their having resulted from differentiation in place of a gabbroic anorthosite intrusion. This occurrence is thought to be a unique example of the Adirondack type of anorthosite, and supports Buddington's hypothesis of evolution of anorthositic rocks from a gabbroic anorthosite magma.

Type
Articles
Information
Geological Magazine , Volume 93 , Issue 4 , August 1956 , pp. 287 - 300
Copyright
Copyright © Cambridge University Press 1956

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Footnotes

1

Published by permission of Director, Geological Survey of India.

References

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