64> Geological Society : Mr. Murchison's 



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 on 

 the banks of the river Voltchia, 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 a smaller 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 cretaceous 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 in 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. 



Permian System. (Zechstein of Germany — Magnesian limestone 

 of England.) — Some introductory remarks explain why the authors 

 have ventured to use a new name in reference to a group of 

 rocks which, as a whole, they consider to be on the parallel of the 

 Zechstein of Germany and magnesian limestone of England*. They 



* " I have recently been informed by M. A.. Erman, that an erroneous 



