SOURCE AND DISTRIBUTION OF THE COLD. 



351 



should in places have been swept downward beyond the limit of the area of 

 productive quartz mining, is something not at all difficult to understand, when 

 we consider the manner in which these gravels have been accumulated and 

 moved from their original position, under the influence of powerful currents 

 of water. Some very fine gold has been carried, no doubt, to a considerable 

 distance from its native bed, and deposited upon strata which w r ere not in 

 the least auriferous; but the coarser portion of the gold remains either on 

 or in close proximity to the place where it originated. Whether the large 

 pieces of this ductile metal could be reduced by abrasion to particles so small 

 as to be carried to a very great distance is not sufficiently well made out ; 

 but the gold, as it was originally formed in the quartz, seems, in very many 

 localities, to have existed chiefly in the form of very minute particles, not 

 visible to the naked eye. The abrasion of the quartz must set these free, 

 and they might, as w T e may suppose, be easily transported with the aid 

 of water. 



If there is, as Mr. Goodyear thinks not unlikely, an immense amount of 

 the precious metal buried in the detritus of the Great Valley, there is but 

 little encouragement to look forward to a time when it can be profitably 

 separated from the sand with wdiich it is associated. 



That the distribution of the gold in the gravel should be irregular and that 

 it should be widespread are conditions which seem quite in harmony with 

 its origin. Quartz veins are very generally distributed through the bed- 

 rock series ; a large portion of these contain some gold, many of them are 

 rich enough — in places, at least — to pay for working. Whether the quartz 

 veins in the bed-rock, as they at present exist, contain gold enough to furnish 

 by their abrasion a quantity of the metal sufficient to correspond with what 

 has formerly been accumulated in that w r ay — equal quantities in each case 

 being assumed, of course, as having been worn away — as a matter of con- 

 siderable doubt. Yet the statement that the bed-rock at present would not 

 furnish as rich a gravel under the same conditions, as to abrasion and accu- 

 mulation, as those of the Tertiary gravels, is not one susceptible of positive 

 proof. It can only be said that it appears — to the writer, at least — very 

 clear that the older gravels have been formed from a material considerably 

 richer in gold on the average than is the present bed-rock of the region. 

 That this should be so, however, is not at all surprising, but, rather, in 

 harmony with the general results of observations in mining regions. How- 



ever unwilling those who have mining property for sale may be to admit it, 



