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Authors
Affiliations
1 Department of Earth Sciences, Indian Institute of Technology, Powai, Bombay 400 076, IN
2 Department of Geology, University of Leicester, Leicester LEI 7RH, GB
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 46, No 2 (1995), Pagination: 125-137
Abstract
New whole-rock rare earth element (REE) data for the metacarbonate rocks interbedded with schists at Vinjamur in the Nellore Schist Belt of Andhra Pradesh, show low total REE contents (Σ9-128 ppm) that are inconsistent with an igneous carbonatitic origin but which correspond more closely with a sedimentary limestone origin. The REE data of these rocks however, do not give absolute discrimination between marbles of meta-limestone and metacarbonatite origin. Micro-probe analytical data give better discrimination, and the chemical compositions of the calcite, micas, amphibole, plagioclase, apatite, monazite and staurolite in the Vinjamur marbles give strong and consistent evidence of a metamorphosed sedimentary rather than an igneous origin.
Keywords
Carbonatites, Vinjamur, Nellore Schist Belt, Andhra Pradesh.
