Chap. XIV.] 
PALEOZOIC SUCCESSION IN KTTSSIA. 
367 
In making these brief observations on the Carboniferous deposits of 
Russia, and in referring to the details given in ' Eussia and the Ural 
Mountains/ I wish my readers to understand that, as it was my painful 
task to acquaint my kind friend and patron, the late Empeior Nicholas, 
with the important but disagreeable fact that all Northern Russia must ever 
be exempt from coal, inasmuch as the rocks which there rise to the sur- 
face are of an age anterior to the oldest formations in which coal exists, it 
was at the same time a pleasing duty to hold out a different prospect for the 
southern part of his great Empire. Thus I could well declare that there 
the very same limestones which are so poor in coal near Moscow assume 
rich coal-bearing qualities as they roll over southwards in great undula- 
tions beneath the Secondary formations, as proved by the outcrop of rich 
masses on the Donetz. Knowing, further, that this phenomenon extended 
even to Eregli, at the south end of the Black Sea, I naturally impressed 
upon the Imperial Government the high probability, if not almost certainty, 
of finding large undisturbed coal-fields beneath the horizontal Secondary 
rocks that occupy the flat and undulating steppes to the east of the River 
Donetz. (See ' Russia-in Europe/ vol. i. p. 118.) 
In stating that identical formations have very dissimilar mineralogical 
characters in tracts distant from each other, we have only to point to dif- 
ferent parts of the vast Russian Empire itself. Thus, whilst the soft Lower 
Silurian clays and sands of St. Petersburg have their equivalents in the 
hard schists and quartz-rocks with gold-veins in the heart of the Ural 
Mountains, the equally soft red and green Devonian marls of the Yaldai 
Hills are represented on the western flank of that chain by hard, contorted, 
and fractured limestones, as in the preceding sketch, made in the gorge of 
the Tchussovaya. 
The deposits of Silurian, Devonian, and Carboniferous age which have 
remained spread out in wide, horizontal, and slightly broken masses over 
Russia-in-Europe, have, we have seen, been so thrown up in the Ural 
Mountains as to constitute metamorphosed and highly mineralized rocks, 
out of whose debris the Permian deposits were formed. Other views 
given in a subsequent Chapter on the auriferous rocks will realize to the 
eye the condition of the more central and completely altered rocks of that 
chain. In the meantime it may be stated that hard and crystalline, or 
slaty Palaeozoic strata, associated with numerous erupted porphyries and 
greenstones, form the nuclei of all the mountainous ridges in Siberia, 
whether in the lofty Altai on the south-east, where some of them have 
been well described by M. Pierre de Tchihatchef *, or in those hills which 
form separating barriers between the great rivers Ob, Jenissei, and Lena, 
and extend to the Sea of Ochotsk and Behring's Straits on the north-east. 
These phenomena, indeed, have been further traced over vast regions of 
* See the magnificent work, ' L' Altai Orientale,' of M. Pierre de Tchihatchef. Some Devonian 
fossils have been found near Lake Baikal. 
