260 SCHUCHERT— BLACK SHALE DEPOSITION. [May 7, 



The copper-bearing shales usually succeed the basal conglomer- 

 ates or sands and finally become gradually more and more cal- 

 careous, passing upward into the normal Zechstein dolomite of wider 

 distribution. The latter has an abundant though monotonous fauna 

 indicative of peculiar marine conditions and not much like that of 

 the Tethyian mediterranean to the south, which is of normal sea 

 environment. The paleogeography indicates an inland sea, bounded 

 by continuous land, in the north by Fennoskandia across to England, 

 thence south to France and Belgium, and east over South Germany 

 to Bohemia. In the east only were there limited connections with 

 the Russian and Arctic Zechstein sea. The previous orogenic move- 

 ments resulting in the Paleozoic Alps of central Europe had been 

 greatly reduced, so that the streams flowing into this Permian sea 

 were sluggish and delivered only the finest of muds and solution 

 materials, while those flowing out of regions of igneous rocks were 

 charged in addition with copper, zinc, and silver. 



The Kupferschiefer are fissile, tough, dark to black, highly 

 bituminous (6 to 20 per cent.), clay shales with considerable cal- 

 careous material that increases in amount upward (locally to 45 

 per cent.). Copper sulphides variable in quantity and nature are 

 present, and because of this ore the strata have been mined in 

 Germany for seven hundred years. Under the microscope the shale 

 is seen to be made up of finest clay substance colored yellow-brown 

 to black by bitumen. Throughout the clay there are scattered, 

 layered, or aggregated in the form of thinnest lenses varying 

 amounts of tiny crystals of calcite and needle-like splinters of quartz. 

 Black coaly dust is also more or less abundant and especially among 

 the clay particles. 



The flora and fauna of the Kupferschiefer are small and at best 

 do not include more than i land stegocephalian, 2 land reptiles, 17 

 fishes (5 selachians, i crossopterygian, the rest ganoids) with 

 structures indicating forms that lived on or near the bottom of the 

 waters, i nautilid, i gastropod, i scaphopod, 10 bivalves, 3 bryozoa 

 (FenestelHdse), 5 brachiopods, i problematic starfish, and 11 species 

 of land plants. This assemblage is brought together from many 

 localities and the species of fishes are usually based on single speci- 

 mens, indicating that the biota is not a natural assemblage, but is 



