ane 
Mineralogy and Greology. 273 
formed, and therefore that in ancient times, as at the present day, a 
great trough existed between these opposite continental masses of land. 
This early elevation was probably unaccompanied by any great frac- 
tures; for the lower Silurian rocks of both lands have still preserved a 
general horizontality, which is the more remarkable in the case of 
Russia, as it has been shown that the sediments, after having been 
raised, must again have been depressed to permit of copious marine 
accumulations of Devonian age upon their surface. In like manner, 
we must believe from the evidences of conformable apposition of the 
Devonian and carboniferous deposits of Russia, that no sort of disturbing 
influence could have existed in these regions when the one formation 
_ succeeded to the other. The uppermost beds of the Devonian, loaded 
with Holoptychius and Onchus, Coccosteus, Placosteus, and Dendrodus, 
are at once conformably surmounted by strata containing the most uni- 
versally diffused carboniferous types. In short, fishes identical with 
those of the Old Red Sandstone of Scotland, are invariably surmounted 
by the Stigmaria ficoides and the large Producti of our British moun- 
tain limestone ;, and thus the examination of Russia has taught us, not 
only in this instance, but also in the overlying Permian succession, that 
the great changes in animal life have not been dependent on physical 
revolutions of the surface, but are distinct creations, independent of 
any such proximate local causes; though I would by no means deny 
that the grand operations of change which have affected the conter- 
minous regions of Russia did not tend to produce these results. 
“The first elevation and depression of the lower Silurian strata 
having been moderate, and probably not extensive, and those strata 
having, during the long succeeding Devonian and carboniferous periods, 
remained beneath the sea, in which these sediments were accumulated, 
we next reach that period of disturbance which is so strongly marked 
in nearly every part of Europe, or that which followed the close of the 
carboniferous epoch. Then it was that the whole of the older palzo- 
zoic series of Northern Russia was raised up in lines extending from 
8. W. to N. E. And, although even then their elevation must have 
been infinitely more equable than any of those upheavals which have 
determined the strike and escarpments of rocks of the same age in 
Western Europe, we cannot imagine the upward movement of such 
enormous masses from beneath the sea to some height above it, without 
the accompaniment of some of those transverse fissures and breaks, 
which, though feeble in the ey elevated tracks, increase in inten- 
sity, with the amount of upheaval.” 
15. Lines of Ancient Level of the Seain Finmark ; by M. A. Bravats, 
(extracted from the Quart. Jour. Geol. Soc., No. 4, 1845, p. 534.) — 
M. Bravais has ascertained two distinct lines . elevation around the 
Szconp Seriss, Vol. I, No. 2.—March, 1846. 
