Age levels of Precambrian orogenic cycles of India

Abstract

The paper reviews critically the present status of knowledge on the Precambrian orogenic cycles of India. The Precambrian age data obtained by Pb-U-Th, alpha-helium and Rb-Sr methods are presented cycle-wise, and the degree of dependability of each determination is indicated. The following cycles have so far been delineated - Dharwar (2300±100 M. Y.), Eastern Ghats (1625±75 M. Y.), Mahanadi (1350±200 M. Y.), Satpura (955±40 M. Y.), Delhi (735±30 M. Y.) and Kishengarh (580±20 M. Y.) and it is shown that these cycles have equivalents in several parts of the world. These results are discussed in relation to the tectonics of India. A comprehensive programme of dating the Precambrian geological formations of India is suggested.