FRENCH AND ENGLISH EQUIVALENTS OF THE PERMIAN SYSTEM. 203 
Heidelberg to Baden-Baden. At the latter place, the formation assimilates to its 
type in the Vosges mountains on the opposite bank of the Rhine, where it has 
been admirably described by M. Elie de Beaumont under the name of “ Greis 
de Vosges,” and clearly separated by him from the overlying Trias. As in the 
Vosges, the Zechstein is omitted at Baden-Baden, and the series consists, in as- 
cending order, of a conglomerate often composed of granitic, porphyritic and older 
slaty rocks, succeeded by sandstone and shale, both red, wdiite and mottled. 
Though we entertained no doubt when on the spot, that these strata, as well as 
those of the Vosges mountains, through which we passed, were the equivalents of 
our Permian rocks, it is a high gratification to be able to state, that upon consult- 
ing M. de Beaumont, we find this eminent geologist is quite of our opinion, and 
that he adopts with us the classification by which our Permian group, compre- 
hending the Rohte-todte-liegende, the Zechstein and the lower Bunter Sandstein, 
is represented in the Rhenish country and in France by the “ Gres des Vosges 
In the comparison, however, with Central Germany, it is well to state, that the 
Russian succession presents few or no traces of the thick development of red sand- 
stone and conglomerate which is distinctly intercalated between the carboniferous 
rocks and the Zechstein 4 , as might be expected in a flat and undisturbed region. 
In some Russian tracts, indeed, we have shown, that the Zechstein or Permian 
fossils imbedded in marlstone and limestone succeed, with scarcely any other 
intervening rocks than bands of gypsum, to the great mass of the carboniferous 
limestone. In other districts, however, grey grits and sandstones underlie as 
well as overlie those courses of limestone which represent the Zechstein, whilst 
the conglomerates chiefly cover the calcareous zone. But we must not attach 
undue importance to the identification of mineral structure in establishing a suc- 
cession in synchronous deposits of distant countries. We have already seen, 
that with a most striking similarity in the general distribution of life, between 
each great palaeozoic system of Russia and its equivalents in Western Europe, 
the examination of Russia has revealed to us very considerable discrepancies in 
the nature of the imbedding rocks. To recede, for example, no further than the 
immediately subjacent deposit, we learn that the great masses of the coal-fields of 
1 See M. de Beaumont’s view of the Gres de Vosges, Mem. pour servir, vol. i. and " Description de 
la Carte Geol. de France,” vol. i. p. 391 et seq. 
4 It is very probable that certain sandstones and conglomerates (not the goniatite grits of Artinsk), on 
the western flank of the Ural Mountains, may represent, as before said, the Rohte-todte-liegende, a point 
to which we shall revert in Part II. See Table with the Map. 
