250 



NORTH AMERICA (GEOLOGY.) 



The musk-ox, the reindeer, and the white bear are 

 found only in the most northern regions, Carnivo- 

 rous animals, such as the bear (the black bear and 

 the grisly bear), the wolf, the cougar (panther), 

 lynx, &c., are numerous in the unfrequented parts of 

 the country. All the domestic animals of Europe 

 the horse, ox, sheep, goat, ass, dog, hog, and cat 

 liave been introduced into America, and some of 

 them have increased to such a degree that they form 

 large herds in a wild state. Bees are numerous in 

 the forests. North America harbours some dan- 

 gerous reptiles, of which the rattlesnake is the most 

 formidable. Mosquitoes are not less busy on the 

 borders of the Arctic sea than on the shores of the 

 Atlantic. The turkey is a native of America, and 

 was first introduced into Europe in 1525. The mock- 

 ing-bird is celebrated for its miraculous power of 

 song ; the humming-bird for its beauty and diminu- 

 tive size ; the wild pigeons darken the air. There 

 are numerous other birds peculiar to this continent, 

 and many, such as the eagle, owl, crow, hawk, swan, 

 goose, duck, &c., which present specific differences 

 from those of the same name in the eastern continent. 

 The coasts and inland waters swarm with waterfowl. 

 Alligators are found in the southern rivers ; pikes, 

 sturgeons, trout, eel, and salmon fill the waters. The 

 great bank of Newfoundland and the neighbouring 

 coasts abound in cod. The seal, walrus, &c., are 

 found. For the natural history of North America, 

 the reader may consult Godman's Am. Nat. Hist. 

 (Mastology), and Richardson's Fauna Bor. Am. ; 

 Wilson's and Audubon's Ornithology; Michaux's, 

 Barton's, NuttaU's, Bigelow's botanical treatises; 

 Cleaveland's Mineralogy; Silliman's Am. Journal of 

 Science, &c. 



The climate of North America is known to differ 

 from that of the eastern continent, the quantity of 

 heat in the same parallels of latitude being less in 

 the former than in the latter. The difference, how- 

 ever, is not so great as was formerly supposed. It 

 has been considered that there was a difference of 

 temperature of several degrees between places under 

 the same parallel on the Atlantic coast and the Mis- 

 sissippi Valley. This supposition, founded on the 

 fact, that certain vegetable productions were found 

 in more northern latitudes in the latter than in the 

 former, has been shown to be erroneous by Hum- 

 boldt. That distinguished philosopher explains the 

 phenomenon by an examination of the form and direc- 

 tion of the valleys in these two regions. In the At- 

 lantic region they are transverse, or run east and 

 west, and therefore the propagation of plants north- 

 wardly was obstructed, while the great Mississippi 

 Valley opens to the south, and therefore presents no 

 obstacles to the migration of vegetables towards the 

 north. The temperature on the western shores of 

 North America seems to be considerably higher, 

 however, than in the regions east of the Rocky 

 mountains, and to correspond very nearly with that 

 of the Atlantic countries of the eastern hemisphere. 

 Further details on this subject will be found under 

 the heads Climate, Temperature, and Winds. 



The Geology of North America, or an account of 

 the different rocks which constitute the material of 

 this continent, and a description of the various modes 

 of arrangement observed by them, 1s no less a sub- 

 ject of economical interest than of scientific curiosity, 

 since to the existence of certain rock formations is 

 due the fertility of a country in agriculture, and its 

 richness in coal, salt, the useful metals, and other 

 mineral productions necessary to human support ; and 

 from a knowledge of their relations, many interesting 

 conclusions are derived relating to its antiquity and 

 those great revolutions which it experienced prior to 

 all historical records. Commencing this sketch with 



the northern extremity of the continent, where the 

 severity of an arctic climate will scarcely allow of a 

 wretched existence even to the hardy Esquimaux and 

 G reenlander, the rock strata are in many places in- 

 capable of being observed, except for a short period 

 during the year, while in others, they remain for ever 

 concealed by those immense accumulations of ice, 

 which, from their extent and perpetuity, seem almost 

 entitled to the consideration of geological formations.* 

 Notwithstanding the obstacles to geological research, 

 however, much information, with regard to the for- 

 mations of this remote region, has been collected 

 through the voyages and travels of captains Franklin 

 and Parry. The prevailing character of these coun- 

 tries is primitive, with occasional tracts of transition 

 and secondary. An extensive coal formation occu- 

 pies the banks of the Mackenzie river, where the beds 

 of lignite "are subject to spontaneous combustion 

 Bituminous coal, also, which some geologists have 

 conceived belonged only to temperate latitudes, is 

 found at Melville island and in Old Greenland. f A 

 larger section may next be considered, comprehend- 

 ing Labrador, the two Canadas, and an extensive 

 tract upon the northern side of the almost unbroken 

 chain of lakes running from lake Superior to the 

 Great Slave lake. Labrador, with its succession of 

 lofty and naked hills, many of which attain the eleva- 

 tion of several thousand feet, may be considered as 

 belonging almost exclusively to the earlier forma- 

 tions; while the country upon the north of the St 

 Lawrence, though abounding in this class, also con- 

 tains extensive transition and secondary deposits. The 

 remainder of the present tract, from the outlet of lake 

 Ontario to its distant western extremity, is remark- 

 able for a continuous chain of primitive rocks, whose 

 breadth, except in one place, where it was 240 miles, 

 lias not been determined. J In turning to view the 

 geological features of another extensive portion oi- 

 the American continent, our attention is arrested by 

 the Rocky mountains, the most elevated land upon 

 its surface, and which skirt its western coast from the 

 isthmus of Panama to the Arctic ocean, and are, no 

 doubt, a continuation of the Andes of the southern 

 hemisphere. Although but partially explored, their 

 primitive character is clearly established. Their 

 eastern sides are covered, to the height of 200 or 300 

 feet, with a sand-stone consisting of the ruins of the 

 granitic rocks upon which it reposes, whose disinteg 

 ration was apparently effected by the gradual agency 

 of an ancient ocean once occupying the immense 

 plane or basin now extending eastward from the base 

 of these mountains to the great chain of the Alle- 

 ghanies. This vast basin, whicli has for its bounda- 

 ries the Rocky mountains, the primitive chain bor- 

 dering upon the great lakes before alluded to, the 

 Alleghany mountains, and the gulf of Mexico, and 

 which includes twenty-five degrees of latitude, and 

 nearly double that number of degrees of longitude, 

 is one great secondary formation. It is free from any 

 considerable inequalities, though obviously not level ; 

 since its surface is drained by the three great streams, 

 the Mackenzie, the St Lawrence, and the Mississippi. 

 It abounds in all those peculiar aggregates which 

 belong to this formation, as well as in their ordinary 

 accompaniments coal, gypsum and salt, lead and 

 iron. Along its eastern base, so far as it has been 

 explored in the Missouri country, it contains the 



* A single deposit of this abundant substance in Greenland, 

 the Rheinwald glacier, is said to be four miles long, by two in 

 breadth, and from several hundred to one thousand fathoms in 

 height, consisting' of pure ire, precipitated from the neighbour- 

 ing mountains, and arranged in perpendicular columns, with a 

 cavern opening into its eastern side of great extent. Traveh 

 and Voyages of Captains Parry, Ross, Franklin, and fielzoni, 

 (London, 1826', p. 263). 



+ Captain Parry's Third Voyage. 



t Captain Franklin's Second Expedition. . 



