RIDGES SOUTH-WEST OF ZLATAUST. 
429 
disposed to consider of Upper Silurian age, for reasons which will be given in ex- 
plaining the transverse section, PL III. fig. 1. The country which we would now 
describe, is that which lies to the south and west of the Zavod of Satkinsk, and 
is made of various ridges of palseozoic rocks, watered by the rivers Juriusen or 
Yurezen and Sim, and their affluents. Satkinsk, by which place our chief section 
passes, is distinguished by its black dolomites and contiguous greenstones ; the 
two rocks being in contact. At eight versts to the south of Satkinsk is Mount 
Makarofka, composed of greenstone at its summit, and flanked by slaty, argil- 
laceous schists, which strike about north-north-east, south-south-west, or to the 
east of north 1 . This mount, and that of Ballindisha, the summits of which consist 
of immense masses of quartz rock, form a little ridge extending from north-north- 
east to south-south- west, and parallel to a higher ridge on the west called Silkia, 
also composed of quartz rock ; the valley between them being occupied by lime- 
stone and iron mines. Still further to the south-south-west, the easternmost of 
these branches assumes the name of the Tchuida, also composed of quartz rock, as 
well as the loftier Zigalga (see Map, PL VII.), which runs parallel to it on the east. 
The valley between these ridges, or that of the Bulanka, which we traversed, is 
made of clay-slate, which having a north-north-easterly strike, has a dip of 35° to 
40° to the east-south-east. With the expansion of this valley, an argillaceous and 
fissile limestone is developed (at Perevanchina, fifteen versts east of Yuryusensk), 
which clearly forms a part of the schistose and quartzose rocks in which it is inter- 
calated, and with whose bearing to the north-north -east it entirely coincides : the 
beds of this limestone are all inclined eastwards at various angles from 10° and 
1 5° to near verticality. 
Flanked on the east by a ridge of slaty schist, the little town of Yuryusensk is 
situated in a picturesque longitudinal valley, ornamented, like all the Uralian 
forges, with a Zavod lake, the north-western banks of which consist of abrupt 
faces of limestone, in which we detected Stromatopora concentrica, with Terebra- 
tulae, in beds passing downwards into dolomites; the whole dipping to the east- 
south-east, and therefore under the more ancient slaty schists and quartz rocks 
' A very productive iron mine (brown oxide ?), which supplies the forges of Yuryusensk, Simsk and Ust 
Kataevsk,’ occurs at Bakalsld. The mining stuff is traversed by a highly inclined band of siliceous grit or 
quartz rock dipping to the north-west, and the surface is covered with clay and sand. This iron ore is 
probably of the same age as that which is found in the clefts and in the interstices of all the palseozoic rocks 
on both flanks of the chain, and is evidently an aqueous deposit of much more recent date than the mag- 
netic iron ore. 
3 K 
