Petrographic Characterization and evolution of Eocene Coal from Bapung coalfield, East Jaintia Hills, Meghalaya, North-East India

Abstract

The Bapung coalfield in the East Jaintia Hills of Meghalaya belongs to the Shella Formation of Jaintia Group and is of Eocene age. Thinly bedded seams of about 1 m thick are vastly exposed in the Bapung area. The present study includes petrographic and geochemical characterization of these coals. This study reveals that the Bapung coals are sub-bituminous ‘A’ to high volatice bituminous ‘C’ in rank. These coals are perhydrous in nature with moderately high volatile matter content. The sulphur content is high in these coals having pyrite as the most abundant mineral. Vitrinite is the dominant maceral group constituting nearly 76.5-82.6% of the entire group macerals, while inertinite occurs in subordinate amount and liptinite concentration is insignificant. Facies-critical models used to decipher the paleodepositional environment suggest that anoxic moor condition dominantly prevailed in the paleomire and there was association of peat with brackish water condition which allowed the sulphate reducing bacteria to thrive.