| Age | Formation | Lithological Description | |
| Pleistocene | Tipam Sandstone | Sandstone with little alternating bands of siltstone and shale. | |
| Plio-Pleistocene | BokaBil | Upper Part | Mostly silty shale with sub-ordinate shale and minor sandstone bed and calcareous sandstone band. Shales are laminated, grey to bluish grey color and contain many streaks and lenticles. Yellowish brown colored, medium to fine grained, apparently massive sandstone and siltstone bed have occurred rarely. |
| Lower Part | Mostly shale with subordinate silty shale, frequently channel sand body and occasional massive sandstone bed. Shale is mostly bluish grey colored, thickly laminated and silty shale are grey to light grey colored, thinly laminated with frequent silt streaks. Channel sandstone is yellowish brown to grey colored, fine to medium grained massive sandstone embedded in shale. | ||
|
| Upper Bhuban | Sandstone, shale/silty shale, siltstone, silty sandstone. | |