DIASTROPHISM AND THE FORMATIVE PROCESSES 339 



yet be closely located. But rocks of very late Pennsylvanian or 

 early Permian age have been deposited across the western end of 

 the Arbuckle uplift. They he in a nearly flat position across the 

 eroded edges of several thousand feet of the Pennsylvanian, all of 

 the Mississippian, Devonian, Silurian, and a large part of the 

 Ordovician rocks. ^ The folding of the Wichita Mountains is 

 thought by Taff to have occurred simultaneously with that of the 

 Arbuckle uplift.^ 



Some movements, though they do not appear to have been very 

 pronounced, affected the extreme eastern border of the continent. 

 In the southeastern part of New Brunswick the strata of the Upper 

 Carboniferous^ (or Permo-Carboniferous)'* rest unconformably upon 

 the Millstone Grit at various points. These movements may 

 possibly have affected also the eastern side of the Appalachians 

 farther south, but the intense deformation which developed the 

 Appalachian Mountains, as now known, came later. 



In the Appalachian region, according to David White, there is 

 distinct evidence of a shift in the region of sedimentation or, in 

 other words, a change in the direction of warping of the Appalachian 

 trough at the close of the Westphahan time; for during the West- 

 phalian the maximum subsidence and loading was toward the 

 south, in which region no Stephanian was ever deposited, while 

 in the northern Appalachian region, the greater part of which was 

 exposed during most of the Westphahan time, there occurred the 

 maximum deposition of Stephanian with possibly lack of inter- 

 ruption in its passage into the Permian.^ 



In addition to the better-known cases of mountain development, 

 there are several movements of this general age which cannot be 

 placed very closely with the data now at hand. According to 

 Evans, the eastern Andes of BoHvia, which had been folded in very 

 early times and had again been brought beneath the sea, received 



' J. A. Taff, op. cit., pp. 35-36. 

 ^ Ibid., p. 80. 



3 R. W. Ells, Geol. Survey of Canada, Ann. Kept., I (1885), 7, 29 E. 

 •»L, W. Bailey, "Report upon the Carboniferous System of New Brunswick," 

 Geol. Survey of Canada, XIII (1902), 19 M. 

 5 David White, personal communication. 



