﻿400 Trof. Milne — Across Europe and Asia. 



deposition of the alluvium, which covers areas of vast extent upon 

 the Siberian plains, and up to the present, they must have seen 

 many changes and suffered much degradation, all of which has 

 tended to reduce their original height and bring them to their present 

 form. There is only one other range of any importance which has 

 had time to see and suffer more, and that is the line of hills in 

 Scandinavia which date back to Silurian and Laurentian times. At 

 times the Urals must have stood up like a range of islands, during 

 which period sediments were deposited like those we now see upon 

 their flanks. From the beds of alluvium which I saw in and near 

 Tagil, lying in thick patches high up upon their sides, they must at 

 no very remote period have been almost totally, if not quite, sub- 

 merged, the surrounding waters being probably fresh, and perhaps 

 the same as those from which the Siberian drift was deposited. 

 In Triassic times the waters were probably salt. 



But before saying anything more about these mountains, I will give 

 a general geological sketch of their structure, as compiled from infor- 

 mation I derived in Ekaterinburg and Tagil, which of course relates 

 especially to their appearances in the vicinity of these two localities. 

 If we made an ideal section across the middle portion of this range 

 of mountains, we should see that their nucleus is granitic. This 

 does not appear at all points to occupy the highest position as a 

 saddle to the range, as for example near Nijni Tagil, where, from a 

 cursory examination, a Silurian limestone seems to form the highest 

 ground. Moreover, these central granitic rocks do not occur as a 

 single boss, but rather appear to protrude at several points. Thus 

 near Ekaterinburg, upon the eastern side of the mountains, there are 

 three protrusions of granitic and porphyritic rocks. Eight and left 

 of these rocks, and dipping away from them both east and west, a 

 series of schiefer, gneiss, greenstone, serpentine, limestone, and other 

 crystalline rocks are seen, which, from their stratigraphical position 

 and lithological characters, are regarded as being of Laurentian age. 

 Above these, upon both sides of the range, come the Silurian rocks, 

 which are in turn overlain by the Devonian and Carboniferous for- 

 mations. Upon the western side of the Urals, above the last forma- 

 tion, we get the Permian, and last of all the Trias, this latter resting 

 horizontally upon all the older rocks, which dip away from the axis 

 of the Urals, and have all suffered more or less contortion. On the 

 eastern side of the Urals the Carboniferous formation is buried 

 beneath horizontal Tertiaries. These latter consist of sandstones, 

 whitish clay, and other rocks, in which fragments of lignite and 

 small pieces of amber are sometimes found. 



If the Permian and Triassic strata are absent upon the eastern 

 flanks of the Urals, we here get indications of vastly different physi- 

 cal conditions having existed over portions of Europe and Asia at 

 the close of the Pala3ozoic age. On the one side there may have 

 been conditions purely terrestrial, and on the other a vast expanse 

 of salt inland seas. 



Prom the horizontal position of the Trias, whilst all the older 

 formations dip away right and left from the Ural axis, we may 



