﻿COMPOSTBLA-DANAO COAL FIELD. 389 



Although the region is .maturely dissected, it may be seen that the 

 majority of the hilltops come up to a common plane which does not 

 signify a peneplain, but simply the surface of the great lava flow which 

 just antedated the deposition of the Miocene limestone. 



This section is very rugged and at first sight quite forbidding. The 

 larger part of the people live in barrios and reconcentration camps on 

 narrow ridges. These camps were established in 1903 and 1904 by the 

 Constabulary to protect the people from some bands of "pulajanes" 

 infesting the country at that time. Although at first sight the country 

 would appear to be barren and unproductive, the wash from its decaying 

 limestone and the disintegrated andesite produce a fairly rich soil. I have 

 seen some very good corn in this section. Plate I is a view of the 

 Cot-Cot country which very well shows the general appearance of this 

 dissected Tertiary lava field. 



The most widespread formation is a porphyritic rock which will be 

 described at greater length further on. In many hand specimens it is 

 clearly an andesite, with feldspar and pyroxene phenecrysts in a fine 

 groundmass; in others, all which can be seen are white feldspars (usually 

 kaolinized) in a fine-grained, green groundmass. 



A series of shales, sandstones and graywaekes are found to be exposed 

 where the streams have cut down through this lava capping, where the 

 talus is not too thick, dipping sometimes at high angles and with 

 constantly changing strikes. It would be highly advantageous to be 

 able to map these, giving their underground courses, but the outcrops are 

 not sufficiently numerous or contiguous to do this with any assurance 

 of safety. 



There has been some mineralization in the vicinity of Acsubing Moun- 

 tain, as galena is found in veins in the andesite. We have been able 

 to see these veins only in two localities, but these limited observations led 

 us to believe that the deposits are in the form of a "stock work." 



I have been unable to find any coal in this series, nor have I 

 encountered any fossils, but I have no reason to doubt that the series 

 belongs to the coal measures. A portion of it may be terrestrial in 

 origin, as seems to be the case with the formations to the north of the 

 Cot-Cot and the east of Mount Licos. 



THE MOUNT LICOS REGION. 



This includes both the old Compostela and the Camansi workings and 

 was the principal field in Spanish days. This portion of the district is 

 quite different from the preceding, in that the igneous extrusives are 

 lacking over most of the territory. As the western -part of the field abuts 

 on the igneous basement complex, in our mapjfing we have kept well to 

 the east. By referring to the map, a belt which widens and narrows 

 (represented by the bine color) may be seen; in general it runs in a 

 northeast-southwest direction. This is the productive portion of the coal 



