556 C. SCHUCHERT PALEOGEOGRAPHY OF Js T ORTH AMERICA 



other words, in America these periods belonged to one diastrophic cycle 

 Each part of these movements was of very long duration. From the stand- 

 point of marine invertrebrates, the life of the Permic period — that is, the 

 Permic in the widest sense — was normally developed only in the Trans- 

 Pecos region of Texas. Elsewhere the early Permic waters (Oklahomian) 

 were not normally marine, and therefore retained the hardy Pennsylvanic 

 species, especially the bivalves. Associated with these, however, were a few 

 forms of ammonites, indicative of early Permic types (Artinsk, as this 

 term is now used in the wider sense by most stratigraphers). This was 

 particularly true of the region east of the Mississippi river, while to the* 

 west of this stream the Pennsylvanic waters were more often normally 

 marine, followed in early Permic time by an abnormal sea that deposited 

 over great areas red muds replete with gypsum, some salt, and, locally, 

 dolomites. In the Eocky Mountain area, however, the seas were more nor- 

 mally marine in the Pottsvillian, and in the early Missourian local eleva- 

 tion and shoaling began, with much accumulation of sands. Later this 

 uplift prevented the eastern waters from mixing with those of the Pacific, 

 thus causing the latest Missourian faunas to become very different from 

 those of the Mississippi valley. 



Saint Lawrence sea. — In the maritime provinces of eastern Canada the- 

 Pennsylvanic is well developed and usually of very great thickness. The 

 celebrated Joggins section of Nova Scotia is 13,000 feet in depth, and 

 may extend into the Permic. The Cape Breton series is 10,000 feet 

 thick, and the Pictou field has a similar thickness. The Eiversdale and 

 Harrington river beds and the plant-bearing beds near Saint Johns, New 

 Brunswick, are also of Pennsylvanic age. 



It is very rare that marine fossils are reported from this region, and 

 the few that have been listed indicate Pottsvillian rather than Missourian 

 time. In the Eiversdale has been found Belinurus grandcevus, and Ami 

 has shown the writer examples of Euphemus carbonarius and Leaia from- 

 the same beds. 172 



Pottsvillian or Lower Pennsylvanic. — There is no system of Paleozoic 

 formations in America in so unsatisfactory a condition for detailed corre- 

 lation as the Pennsylvanic. Probably no other system has received so* 

 much attention, and yet on the basis of marine invertebrates the faunal 

 characteristics distinguishing the Ppttsvillian from the Missourian are- 

 still undetermined. It is true that marine life is not generally present in 

 these lower formations ; the literature, however, indicates that such forms 

 have been seen at many localities, but the species are very rarely men- 



172 Ami : Annual Report of the Geological Survey of Canada, vol. 12, 1899, pp. 100A- 

 204A. 



