A status report on age, depositional motif and stratigraphy of Chhattisgarh, Indravati, Kurnool and Bhima basins, Peninsular India

Abstract

An attempt has been made to collate information obtained in recent past from four Proterozoic basins in Peninsular India viz. Chhattisgarh, Indravati, Kurnool and Bhima, hosted within two different cratons viz. Bastar and Dharwar. It is apparent that the larger basins viz. Chhattisgarh, Kurnool has attracted more attention compared to small-scale basins e.g. Indravati, Bhima. Proposition of a new stratigraphic unit of 'Group' status viz. Kharsiya Group and subdividing the basin succession in four-tier viz. Singhora, Chandarpur, Raipur and Kharsiya Formations is a major contribution in Chhattisgarh geology in recent time. Geochronology of tuff beds from both bottom and topmost part of the Chhattisgarh succession and upper part of Indravati succession allowed i) age bracketing the Chhattisgarh depositional history, and ii) drawing correlation between Chhattisgarh and Indravati basin on strong foot hold. The age of Kurnool basin remained elusive because of non-convergence of evidences reported from within and outside the basin. From microfossil assemblage a pre-Varanger glaciation age i.e. >750 Ma is proposed for the Bhima basin. All the four basins are represented by clastic-carbonate mixed sediment succession recording transition from continental/shallow marine to distal marine depositional set up. Sediment was mostly sourced within these basins from adjoining cratons.