STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 9 



Hinterholz, Rachoy found dips of 40 to 60 degrees and one seam, 

 4 feet 6 inches thick, was mined. The coal yielded 66.3 per cent, of 

 high-grade coke, used in iron-making. 



V. Sternbach's section near Grossau is (i) shale, 6 inches; (2) 

 coal and shale, i foot; (3) clay shale, i foot; (4) coal, 3 feet; 

 (5) shale, 6 inches; (6) sandstone, 6 feet; (7) carbonaceous shale, 

 6 inches; (8) coal, 6 inches; (9) carbonaceous shale, 6 inches; 

 (10) sandstone, i foot; (11) shale, not measured. This, like many 

 others, closely resembles typical short sections in Cretaceous and 

 Carboniferous coal measures. The workable seam. Number 4, has 

 lenses of shale, so that not more than three fourths of the output is 

 clean coal. The roof is black shale but the floor is fine to coarse 

 sandstone. The dip is from 55 to 60 degrees and the coal seams 

 are extremely variable ; but the variations seem to be due only in 

 part to serious disturbance. In the Pechgraben area, v. Sternbach 

 saw 6 well-defined coal seams as well as numerous streaks of coal 

 in the great Franz-Stollen, where the dip is 40 to 50 degrees and 

 the rocks as well as the coal are much shattered. The sandstones 

 have been broken into great wedges, which interlock with similar 

 wedges of shale. The coal seams are thin and often are distorted; 

 but they show variations, which clearly are not due to disturbance of 

 the stratification. The third seam, where first opened at the out- 

 crop, consisted of numerous streaks, one to 3 inches thick; it was 

 prospected for a considerable distance in the hope that these streaks 

 would unite ; eventually the mass became 4 feet thick but about one 

 half of the shale still remained. The sixth seam is 9 feet thick in 

 the tunnel, where it has 5 clay partings, in all 3 feet. But this seam, 

 resting on shale with plant remains, is variable; in another tunnel 

 the thickest seam is only 16 inches, while in another it is from 3 

 inches to 2 feet. One cannot determine in the strongly disturbed 

 area whether the seams are lenticular or not, but there are consider- 

 able areas, in which according to the diagrams, there was little dis- 

 turbance and the succession is normal ; in these the lens-form is 

 distinct. The coal is somewhat inferior, having 17.2 per cent, of 

 ash. This Pechgraben coal, according to v. Giimbel,^^ shows woody 



IS C. W. V. Giimbel, " Beitrage, etc.," 1881, p. 160. 



