JAVA 105 



3. Geology and Physical Features. 



The southern coast-line of Java forms part of the lip 

 of the vast basin of the Indian Ocean, and within a short 

 distance of the shore the gi^eat ocean depths are reached. 

 To the north and west a shallow sea dotted with many 

 small islets separates it from Sumatra, Banka, and Blitong, 

 while eastward a prolongation of Madura may be traced 

 to Kangeang and the Paternosters, and Bali is separated 

 by a strait barely a mile and a half wide, and having a 

 depth of only nine fathoms. 



It was formerly believed that Java was almost exclu- 

 sively volcanic, but it is now known that this is far from 

 being the case, the volcanoes resting upon sedimentary 

 rocks of which the greater part appear to be of the 

 Tertiary period, although it has been lately shown that 

 certain fossiliferous strata must be ascribed to the 

 Quaternary period. Granite occurs at the western end 

 of Java, but the plutonic rocks are not common, as in the 

 neighbouring island of Sumatra. With these geological 

 conditions it is not to be wondered at that few minerals 

 are to be found. Coal, indeed, is plentiful, but it is poor, 

 occurs in thin strata, and hardly repays working. Sul- 

 phur is abundant, and a further exploitation of the mineral 

 oils should give good results. 



The great mountains of Java are all volcanic cones. 

 Two of them, Karang and Muria, are isolated from the 

 others, which are situated for the most part near the 

 central line of the island. In the west these volcanoes 

 are grouped together in a mass, and spring from high 

 ground. In the east they are more discrete, and the 

 ground upon which they rest is lower and more open. 

 There are not less than fifty volcanic peaks in the island. 



