188 HISTORICAL GEOLOGY 



North America. Early in the Permian a great salt lake (or series 

 of lakes), sometimes with local fresh-water conditions, extended 

 over western to central Europe from Ireland to central Germany. 

 Red beds, consisting of sandstones, shales, marls, salt and gypsum, 

 together with some coal beds, were formed in these inland water 

 bodies. Fossils prove that marine waters sometimes spread over 

 at least portions of this inland basin. Glacial deposits have re- 

 cently been discovered toward the base of the Permian in Ger- 

 many. Another feature of special interest is the large amount of 

 igneous rock in the form of lava flows, dikes, and tuffs in the Lower 

 Permian, particularly in the British Isles, Germany, France, and 

 the Alps. 



Where the Lower Permian occurs in southern Europe, it is 

 mostly of marine origin. 



About the beginning of the Upper Permian, marine waters 

 appear to have prevailed over the enclosed basin areas of central 

 and western Europe, but soon again those waters withdrew to 

 restore salt lake conditions (Fig. 114). Neither coal nor igneous 

 rock occurs in the Upper Permian, but the greatest salt beds in the 

 world were deposited in northern Germany during late Permian 

 time. Some layers of magnesium and potassium salts were depos- 

 ited with the common salt, one well having penetrated the deposit 

 near Berlin to a depth of 4000 feet without reaching the bottom. 



Upper Permian rocks do not occur in France, and where found 

 in southern Europe they are largely marine. 



In Russia, the tj^pe region for the Permian, rocks of this age 

 underlie much of the country and appear at the surface over a wide 

 area in the eastern part, just east of the L T ral Mountains. These 

 rocks are usually conformable upon the L T pper Carboniferous 

 (Pennsylvanian) . Non-marine deposits, including red beds with 

 salt and gypsum, are common, though at some horizons true 

 marine strata prove incursions of the sea. 



Other Continents. — In many other parts of the world Permian 

 rocks are extensively developed, particularly in northern Asia, 

 China, Persia, northern India (including the Himalayas), South 

 Africa, Australia, Tasmania, New Zealand, Argentina, and Brazil. 

 Continental deposits are common. A most remarkable feature is 

 the widespread occurrence of thick (sometimes from 1000 to 2000 

 feet) glacial deposits in the Permian system in low-latitude coun- 

 tries such as India, South Africa, southern Brazil, and Australia. 



