THE PERMIAN PERIOD 



California, show such ruggedness. The 

 great thrust faults, especially of the south- 

 ern Appalachians where certain great rock 

 masses have been pushed for miles over 

 others, were not produced by single move- 

 ments but rather by many repeated move- 

 ments along the same thrust planes (see 

 Fig. 113). 



Important orogenic movements from 

 Newfoundland to Rhode Island, and also 

 in the Ouachita Mountains of Arkansas, 

 are regarded as having taken place at the 

 same time. Accordingly the whole eastern 

 side of the continent was profoundly af- 

 fected by mountain-making disturbances. 



Other important geographic changes 

 in addition to the above were (1) the 

 warping of the surface of Appalachia as 

 we shall show in our discussion of the 

 Triassic period ; (2) the uplift of the Mis- 

 sissippi Basin, mostly without folding of 

 the strata, east of the Great Plains never 

 again to become submerged to the pres- 

 ent time except along the Gulf Coast ; and 

 (3) the elevation and erosion of most of 

 the Permian areas west of the Rocky 

 Mountains in the United States, which 

 thus accounts for a pretty widespread un- 

 conformity between the Permian and 

 Triassic in those areas. 



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Foreign Permian 



Europe. — The Permian of Europe 

 also shows two rather distinct phases — 

 marine and non-marine — but the system 

 in central and western Europe is usually 

 separated from the underlying Upper Car- 

 boniferous (Pennsylvanian) by uncon- 

 formity, thus presenting a contrast to 



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