RANK EVALUATION OF THE NEYVELI LIGNITE DEPOSIT ON THE BASIS OF REFLECTANCE PARAMETER

The Neyveli field is well known for Tertiary lignite deposits in India . The reflectance of organic constituents (huminite macerals) has been measured to find out organic maturation level (rank) of the main lign ite seam lying either at same time level or at different time levels i n space. The deposits are of sub- bituminous C stage (ASTM) with the m ean reflectance (Ro max. in oil) range from 0.34 to 0.42% (average 0.3 9%). Evidences from rank study indicate that the quality of lignite de teriorates towards southern part of the field.