32 
DISLOCATIONS REFERRED TO ELEVATORY ACTION. 
tion of the mass, must be viewed as parts of the same phsenomenon to which we 
have alluded as occurring all along the Finnish and Lappish frontier, and of which 
the isle of Hochland in the Gulf of Finland is the prominent sign upon the west. 
In a word, we regard all the transversal valleys, by which numerous streams flow 
from the palaeozoic plateau on the south to the Gulf of Finland, as having been de- 
termined at the time when that plateau was raised, and subjected to a tension by 
which it was transversely broken. The causes of this elevation are to be sought 
m the same expansive forces through which the plutonic and eruptive rocks have 
found an issue to the north ; and which, though suppressed in the more southern 
tracts, have manifested their influence in the transverse domes and fissures we have 
just described. We further believe that these upheaving causes have been mainly 
instrumental in the formation of the. larger river gorges, and even perhaps in deter- 
mining the great transverse depression of the Lake Peipus (see Map). These phe- 
nomena afford, therefore, we repeat, a confirmation of the views of fracture as 
resulting from elevation, to which we have previously referred, p. 24 et seq. 
Now here we must observe, that the strata thus affected in the government of 
St. Petersburgh are precisely of the same age as those which at Kinnekulle, the 
Billingen Hills, and other places in Sweden have been perforated and covered 
by basaltic trap, and which on the Lake Wettern we have shown to have under- 
gone great flexures and breaks (p. 17). But whilst we speculate on some of the 
ancient movements which affected this region and parts of Sweden having taken 
place after the completion of the Lower Silurian group and before the accumula- 
tion of the Upper, — movements by which it was placed beyond the influence of the 
waters wherein the Upper Silurian strata were accumulated, and which seem to 
have increased in intensity from south-west to north-east, we must admit that the 
breaks and contortions which have just been described may have occurred at a 
much more recent period, or after the consolidation of the carboniferous rocks. 
This opinion is grounded on the facts, that along the northern frontier (p. 23*) the 
Devonian strata are equally metamorphosed as the Silurian ; and that the carboni- 
ferous limestone of the Valdai Hills has also been affected by similar transverse 
breaks, as will appear in the 5th Chapter. In short, as far as we had the means of 
determining it, the amount of disrupture is frequently coincident with the height 
to which the strata have been elevated, and the greatest elevation certainly took 
place after the completion of the carboniferous limestone. 
Junction of Lower Silurian with Devonian Strata South of St. Petersburgh. The 
