THE RIVERS THE GEOLOGICAL KEYS OF RUSSIA. 
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less geological instruction than the more rapid, north-flowing rivers. But this is 
not the case ; for whilst the streams which flow northwards, from the Valdai and 
its dependencies, expose the older palaeozoic strata in comparatively short distances, 
the Volga, when followed in its long track, affords lessons not less instructive in 
respect to the newer formations. In fact, the promontories which invariably constitute 
throughout so vast an extent the right bank of this mighty stream, by no means 
diminish in altitude with the descent of its waters ; for whether examined at Nijny 
Novogorod, in the cliffs opposite Kazan, in those between Simbirsk and Samara, 
or from thence to Sariitof, the right bank of the Volga maintains an average height 
of 200 to 300 feet, sometimes rising to 400 and 500 feet above the stream. The 
geologist, therefore, often reads an instructive lesson in these cliffs, and traces how 
the younger pakeozoic and secondary strata are related to each other, and how 
they are depressed beneath the more recent accumulations of the southern steppes. 
The north-eastern angle of Russia, which lies between the Glacial Sea, the river 
Dwina and the Ural Mountains, is distinguished by a line of elevations called the 
Timan ridge, the direction of which is at right angles to that of the Valdai, and the 
chief mass of palaeozoic rocks. Far removed from civilization and most imper- 
fectly known to geographers till recently explored by one of our own party, this 
narrow low range, never rising to more than 1000 feet above the sea, is very 
remarkable for its persistence from south-east to north-west, through a space of 
about 500 miles. Almost branching off, as it were, from the Ural Mountains in 
north latitude 62°, it separates, in fact, the great basin of the Petchora from the 
affluents of the Dwina and Volga, and forms the north-eastern stony girdle of 
European Russia 1 . 
The central and southern divisions of the eastern region are diversified by low 
watersheds only, none of which have the persistent character of a chain. Thus in 
the vast government of Vologda, the sources of the rivers Suchona, Jug and Inga, 
which feed the great Dwina in its northern course to Archangel and the White Sea, 
are separated by a tract of small elevation only from the Unja, the Viatka, and the 
Kama, which flow southwards into the Volga. Lastly, the other numerous tribu- 
taries of the Dwina and the Volga, which spring in the Ural Mountains, and 
' The basin of the Petchora and the Timan ridge were surveyed by our associate, Count A. von Key- 
serling, accompanied by Lieut. Krusenstern in 1843 (see pp. 230, 332, 412 et seq.). A separate work 
and map of this region are in preparation by its explorers, in publishing which Count Keyserling describes 
many additional species of fossils. This work will form a sequel to the present publication. 
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