74 E. R. Hoicorth — A Great Post- Glacial Flood. 



black earth ? Here, at all events, there is no room for glacial actionj 

 for the most conspicuously glaciated district in Kussia, namely, its 

 northern part, is quite free from black earth. Nor, so far as we 

 know, is there any evidence that the low range of the Southern 

 Urals was once occupied by glaciers. M. d'Archiac says, there are 

 no traces of glacial action in the Urals (Le9ons sur la Faune 

 Quaternaire, p. 168). Nor, again, do we know of glacial mud 

 anywhere like the Eussian Tschernozom. At first sight, its black 

 colour would suggest that it was merely a vast deposit of vegetable 

 soil. 



Murchison and others have shown good reasons against attributing 

 it to the decay of vegetable matter. Thus speaking of its uniformity 

 Mr. Strangeways says : " It is difficult to imagine that the same 

 plants ever grew in so manj' situations with such opposite asiDects, 

 on such different soils, and over so vast a surface." This 

 view is indorsed by Murchison, who says, that nowhere does 

 it contain a trace of trees, roots, or vegetable fibre. Again, as he 

 says, " if the Tschernozom had been due to the decay of trees, it 

 would have been found largely in North Eussia, where forests have 

 so long existed. But nowhere in North Eussia has it occurred, 

 while it especially abounds in those wide steppe-like undulations 

 which have in all time been void of trees " (Eussia and the Ural 

 Mountains, pp. 557-561). Having discarded this subaerial origin, we 

 may add, that the fact that it contains not a trace of a marine or 

 freshwater organism of any kind precludes our assigning it to a 

 marine, lacustrine or fluviatile origin. "What then remains to explain 

 this curiously distributed mantle of black earth, but the pouring out 

 of a great mass of volcanic mud from some fissures or vents con- 

 temporaneously with the similar pouring out of the Loess ? As the 

 Loess was probably derived from the volcanic disintegration of 

 calcareous rocks, so the black earth was probably, as Murchison has 

 suggested, due to the disintegration of the black Jurassic shale 

 which he desci'ibes as so uniform in colour over all Northern and 

 Central Eussia, and which view is confirmed by the absence of the 

 black earth to the south of certain tracts where the Jurassic shales 

 have apparently never occurred. 



It is confirmed again by the analyses which have been made of it, 

 in which we find a certain proportion of organic matter, which 

 such a high authority as Bischoif attributes to the large amount of 

 bituminous matter contained in the Jurassic shale (see Geikie, 

 op. cit. pp. 242-3.) This view of the origin of the black earth 

 admirably suits the absence from it of stratification and of organic 

 remains ; for these latter, when found in the Loess, were probably, as 

 we shall presently show, derived from elsewhere. The view we 

 would urge, then, is, that the great dislocations of strata which 

 occurred at the time when the Mammoth and his companions dis- 

 appeared, were accompanied by the pouring out of a great quantity 

 of volcanic mud, which in Europe and China is largely represented 

 by the Loess, while in Central Russia it is represented by the black 

 earth. 



