592 Geological Society '. Anniversary Address, 1842. 



called Osars are referred ; the second, the transport of the distant 

 blocks by vessels of ice, when all that part of Europe which they 

 cover was subjected to the immersion of an icy sea. He does not 

 agree with M. Bohtlingk, that the point of departure of the current 

 can be placed in Lapland, but supposes it to have proceeded directly 

 athwart those regions from the pole*. But the point to which I 

 now specially advert is, that in his skilful analysis of this memoir 

 our eminent foreign associate admits floating ice as a vera causa to 

 explain the drift of blocks, just in the same manner as in common 

 with Lyell, Darwin, and others, I have been endeavouring to explain 

 the phEenomenon during the last three years, and thus the inference 

 which was drawn from plain facts is admitted, viz. that the chief 

 tracts covered by erratic blocks were undo" the sea at the period of 

 their dispersion. (Sil. Sj'st. p. 536.) 



Thus far had I written. Gentlemen, — in short I had, as I thought, 

 exhausted the glacial subject at all events for this year, — when two 

 most important documents were put into my hands. The first of 

 these is the discourse of my predecessor, who has so modified his 

 first views, that I cannot but heartily congratulate the Society on 

 the results at which he has now arrived. I rejoice in the prudence 

 of my friend, who has not permitted the arguments of the able ad- 

 vocate to appear as the sober judgment of so distinguished a Presi- 

 dent of the Geological Societyf. In fact, it is now plain that Dr. 



* M. Durocher has made two valuable observations in showing us that 

 the striated and polished surface of the hard rocks is sometimes covered by 

 accumulations of sand and detritus ; and that although proceeding in a 

 general sense from the north, the furthest transported blocks are so distri- 

 buted as to indicate radiation from certain mineralogical centres, much in 

 the same way as our blocks of Shap granite have, on a less scale, been 

 scattered from one point of distribution. In stating,, however, that in the 

 progress of these transported masses to the south, granitic blocks always 

 constitute the outermost zone, it appears to me that M. Durocher has ge- 

 neralized beyond the field of his own observation. In Russia, for example, 

 M. de Verneuil and myself traced greenstone blocks to the same southerlv 

 latitudes as granites. The blocks between Jurievitz and Nijny Novogorod 

 are composed of quartz rock and of the peculiar trappsean breccia known in 

 Russia as " Solomenskoi-kamen," the parent rocks of which we examined 

 in situ near Petrazowodsk (Geol. Proceedings, vol. iii. p. 405), [Phil. JMag., 

 Third series, vol. xix., p. 497], whilst the extreme boundary of these boul- 

 ders extends to Garbatof on the Okka, S.W. of Nijny Novogorod, and 

 consequently very far beyond Kostroma, the limit assigned to them by 

 M. Durocher. Again, if M. Durocher prolongs the northern drift to the 

 flanks of the Ural Mountains he is decidedly in error, for there is no coarse 

 detritus whatever on the flanks of that chain, whether derived from the 

 north or from itself. Of the Tchornoi-Zem, or black earth of the central 

 regions of Russia, to which, quoting Baron A. de Meyendorf, M. de Beau- 

 mont refers in a long note, I will now only say, that having studied the 

 nature and extent of this singular deposit over very wide regions, I intend, 

 with the help of my fellow-travellers M. de Verneuil and Count Keyser- 

 ling, to lay before the public very shortly a sketch of its relations to the 

 northern drift and other superficial deposits of Europe. 



[t The portion of Dr. Buckland's Address which relates to this subject 

 will be found at p. 515 of the present volume.] 



