24 
NORTHERN TRANSVERSE ERUPTIONS AND DISLOCATIONS. 
and broken girdle, which extends from south-west to north-east, upon the frontier 
of Finland and Russian Lapland, and is more or less parallel to the chief axis of 
Scandinavia. Passing to the north of Archangel, the north-eastern extremity of 
this great line of disturbance is represented by the channel of the White Sea, its 
south-western end being equally marked by the Gulf of Finland. Throughout a 
large portion of the intermediate tract, similar eruptive and metamorphic phseno- 
mena are visible, and the chief physical features are everywhere nearly the same. 
The line of separation between the crystalline and sedimentary rocks being, on the 
whole, from south-west to north-east (though curvilinear and adapting itself to 
the contour of the northern continent), that line is, in fact, broken through, at nu- 
merous intervals, either by the eruptive rocks above mentioned, or by numberless 
depressions occupied by lakes and bays, whose major axis is also, on the w T hole, 
from north-west to south-east. Both the linear eruptive ridges and the adjacent 
and parallel depressions are, therefore, transverse to the great line of strike or 
elevation. At the very threshold, then, of a history of the subsoil of Russia, it is 
essential to bear these great features in view, because they explain to us how, by 
eruptions, metamorphism and dislocation, all the original junctions between the 
ancient crystalline and palaeozoic rocks, of which we have such clear evidences in 
Scandinavia, have been obliterated in Russia. These phenomena are further, we 
think, of deep interest in confirming, on a great scale, the accuracy of a view in 
geological dynamics which has recently been worked out in the British Isles by 
Mr. Hopkins 1 , who has shown that in the production of any great line of elevatory 
disturbance, whether affecting straight, curvilinear or ellipsoidal masses, the strata 
must have frequently been rent by fissures at right angles, or nearly so, to the 
chief line of strain or elevation. Now, the Finnish and Lappish frontier of Russia, 
marking a great geological boundary, presents us with such transverse chasms on 
a grand scale ; for they constitute the marine bays of Archangel, Kundulaska and 
Onega, and the great freshwater lakes of Onega and Ladoga, with innumerable 
smaller sheets of water, as well as parallel ridges of eruptive matter, all of which 
are transverse to the direction of the strata. The plu tonic force has thus found its 
way to the surface through fissures or rents which have given free vent to ebullient 
matter formerly beneath the crust. 
1 See British Association Reports for 1836, Tr. Sec. p. 7S, and Proceedings of the Geological Society 
of London, vol. iii. p. 363. A memoir, fully illustrative of the views of Mr. Hopkins, is about to appear 
jn the 1st part of the seventh volume of the Transactions of the Geological Society of London. 
