Tilhar Fm

The formation was proposed and named after the town Tilhar near Badaun, U.P by Shukla 1973. Holo: Tilhar Deep-1, Latitude: 28o 01' 55" N, Longitude: 79o 45' 00" Drilled depth: 2225 m. The top of the formation is at 1718 m and bottom at 2098 m. This formation is present only in Puranpur and Gandak depressions of Ganga Basin.

Clayey limestone. In the type area, and bottom part is predominantly composed of micritic limestone; the middle part is dark grey to greenish grey, splintery shale and the upper part of the formation consist of micritic limestone. In Puranpur-2 it is composed of upper greenish grey, whitish grey and reddish brown, compact, massive, at places dolomitic argillaceous limestone with thin bands of chocolate brown, to purplish brown and greenish grey, fissile, splintery shale. The bottom unit (115 m) consist of alternating sequence of argillaceous limestone and shale. In Gandhak depression this formation is composed of shale, siltstone, silty shale, thin limestone bands and minor sandstone. Thickness of this formation varies from 195 to 380 m thick.

Spongiophytoni Protole

This formation represents widespread development of a restricted semi-arid carbonate shelf environment and indicates that tectonic activity and associated clastic input were limited. A transgression resulted in retreat of the carbonate shelf environment and establishment of fine clastic dominated outer shelf environment. The relative abundances of carbon and oxygen isotopes are indicative of mixed environment (Uniyal, 1991).