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Authors
Affiliations
1 Department of Geology, Friendship University, Moscow, RU
2 Centre for Earth Science Studies, Trivandrum 695010, IN
3 IGEM, Academy of Sciences, Moscow, USSR, RU
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 23, No 9 (1982), Pagination: 458-462
Abstract
K/Ar mica age of chrysoberyl-bearing pegmatites from four localities of Trivandrum district, Kerala ranges from 445 to 474 m.y., with a mean around 460 m.y. There is a close agreement between the ages of the concordant and cross-cutting pegmatites, between muscovite and biotite ages, as also between various size fractions. Chrysoberyl occurs within feldspars in association with quartz and muscovite. Since the formation of chrysoberyl-quartz association requires a higher pressure or temperature, the reported age would indicate the time of emplacement of the chrysoberyl-bearing pegmatites at the closing phase of a major tectonomagmatic event. It is interesting to note that these pegmatites of south-western India are younger compared to those of other localities viz., Rajasthan, Bihar. Nellore and Mysore.
