SUB-MARINE ORIGIN OF THIS COAL. 
113 
any means so rich in coal, coal-shale and plants, as this Russian deposit, which 
is the more remarkable per se, when compared with the strata of the same age 
previously described in the basin of Moscow, where there is not a trace of car- 
bonaceous matter or black shale in deposits containing the same species of 
Spirifer and Productus. Instead of the grey and dark bituminous limestones 
of this southern tract, the whole calcareous mass around Moscow, and extend- 
ing to near Archangel, is, as we have before shown, a pure white limestone, 
with some inosculating hands of magnesian character, and also of red and 
green marls and sands. In the Valdai Hills and in the governments of Tula 
and Kaluga, coal, on the contrary, is found only in strata beneath the lowest 
zone of carboniferous limestone, as in Berwickshire in the British Isles ; whilst 
in the south of Russia we are as yet unacquainted with any notable seam of coal 
so low in the system, unless it be the anthracites of Popofskoe and the Lower 
Donetz. 
The tabular view, therefore, which we have prepared and annexed to the Map, 
and which exhibits on one side of the coloured scale a central mass of pure 
limestone (Moscow), graduating on the other side into a series of shale and 
grit, with thin courses of limestone (Donetz), conveys a true picture of the great 
difference in composition between the same carboniferous masses in the northern 
and southern regions of Russia. 
In regard to the theory of the origin of coal, which has of late attracted so much 
the attention of English geologists, the sections of Lissitchia-Balka and of the 
southern regions of Russia assure us, that the hypothesis of the formation of coal- 
beds by masses of vegetation, and the ground on which they grew having subsided 
in situ (the truth of the application of which to some coal-basins we do not dispute), 
cannot be applied to the cases in question, any more than to the pure marine coal- 
beds of the northern districts of Northumberland, and the north-western parts of 
Yorkshire, &c. It is true, indeed, that several of the seams of coal at Lissitchia- 
Balka have a sub-stratum of argillaceous schist, and that perchance these sub- 
strata might be identified lithologically with the bottom or fire-clay of the observers 
who support that view. But what does this prove ? Supposing even that it was 
a creeping plant that grew upon the spot, is the Stigmaria ficoides alone there ? 
By no means, for we meet with a confused assemblage of many terrestrial plants 
both above and below the coal-seams ; whilst from the uppermost to the lowest 
bed, throughout a thickness of about 800 feet, the shells are exclusively of marine 
