446 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



The upper deposits show none of the regularity characterizing those 

 of the lower division. The coal group consists of dark gray to 

 almost black shale and sandstone, with thickness of not more than 

 20 meters. The seam of anthracite is from 80 to 120 centimeters 

 thick; the dip at the important mine is toward north-northwest at 

 abut 30° and there is little variation in thickness. The coal is clean 

 anthracite throughout, except locally, where a thin black parting 

 with some pyrite is found. The volatile varies from 6.2 to 6.8 per 

 cent, and the ash from 6.4 to 9.4; complete analysis gives carbon, 

 88.90; hydrogen, 2.91; oxygen and nitrogen, 2.10; sulphur, 1.49; 

 water, 1.80; ash, 2.80. 



Dips vary from i to 45° and the whole district is much broken 

 by faulting. 



Germany. 



Saxony. — The coal basins of Saxony, in the southern part of the 

 kingdom are small, but the seams are often thick, yield good coal 

 and are of great economic importance. The Zwickau and Lugau 

 areas, known as the Erzgebirge basins, are at the southwest and the 

 Dohlen (Plauenschen Grundes) is at a few miles away toward the 

 norheast. Coal has been mined in some localities for centuries and 

 the region has been studied by many geologists.*^ 



The petty basins of Hainichen and Ebersdorf on northeastern 

 border of the Carboniferous region hold deposits of Culm age. The 

 lower division or Grundconglomerate has maximum thickness of 

 2,000 feet, but this decreases rapidly toward the south until the 

 whole Culm is barely 1,700 feet, of which not more than one half 

 belongs to the lower division. The coal-bearing or upper division, 

 consisting mostly of sandstone, has four thin seams, which have been 



*2 The works examined are H. B. Geinitz, " Die Steinkohlen Deutsch- 

 lands und anderer Lander Europa's," Band I., 1865, pp. 45-90; H. Mietzsch, 

 "Geologic der Kohlenlager," 1875, pp. 150-156; " Erlauterungen, etc., Blatt 

 III., 1877; Th. Siegert, "Erlauterungen, etc., Th. Siegert, "Erlauterungen, 

 etc., Das Steinkohlen-revier in Lugau-Oelsnitz," 1882 ; J. T. Sterzel, " Er- 

 lauterungen, etc.. Section Stellberg-Lugau, Blatt 113"; "Palaeontologische 

 Character des Steinkohlenformation und das Rothliegende von Zwickau," 

 2te Aufl., 1901 ; R. Hausse, " Steinkohlenbecken der Plauenschen Grundes 

 (Dohlener Becken)," 1892; A. Dannenberg, "Geologic der Steinkohlenlager," 

 Band L, 1908, pp. 199-224. 



