CONTINENT 



— DEEP SEA BASIN 

 VOLCANIC ISLANDS 



CONTINENTAL 

 SHELF 



<^fiO$T ^<^^^ 



FIGURE 1. Cross Section of the Earth— 5/iou;ing its concentric 

 shells. The vertical scale of the continental granite is greatly 

 exaggerated; at its greatest depth, this granite does not exceed 

 fifty miles in thickness. 



