PERMIAN ROCKS SOUTH OF ORENBURG. 
183 
Whilst we have noted the existence of rock-salt in the Permian system, as well 
as of numerous saline springs, the latter only are known in the overlying marls and 
sands, and we have before stated, that these saline springs rise from great depths, 
both at Totma in the government of Vologda and at Balachna on the Volga above 
Nijni Novogorod. It is well, therefore, to bear in mind this circumstance, since 
it induces us to believe in the probable existence of subterranean masses of rock- 
salt in deposits of higher antiquity than those in which they, for the most part, 
prevail in Western Europe. Hence also it is to be inferred that salt-wells may be 
sunk with effect on the Artesian principle, in many parts of a vast basin which 
we have shown to be surrounded by older deposits (see Map). 
Permian Rocks south of Orenburg . — In the south-eastern region where rocks 
of this age occur, we perceived that along a certain line, Permian limestones 
similar to those we have before described, are thrown up in isolated hummocks or 
cones, the strata of which are often highly inclined. Such a line of disruption has 
been traced from north-north-east to south-south-west, and slightly divergent from 
the chief axis of the Ural. The hills of Grebeni afford, as before said, a good 
example of these dislocations, and to the south-south-west of Orenburg, in the 
steppe of the Kirghis, we met with a fresh example of them upon the same line 
at Mertvi-sol (or the dead salt) (see Map). This little elevation is also interest- 
ing, as it afforded us the best means of forming our conjectures respecting the 
geological age of the great adjoining masses of rock-salt and gypsum which occur 
at Illetzkaya-Zastchita. 
These hills present beds of limestone perfectly undistinguishable from the Per- 
mian limestones (a) of Grebeni and other places, and which plunge to the east under 
the red grit of Orenburg (6), with traces of copper ores. Beds of white gypsum oc- 
cur, partly in the form of Selenite (c) and partly dark-coloured and compact. From 
these gypsum beds a brine spring issues, which, as it cannot be derived from waters 
traversing the overlying red strata, probably rises from rocks of the same age as 
those which we have described at Sergiefsk as the seat of so much saline matter. 
31 . 
Limestone Hills, Mertvi-sol, 
Salt springs. 
This limestone of Mertvi-sol contains the same fossils as that of Grebeni, viz. 
2 b 2 
