272 
CHALK ON THE BANKS OF THE RIVER URAL. 
dication of their belonging to the same epoch, we could easily have solved such 
a question, by placing all the sands, clay-stone, &c. of the southern regions in the 
tertiary series. But the clear sections of Kursk and numerous other places con- 
tradict such a classification ; whilst the structure of Saxony and the adjacent 
parts of Germany support the view which we have adopted, by distinctly proving, 
that the very uppermost beds of the Cretaceous group are often siliceous sand- 
stones. In describing the tracts of this age along the Lower Volga, we shall pre- 
sently show how, as at Kursk, siliceous sands with beds of marlstone and clay- 
stone are interlaced with the white chalk, and form with it one inseparable series. 
In the mean time let us say a few words on the chalk of the far-distant south-eastern 
steppes, on the banks of the river Ural. 
Chalk on the hanks of the Ural. — The most remote country in which we observed 
true chalk, was on the banks of the river Ural, about 150 versts south-west of 
Orenburg, where it forms a zone of about 160 versts in width, extending from the 
junction of the Utva with the Ural on the north-east, to the country beyond Uralsk 
on the south-west. The greatest length of this zone, we had no means of deter- 
mining, in that wild region of Kirghis and Cossacks, the extreme boundary of 
the Russian empire ; but from what we could ascertain, the chalk ranges from the 
banks of the Ural, where we examined it, to beyond the sources of the Kamelik, a 
tributary of the Volga on the west, and on the east towards the rise of the Utva. It 
may, indeed, have a much wider range than we have assigned to it on our Map, 
for Pallas has spoken of chalk on the European side of the Ural, near the 
sources of the Busuluk river 1 , and it may therefore occur to a small extent on the 
north side of the Jurassic rocks which are laid down upon our Map. For our own 
part, we observed chalk at the hill of Semipolatnoi on the river Utva, and also on 
the opposite bank of the Ural river, at the Cossack outposts of Baratinskoi, Zenu- 
arzof, and Rubeshnoi, where it is white, without flints, in horizontal beds, and con- 
tains Inoceramus Cuvieri and Belemnites. The alluvial plain on which is placedUralsk, 
the chief town of the frontier Cossacks, is almost surrounded by chalk (see Map), 
which to the south sinks under the tertiary sands of the steppes of the Kirghis. 
Cretaceous rocks of the Volga below Simbirsk. — In describing the range of the 
' We so much respect the authority of Pallas on every point, that we scarcely dare to express a doubt 
respecting this chalk near the sources of the Busuluk. As, however, in passing from Orenburg to Samara, 
we traversed the Obschey Sirt (see Map), and saw nothing but Permian rocks, we venture to surmise, 
that the rock supposed to be chalk, may prove to be one of the white marlstones, or limestones so abun- 
dant in the red Permian deposits ? 
