Mineralogy and Geology. | +921 
_ age of these deposits and of the gold veins PPA semsiancic 
date and little, if at all anterior to the destruction of the mammoths. 
~ Mr. Murchison concludes that what we now call the Ural deansidloa 
constituted, at the period of the formation of the cupriferous gravel now 
found on the Permian plains, (west of the Ural,) the rocky shore of a 
_very ancient and probably low continent, from which powerful streams 
descended into a western sea, From the entire absence of gold in all 
the deposits: there found, and in the earlier ‘reliquix” of this chain, 
as the carboniferous conglomerates, he infers, with inductive certainty, - 
that this old continent afforded no gold; for had it been so, some 
trace, however slight, of gold or platinum must have been found in the 
Permian debris ; and yet the long and patient workings of the detrital 
copper, mines on the European side of the chain have never disclosed 
sucha thing.. From these and other data, he concludes that the chain 
becamewvauriferous during the most recent disturbances, by which it 
was affected, and after the highest peaks were thrown up, when the 
present water shed was established, and when the syenitic granites and 
other. tb ait Soe recent eee rocks were senate along its eastern 
cael The only dpistrnss in #hich: grin ipa portions of gold and losis 
lens been found, is that in-which remains of mammoths and rhinoce- 
roses have also been detected, and coupling this fact with the omission 
of all auriferous veins in the more ancient alluvia of the chain, there 
can be no doubt that in this region, gold was one of the most recent 
mineral productions anterior to the historic era.” ‘“ We believe, then, 
that before the surface assumed its present outline, the tract we now 
call the Ural mountains was.a low ridge, extending from north to south, 
and forming the western shore of a continent on which such animals 
lived and died during long ages.” (475.) 
- The gold detritus of the Ural is not the residue. of rivers and. stream- 
lets, but is a coarse gravel and shingle, composed chiefly of moderately 
sized and small subangular fragments of the adjacent rocks. The 
sides of the Ural are devoid of those great transported, and rounded 
blocks, which cover the Scandinavian and other chains; every loose 
fragment having been derived from an adjacent elevation, and washed 
‘down in strict relation to the chief existing features. of the land. The 
term drift cannot be correctly applied to the Uralian masses, which are 
purely local; neither do the sides of the mountains exhibit strie of 
denudation, nor polished surfaces. 
The gold mines of Ekaterinburg are interesting as offering the only 
subterranean shafts in all this. region, by which gold is still extracted 
from the parent rock. The mines have furnished from 1745 to 1841, 
52,000,000 poods of ore stuff, (about 940,000 a of 2,000 Ibs.) and 
_ Sxcoxp Series, Vol. 11, No. 4.—July, 1846. 
