ScholarLens Back to search
1981•Journal of the Geological Society of IndiaRequires access

40K/40Ar Ages of a Suite of Lower Palaeozoic Post-Tectonic Granitoids, Southern India

M. N. Balasubrahmanyani, Amitabha Sarkar

Open publisher page 5 citations

Abstract

Four 40 K/ 40 Ar mica ages of the granitoid suite around Kadavur range from 475 to 527 Ma with a mean around 500 Ma. Since (i) there is a close agreement in mica ages between variants of the granitoid suite and between size fractions and (ii) the dated minerals are from post-tectonic, undeformed and unmetamorphosed rocks, this mean age appears to closely approximate the age of intrusion of the granitoids. One hornblende separate from the older invaded hornblende leuco-gabbro of the Kadavur gabbro-anorthosite complex with a 40 K/ 40 Ar age of 492 Ma is most probably a thermally reset age.

About this research paper

What this paper is about

Four 40 K/ 40 Ar mica ages of the granitoid suite around Kadavur range from 475 to 527 Ma with a mean around 500 Ma. Since (i) there is a close agreement in mica ages between variants of the granitoid suite and between size fractions and (ii) the dated minerals are from post-tectonic, undeformed and unmetamorphosed rocks, this mean age appears to closely approximate the age of intrusion of the granitoids. One hornblende separate from the older invaded hornblende leuco-gabbro of the Kadavur gabbro-anorthosite complex with a 40 K/ 40 Ar age of 492 Ma is most probably a thermally reset age.

Why it matters

OpenAlex reports 5 citations for this work. Citation counts describe recorded attention and do not establish research quality.

Key contribution

A contribution statement is not available in the OpenAlex record.

Method / approach

Method details are not available in the OpenAlex metadata.

Main findings

Findings are not separately available in the OpenAlex metadata.

Limitations

Limitations are not available in the OpenAlex metadata.

Applications

Application details are not available in the OpenAlex metadata.

Available abstract

Four 40 K/ 40 Ar mica ages of the granitoid suite around Kadavur range from 475 to 527 Ma with a mean around 500 Ma. Since (i) there is a close agreement in mica ages between variants of the granitoid suite and between size fractions and (ii) the dated minerals are from post-tectonic, undeformed and unmetamorphosed rocks, this mean age appears to closely approximate the age of intrusion of the granitoids. One hornblende separate from the older invaded hornblende leuco-gabbro of the Kadavur gabbro-anorthosite complex with a 40 K/ 40 Ar age of 492 Ma is most probably a thermally reset age.

Key concepts: Gabbro, Hornblende, Geology, Anorthosite, Geochemistry, Tectonics, Paleozoic, Intrusion

Related papers

Related paper 1Related paper 2Related paper 3
Back to paper searchBrowse research topicsOriginal source
40K/40Ar Ages of a Suite of Lower Palaeozoic Post-Tectonic Granitoids, Southern India — Research Paper | ScholarLens