Geological Society. 497 



land. Near Nijnii Novogorod large blocks of a very peculiar trap- 

 pean conglomerate were detected, which had been derived from a 

 rock in situ N. of Petrazowodsk, a distance of nearly 600 miles. In 

 endeavouring to account for the immense distances to which these 

 blocks had been transported, the authors expressed their belief that 

 they had been floated in former icebergs, which breaking loose from 

 ancient glaciers, which they suppose may have existed in Lapland and 

 the adjacent tracts, were dislodged upon an elevation of the northern 

 chain, and impelled southwards into the sea of that period, in which 

 the post pleiocene shells, to which allusion has been made, were ac- 

 cumulated. In the relation of the blocks to the sea shells, they con- 

 ceive that Central Russia presents an exact parallel (though on a 

 much grander scale) to the phaenomena described by one of the au- 

 thors in the central counties of England, where a similar collocation 

 was accounted for, by supposing that the northern blocks were borne 

 thither in vessels of ice, which in melting dropped them upon what 

 was then a sea bottom*. 



Glacial Action. — After alluding to the works of Sefstromf and 

 Botlingk upon the supposed " diluvial" currents of Scandinavia and 

 Lapland, as evidenced by the parallel striae and polishing of the sur- 

 face of the hard rocks of these regions, the authors describe the most 

 southerly of the scratches, which came under their notice near Pe- 

 trazowodsk, on the lake Onega, no such markings having anywhere 

 been observed in Central Russia. They then examine the applica- 

 bility of the glacial theory, as proposed by M. Agassiz, to the tracts 

 of Russia under review. Starting from what they conceive to be an 

 axiom, that the advance of every modern glacier depends upon the 

 superior altitude of the ground behind it, they show, that if certain 

 parallel stria;, observed by M. Botlingk, and others noted by them- 

 selves, are to be taken as proofs of the overland march of glaciers, 

 such bodies must often have been propelled from lower to higher 

 levels. For the proofs of this they refer to the eastern sides of the 

 Bothnian Gulf, where M. Botlingk found the striae (" diluvial schram- 

 men") directed in common with the boulders from N.W. to S.E.; 

 and yet any glaciers which bore these blocks must have advanced 

 from Scandinavia, across the Baltic Sea, and then have ascended 

 the rocky tract in question. Again, near Petrazowodsk, in the isles 

 of the lake Onega, the authors observed such striae exactly parallel 

 to the major axis of the lake, N.N.W. and S.S.E., even from a good 

 many feet under the clear fresh water, and thence rising to the height 

 of twenty feet above the summer level of the lake on the sloping 

 surfaces of the rock. They then argue, that in this tract there are 

 no hills of sufficient altitude on the N.N.W. to account for the de- 

 termined forward direction to the S.S.E.; and as a still further rea- 

 son for rejecting the application of the "Alpine glacial theory" to 

 this country, they add, that as the striae in one region have all a 

 given and parallel direction, so must the supposed glacier not only 



* Silurian System, p 535 et seq. 



[f A translation of M. Scfstrom's paper on this subject will be found in 

 Part ix. of Taylor's Scientific Memoirs. — Edit] 



Phil. Mag. S. 3. Vol. 19. No. 126. Dec. 1841. 2 K 



