342 STRATIGRAPHICAL GEOLOGY 



Central Germany. In the central part of Germany (Thuringia 

 and Saxony) the passage-beds are absent, and the Permian is more 

 or less unconformable to the Carboniferous ; but the Lebach Group 

 is well represented, and has yielded many amphibian remains, e.g. of 

 Branchiosaurus, Archegosaurus, and Pelosaurus. Its chief develop- 

 ment is in the Erzgebirge basin near Chemnitz and Zwickau, where 

 it consists of coal-bearing beds, with the usual plants in the lower 

 part, together with beds of volcanic tuff and sheets of trachytic lava ; 

 and these beds are overlain by a set of red breccias, conglomerates, 

 and sandstones, largely composed of the debris of contemporaneous 

 volcanic rocks. 



The Saxonian of this region is a thick mass of conglomerates, 

 sandstones, and marls, the predominant colour of whicli is red or 

 reddish brown. These beds have a thickness of about 1600 feet in 

 Saxony and nearly 2000 in Thuringia. No fossils occur in them 

 except plant remains and the footprints of reptiles and amphibians, 



CTiemnitz y P t 



Fig. 111. SECTION THROUGH THE ERZGEBIRGE BASIN (by Siegert). 



v. Sandstones and tuft's. r. Lebach Beds. s. Silurian. 



P, t. Lavas and tuffs. c. Coal-measures. p. Archaean. 



so that the whole formation up to the top of the Saxonian appears 

 to be of lacustrine and terrestrial origin. 



The succeeding division is largely marine, and includes the 

 Zechstein limestone, but as that is really only a small portion of it 

 the name Thuringian is a much better one. This group of beds 

 occupies a considerable area in Central Germany, spreading round 

 the mountain ranges of the Thuringerwald, the Frankenwald, the 

 Eeisengebirge, and the Harz, and passing everywhere below the 

 overlapping Trias and Jurassic strata. In its typical development 

 it is a series of limestones and shales of no great thickness, from 

 400 to 500 feet, but in certain localities it is expanded by the 

 intercalation of enormous masses of gypsum and rock-salt. In the 

 Mansfeld district it has the following components : 



Upper /Red clay and gypsum. 

 200 feet\ Clays with lenticular beds of limestone. 

 Middle/ Dark bituminous limestone and shale. 

 150 feet\ Gypsum and dolomitic breccia. 



( Magnesian limestone (the Zechstein). 

 - I Bituminous shale (Kupferschiefer). 

 (Calcareous sandstone and conglomerate. 



