Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

R. N. Hota ¹

Affiliations
1 Department of Geology, Ravenshaw College, Cuttack-753003, Orissa, IN

Abstract

Quantitative stratigraphic correlation of lithounits and microfacies of Barakar succession in two widely separated borehole sections from Talchir coalfield, Orissa display strikingly different results. When major lithounits are considered, one-to-one correspondence between the two sections becomes significant and indicates the continuity of single homogeneous succession deposited under an identical depositional environment. Lack of significant correlation of microfacies, on the other hand, suggests existence of different subenvironments at different places during each phase of sedimentation. Thus a coal seam is likely to be restricted in its lateral continuity and show differences in the nature of floor and roof rocks, which are vital for safe and economic mining.

Keywords

Quantitative Stratigraphic Correlation, Barakar Formation, Depositional Environment, Talchir Coalfield, Orissa.

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R. N. Hota ¹, K. L. Pandya ¹

Affiliations
1 P. G. Department of Geology, Utkal University, Bhubaneswar - 751 004, Orissa, IN

Abstract

First-and second-degree polynomial regression lines were fitted to data sets consisting of total thickness of strata, number of coal cycles and average thickness of coal cycles of the Barakar Formation of Talchir coalfield. The second-degree lines do not make any statistically significant contribution to the regression variance explained by the first-degree lines which demonstrate the relationship between the data sets explicitly. Significant direct relationships are observed between the total thickness of strata and number of coal cycles, as well as between total thickness of strata and average thickness of coal cycles. On the other hand, significant inverse relationship exists between number of coal cycles and their average thickness. The study suggests that the Barakar succession is fluvial, and the successive coal cycles were generated by lateral migration of meandering streams in response to intrabasinal differential subsidence.

Keywords

Net Subsidence, Coal Cycles, Meandering Stream, Depositional Environment, Intrabasinal Differential Subsidence, Barakar Formation, Talchir Coalfield, Orissa.

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