136 RANIGANJ COAL FIELD. [CHAP. VI. 



In all three cases, indeed, the evidence amounts only to this, that there- 

 are coarse sandstones and conglomerates of later date than Damuda age ; 

 that in Orissa and Central India the beds are of great thickness (2,000 

 to 3,000 feet), cover considerable areas, and rest unconformable upon the 

 Damuda rocks. In the Damuda Valley there is no great thickness nor 

 extent of the beds, and they rest, whether unconformably or not, is not 

 clear, upon a formation unknown in the other two localities. As 

 the Damuda rocks are certainly not of later date than Oolitic age,* 

 the newer beds may belong to any subsequent epoch. 



There is, however, a group of beds in the Rajmahal Hills, which 

 presents greater facilities for identification. No description of it has 

 been published, and it is therefore necessary briefly to allude to the 

 general section of the formations there occurring, a sketch of which 

 has already been given by Dr. 01dham,-f- in anticipation of the full 

 description of them. The section is : — 



1. Trap, with inters tratified beds of shale > 



and occasionally of sandstone. I Rajmahal group. 



2. Coarse grits and conglomerates. J 



3. Sandstone, shale and coal. Damuda group. 



The higher portion of the Rajmahal group, viz. the traps and inter- 

 trappean shales, resting unconformably upon the grits and conglomerates, 

 which again are unconformable upon the Damudas. These grits and 

 conglomerates appear to belong to the Rajmahal group, (they are cer- 

 tainly in no way connected with the Damuda series,) and form beds 



(Subsequent research lias shown the existence of vegetable remains, stems, &c, in the 

 Panchet Hill rocks, which would appear to afford an additional reason for connecting these 

 with the Mahadeva group of Cuttack. But the evidence at best is as yet exceedingly defi- 

 cient.— T. Oldham.) 



* Beds of the lowest Cretaceous group rest in Madras unconformably upon rocks of Rajmahal 

 age, and the latter are far newer than the Damudas. — Mem. Geol. Survey of India, Vol. II., 

 page 323. 



f Mem. Geol. Survey of India, Vol. II., page 313. 



