Dinaipur Fm

Holo: Lahil-1, Latitude 26o 02' 22" N, Longitude 87o 53'35" E, Drilled depth: 3335.20 m. The top of the formation is at 2078 m and bottom at 2640 m. Shukla et al. (1993)

Sandstone with Coal. The formation is represented by alternations of sandstone, siltstone, carbonaceous, shale and coal seams. This formation is finer in grain size with lesser frequency of coal seams in comparison to the underlying Katihar Fm. Sandstone is light grey to grey in color, fine to medium grained, occasionally coarse grained, hard, compact and calcareous in nature. It is made up of subangular, subrounded grains of quartz, feldspar and opaque minerals with few brownish red and green colored minerals, Carbonaceous shale is black in color, hard, compact and micaceous, Siltstone is bluish-grey to grey in color, hard, compact, micaceous and non-calcareous. Coal is pitch black in color, soft, compact, sub-bituminous in nature containing very bright to dull colored laminae. The thick of coal seams varies from .5 to 2 m. Total number of 23 coal seams were identified with a coal to non-coal ration of 1:29. The thickness of this formation ranges from 420 m to 562 m.

The Dinajpur Formation is characterized by a) dominant occurrence of Striatopodocarpites and Scheuringipollenites, b) significant but rare presence of Klansipollenites and Inaperturopollenites, and c) common occurrence of Faunipollenites trilete spores