390 
BISSERSK AND CIIRESTO-VODSVISGENSK. 
versts to the north of that place, where they are specially distinguished by con- 
taining that beautiful green mineral “ Ouvarovite,” so peculiar to the Ural Moun- 
tains and Siberia. This line of eruption, it will be observed (see Map), is parallel 
to the crest of the Ural. In looking at these rocks of Bissersk and those of Nijny 
Serginsk as two north and south 1 lines of eruption, the geologist may well account 
for the great breaks and occasional metamorphism of the intermediate strata, of 
which we have just treated as exposed upon the Tchussovaya. But between these 
small lateral and western lines of eruption and the chief ridge of the Ural, where 
other eruptive rocks appear, many sedimentary deposits occur, and just as in other 
traverses we perceived, that in proportion as the strata approach the grander lines 
of igneous protrusion, so are they more metamorphosed and crystalline. 
For a few versts to the east of Bissersk no rocks appear through the deep and 
heavy alluvia and morass, hut on reaching the little depression in which gold 
and diamond alluvia occur (twelve versts east of Bissersk), strong ledges of black 
dolomitic limestone have been laid open, which strike from 35° west of north to 35° 
east of south. In some places, where the alluvia have been removed, the beds are 
seen in highly inclined positions, sometimes vertical and at others inclining 70° to 
80° towards the Ural. These dolomites, in the least altered parts of which we de- 
tected a few imperfect organic remains (Corals, Terebratulas, Spiriferae, &c.) , have 
much the aspect of those on the Tchussovaya, except that they are still more cry- 
stalline. They are flanked on the west, and in fact pass into talcose schists, with 
bands and flattened concretions of quartz, and as both these rocks have clearly 
been altered, we conclude that the same causes have affected each of them. In 
fact, we observed between the beds of the dolomite, laminae of talc schist similar 
to those which occur in the talcose and quartzose rocks of the adjacent moun- 
tains. 
Throughout the greater portion, however, of the tract around Chresto-vodsvis- 
gensk, the subsoil is completely hidden from view by thick mounds of gravel, for 
the most part very coarse, in which the gold ore occurs, and in which a few dia- 
monds have been detected. To these a future reference will be made, and we now 
proceed to describe the passage of the Ural by the mountain of Katchkanar. 
Passage of the Ural by the Katchkanar to Turinsk and Verlchoturie . — The road 
by which we were to pass the Ural (for the greater part a mere horse track), not 
having been used for some years, it was necessary to send workmen in advance, 
1 See page 354. 
