STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 25 



are in a mass of black shale, about 70 feet thick. Equisctum 

 columnare is abundant in the black shales and beautiful specimens 

 have been obtained from the roof of the upper seam. This seam, 4 

 feet thick where first seen, is from 3 to 24 feet. Occasionally it 

 divides into two or more benches, of which only one is persistent. 

 The coal of Lilienfeld and Kleinzell yields 72 to 74 per cent, of good 

 coke and ash is from 8 to 14 per cent, in the raw coal. 



Hertle examined the area near Kirchberg on the Pielach River 

 where the black shale mass has 4 seams of coal. This shale is 40 

 feet in one tunnel, 48 to 60 in another, while in a third it is not 

 less than 100 feet. In one tunnel, the middle seam is ^2 feet above 

 the lower one ; followed westward, the interval becomes 50, 30 and 

 18 feet. A similar convergence is that of the middle and upper 

 seams, which actually unite with increased thickness. These rela- 

 tions existed before disturbance occurred. Dips in this district are 

 from 40 to 70 degrees. The coal throughout is tender and caking, 

 giving 67 per cent, of good coke; but the ash is high, averaging 15.8 

 per cent. In the Rehgarten area, the coal is cleaner, having only 9 

 per cent, of ash. Here distortions of the rocks are few but other 

 troubles are encountered ; the seams thin away and frequently they 

 pass into carbonaceous shdle. Hertle's descriptions make it clear 

 that the seams are lenses, sometimes joined by carbonaceous shale, 

 but at other times wholly separate. The " horseback " seems to be 

 a feature here, as in the older as well as in the newer coals. One 

 tunnel, reached sandstone, with no admixture of clay or coal, at 480 

 feet from the mouth. It was pushed through the rock and again 

 reached the coal. The lower seam at Loichgraben yields a good 

 coal, but that from the upper seam has 52 per cent, of ash, though 

 it looks like excellent coal. 



Rachoy found plant-bearing shales as roof of coal seams near 

 Lunz and he says that, near St. Anton, a bituminous limestone is 

 the roof in some mines. The coal at several localities is good but 

 at others the ash is very high, while the coal externally resembles 

 the best in the district. This area is on the westerly side of the 

 Lunzer region and, in most cases, the seams are thin. 



Zincken^*^ states that plant-bearing shales are the roof at many 



^^ C. F. Zincken, " Erganzungen, etc.," 1878, pp. no, in. 



