VARIOUS LEVELS OF RAISED SEA BOTTOMS. 
331 
northern hemisphere was nearly the same. To this point, however, we shall re- 
turn in a concluding chapter of Part II., w’hen we consider the transport of erratic 
blocks. 
In previous pages we have more than once adverted to the strict conformity 
with which deposits of very different age succeed each other in various parts of 
Russia, and we have guarded our readers against the inference, that such relations 
should be taken as any proof of the overlying stratum having been formed imme- 
diately after that which is subjacent. We now adduce still stronger evidence, that 
great oscillations between land and water must have taken place, without in the 
slightest degree deranging the position of the strata of anterior epochs, which, for- 
merly depressed beneath the sea, were raised to the surface, and now form part of 
the continent. 
A section near the mouth of the Vaga exhibits the same post-pliocene beds 
perfectly conformable to limestones with Producti and corals of the Permian rocks, 
as expressed in this wood- 
cut. If unacquainted with 
the great distinctions between 
the Palaeozoic shells beneath, 
and those of post-pliocene 
age above, an observer might 
indeed, be here led to view 
them as parts of an undi- 
vided or unbroken series ; but geology teaches us, that an enormous interval 
elapsed between their formation, during which the older Permian strata, first 
elevated and removed from the influence of marine deposits, were, after a long 
lapse of ages, submerged and covered by the sand and mud with post-pliocene 
shells, and afterwards raised into their present position. And yet with all this 
oscillation, these shells being now about 150 feet above the sea, the most perfect 
parallelism between the two sets of strata is preserved 1 . 
In speaking of this amount of elevation, it is important to recollect, that the beds 
at Uddevalla, 1000 miles distant from those of the Dwina, and in which some of 
the same species are found, are about 200 feet above the sea, and that similar beds 
1 Considering that the Dwina descends from Ust-I' aga to Archangel, a distance of about 240 versts, 
it is not unreasonable to suppose, that the pleistocene beds at the former place lie at the height of 150 
feet, and barometrical observations of Count Keyserling lead to the same inference. 
