Reviews — Geology of Prussian- Silesia. 323 



ores. It occurs near Beunisch, eastwards of Frendenthal. Judging by the twelve 

 species of fossils (p. 29), some of which occur also in Westphalia, and also from the 

 stratigraphical position of these beds, it seems probable that they are equivalent to 

 the Upper Devonian formation in Western Germany. 



B. The Devonian Formation West of the Jurassic Hills in Foland forms small 

 isolated cliffs in the surrounding Muschelkalk, but it is easily identified with the 

 Devonian rocks of the Eifel in Western Germany, by a large number of well- 

 preserved fossils (see pages 33 and 37). 



C. Carboniferous Formation. — A. Lower group. 



Culm. — This consists mostly of grey sandstone and clay-slate of a thickness of 

 several thousand feet. Its strike is from N. to S., it dips East ; the strata stand nearly 

 vertical, resting conformably on the Devonian Formation. 



It forms to the east and south of the crystalline Altvater, a hilly country, the 

 Niedere Gesenke, of about 800 square miles in extent. The end of the Devoniun and 

 the beginning of the Culm formation is very difficult to determine, as the lithological 

 character of the two is very persistent, namely, an alternating succession of Grauwacke 

 and Clay-slates. A long list of fossils (page 54, et seq.) follows. 



A comparison of the Culm strata of Upper Silesia with that of other countries 

 shows its great resemblance to the Culm formation of the Upper Harz. In both 

 districts sandstones and Clay-slates form the bulk of the formation, and land-plants 

 and marine animals occur in association. Eoemer comes to the conclusion that the 

 Culm beds of Upper Silesia were not only synchronous with the upper strata of the 

 Mountain Limestone, but that they represent the whole series of it.^ 



Mountain Limestone was only observed in the most south-eastern part of the Coal- 

 basin of Upper Silesia, in Poland. Near Krzeszowice a considerable number of fossils 

 were obtained (page 59), which identify the stratum as belonging to that formation. 



B. Upper group. Coal-measures. 



The Coal-basin of Upper Silesia and Poland is covered by deposits of Diluvium 

 over nearly its whole area, out of which several isolated portions of the coal-bearing 

 formation crop up. The most extensive of these Coal-measure islands is situated 

 between Gleiwitz and Myslowitz. The Silesian Coal-basin is only part of the vast 

 and extensive Coal-basin which reaches from Hultschin and Mahrisch-Ostrau, in 

 Austria, to Siewierz, in Poland, and again from Tenezynek, near Krzeszowice, beyond 

 Gleiwitz. The whole area of this large basin (after the Westphalian basin, the 

 largest on the Continent) amounts to about 1600 English square miles. The formation 

 presents physically a low hilly country, which only in the south-western end of the 

 basin reaches a height of about 1100 feet above the level of the Baltic Sea. Sand- 

 stone, of a coarse grain, with large pebbles of quartz and small particles of mica and 

 ordinary Clay- slate, are the principal features of this formation. The latter contains 

 often argillaceous Sphserosiderite, which is worked. The Coal-beds are found through- 

 out the depth of the formation ; some of these beds have a thickness of from 45 to 50 

 feet. The thickness of the whole beds is calculated to be 333 feet, whilst the pro- 

 duction of coal in 1867 amounted to 92 millions of cwts. in the Prussian share of the 

 basin. 



Amongst the other minerals found in this formation we have Lowigite, Carolathin, 

 Anthrakoxen, Galena, Schaalenblende, Schwerspath, Braunspath, etc., etc. 



The stratification of the Coal-basin is almost horizontal, and only shows much dis- 

 turbance near Mahrisch- Ostrau in its south-western extremity. 



Then follows a list of land-plants, one species of spider,^ and 36 species of marine 

 fossils, found in the Coal-measures of Silesia (page 78, et seq.). 



A comparison of the character of the Silesian Coal-measures and the Fauna with 

 that of other European Coal-basins gives the following results : — 



1. That the Fauna of the Coal-measures has much affinity to that of the Mountain 

 Limestone, although it possesses a peculiar character. 



2. The remains of marine animals are most frequently met with in the lower 

 strata of the formation. 



3. The marine fossils in the Upper Silesian Coal-mines agree not only in the genera, 

 but also in most of the species, with those of Coalbrook-dale, in England, of Chokier- 



1 It may be remarked here, that the Austrian geologists held this opinion long since ; it is not, 

 therefore, a novel suggestion. 



2 See Geol. Mag., 1865, Vol. II., p. 468, named by RiJmer ProtoUjcosa anthracophua. 



