Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

N. V. Chalapati Rao ¹, V. Madhavan ²

Affiliations
1 Bullard Laboratories, Department of Earth Sciences, University of Cambridge CB3 OEZ, GB
2 Department of Geology, Kakatiya University, Warangal 506009, Andhra Pradesh, IN

Abstract

Detailed petological and geochemical studies pertaining to the lamproitic body recorded by the Geological Survey of India at Ramannapeta-Ustapalle, Krishna district, Andhra Pradesh, are presented. Unmistakable lamproite signatures like the presence of Ti-rich potassic richterite, abundance of Ti-rich, Al-poor phlogopite and Ca-rich, Al-poor clinopyroxene, absence of primary calcite, paucity of typical kimberlite indicator minerals and the ultra potassic nature are recognised. Major oxide as well as the trace elemental abundances of the body are observed to be similar to those of the Chelima lamproites occurring within the intra-cratonic Cuddapah basin. The available radiometric ages of all the known Indian lamproites and kimberlites are taken into consideration and a mid-Proterozoic lamproite event in the Indian sub-continent is postulated.

Keywords

Geochemistry, Lamproite, Krishna District, Andhra Pradesh.

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N. V. Chalapati Rao ¹, Debajyoti Paul ², Ashima Saikia ³

Affiliations
1 Banaras Hindu University, Varanasi, IN
2 Indian Institute of Technology, Kanpur, IN
3 University of Delhi, IN

Abstract

No Abstract.

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