DEVELOPMENT AND ARRANGEMENT OF MOUNTAINS 523 



the question of the apparent evidence of glaciation. This he did, with 

 the result that he now believes that torrential wash in volcanic regions 

 explains all the phenomena very satisfactoriW. Even striae were found 

 on the rocks, hut many of these "evidences" now are looked on with sus- 

 picion. The writer would here make a suggestion to all workers who 

 think they see signs of glaciation in tropical regions, since evidences of 

 glaciation have been coming forth rather rapidly of late from some 

 slightly suspected corners of the earth: most of these undoubtedly are 

 genuine, but some of the cases might be explained more simply. 



Along the east coast is a range of mountains of which we know practi- 

 cally nothing. In places this range attains an elevation of 6,000 feet, 

 but in the main it is much lower than the one first considered. It also is 

 known to be largely volcanic in origin, having an active vent, Mount 

 Cawa, near its northern extremity. This is a very sparsely inhabited 

 part of Luzon. 



Just northeast of the central plain these two ranges coalesce to form 

 what Adams^ has called the "Central Knot." This constitutes the high- 

 land country of N'ueva Viscaya. 



On the west, in northern Luzon, we find the Coast Eange, known locally 

 as the Malaya Eange, which is narrow, but in places runs up to 6,000 feet 

 or more. This also is andesitic, with some sediments found high up at 

 various points. 



In southwestern Luzon there is the Zambales Eange, which consists of 

 a line of more or less isolated old volcanic stocks in various degrees of 

 denudation. The highest points in this line are Mount Pinatuba, about 

 6,000 feet, and the magnificent cluster of peaks known as Mount Mari- 

 veles, about 6,500 feet, at the entrance to Manila Bay. 



In southeastern Luzon there is the altogether different type of moun- 

 tain, a cluster of more or less recent dormant volcanoes, the commanding 

 figure of which is Mount Mayon, a very perfect cone about 8,000 feet, 

 near which is the city of Legaspi. 



. In the Visayan Islands we usually find only one cordillera to each of 

 the small islands of which it forms the backbone. In Panay there are 

 peaks in the cordillera over 7,000 feet, while in Cebu 3,000 feet is about 

 the limit. The Negros cordillera is not so well defined, but has one domi- 

 nating peak about 8,000 feet in elevation — the active volcano of Canlaon. 

 Not much is known about the mountains of Leyte and Samar beyond the 

 fact that there are some moderately high peaks of volcanic origin. 



When we come to Mindanao we note an interrupted volcanic chain 



* G. I. Adams : Geological reconnaissance of southwestern Luzon. Philippine Journal 

 of Science, vol. v, pp. 2, 31. 



