318 The Philippine Journal of Science 1915 



the bottom of some pool. Solfatarism is common on Isarog, and 

 the presence of mercury in the vicinities of some of the solfa- 

 taras is not impossible. 



COAL 



There is an outcrop of coal in the sedimentary rocks along 

 Caramoan River about 2 kilometers upstream from the Guijalo- 

 Caramoan road. The outcrop has been known for at least 

 seventy years. The bed is about 50 centimeters thick, and the 

 coal is a dirty black lignite. The strike is nearly north, and 

 the dip is westward at a high angle. Isidro Sainz de Baranda, 

 the first inspector of mines under the Spanish regime, and a 

 capable man, believed the coal from this outcrop to be of good 

 quality. No tests have been made of it, but its appearance is 

 not promising, and the outcrop indicates too thin a bed to be 

 commercially important. Several concessions for this coal were 

 sought in Spanish times, and in 1898 a concession was finally 

 granted, but title was never perfected under the American laws. 

 The vicinity of Guijalo was formerly known as Puerto de Minas in 

 anticipation of its importance as a shipping point for this coal. 



I was informed that coal had been found in the hills near the 

 barrio of Parubcan and was shown a specimen of good coal 

 which was alleged to represent the outcrop. I was unable to 

 find the coal in place, however, even with the assistance of 

 several guides. If the beds of schist at Parubcan inclose coal, 

 it should be a coal of good quality because of the metamorphism 

 it must have undergone. 



CLAY 



The light-colored talc-schists in the vicinity of Lagonoy are 

 used as paint clay in the neighboring towns. The paint is 

 grayish white and adheres tenaciously to wood. A good white 

 clay is obtained at a place called Sulpa on Looc River, between 

 Tinambac and Siruma, in the northeastern part of the peninsula. 

 This clay appears to result from the decomposition of quartz- 

 feldspar rocks which occur as dikes in the schistose andesite. 

 The clay is plastic, although in the crude state it contains frag- 

 ments of quartz, and should make a fair grade of pottery or 

 refractory ware. 



STONE AND GRAVEL 



Possibly some of the marbles and limestone on Caramoan Pen- 

 insula could be exploited for construction purposes. The marble 

 in the vicinity of Sabang is most conveniently located, and if 

 there were a demand for it, could be quarried advantageously. 



A heavy, dense, dark-colored schist from northwest of Lago- 



