CARBONIFEROUS LIMESTONE AND PORPHYRY OF KAMENSK. 
365 
limestone, rises in low protuberances through the rich black earth. This is most 
probably an Upper Silurian rock, for it is absolutely made up of Pentameri, some of 
which, of great size (a variety of our P. Vogulicus ) , are closely allied to the Pentamerus 
Knightii. It will afterwards be shown, that such a rock appears in other parallels ot 
the Ui’al, even in the richest mining tracts, in describing which we shall more 
specially advert to the specific forms of the shells, since those at Crasnoi-glasnova 
were so welded into the rock, that good specimens were not to be obtained. In the 
mean time, this short digression has been made in order to show, that even in 
this tract there was once a palaeozoic succession from Upper Silurian to carbonife- 
rous strata, however difficult is the task of now putting together their disjointed 
fragments. 
Returning to our traverse by the river (PI. II. fig. l.)> the lower black limestones, 
schists, grits, &c. on the Issetz, which we consider Devonian, are succeeded on 
the east by a very copious development of limestone, which is unquestionably car- 
boniferous. For some distance this rock is almost in a crystalline condition, its 
surfaces are much eroded, and numerous indentations and fissures are loaded with 
the hydrate of iron. Near the gorge called Petersgal (Peter’s gate), this lime- 
stone rises up into serrated and picturesque forms, about 200 feet in height, amid 
which the river winds, the cliffs exposing caverns at heights of upwards of 100 feet 
above the water. Though much thrown about and contorted, this rock occa- 
sionally resumes the ordinary aspect of the English mountain limestone, and con- 
tains characteristic fossils 1 . 
To the west of the shale which flanks this mass, the banks of the river become 
lower, and the first visible strata near the village of Bayanova are altered limestones, 
with bedded trap, or schaalstein, in which copper ore occurs, with some nests 
of malachite ; whilst the chief rock of the track is a red quartzose porphyry, 
somewhat different from any seen in the higher part of the Issetz, and which passes 
here and there into eurite and compact felspar rock. To the north ot this point 
lies the Imperial Zavod of Kamensk*. When thrown off by the porphyries ex- 
posed on the Issetz, the carboniferous limestone occupies four or five distinct ledges, 
and as along the Issetz, reposes on conglomerates and grits, which constitute, there- 
fore, either the base of that system or the upper part of the Devonian. 
, Product™ gigas P striatus, Fisch. (anomala. Sow.), Spirifer striatus, S. rj labor. Sow., Caryophyllia 
fasciculate (Flem.). Another coral seen by Mr. Lonsdale seems to be a new species of Lithodendron. 
* At Kamensk we were hospitably entertained by Major Barotzi, d.rector of the Zavod. 
3 B 
