Lithofacies and Environments of Deposition of a Part of Talchir Group, Talchir Gondwana Basin, Orissa

The Talchir sequence is divisible into three units named informally as 'Unit A', 'Unit B' and 'Unit C' from the base to the top. Eleven lithofacies have been recognised. The lithofacies associations and their inter-relationships suggest deposition of Unit A in a network of alluvial braided stream environment merging into a lake. Unit B represents three phases of delta advance into a lake basin with the development of prodelta, delta slope, subaqueous delta platform and deltaic distributary sediments. The sediments of Unit C were laid down in a quiet lake basin of moderate depth with the sedimentation being from suspension and chemical precipitation followed by intermittent clastic density underflows.