322 Reviews — Geology of Prussian- Silesia. 



The Geology of Prussian-Silesia.' 



THIS valuable work was prepared and published by direction of the Government 

 of Prussia, who also appointed Dr. Roemer, Professor at the University of 

 Breslau, as Superintendent of the Geological Survey of the Province of Silesia, so 

 important as regards its mineral wealth. Dr. Roemer has shown himself admirably 

 fitted for this task by completing, during the years 1862-69, a geological map 

 (scale — ^^550)' *° which this book, with its numerous plates of fossils, sections, etc., 

 etc., forms the key. 



The author commences with the crystalline rocks, which appear only as a small 

 zone at the western part of the section at Leobschiitz, as Gneiss, Mica-schists, and 

 Granite. 



Gneiss occurs as a small zone between "Wiirbenthal and Zuckmantel and Neisse, 

 where it underlies Lower Devonian strata. Quartz -reefs, with insignificant indica- 

 tions of Copper-pyrites and Pecherz, also Malachite, and earthy Kupferlazur. 



Mica-schists are limited to one locality near Ziegenhals. 



Granite appears in dykes in a few localities, where it has burst through Mica- 

 schists (as at Freiwaldciu and Niklasdorf ), or through Gneiss (as at Deutschwette 

 and Ludwigsthal). 



EocJcs. — I. Paleozoic Group. 



A. Devonian formation on the Eastern slopes of the crystalline Altvater-mountains. 

 1. Wiirbenthal Quartzite and Clay-slate QLower Devonian) are characterized by 

 white quartzite and black clay-slate, the latter with beds of crystalline limestone. 

 The strata are raised up and much disturbed, striking from S. to N., and are over- 

 lain by " Engelsberg beds." They form a mountainous country, attaining heights of 

 3000 feet, and with deeply eroded valleys. In the map it is represented by a narrow 

 zone between Neu-Vogelseifen and Ziegenhals, from whence it passes into Austrian- 

 Silesia. 



Eruptive Rocks. — Diorite and Diorite-schists are principally found within the 

 Mica-schists, and occur only in one locality, at the Querberg_ in Quartzite. They 

 form many of the highest points in the Lower Devonian formation; for instance, near 

 Wiedergriin, Carlsbriinn, Engelsberg, etc., etc., in a N. and S. direction. 



(5,.gs._G-old-bear)ng pyrites (iron and copper) occur not far from Zuckmantel 

 in Austrian-Silesia. Small crystals of these pyrites occur in the Quartzites and Clay- 

 slates, partly in true veins, partly only as traces diS'used through the rock. At some 

 places gold occurs in zinc-blende. Besides gold, magnetic-iron-ore, galena in con- 

 nexion with zinc-blende, copper-pyrites, iron-pyrites are also found. Haematite is 

 likewise worked to a great extent, but not in the Prussian portion of Silesia. Other 

 minerals, as Cyanite, Staurolite, Garnet, Faserquartz, are obtained from the Lower 

 Devonian Quartzites. 



Near Wiirbenthal, in Austrian- Silesia, from whence the stratum was named, fossils 

 were found in the white Quartzite, in all twelve species (p. 14), of which three 

 (the only determinable ones) agree with species from the Lower Devonian formation 

 near Coblenz-on-the-Rhine. 



These beds must rest upon crystalline rocks, as Silurian strata are entirely wanting 

 in Silesia. 



2. Engelsberg Grauwacke rests upon the former bed, and consists of Grauwacke and 

 Clay-slate, striking from N. to S., and dipping E. In the sandstone and slates 

 cleavage can frequently be observed. It covers an area of 192 English square miles 

 in Austrian- Silesia and Moravia. A few traces of fossils (p. 20) were found near 

 Engelsberg. This system is overlain by 



3. The Bennisch beds, consisting of grey sandstone, clay-slate, and quartz -con glo- 

 merate, with amygdaloid diabase and subordinate occurrences of limestone and iron- 



1 Geologie von Oberschlesien. Ein Erlauterung' zu der im Auftrage des konigl. Preuss. 

 Handels Ministeriums von dem Verfasser bearbeiteten Geologischen Karte von Oberscblesien in 

 12 Sektionen, etc., etc. Von Dr. Ferd. Koemer. Breslau, 1870. Royal 8vo., pp. 587. Mit 

 Atlas Taf. 50, karten und profile. 



