HOCHSTETTER BOHEMIAN LIGNITES. 11 



On the Lignite Basin o/*Falkenau and Elbogen, m 

 Bohemia. By Dr. F. Hochstetter. 



[Proceedings Imp. Instit. Vienna, Feb. 19, 1856.] 



This basin, 3 Austrian miles in length and 1^ in breadth, lies in a 

 depression between the Carlsbad Mountains and the Erzgebirge, 

 and is really the central portion of the Egra basin, being separated 

 from the upper basin by the mountain-range of Maria Kulm, and 

 from the lower one by the basaltic rocks near Saatz and Teplitz. 

 The basis of the lignitiferous deposits consists of loose sandstones, 

 conglomerates, and quartzose sandstones (with siliceous cement of 

 extraordinary coherence), appearing in some localities only in the 

 form of blocks. Near Altsattel the sandstones, which attain a thick- 

 ness of 100 feet, contain numerous vegetable remains, including 

 Palm-leaves. These sandstones are overlaid by clays, 10 to 20 feet 

 in thickness, some plastic, others sub-schistose, varying greatly in 

 colour, and in some localities pyritiferous enough to serve, on a large 

 scale and with great advantage, for the manufacture of sulphur, 

 alum, sulphate of iron, and sulphate of copper. The clays include 

 numerous beds of good lignite, and sometimes of excellent glance- 

 coal. These lignitiferous deposits are disturbed, broken, and dis- 

 located in their stratification. They are of ante-basaltic date, while 

 similar post-basaltic deposits overlie them in horizontal and undis- 

 turbed stratification. The erupted basalt of North-west Bohemia 

 occurs between these two deposits. The superior post-basaltic divi- 

 sion is characterized by beds of basaltic tuff, thick beds of lignite of 

 inferior quality, finely laminated, tough shales (with remains of in- 

 sects and vegetables), limestones (with Helices) and quartz-rock 

 (both the latter of freshwater origin), and by an abundance of hydrous 

 oxide of iron and sphserosiderite, distributed in the uppermost ferru- 

 ginous clay. Kaolin-deposits occur at Zettlitz, near Carlsbad, and 

 at many other localities ; they seem to be local results of the decom- 

 posing action of tertiary waters on the granite beneath. Porcellanous 

 jasper and bacillary iron-ores, &c., the ordinary products of the 

 spontaneous combustion of the lignite-beds, occur around Carlsbad 

 and Falkenau. 



The distinction of ante-basaltic and post-basaltic deposits in the 

 Hgnite-basin of Elbogen leads to a geological question of general 

 interest. The ante-basaltic deposits occur not only at the bottom of 

 the basin, but on the slopes and even on the tops of the neighbour- 

 ing mountains, as high as 2100 feet above the level of the sea, where 

 they are overlaid by basalt, and where the hgnites are still worked 

 for fuel. The post-basaltic beds occur exclusively within the basin 

 itself. These circumstances indicate considerable disturbances con- 

 nected with the basaltic eruptions, which are generally explained by 

 supposing a last and general upheaving of the Erzgebirge and the 

 Carlsbad Mountains, posterior to the lignite-period. Dr. Hochstetter 

 is of opinion that both these mountain-chains occupied their present 

 level long before this period, and that the immense basaltic masses 



