STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 433 



the results of his own investigations with those of other observers. 

 According to Dannenberg, the Lower Carboniferous of the Kulm 

 stage is present in the Walclenburg district on the northern and east- 

 ern sides ; it consists chiefly of coarse material but sandstone and 

 shale are in the upper part, with occasional limestone. The colors 

 are gray, brown and red. Organic remains are rare and the few 

 animal remains belong to marine types. 



The Upper Carboniferous, resting unconformably on the Kulm, 

 is a monotonous accumulation of conglomerates and sandstones ; 

 these are usually almost white, but locally in rather wide spaces 

 these beds, owing to infiltration of iron salts, are red and very 

 similar to Rothliegende. The proportion of shale is remarkably 

 small and it is found almost wholly in association with seams of 

 coal. The divisions are 



Radowenz beds Upper Ottweiler 



Schwadowitz beds Lower Ottweiler 



Schatzlar beds Saarbriick 



Waldenburg beds Sudetic 



Marine fossils are absent and the only animal remains belong to 

 fish, phyllades and ostracoids, which may be either fresh-water or 

 brackish water-forms. The Rothliegende boundary cannot be de- 

 termined ; Coal Measures pass upward gradually and, in the south- 

 west wing of the basin, the similarity of the rocks is so great that 

 Upper Carboniferous was mistaken by some observers for Roth- 

 liegende. Local discordance has been discovered here and there in 

 the Upper Carboniferous, there being local gaps in the succession; 

 similar discordance between Upper Carboniferous and the Rothlie- 

 gende has been observed, but evidence of general discordance be- 

 tween Upper Carboniferous and Permian remains to be discovered. 



Groups of workable coals are in all the stages, but they are sepa- 

 rated by thick deposits of barren rock. The irregular deposition 

 of the several stages and the notable variations in thickness of coals 

 lessen greatly the importance of this field. No coal seam is per- 

 sistent throughout the exposed area of its stage; each decreases in 

 all directions from a maximum and not a few seams disappear. 

 No definite relation exists between depth from surface and the 



