98 



EARTH FEATURES AND THEIR MEANING 



The earth's volcano belts. The distribution of volcanoes is 

 not uniform, but, on the contrary, volcanic vents appear in definite 

 zones or belts, either upon the margins of the continents or included 

 within the oceanic areas (Fig. 89). The most important of these 



FIG. 89. Map showing the location of the belts of active volcanoes. 



belts girdles the Pacific Ocean, and is represented either by chains 

 or by more widely spaced volcanic mountains throughout the 

 Cordilleran Mountain system of South and Central America and 

 Mexico, by the volcanoes of the Coast and Cascade ranges of North 

 America, the festooned volcanic chain of the Aleutian Islands, and 

 the similar island arcs off the eastern coast of the Eurasian con- 

 tinent. The belt is further continued through the islands of 

 Malaysia to New Zealand, and on the Pacific's southern margin 

 are found the volcanoes of Victoria Land, King Edward Land, 

 and West Antarctica. 



This volcano girdle is by no means a perfect one, for in addi- 

 tion to the principal festoons of the western border there are many 



FIG. 90. A portion of the "fire girdle" of the Pacific, showing the relation'of the 

 chains of volcanic mountains to the deeps of the neighboring ocean floor. 



