39 



The Carboniferous series is found in the northern and central portions of Rus- 

 sia, but only the lower or calcareous beds occur, with sandstone, bituminous shale, 

 and thin beds of impure pyritous coal, wilh the usual vegetable remains of coal 

 measures. These are overlaid by a limestone somewhat similar to the British 

 magnesian limestone, and sometimes resembling pisolite, while another is white, 

 and not much more compact than the calcaire grassier of Paris. 



This white producta limestone stretches to the distance of a thousand mile^. It 

 has been called by some chalk, to which it bears a resemblance in containing no- 

 dules of flint, (chertl) sometimes coated with corals. With this are associated 

 immense beds of gypseous alabaster ; and thin bands of limestone alternate with 

 it, which has been determined to be, from its fossils, the true mountain limestone 

 of the coal measures. No workable beds of coal can be expected to be discovered 

 south of Moscow. 



Oolitic series. — It had long been a matter of doubt whether a series of strata 

 could be found to connect the lower carboniferous beds with certain rocks of the 

 oolitic series which were known to exist in the south of Russia. Some of those 

 beds which rest on the great red formation along the banks of the Volga unques- 

 tionably belong to the middle oolite, as they contain the ammonites and belemnites 

 identical with those belonging to that order. Some of the shells, however, resem- 

 ble the lias ; and on this point Mr. Murchison reserves his opinion till comparisons 

 can be made of the fossils. The shales of the oolite rest directly on the white car- 

 boniferous limestone of Moscow. 



Ferruginous sands cover the lias. In these are found large concretions of grit 

 used for mill-stones, but no fossils as yet have been discovered in them. 



Chalk. — The cretaceous system is very extensive, but was not on this occasion 

 particularly examined. 



Tertiary deposites. — Such deposites have not been discovered in the northern 

 or central regions of Russia. 



Younger Pliocene, (Pleistocene.) — Before the visit of these gentlemen, it was 

 supposed that all the great masses of superficial detritus were referable to the dilu- 

 vium epoch, in which the remains of the great extinct quadrupeds were also im- 

 .bedded. They had not the leisure, however, to make a thorough examination of 

 this interesting subject, but they were -satisfied that it was divisible into several 

 ages. They discovered as many as fifteen or sixteen varieties of shells of modern 

 species. Mr. Lyell confirms this, and identifies them with the Udda-valla group. 

 * This demonstrates that, at a modern period, the whole of the vast flat country of 

 Russia was under water, and the eastern shores of the sea extended to the foot of 

 the Ural Mountains. 



Drift and Erratic iHlocks. — All the older formations are covered with detritus, 

 the large granitic boulders of which, with the pliocine which they had discovered, 

 were all derived from the north. This subject they intend to make the matter 

 of a separate work. 



Mr. Lyell spoke of the great importance of these discoveries in removing doubts 

 as to the new arrangements of the British rocks, especially in reference to the iden- 



