A STUDY OF COAL FACIES IN THE KORBA SUBBASIN, MAHANADI VALLEY, INDIA

In the Korba sub-basin an effort has been made to study the coal facie s with the help of maceral content, microlithotypes, chemical constitu ents of coal and by depositional milieu. Macerals like vitrinite when associated with sporinite strongly characterised freshwater conditions . i.e.. limnic and telmatic. Microlithotypes of this sub-basin mostly reflect conditions of a high groundwater level in a swamp forest. Micr olayering observed in clarites suggest a certain phase of stagnant wat er conditions in a subsiding sub-basin. Durite indicates sub-aquatic f acies. Carbominerite is more useful in studying lateral facies and the decrease of carbominerite content towards the eastern part of the sub -basin points to the existence of eutropic swamp conditions. The low c oncentration of boron. low sulphur content and the presence of germani um in all blocks of the sub-basin reflects limnic and telmatic coal fa cies in freshwater swamps. The depositional milieu favoured the existe nce of limnic and adjacent telmatic conditions.