76 hughes: southern coal-fields ov iiewah gondwana basin. 



my remarks under the present section of Economic Geology to the facts 

 in connection with the coal of the Umaria field, its greater geographical 

 importance, and the more complete determination of its value as com- 

 pared with those of the other coal-measure areas, having made it the real 

 gauge of their present worth. 



As at present proved in No. 7a bore-hole, there is a maximum thick- 

 Thickness of coal in ness °^ 24 ^ ee ^ °^ coa ^ a ^ a depth of 184 feet from 

 No. 7a bore-hole. ^ e sur f ace . This is accumulated in two seams 



measuring respectively 13 and 11 feet, and separated by 25 feet of car- 

 bonaceous sandstone. The outcrop of the lower of these is visible in the 

 Umrar river near Kalesar. It is traceable thence westward through 

 ravines and gullies south of and near to No. 1 shaft. From that point, 

 there is no sign of coal in the direction of the Narsara Nala or elsewhere, 

 and it becomes a matter of supposition as to how the outcrop runs. 

 Probably the strike changes, and veering to the north-west and north 

 gradually becomes parallel with the Chatan range of hills. Speaking 

 generally, the dip of the measures within the exposed limits of the field 



is to the north-east at a low angle ; but from the 

 Local variations of dip. . 



evidence in No. 2 shaft there is the probability 



of local variations, for the level course at that spot in the field is 



north-east and south-west. Such variations, however, are always to 



be expected, and do not affect the main dispositions for the working of a 



colliery. 



There is no evidence of the second seam at the surface, but I think 

 that the journals show it to be nearly co-extensive with the lower 

 seam. Many of the borings were not carried through the whole 

 thickness of the coal bands, but such as were, bear testimony to two 

 seams, — as, for example, those where the shafts are placed, and Nos. 7a 

 and 16. 



In speaking of the thickness of the coal, then, we may reasonably 

 assume that after excluding a superficial breadth of 500 feet from the 

 outcrop of the lower seam, measured in the direction of the general dip, 

 there is quite 20 feet of it. 

 ( 212 ) 



