SUBMARINE MOUNTAINS 95 



material and thermal content, the mountain chain along the 

 negative strip will in all probability never rival even the Swiss 

 Alps in height. 



West Indian Chain. — The number of gravity stations in the 

 West Indies is comparatively small, but there can be little doubt 

 as to the general continuity of the negative strip in the region. 

 The broken line of Figure 47 represents the trend of its axis. 

 With average width of about 100 miles, the belt is strongly 

 curved, and here also with convexity toward the ocean. Few 

 islands are found within the limits of the strip, and therefore 

 evidence of violent disturbance of the rocks in the belt is 

 meager. However, strong deformation is clear in Trinidad, 

 Barbados, and Cuba, and, as in the East Indies, is of Tertiary 

 age. Just as Timor, Roti, and other islands of the Asiatic strip 

 show upheaval after the crushing of their rocks, so Barbados 

 and Cuba at least have recently been uplifted hundreds of feet. 

 And one more similarity: both strips are located in archipela- 

 goes elsewhere unrivalled. 



In view of so many like features, Professor Hess was already 

 prepared to accept the conclusion of Vening Meinesz that both 

 had the same type of origin, and added another argument. 5 

 At intervals along the course of a mountain chain geologists 

 often find large bodies of rock which, in the molten state, was 

 thrust into the mountain roots during, or soon after, the time 

 of greatest crushing. These huge melts have crystallized into 

 rock typified by the species called peridotite. (See page 58.) 

 Such masses, now cool and crystallized, are particularly abun- 

 dant along the arcuate, dry-land ranges of the western Pacific. 

 Now, after study of the Asiatic and American strips, Professor 

 Hess has been able to show that similar large bodies of these 

 otherwise rare rocks appear in the islands along each strip. 

 This generalization leads to one more suggestion of essential 

 identity between strip and mountain chain of the dry land. 



