Petrology of oligocene coal, makum coalfield, assam, Northeast India

There are five workable coal beds in the Tikak Parbat Formation of the Barail Group in the Makum coalfield, Tinsukia District, Assam. Two of these beds, 18 and 6 m thick, are persistent across the field. The coal is high volatile bituminous B/C, has excellent coking properties, and is of great importance as a blending coal to improve the coking properties of the lower-quality Gondwanan coals.These coals are bimacerites as vitrinertite or trimacerites as duroclarite. Virtrinite predominates with minor amounts of other macerals and minerals. The high percentage of vitrinite indicates that the bark and woody tissues were the dominant contributors to the precursor peat. These peats were strongly decomposed under anaerobic conditions as indicated by the abundance of the collinite type of vitrinite.