1869.] Geological Notes on the Ehasi Hills. 23 



the whole eastern side with the hill slopes, are of nummulitic lime- 

 stone, which here abuts on the plains ; the Ronga flows out through 

 the mass of it, which dips 25° south, in hard thick beds, and is the 

 first point on this side, where it is worked for the Calcutta lime trade. 

 A limestone quarry, with a shallow canal approach for canoes, occurs 

 about 1J miles to the east of Bagoli, worked I believe by the Manager, 

 C. K. Hudson, Esq. of the Inglis estates. The Ronga river takes its 

 rise immediately under, and to the south of the Nongkulang hill series, 

 and has one point of interest, but I was unable, from want of leisure, 

 to follow up and examine it. Much coal is to be seen in the bed of 

 the stream brought down from above, and can be no other than an 

 outcrop of that in the infra nummulitic beds seen and described at 

 Nongkerasi ; what its extent may be here in the Ronga, it is impossi- 

 ble to say, but it deserves examination. A subsequent attack of fever 

 prevented my penetrating further to the east of this line, in the most in- 

 teresting and promising part of this geological district, where the useful 

 mineral beds approach so near the plains with the magnificent water 

 carriage which the Um Blay must offer at this very point. I do not 

 think it likely that the coal will be found again near the base of the 

 hills, west of the Moishkulla or Rungsiang river, for a very consider- 

 able distance. The general strike has assumed too strong W. N. W. 

 direction, towards the culminating point Wanrai, and the tertiary 

 sandstones appear very persistent, and with greater breadth, west of 

 Chanda Dinga, owing to the slight extension of the hills southward. 

 Returning to Gilla Gora, I carried my survey along the base of the 

 hills westward, crossing the Rongsiang, near longitude 91°, and on to 

 Chanda Dinga, in order to ascend and observe angles at the fine 

 elevated hill of Marang Thang. 



All belongs to the older tertiary series here ; the principal and most 

 noticeable feature of the rock being, the great increase of dip in this 

 direction, coming in with the newer beds of the series (this is shown in 

 Section B, Plate III), until at Chanda Dinga, the beds are almost 

 perpendicular into the plain, forming here a bare flat rock on the hill 

 . side, marked in the old revenue map, as Chanda Dinga stone. The 

 beds here had assumed that coarse texture, with light brown, or gray 

 tint, lithologically so exactly similar to rocks of the Siwaliks, — even 

 to the scattered strings of water-worn small pebbles, met with in the 



