Early Permian Barakar Formation from Umrer Coalfield, Nagpur District (M. S), India: Lithofacies Characteristics and Depositional Environment

• Published in: Journal of geosciences, Osaka City University Osaka City University, 2012-03, Vol.55, p.11-19
• Main Authors: Murkute, YA, Joshi, S P
• Format: Article
• Language: English
• Subjects: Indexing in process
• ISSN: 0449-2560

The Umrer coalfield (Lat. 20 degree 50' 00" - 20 degree 52' 50" N: Long 79 degree 16' 00" - 79 degree 18' 30" E) representing Umrer Coal basin is one of the four huge coal producing Gondwana basins in Maharashtra. This coalfield represents the trough which is subparallel to the main Pranhita-Godavari Graben (PGG). In accessible cliff, the lower, middle, and upper Barakar sequences are marked out. Five lithofacies, viz., conglomerate/pebbly to very coarse sandstone (Lcps), large-scale trough cross-bedded sandstone (Lls1), large-scale tabular cross-bedded sandstone (Lls2), horizontal bedded sandstone (Lhs), and carbonaceous shale (Lcs), are recognized in the lower part of the Barakar Formation. Five different lithofacies viz., large-scale trough cross-bedded sandstone (Mls1), large-scale tabular cross-bedded sandstone (Mls2), horizontal bedded sandstone (Mhs), ripple laminated sandstone (Mrs), and carbonaceous shale and coal (Mcs), are noticed in the middle sequence of the Barakar formation. In the Upper Barakar sequence, large-scale trough cross-bedded sandstone (Uls1), large-scale tabular cross-bedded sandstone (Uls2), horizontal bedded sandstone (Uhs), ripple laminated sandstone (Urs), and ferruginous shale (Ufs) are recognized. The association of these lithofacies and their fining-upward characteristic represents typically the aggrading and coalescing braided fluvial system at the base and point bars of meandering river deposition at the middle sequences with the overbank vertically accretionery deposition and backswamp deposits at the top. The paleocurrent directions worked out from directional features like cross-beddings and laminations suggest unimodal, northwesterly paleoflow for these Barakar sediments.