316 ^^^6 Philippine Journal of Science 1915 



and sugar planting are remunerative in the vicinity of Mount 

 Isarog. 



The alluvial and littoral deposits support the larger part of 

 the population. These formations and the Isarog tuff and 

 agglomerate yield rich soils and lend themselves to agricultural 

 development. The volcanics on the north coast, on the contrary, 

 appear to support little vegetation. No attempt has been made 

 to cultivate this part of the peninsula, but in place of the heavy 

 forests which abound in some other parts of the area the natural 

 vegetation on the tuffs and flows consists principally of hardy 

 cogon grass. There is no evidence that this region ever was 

 forested. The sedimentary rocks are also comparatively barren 

 of vegetation. However, the original forest has been cut away 

 over the sedimentaries, permitting the cogon grass to replace it. 

 Except for the crystalline limestone this formation should 

 disintegrate rapidly enough and form a fairly good soil. The 

 metamorphic rocks appear to yield good soils in spite of their 

 induration; at any rate, they support a splendid forest growth. 

 The Caramoan forest concession, which is considered to be par- 

 ticularly valuable, covers principally metamorphic rocks and 

 the Isarog tuff-agglomerate formation. The unaltered igneous 

 rocks, again, are comparatively barren ; cogon grass and a small 

 evergreen tree, said to be a variety of "iron wood," mark the 

 igneous exposures. 



GOLD 



The quartz lenses in the schists carry a trace of gold ; so, also, 

 do the pyrite lenses. But there is no evidence of valuable gold 

 deposits on Caramoan Peninsula. Becker ^- was led to the 

 conclusion that "in all cases in the Philippines of which the 

 details are known, crystalline schists accompany gold-quartz 

 veins, copper ores, iron ores, and galena." If this condition 

 really existed, it might be assumed, conversely, that an area of 

 crystalline schists would be likely territory for the gold pros- 

 pector, but the case of Caramoan Peninsula does not bear out 

 this conclusion. As a matter of fact, subsequent work has shown 

 that some of the more important gold deposits in the Philippines 

 are not related to the crystalline schists. Moreover Becker 

 believed most of the Philippine crystalline schists to be of com- 

 paratively great age and had in mind such older crystalline 

 schists. Therefore the Caramoan schists, being geologically 

 young rocks, would not be expected by Becker to contain gold. 



'"Becker, George F., 21st Annual Rept. U. S. Geol. Surv. (1901), 237, 

 reprint. 



