DEVONIAN AND CARBONIFEROUS LIMESTONES. 
387 
courses of impure limestone, on the whole resembling the older beds upon the 
Serebrianka, p. 383. 
In proceeding thus far, by the devious turns of the Serebrianka and Tchussovaya, 
we had therefore learnt, that the whole region was chiefly made up of lower palaeo- 
zoic rocks, the folds of which opening out in proportion as they receded from the 
chief axis of the Ural, at length throw off troughs of carboniferous limestone — that 
we had, in short, advanced from older to younger deposits. 
This inference was completely confirmed by a further descent of the Tchusso- 
vaya from Oslanski Pristan 1 to Ust-Koiva, which occupied us two days. In this 
space (of not less than thirty English miles in a straight line, and perhaps double 
that distance by the stream), in which the river Tchussovaya meanders nearly 
transverse to the strike of the strata, we passed over striking flexures, in which true 
Devonian masses, one of them exhibiting bands of hard, thick-bedded dull red 
sandstone, with greenish spots and blotches very much resembling the old red 
sandstone of the Highlands of Scotland, are associated with and overlaid by impure 
and other limestones, with characteristic Devonian fossils, whilst these are in their 
turn surmounted by great masses of true carboniferous limestone. 
Further to the west we took leave of the older schists and psammites, and 
thenceforward were in a more purely calcareous tract. At Tchismar there is a 
striking anticlinal, where Devonian limestone and calcareous shale dip off to the 
east and west from underlying reddish rocks. In the upper strata near this place 
we collected the Lithoclendron cwspitosum in as great profusion as at Lustheide on 
the Rhine, together with Favosites polymorpha, Stromatopora concentrica, Spirijer 
Murchisonianus, &c. From this point, indeed, to Kinish, or Kumuish, on the left 
bank, the river flows in limestones for the most part Devonian, and often in the 
state of dolomite, and which are surmounted by carboniferous limestone, of which 
we traced a few characteristic fossils at intervals, though usually the latter rock 
seemed to contain Encrinites only. Although the natural sections convinced us 
that two limestones, the lower dark and white-veined, containing Devonian lossils, 
and the upper light grey, containing carboniferous fossils, are occasionally in juxta- 
position on the banks of this river, we cannot pretend accurately to define each 
junction. We will simply say, that the one, if not directly incumbent on the other, 
is separated only by a few hands of grauwacke grit. 
1 This place is the port on the Tchussovaya for the mineral produce transmitted from Kushvinsk and 
Serehriansk. 
