STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 441 



with the Kladno Hauptflotz at base. The Lubna and the Niirschan 

 coals belong to the coal group in lowest part of the gray sandstone. 



Dannenberg^® states that the Lower Carboniferous and the Wal- 

 denburg (Sudetic or Schlesische stage) are wanting and that the 

 series begins with the Saarbriick, to which he refers the Kladno- 

 Pilsen sandstones as equivalent to the Schatzlar beds of Silesia ; but 

 the upper part of those beds are now regarded as belonging at the 

 base of the Ottweiler and as equivalent to the Schwadowitz beds. 



The Teinitzler beds (Hexenstein of Silesia) and the Schlaner 

 (Radowenz) represent the Ottweiler, and the Lihnauer are regarded 

 as undoubtedly Rothliegende. The Saarbriick consists chiefly of 

 thick sandstones and conglomerates ; the Ottweiler is mainly red 

 shales and sandstones, but it has much gray shale and white sand- 

 stone. The Rothliegende (Lihnauer) has its characteristic flora. 

 Deposition apparently was continuous throughout and at some local- 

 ities the higher beds distinctly overlap the lower. The Lubna- 

 Niirschan coal seam is proved to belong to the basal coal group not 

 only by stratigraphical relations but also by the associated flora, 

 which is Carboniferous. 



The several basins from north to south are the Kladno-Schlan- 

 Rakonitz, which is west from Prag and north from the Bersum 

 River ; the Pilsen and farther south the small areas of Radnitz, Mi- 

 roschan and Merklin. 



The KladnO'-Rakonitz basin, extending southwestwardly from 

 Kralup to beyond Rakonitz, has a gross area of not far from 450 

 square miles (1,100 to 1,200 square kilometers), but the productive 

 area is very much less. The stratigraphy is simple as it is not ob- 

 scured by disturbance, the dip rarely exceeding 6°, except on the 

 extreme border, where it becomes at times 15° or 20°. The largest 

 coal seam, known as Grundflotz or deep Radnitz, is at the base, 

 often separated by only a thin deposit from the older rocks. Lo- 

 cally it becomes 6 meters thick, but ordinarily it is so dirty as to be 

 worthless. 



The Hauptflotz or Upper Radnitz seam, 3 to 18 meters above 

 the Grundflotz, has been traced for 60 meters along the strike and 

 has been followed for 4 kilometers along the dip. It is extremely 



36 A. Dannenberg, " Geologie der Steinkohlenlager," pp. 232-257. 



