APPENDIX. 57 



trap ; and say that at Weiragad (about 80 miles S.E. of Nagpur) 

 there is no sandstone, but quartzose metamorphic rocks only. 

 At that place the diamonds occur in a lateritic conglomerate which 

 overlies the sandstone in other places, and in which ferruginous 

 cements occur formed from the deti-itus and boulders of adjoining 

 formations ; and this they hold to be the diamond conglomerate. 

 It is therefore assumed to be younger than the overlying trap 

 formation. Above comes in a series of deposits, the lowest of 

 which is brown, the middle red, with existing fluviatile shells, land 

 shells, and bones of mammalia (which Professor Owen has since 

 determined to be those of buffalo and antelope) ; tusks of a 

 large animal were also found in the broAvn cla.y. The uppermost 

 deposit of all is the regur or black cotton soil, in which kunkur 

 is mixed. Bones of oxen and sheep are found in it. 



Messrs. Hislop and Hunter consider these hlach and red clay 

 beds to belong to the Fost-pliocene formations ; the brown clay to 

 the newer Pliocene. 



Assuming these Nagpur deposits to be correctly placed, 

 diamonds of India are still, according to evidence collected from 

 other authorities, and already considered, traced to a conglomerate 

 which may be more recent than our basalts on the Cudgegong, 

 but may not be more recent than some of those at Ballarat, but 

 which seems to have derived its pebbles and boulders from 

 Palseozoic and Metamorphic and oi-dinary igneous rocks ; laterite 

 itself covers rocks alike of every older epoch. Occurring as 

 this detrital covering does all over India, and having the same 

 relative position to all kinds of rocks, and at all heights up to 

 that of at least 8,000 feet above the sea, the idea of diamond 

 belonging to it as its actual source is not sustainable. 



In a subsequent paper (Q.J.Gr.S., vol. xvi.) the Eev. S. Hislop, 

 one of the authors, considers the Intertrappeau Tertiary bed as 

 Lower Eocene, producing good fossiliferous evidence for this 

 opinion ; and shows that the Mahadeva or Bangnapilly sandstone 

 is of about the same age, in which Dr. Oldham seems to coincide. 

 (^Memoirs of India, vol. 1, 171.) Hislop's views have not been 

 thoroughly received by other geologists ; and doubts have been 

 expressed as to whether the trap and basaltic formations of India 

 are not all of one age. 



If we compare the Indian with the Cudgegong diamond 

 deposits, the older of which, and from which the younger is 

 derived, underlies the trap (basalt), it will be seen there is a 

 difficulty to be reconciled with respect to each ; and if the 

 diamond conglomerate of India be Lower Eocene, that difficulty 

 is complicated by assuming that the Cudgegong deposit is Pliocene. 



On reviewing the whole evidence I am inclined to believe that 

 unless they are much younger than the Pliocene or Pleistocene 

 epochs, in fact of recent origin, they must be considered as drifted 



