1845] Diluvial and Wave Translation Theories. 221 



Mr. Murchison, the late distinguished President of the Geological 

 Society, and M. Vernenil, reject the Alpine glacial theory, considering 

 it as totally inapplicable to the boulder formation overspreading great 

 part of Russia ; the large granitic and other crystalline blocks of which 

 (previously alluded to) have attracted so much attention from the days 

 of Pallas up to the present time. These blocks, which have all been 

 evidently derived from the North, are shown to have been deposited 

 under the sea, or in other words, on a sea bottom, since they cover 

 marine shells of the post-pleiocene period. The smaller blocks of the 

 detritus are in general carried to greater distances than the larger ; the 

 distance being sometimes 1000 miles from the parent beds to the 

 N. W. As in the English deposits, although a large proportion con- 

 sisted of material brought from a distance, yet it contained a con- 

 siderable portion of the detritus of the subjacent and adjacent rocks, 

 the nature of which was often indicated from the colour of the 

 superficial clay and sand. Mr. Murchison and M. Vernenil obser- 

 ved no instance of any substance having been transported from 

 S. to N. except by the modern action of streams, and by local causes 

 dependent on the present configuration of the land. 



In room then of the Alpine glacial theory these authors substitute 

 that of Icebergs. They believe that these great blocks have been trans- 

 ported on floating icebergs set adrift from ancient glaciers supposed 

 to have existed in Lapland and the adjacent tracts ; from the northern 

 chains of which the blocks were originally dislodged and impelled 

 southwards into the sea of that period, in which the post-pleiocene 

 shells they are now seen to rest upon were accumulated. 



They did not observe any parallel striae or polishing of the surfaces 

 of the rocks of Central Russia, but describe the most southerly of 

 the scratches which came under their notice near Petrazowodsk on 

 the Lake Onega. 



They consider these marks may have been caused by the icefloes 

 and detritus dislodged and set in motion by the elevation of the 

 northern continental masses, grating upon the bottom of the sea ; since, 

 if they were caused by the overland march of glaciers, the glaciers 

 must have been propelled from lower to higher levels, which is 

 against what they conceive to be an axiom, viz., that the advance 

 of every modern glacier depends on the superior altitude of the 

 ground behind it. 



