723 
the beds, which are neither so numerous nor so good as at the 
former place, are inclined at 50°, and eveh at 70°, and are full of 
extensive faults. 
The carbonaceous strata (often worked by the small proprietors 
‘and Cossack and Russian peasants) are described in several places, 
and the same geological relations are shown to prevail, the coal 
beds being stated in all cases to be subordinate to the mountain 
limestone series, whilst certain overlying shales, sandstones, &c., 
which were observed in one corner of the district, contain few or no 
traces of coal. | 
At the western extremity of this region, the coal-bearing strata 
thin out into sandy masses, which repose unconformably on certain 
highly inclined quartzose, gneiss and granitic rocks, that appear oa 
the banks of the river Voitchia, and extend to the Dnieper and the 
cataracts of that river near Ekaterinoslaf, To the south-west, near 
Karakuba and towards Mariopol, in a tract occupied by Greek colo- 
nies, similar primary rocks appear, penetrated both by granite and 
porphyry, whilst to the south-east and north the whole carbonaceous 
region is overlapped partially by red sandstone with gypsum, as 
near Bachmuth, but more generally by cretaceous and tertiary rocks. 
The former, in the state of white chalk, occurs in a large zone in 
the north, and in asmaller band at the southern limits of the coal tract. 
The dislocations and upheaval of the subjacent rocks extend to 
some distance to the north of the chief carbonaceous masses; for at 
Petrofskaya, considerably to the north of the nearest outcrop of the 
chief coal-field, coal with carboniferous limestone is upcast to the 
surface in highly inclined positions, surrounded by nearly horizontal 
strata of the Jurassic and cretacecus epochs, and generally so ob- 
scured by drift and clay, that it is well seen in one ravine only. 
Coal, however, has been detected at adjacent places in sinking for 
water. 
The uppermost members of the carboniferous system are not 
observable in the North of Russia, or ia the Moscow basin, where 
Jurassic strata repose at once upon true carboniferous limestone; 
but in the southern coal-tract, just alluded to, there are, as before 
said, beds of shale and sand which overlie this limestone series, and 
yet are unproductive of coal (north of Gorodofka). On the western 
flanks of the Ural mountains, however, as will be shown in the next 
memoir, to the east of Perm, and at Artinsk, are sandstones and 
conglomerates with plants passing occasionally into calcareous grits 
with Goniatites, which, as seen on the banks of the Tchussovaya 
and near Artinsk, are superior to the great carboniferous limestone. 
Very thin courses of coal only are observed at intervals in this upper 
member of the system, and the Goniatites which it contains belong, 
as a whole, to that division of the family which characterizes the 
uppermost member of the carboniferous limestone and certain coal- 
fields (Coalbrook Dale) of Western Europe. There is a consider- 
able development of this subdivision on the flanks of the Guber- 
linski hills, and partially on the south-western edges of the Ural 
east of Orenburg. 
3M 2 
