3G PHYSIOGRAPHIC GEOLOGY. 



The East and West Indies are very similar in their relations to the 

 continents and oceans. Ahout the East Indies Asia lies to the north- 

 west and Australia to the southeast, just as North and South Amer- 

 ica lie about the West Indies ; and the North Pacific and Indian Ocean 

 have the same bearing about the former as the North Atlantic and 

 South Pacific about the latter. The parallelism in the bends of the 

 great chains is, hence, only a part in a wide system of geographical 

 parallelisms. 



(4.) The American continents. — In North America, the northwest 

 system is seen in the general course of the Rocky Mountains, the 

 Cascade Range and Sierra Nevada; in Florida; in the line of lakes, 

 from Lake Superior to the mouth of the Mackenzie ; in the south- 

 west coast of Hudson's Bay ; in the shores of Davis' Straits and Baf- 

 fin's Bay ; and with no greater divergences from a common course 

 than occur in the Pacific. The northeast system is exemplified in the 

 Atlantic coast from Newfoundland to Florida, and, still farther to the 

 northeast, along the coast of Greenland ; and to the southwest, along 

 Yucatan, in Central America. The Appalachian Mountains, the river 

 St. Lawrence to Lake Erie, and the northwest shore of Lake Superior, 

 repeat this trend. 



There are curves in the mountain-ranges of eastern North America, 

 like those of eastern Asia. The Green Mountains run nearly north- 

 and-south ; but the continuation of this line of heights across New 

 Jersey into Pennsylvania curves around gradually to the westward. 

 The Alleghanies, in their course from Pennsylvania to Tennessee and 

 Alabama, have the same curve. There appears also to be an outer 

 curving range, bordering the ocean, extending from Newfoundland 

 along Nova Scotia, then becoming submerged, though indicated in the 

 sea-bottom, and continued by southeastern New England and Long 

 Island. 



Between this latter range and that of the Green Mountains lies one 

 of the great basins of ancient geological time, while to the westward 

 of the Green Mountains and Alleghanies was the grand Interior basin 

 of the continent. The two were to a great extent distinct in their ge- 

 ological history, being apparently independent in their coal-deposits 

 and in some other formations. 



In South America, the north coast has the same course as the Ha- 

 waian chain, or pertains to the northwest system ; and the coast south 

 of the east cape belongs to the northeast system. Hence the outline 

 of the continent makes a right angle at the cape. The northwest 

 system is repeated in the west coast by southern Peru and Bolivia, 

 and the northeast in the coast of northern Peru to Darien : so that this 

 northern part of South America, if the Bolivian line were continued 



