690 GEOLOGY 



scenery. In these regions the dolomite (limestone) stands up in 

 bare, bold-faced walls, peaks, and towers, surrounded and sepa- 

 rated by valleys and passes clothed with abundant vegetation. 

 The decay of the projecting limestone leaves little soil behind, and 

 the little which is formed is promptly carried away by wind and 

 rain. 



The Trias of the Italian Alps is the source of the Carrara marble. 

 The Trias of the western Alps is largely non-marine, and in some 

 parts of Switzerland the Upper Trias contains coal and igneous rocks. 



Other Continents 



Asia. The marine phase of the system, similar to that of 

 southern Europe, is continued eastward to southern Asia. It is 

 also found in the high latitudes of Asia, including numerous islands 

 north of the mainland. The Trias is generally conformable on the 

 Permian and beneath the Jurassic. 



South America. No marine deposits of Triassic age are known 

 east of the Andes, but coal-bearing Trias occurs in Argentina and 

 Chile, and marine beds at various points in the Andes. Thus it 

 is clear that the site of parts of this great system of mountains was 

 beneath the sea in the Triassic period. 



The Triassic system is represented also in South Africa, Aus- 

 tralia, New Zealand, and New Caledonia. 



THE LIFE OF THE TRIASSIC PERIOD 



The remarkable physical conditions that dominated the land 

 and impoverished its life in the Permian period still held sway during 

 the earlier part of the Triassic. In their general biological aspects, 

 as in their physical conditions, the two periods were much alike. 

 Toward the close of the Triassic there was a pronounced change. 

 The land became lower and the sea encroached upon it, bri Hiring 

 about appropriate changes in life. Nearly all that is known of 

 North American Triassic life belongs to the later portion of the 

 period. 



