AVIFAUNA OF CHOTA NAGPUR. 36'3 



The limestones are not of much use, as they generally contain 

 foreign minerals, such as tremolite or serpentine. 



The copper ores above-mentioned occur in a remarkable 

 deposit, which is traceable in the northern part of Singhbhum 

 for a distance of eighty miles. Two attempts to work this 

 copper by European enterprise completely failed. Chiefly, I am 

 inclined to believe, in consequence of injudicious management. 

 At any rate it is apparent that the deposit has not by any means 

 been fully opened out, and that the possibility of a profitable 

 exploitation has not been fully tested. 



By the ancients (Jains)* mines were opened up at the out- 

 crop all along the eighty miles — wherever the ore appears. The 

 European companies put down a few shafts and drove several 

 adits into the hills, but no great depth was attained anywhere. 



The next series of rocks in the ascending scale is that 

 known from the place where it was first discriminated as 

 the Talchir. It underlies the coal measures ; but the chief point 

 of interest connected with it is that the original supposi- 

 tion of the boulder beds which it contains being of glacial 

 origin has, by the discovery of lines of glaciation on some 

 of the boulders, been placed beyond a doubt. 



The occurrence of huge boulders resting in a bed of silt, 

 in some cases at a considerable distance from the source from 

 which their mineral characters show them to have been derived, 

 thus finds a complete and satisfactory explanation. 



The fact of the establishment of evidence of a glacial period 

 once having existed in these latitudes is one of almost cosmical 

 importance, and it comes rather within the range of the astrono- 

 mer than of the geologist to determine what can have been 

 the conditions at that time which would have been consistent 

 with the existence of glaciers. 



Of course could we see our way to believing that the 

 Peninsula was once some 12,000 to 15,000 feet higher above the 

 level of the sea than it is at present, that in itself would be 

 explanation sufficient, but it seems probable that the cause 

 was not a mere local one. 



Rocks of the Talchir series occur underlying the coal mea- 

 sures in the Damuda valley, and also on the higher level of the 

 Hazaribagh plateau. In Sirguja and the neighbouring districts 

 they cover large areas, whence they stretch southwards and 

 westwards by more or less detached exposures towards the plains 

 of Chatisgurh. 



* Note. — See on the ancient copper miners of Singhbhum. P. A. S. B., June 1869, 

 p. 170, and on the copper deposits of Dhalbhum and Singhbhum. Records of the 

 Geological Survey of India, 1870, p. 86. 



