Proterozoic Basins of Peninsular India: Status within the Global Proterozoic Systems

Abstract

This compilation is intended to present a snap-shot of the current status of the knowledge on the Proterozoic sediments
and tectonic events that are preserved in Peninsular India; on the backdrop of the growing understanding of global events
and environmental evolution during that period. Proterozoic sediments in Peninsular India are found in two contrasting
categories of basins. Narrow linear intercratonic belts host terrigenous and marine sediments, often interbedded with
volcanics and volcaniclastics; that are deformed, metamorphosed and occasionally intruded by granitic bodies. These belts
abut with a tectonic contact with wide, unmetamorphosed platform sediments from epicratonic basins with limited igneous
activity associated within them; clubbed as the Purana Basins of Peninsular India. Although traditionally the former
(mobile belts) were considered to be older and different from the latter, emerging geochronological data demonstrates that
they were coeval products of basins evolving adjoining each other in diverse tectonic setting. Available knowledge on these
basins is summarised within the framework of the emerging understanding of the Proterozoic geohistory punctuated by
assembly and break-up of supercontinents, progressive oxygenation of the atmosphere, changes in the sea-water chemistry;
establishment of the continental free-board and the generic environments that laid the foundation of biotic evolution.
Although significant advances have been made in the last decade in the knowledge of these sediments, much more is required
to achieve the desired precision and resolution.