

TRANSACTIONS OF THE SECTIONS. 45 



may entitle it to be referred either to the base of the carboniferous or to the upper 

 part of the Devonian system. 



The great lead-bearing magnesian limestone of Ohio and Indiana (Silurian) is 

 stated to agree in great part with that of Niagara. 



After thus giving a general sketch of the Memoir, the President then called the at- 

 tention of the Meeting to the very valuable collection of fossils by which it was illus- 

 trated, and expressed his belief that their study, and a close comparison of them 

 with the typical forms of the same age in the British Isles, would lead to very curious 

 results touching the distribution of animal life in deposits of synchronous date found 

 at great distances from each other, and in which the variations in the same species 

 would be found to be analogous to those which now prevail in living nature in similar 

 species which inhabit basins remote from each other. 



The President, in highly eulogizing the merits of Dr. Dale Owen, begged to re- 

 mind the Meeting that the coal-field of which he treated was nearly as large as all 

 England. 



On the Geological Structure of Russia (delivered at an Evening Lecture). 

 By R. I. Murchison, Pres. G.S. 



Mr. Murchison gave a general sketch of the geological structure of Russia in Eu- 

 rope and the Ural Mountains, which was illustrated by numerous large coloured sec- 

 tions and a map. In explaining the chief results of the labours of his friends Count 

 Keyserling, M. de Verneuil, and himself, he showed how the researches of two 

 summers had enabled them to produce a classification of the sedimentary deposits 

 which exclusively occupy the flat regions of Russia, where they are exempt from the 

 intrusion of igneous rocks; and also how the older members of the series, when 

 altered by such igneous agency, as in the Ural Mountains, were the seat of various 

 ores and minerals. 



After pointing out that, from the very distinct characters of the fossils of each 

 group of the palaeozoic rocks, the divisions of Silurian, Devonian (or old red) and 

 carboniferous strata were unequivocally sustained over an enormous area, he stated 

 that these masses were surmounted by a great development of red sands, marls and con- 

 glomerates, with beds of magnesian limestone, salt and gypsum, the whole constitu- 

 ting a system which is the equivalent of that group in western Europe of which the 

 zechstein or magnesian limestone is the centre. Insisting upon the independence 

 of the Permian rocks (so called because most spread out in Permia), as proved by 

 their imbedded fauna and flora, including thecodont saurians and plants of peculiar 

 forms, Mr. Murchison dwelt upon the singularity of this vast deposit, in being to so 

 great an extent impregnated with copper ores, which mixed with the sand, grit 

 and marl, form regular beds, the origin of which he referred to ancient cupriferous 

 sources having flowed from the Ural Mountains, when the Permian strata were accu- 

 mulating in an adjacent sea. Passing rapidly over the consideration of the secondary 

 and tertiary deposits, Mr. Murchison then made some statements confirmatory of his 

 opinions expressed at the Glasgow Meeting of the British Association, concerning 

 the transport of the large erratic blocks which cover such large tracts of the northern 

 and central governments of Russia and the adjacent countries of Germany, which 

 having been deposited on what he conceives to have been the bottom of a sea, were, 

 he conceives, carried to their present positions by floating icebergs liberated from 

 ancient glaciers of the North. On the present occasion he showed, that such 

 phasnomena, grand as they are, are after all local only, in reference to the surface cf 

 the planet ; for an examination of the Ural Mountains had convinced him that up to 

 60° north latitude they never could have been the seat of glaciers, because their flanks 

 are entirely void of coarse and far-transported detritus, though some of their peaks 

 rise to upwards of 5000 feet above the sea. In confirmation of this opinion it was 

 further said, that none of these stria? (which are appealed to as proofs of glacial 

 action) were observed upon the surface of the Ural rocks, though such marks are 

 apparent in some of those tracts of Russia in Europe, over which the northern blocks 

 have been transported. 



Mr. Murchison concluded by a warm compliment to the Emperor, and to the 

 Russians of all ranks, for the very kind reception, and for the cordial and liberal man- 



