422 
GYPSUM OF THE RIVER SINARA. 
posed of crystalline rocks, some of which have been already alluded to, and others 
have been described by Humboldt and Rose. Believing that a tract in which the 
copper mines of Gumachefsk and Polefsk, so well known for their imbedded 
minerals, including marbles, veinstones, &c., could afford few or no traces of 
organic life, we did not examine it, but deflected from the chain to make the sec- 
tion on the Issetz, already described, and did not regain the mountain slopes till 
we reached the environs of Kishtymsk *. 
Quitting the Issetsk and the little oasis of Silurian rock at Crasnoi-glasnova 
(p. 364), we bent our steps obliquely towards the eastern slope of the Ural. Fora 
considerable space around Crasnoi-glasnova the surface is occupied by rich black 
earth, the “ tchornozem ” of the Russians, of which we shall treat hereafter, men- 
tioning it in this place only, in order to note, that we are unacquainted with any 
such deposits on the flanks of the Northern Ural. In this tract is also situated the 
brackish lake of Shablish, which having scarcely any outlet, may possibly derive 
its saline properties from springs flowing through subjacent rocks. We perceived, 
indeed, another geological feature in the neighbourhood of this lake, which led us 
to infer, that saliferous deposits, similar to some of those of Russia in Europe, 
might exist beneath the superficial covering of black earth and local detritus. 
Being informed by the peasants, that gypsum occurred in a little mount about 
twenty- five versts south-east from Bagariatsk, we travelled from that place to ex- 
amine it. Passing by the lake and village of Ognova, in a flat country covered by 
black earth, we found the gypsum exposed in a gentle rise on the right bank of the 
river Sinara, and not far distant from its junction with the Sinera. Though the 
quarry had not been worked for fifteen years, the open cuttings were still sufficiently 
visible, and a section of about thirty feet deep plainly exposed courses of thinly 
i Whilst two of us, Mr. Murchison and M. deVerneuil, were thus employed upon its eastern flank, 
Count Keyserling repassed the Ural to Sergiefsk, and descended the streams to the banks of the Ufa, 
thereby ascertaining the junctions between the older palaeozoic rocks and the grits of Artinsk (see ante, 
p. 128). After these independent explorations we again met at Zlataust, whence, after some conjoined 
explorations, M. de Verneuil and Count Keyserling passed from the Ai to Satkinsk, Siinsk, Uta and 
Orenburg. From Zlataust Mr. Murchison again took the Asiatic side, and, accompanied by Lieutenant 
Koksharof, re-crossed to Miask and the Ilmen Hills, examined the auriferous tracts there and at Cossatchi- 
datchi, from whence he traversed the steppe to Troitsk, and thence regained the Ural river, following it 
to Orsk and Orenburg. Afterwards, in company with M. de Verneuil, he made sections across the clmip 
from Orenburg to Verch-Uralsk, and from that place to Sterlitamak, whilst Count Keyserling traversed 
the Kirghis steppe by Mount Bogdo, &c. 
