440 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



few in number, vary greatly ; the deposits were laid down in deep 

 troughs on Cambrian and Pre-Cambrian rocks and decrease toward 

 the middle line of the trough. The unevenness of the surface ex- 

 plains absence of lower members at some localities. The succession 

 is Coal Measures and Rothliegende and the passage from one to the 

 other is so gradual that no boundary can be determined ; the relation 

 of Upper Carboniferous to Permian was in dispute for a long time 

 and, even now, the matter seems to be undetermined at several 

 localities. Katzer and others of the older workers divided the de- 

 posits into the Radnitz beds at the base, belonging to the Coal Meas- 

 ures, followed by a Middle Zone, with the Niirschan coal seam, and 

 on top, the Kounovaer beds ; the last two were thought to be Per- 

 mian. Borings made in areas where exposures are rare, led v. 

 Purkyne^* to a different conclusion. The succession in a boring 

 made where the Pilsen Basin is deepest and where exposures are 

 rare, is, descending: (i) Upper red clay shales, red and variegated 

 shale and sandstone, 155 meters; (2) upper gray clay shales, with 

 gray to white sandstone and coal seams, 180 meters; (3) lower red 

 clay shales, red and variegated shale and marly shale with arkose, 

 52 meters ; (4) lower gray shale, gray shale and gray to white 

 arkose, with at least 9 coal seams, 419 meters. He thinks that 

 earlier students had failed to recognize the existence of two red 

 deposits, for no borings had been made and exposures are very rare. 

 The Lubna coal seam and the Nyran cannel are at the same horizon. 

 Each of the coal-bearing divisions, composed of gray to black shale 

 and gray to white sandstone, underlies a division of red shales and 

 sandstones, barren of coal. 



Weitkofer,^^ in a review of the northern basins, grouped the 

 Permo-Carboniferous deposits into: ((/) Upper red clay shale, Lih- 

 naer beds; (c) dark gray clay shales, Schlaner beds, containing the 

 Pilsen and Schlan coal seams; (b) lower red clay shales, Teinitzler 

 beds, 190 meters, with no fossils aside from stems of Araucarites ; 

 (a) gray sandstone group, Kladno-Pilsener beds, 300 to 400 meters, 



3* C. R. V. Purkyne, "Zur Kenntnisse der geologische Verhaltnisse der 

 mittelbohmischen Steinkohlenbecken," Verh. k. k. geol. Reichsan, Jahrg. 1902, 

 j)p. 122-125. 



^^ K. A. Weitkofer, " Geologische Skizze das Kladno-Rakonitzer Kohlen- 

 becken," the same, pp. 399-420. 



