POSITIVE ELEMENTS 469 



"The region toward the Atlantic border, afterward raised into the Appa- 

 lachians, was already then, even before the Lower Silurian era closed, the 

 higher part of the land" (319). "We hence learn that in the evolution of the 

 continental germ, after the appearance of the Azoic nucleus, there were two 

 prominent lines of development, one along the Appalachian region, the other 

 along the Rocky Mountain region — one, therefore, parallel with either ocean. 

 Landward, beyond each of these developing areas, there was a great trough or 

 channel of deeper ocean waters, separating either from the Azoic area" (344). 



The name Appalachia was given by Williams. 86 The term Appa- 

 lachians was applied to these mountains by the Spaniards under De Soto, 

 the word being derived from the neighboring Indians. 



Archiguiana. 87 — This element comprises Venezuela and Guiana, and at 

 times, according to Yon Ihering, the Antilles also. Suess has likewise 

 defined this very ancient shield. In its history it is comparable to Lau- 

 rentia, since through the action of the Pacific ocean the accretions of 

 Paleozoic South America formed around its southern and western sides, 

 ivhile the effects of the Caribbean were slight, having practically the same 

 yalue as those of the Arctic ocean on Laurentia. 



Bretonia. — See Acadia. 



Cascadia. — Dana 88 thought that there might be an ancient protaxis 

 along the Sierra Nevadas, the Cascades of Oregon and Washington, and 

 ihe ranges of western British Columbia. According to G. M. Dawson, 89 

 the Gold ranges were an old protaxis. This entire region exhibited no 

 Imown Paleozoic sediments until Carbonic times, and it is represented as 

 land in the authors map. Cascadia was a bordering positive element, and 

 owing to the pressure and subsidence of the vast Pacific ocean it had at 

 •different times been subject to great volcanic activity. The first seismic 

 period was coincident with the late Devonic of California, but during the 

 late Paleozoic and early Mesozoic volcanic action appears to have been as 

 great as in Cenozoic time. 



Various geologists have included Cascadia in the Eocky mountain or 

 Cordilleran land, the southern end of which was pointed out by King; 90 

 latterly Willis 91 has defined this as the Pacific element. 



Central Newfoundland range. — See Newfoundlandia, under Acadia. 



8a Williams : American Journal of Science, vol. 3, 1897, p. 397. See also Willis : Bull. 

 'Geological Society of America, vol. 18, 1907, pp. 394, 398. 

 S7 Von Ihering: Archhelenis und Archinotis, 1907, p. 111. 



88 Dana : Bull. Geological Society of America, vol. 1, 1890, p. 45. 



89 Dawson : Ibidem, vol. 12, 1901, p. 84. 



80 King: TJ. S. Geological Exploration, 40th Parallel, vol. 1, 1878, p. 247. 

 1,1 Willis : Bull. Geological Society of America, vol. 18, 1907, pp. 396, 398. 



