208 Becker — Auriferous Conglomerate of the Transvaal. 



of either the impregnation or the precipitation theory. The 

 beach deposits of the Pacific form an excellent instance of such 

 marine placers, although they are not so rich as those of the 

 Rand. On the other hand, no case is known of an extensive 

 gold deposit which is certainly an impregnation in sand or 

 gravel, nor is there an established case of marine precipitation. 



There seem to be no other possible theories besides those 

 discussed, but Messrs. Smith and Hammond are of the opinion 

 that the gold is partly detrital and partly in place in the 

 banket. Speaking with exactness, I agree with them, for, as 

 has been mentioned, the white quartz veins are not absolutely 

 barren. To my mind, however, it seems conclusively proved 

 that only a minute fraction of 1 per cent, of the gold has this 

 origin, for I see no reasonable evidence that any portion of the 

 gold excepting that to be found in the white quartz seams is 

 untransported. 



On the theory which I have adopted the auriferous banket 

 should be found to stretch along a line of ancient coast bound- 

 ing an area in which gold-bearing quartz veins were rich and 

 numerous. How large this area may have been, and therefore 

 how long its ancient coast was, it is as yet impossible to say ; 

 but the indications are that the area was extensive and the coast 

 long. Doubtless some portions of the coast will furnish only 

 banket too poor to work, but until the Lower Cape formation 

 has been traced across the continent of Africa other spots as 

 rich as the Rand may be hoped for. 



Washington, D. C, February, 1898. 



