16 PROCEED IlfGS OF THE GEOLOGICAL SOCIETY. [NoV. 8, 



period of tlieir deposition ; but no recent fossils have been found in 

 these gravels, although thousands of diggers have been working at 

 them for many months. Only large quantities of worn fragments 

 of fossil wood and two or three pieces of fossil reptilian bones, all 

 from the older formations, have been met with. 



The fragments of pierced Ostrich egg-shells found at Du Toit's 

 Pan, although of considerable antiquity, evidently belong to a far 

 more recent deposit, and have been buried in the silt of a " Pan " 

 or " Pontein," which was the drinking-place of some primitive tribe 

 of Bushmen. 



The absence of recent remains and the frequent fragments of 

 ancient fossils are of great value in the history of some of these 

 gravels. Again, the worn and highly polished surfaces of nearlj'- all 

 the fossils and pebbles, together with the Jiattened and ivedge-UJce 

 shape of many of them, are highly suggestive. Running water 

 would have rounded them. And not only are the small pebbles 

 highly polished *, but very many of the large boulders have their 

 surfaces smoothed and polished. In the excitement of diamond- 

 hunting, however, few have thought of looking for strise or 

 scratches upon any of them (see Postscript). Lastly, on the Dia- 

 mondia side of the river, the rocks themselves marked 6 in the Sec- 

 tion, fig. 2, have the same smoothed and rounded appearance. 



The conclusions to be drawn from the foregoing facts appear to 

 be these : — 



1st. That large portions of the diamond-bearing gravels are not 

 of local origin, but must have travelled long distances, gathering 

 and carrying with them fragments of the various rocks over which 

 they passed in every stage of their journey. 



2nd. That, as many of their constituents are found in the Quath- 

 lamba or Draakensberg, it is highly jjrobable that a large portion 

 had its origin in that range, or in its northern offshoots. 



3rd. That, although it has yet to be determined whether the fixed 

 rocks that contain diamonds are to be found in the mountains men- 

 tioned, or whether these gems have been intermingled with the 

 gravels at any intermediate stage of their passage downward to 

 their present site, it seems certain, from the appearance of many of 

 the diamonds discovered, that a large number must have travelled a 

 considerable distance, and that the numerous broken ones have been 

 fractured by the grinding power of the massive boulders with which 

 they are so frequently associated. 



4th. That the vast unstratified deposits, the promiscuous piling 

 together and interminghng of boulders, the remarkable polish of 

 many of them, the terrace-like mounds and accumulations, all 

 evince physical conditions far diff'erent from those at present in 

 operation ; while the entire absence of all recent fossils in these 

 gravels almost forces upon us the conviction that they must have 



* This peculiar polish of pebbles and fossils is observed in Australia and 

 elsewhere, as remarked by the Rev. W. B. Clarke, F.G.S., in his Address, Hoy. 

 Soc. N. S. Wales, May, 1870, who refers to drifting sand and silicated water 

 as being probable agents under some circumstances. — T. E, J. 



