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 great 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, 
