RELATIONS OF CRETACEOUS TO TERTIARY STRATA. 
277 
Seeing, therefore, in a country which has been subjected to few or no great 
dislocations, that the white chalk reappears at intervals upon the same level as 
certain beds of white and gray claystonc and sandstone, we came to the conclusion, 
that the latter must here constitute the dominant portion of the Cretaceous system, 
in which the white chalk occurs in large occasional masses only. Led as we were 
to this conviction by the general structure of the country on the Lower Volga, 
we were still more impressed with it, when in our examination of the Steppes 
of the Don and the governments of Kharkof and Kursk we found, as already 
stated, an abundant development of similar rocks, in none of which could we de- 
tect the trace of any tertiary shell, but in which, to the evidences collected on the 
Volga, we added, as already stated, that of a Belemnite with Terebratulae and 
Polypifers, unquestionably of cretaceous age. 
A traverse which we made from the chalk of Bielaia-glina to Antipofka 1 on the 
Volga, also confirmed us in our views of the order of superposition. Leaving the de- 
nudations in the white chalk, we there passed over a plateau of sandy and quartzose 
character, the beds of which, distinctly overlying the chalk, seemed to incline gra- 
dually upon a long slope, so as to form the base of certain shelly beds, which upon 
the Volga are loaded with fossils of Eocene age, the whole as represented in this 
drawing. 
SECTION SHOWING THE GENERAL RELATIONS OF THE CRETACEOUS AND TERTIARY STRATA. 
w.n.w. » 43, 
Bielaia-glina. 
E.S.E. 
Antipofka. 
d. Tertiary sands. 
c. Clay and sand with shelly concretions (Bognor and London clay-shells). 
b. Sands and claystone, ike., forming the passage from cretaceous to tertiary rocks. 
a. White chalk, with Terebratulse and other fossils. 
The tertiary sands and marlstone of Antipofka very much resemble the beds we 
have been considering as cretaceous, and though we had not time to make detailed 
researches, we have very little doubt, that a thorough exploration of the adjacent 
ravines will afford evidence of a passage from the white chalk, through a group of 
claystones, sands, &c„ into true tertiary deposits, the lower portion of which have 
to a great extent the same mineral characters as the upper cretaceous. 
From sections, then, as well as from the general structure of large provinces, we 
are impressed with the belief, in a gradual mineralogical and stratigraphical trans- 
» We were of course led to Antipofka by tlie well-known description of Pallas. 
2 o 
River Volga. 
