FORMER GLACIATION OF NORTHWESTERN RUSSIA, 367 



extending over Finland, it came from the Scandinavian Range. The moun- 

 tains occupying the Kola Peninsula would appear to have been heavily gla- 

 ciated also ; but the direction of the striae, so far as known, does not indicate 

 that to be the region from which moved the ice sheet by which Finland was 

 covered. 



It is a little curious that the difterent writers on the glacial geology of 

 Northwestern Russia differ so much in opinion in regard to the important 

 point of the constancy in the direction of the stria3. More minute investiga- 

 tions in that country seem to be much needed. Beyond the limits of the 

 striated region there is a wide belt over which gravel and boulders are more 

 or less irregularly scattered, extending almost as far south as the parallel of 

 51°.* That this transportation of detrital material over the southern and 

 southeastern portion of the " drift region," and beyond the area of striation, 

 W!is largely effected by icebergs seems to be admitted by all or nearly all 

 those who have written on the glacial geology of Russia. Yet the fact that 

 marine remains have not been found in these deposits is a stundjling-block 

 in the way of the acceptance of this theor}^, although it does not render any 

 other more plausible. We have only to say, with Helmersen, " that they 

 may yet be found, since our [the Russian] diluvium has been so little in- 

 vestigated." 



How far into Russia did the ice sheet originating in the Scandinavian 

 mountains extend ? How much of the distribution of the boulders, and of 

 the detritus generally, was done by water, and how much by ice ? What 

 was the relative importance of the Avork of glaciers and icebergs ? These 

 are the questions which the Russian geologists have found it so difficult to 

 answer. And similar questions raise similar difficvdties as asked with refer- 

 ence to North Germany, Holland, and even the British Islands. Over all 

 the region to the south and southwest of the Scandinavian glacial centre 

 various marks of the former presence of ice are met with, complicated with 

 abundant indications of the work of water. The delineation of the exact line 

 at which the moving ice sheet stopped, when at its greatest extension, has 

 not yet been so satisfactorily accomplished as to command the assent of all 

 geologists. Indeed the phenomena are extremely perplexing, and although 



* The southern and southeastern " limit of northern boulders " is marked in JIurchison's map (in "Russia and 

 the Ural Mountains ") as having its most southern point near Voroneje, in latitude 51° ; thence it trends to the 

 northeast, aud just before reaching tlie Ural, in latitude 62°, bends sharply back to the northwest and meets the 

 coast of the Arctic Sea only a little to the east of the Kola Peninsula. 



