018 Proceedings of the Asiatic Society. [No. 6. 



interest in the history of the formation of these hills. Dr. Hooker was not 

 fortunate enough to have met with any of these, and speculates on the 

 absence of any traces of these rocks. 



Associated with this group of rocks, occur the deposits of coal which 

 have been stated to occur in this district. There does not, however, appear 

 to be a sound prospect of the discovery of any seam or bed of coal, suffi- 

 cient in quantity to form a useful source of supply. In the Sewalik hills to 

 the north-west, beds of lignite and of coal have also been found ; but all 

 the analogies of the rocks are against the supposition that such small beds 

 will prove continuous, or large. 



Passing now to the Khasia hills, the geological structure is very different. 

 These hills rise from the great flat of the plains almost like a perpendicular 

 wall of rocks, of which the greater portion is composed of sandstones of 

 various tints, often calcareous and ferruginous, all associated with nummu- 

 litic limestones. The geological age of these rocks is well marked by this 

 latter deposit, above and immediately in connection with which, occurs the 

 coal of Cherra Poonji. There are no well marked traces of the newer rocks, 

 above the nummulitic group, at Cherra Poonji, while this group rests imme- 

 diately upon the micaceous, and gneissose metamorphic rocks below. All 

 the known beds of coal in this district, occur in this series of rocks, which 

 must be referred to the older tertiary epoch. 



Passing now to the Rajmahal hills we find there resting distinctly and 

 without any other intervening beds, on the metamorphic gneiss and schists 

 of the plains of Bengal, a series of sandstones and shales with coal of a 

 very different character from either of the group above alluded to. The 

 connection of these beds with the great coal-yielding group of Ranigunj, 

 and of the Burdwan coal field is perfectly established not only by the simi- 

 larity of mineral character and of imbedded fossils, but also by the occur- 

 rence, at intervals within the intervening space, of patches of the same rocks, 

 now detached and left as monuments of the vast denudation that has taken 

 place, and of the original continuity of the rocks. 



In the Damoodah coal-field it is well known that these rocks are cut up 

 by numerous trappean dykes, but in the Rajmahal hills, the exhibition of 

 volcanic forces has been on an infinitely larger scale. There we find great 

 sheets of lava poured out over these sandstone shales : and this flow of 

 igneous matter again covered up by other mechanically deposited beds, 

 containing fossil remains similar to those in the beds beneath : And this is 

 repeated several times. In all these cases, the uppermost beds of the mecha- 

 nical rocks have been greatly altered, indurated and baked by the contact of 

 the great mass of molten matter above : while on the several flows of the 

 trappean character, the bedded rocks rests quite unchanged, and in several 



