THE PERMIAN PERIOD. 627 



The Rothliegende is often unconformable on the Carboniferous. 

 The character of the formations and of their fossils is such as to show 

 that much of the sediment was accumulated in inland seas, and in 

 salt and fresh lakes. Gypsum, salt, and a meagre fauna of dwarfed 

 and stunted species, some of which are of certain marine types, 1 are 

 among the distinctive marks of the series. To these inland areas 

 of sedimentation the sea sometimes had access, as the nature of the 

 formations and their fossils show. It may have had limited access, 

 even while the salt and gypsum beds were being deposited. There 

 were lakes of fresh water also in which sediments gathered, and in 

 these parts of the system, fossils of terrestrial as well as lacustrine 

 life are found. Even in some of the Permian limestones (as in France) 

 fresh-water fossils only are found. The shallow-water or subaerial 

 origin of much of the Permian is shown by the sun-cracks, rain-pit- 

 tings, ripple-marks, etc. Tracks of terrestrial and amphibious animals, 

 impressed in the muds and sands while they were accumulating, are 

 also found. 



In keeping with the conditions of its origin, the Rothliegende often 

 contains beds of coal. This is the case in France, where one coal- 

 bed attains a thickness of 82 feet; 2 in Saxony, in the Harz, Schwarz- 

 wald and Thiiringerwald mountains; and in Bohemia where the valu- 

 able coal-beds occur in the Rothliegende more than in the Carbon- 

 iferous. 3 In the region of the Ural mountains, too, the Lower Per- 

 mian beds are non-marine and coal-bearing. 4 



Especial interest attaches to the conglomerates and breccias of 

 the system because of their likeness to glacial drifts This likeness is 

 found not only in the presence of large bowlders, but in their character 

 and in the matrix in which they are set. Furthermore, the stones 

 have now and then been observed (Midlands and west of England) 

 to carry marks which have been thought to be glacial striae. This 

 origin of the marks, however, has been called into question. The con- 



1 Kayser, op. cit., p. 226. 



2 Idem, p. 253. 



3 Idem, p. 230-238. 



4 De Lapparent, Traite de Geologie, p. 969. 



5 Ramsay, Q. J. G. S., 1855, p. 185; and Geikie, op. cit., p. 1064. There seems to 

 be some question as to whether these formations should be referred to the Carbonifer- 

 ous or the Permian. 



