Habitation and Destruction of the Mammoths. 425 



Granting these premises, all the relations of the Uralian mammoth 

 alluvia may, it appears to us, be rationally explained ; for in some of 

 the most violent movements of elevation which gave rise to the pre- 

 sent central watershed, we may readily conceive how, their barriers 

 being broken down, these lacustrine waters were poured off, and how 

 their shingly bottoms and shores, already containing bones of mam- 

 moths, were desiccated and raised up into the irregular mounds 

 which now constitute the auriferous alluvia. The very nature of the 

 auriferous shingle, with its subangular fragments, so completely re- 

 sembles the detritus of lakes, and it is so unlike the gravel formed on the 

 shore of seas, that independent of the entire absence of any marine 

 remains whatever of tertiary or recent age, all along the immediate 

 eastern flank of the Ural mountains, we have no hesitation in believ- 

 ing, that the gold detritus was accumulated during a terrestrial and 

 lacustrine condition of the surface. One fact only which we have 

 mentioned seems, at first sight, to militate against this view, viz., 

 the deeply eroded surfaces of some of the palaeozoic rocks. But how- 

 ever these appearances may have been produced, it is manifest they 

 could not have resulted from the denuding action of the same water 

 in which the shingly and slightly rounded angular detritus was formed. 

 Such abraded surfaces may, to a great extent, have been produced, 

 at periods long anterior to that of which we are now treating, and 

 when the edges of the palaeozoic strata, first emerging from beneath 

 the sea, left their irregular and water-worn surfaces to be filled with 

 terrestrial and lacustrine deposits of after days. 



In some cases, however, the denuding and abrading power of 

 waters, produced both by the bursting of lakes and the change in 

 the direction of the currents, must have been very considerable, for 

 such alone would account for several of the appearances we have 

 spoken of, and the transport of large blocks and enormous pepites 

 of gold into broad lateral depressions. 



In proposing a lacustrine entombment for the Uralian mammals, 

 we are borne out by the constant position of thick masses of silt and 

 clay overlying the coarser shingle. If the deposits had been sub- 

 marine — even if no traces of shells were visible, there might have 

 been some indications of the action of the waters — some appearance 

 of a coast line ; but nowhere can the geologist imagine such a former 



