SECTION FROM STERLITAMAK ACROSS THE PERMIAN DEPOSITS. 149 
In proceeding northwards from Sakmarsk to Sterlitamak, we no longer met 
with the limestone containing fossils of the Zechstein ; but near the mines of 
Voskresensk (still nearer to the Ural), we were once more amidst cupriferous con- 
glomerates, inclined to the west and reposing upon a white limestone without 
fossils. 
Though our time did not permit us to make many transverse sections, still by 
ascending the Sakmarka, where its course lies from east to west (see Map), we ascer- 
tained, that a considerable tract of red country is there interpolated between the 
zone of limestone with zechstein fossils (just mentioned), and the flaglike and 
upper beds of the carboniferous limestone. The latter forms the outer or western 
edge of the picturesque hills, among which General Perofski, the Governor- 
General of Orenburg, has his summer residence. In our journey, however, from 
Orenburg to Voskresensk, we necessarily regained the flank of the carboniferous 
limestone, and in its vicinity we again obtained proofs of the existence of a white 
limestone without fossils, as above stated, dipping under and surrounded by cop- 
per grits and siliceous conglomerates. This excursion, therefore, confirmed our 
view of the existence of two calcareous zones, as proved by the section from the 
Gourmaya Hills to Orenburg. We shall presently offer similar evidences in a 
section from Sterlitamak to the environs of Bielebei, and in the next chapter a like 
sequence will be indicated in the account of our ascent of the great Dwina from 
Archangel to Ustiug. 
In the parallel of Orenburg, we found a system of red grits, marls, conglomerates, 
&c., spread out over the whole country between that city and Samara on the Volga, 
with scarcely a trace of limestone. The higher part of this region, which divides 
those streams from the valley of the Ural, and is known as the Obschey Sirt, is 
not, as some authors supposed, a ridge of crystalline rocks, but simply a low and 
scarcely perceptible watershed, which is traversed by the road from Orenburg to 
Samara, where it consists of red sandstone, in parts hard, solid, and slightly 
micaceous, with subordinate, concretionary beds approaching to conglomerates. 
To the east of the fort of Borsk a natural section of about 100 feet exposes in ascending order the following 
beds 1. Solid red sandstone. 2. Red shale. 3. Red sandstone. 4. Red shale. 5. Reddish coarse-grained grit 
of some thickness. 6. Red shale. 7 . Thin bed of red and green sandstone. 8. Course of conglomerate. 9. Red 
sand with concretions. 10. Red shale. 11. Conglomerate, with fragments and concretions of marl, &c., and 
hones of Saurians. 
In the ensuing chapter we shall treat of the extension of the Permian rocks to 
the south of Orenburg, and into the steppes of the Khirghis, where they are charac- 
x 
