470 
LOCAL CHARACTER OF THE URALIAN DETRITUS. 
tract of the Ural or Siberia, and observe that the affluents of the rivers are 
chiefly the sites which the gold detritus occupies, might naturally be led to 
infer, that it was nothing but the residue of rivers or streamlets. This, however, 
would be a gross misapprehension. The gold alluvia of the Ural (sand it can very 
rarely be called) is a gravel seldom less coarse than that around London and the 
east of England, and for the most part a shingle, composed chiefly of moderately- 
sized and small subangular fragments of the adjacent rocks. It is, in short, that 
portion of the detritus of this chain, which has been derived from such rocks as 
have been impregnated with gold, or which contained gold-bearing veins. With 
the exception of the presence of very minute portions of gold, platinum or mag- 
netic iron disseminated in it, and which are very rarely perceptible to the eye, it is 
nothing but the debris of certain mineralized masses which have been formerly shed 
off from the flanks of these mountains, and have partially filled up the depressions 
adjacent to them. 
Unlike the Scandinavian and other chains, which burthened with much detritus 
have cast off portions of it to great distances from their flanks, the sides of the 
Ural are void of all such far-transported or rounded blocks ; every loose fragment 
having been derived from an adjacent elevation, and having been usually washed 
down, in strict relation to the chief existing features of the land '. In fact, the 
term drift is not correctly applicable to these Uralian masses, which are purely 
local, and in which there are none of those boulders, that in other countries have 
been transported across hills and valleys, far from the place of their origin. Neither 
do the sides of the mountains exhibit striae of denudation nor polished surfaces; and 
all the superficial detritus, without exception (parts of which only are auriferous), 
is strictly local. Let us now consider the nature and relations of the gold accu- 
mulations, at a few of the principal sites where they are worked. 
Gold Mines of Berezovsk near Ekaterinburg . — These mines, situated about twenty- 
five versts to the north-north-east of Ekaterinburg, have long been most productive, 
and are interesting to the geologist and mineralogist in offering the only subterra- 
nean shafts in all this region by which gold is still extracted from the parent rock 1 2 . 
1 The same distinction was formerly pointed out between the local drift of Siluria and the foreign or 
northern drift of England. See Silurian System, p. 509 et seq. 
2 From the year 1745, to the time of our visit, 1841, these mines had afforded 52,000,000 of poods 
of ore-stuff which had yielded 679 poods of gold. The proportion of gold to the vein-stone or detritus 
necessarily varies exceedingly in different localities, and from time to time, even at the same place. At 
