X, A, 5 Pratt: Reconnaissance in Caramoan Peninsula 319 



noy is used by the Filipinos to manufacture whetstones for 

 sharpening bolos. The stone appears to serve this purpose 

 very well, but the demand for whetstones is not great enough 

 to make the manufacture steady or profitable. 



At several places along the southern coast, between Sabang 

 and Parubcan, there are extensive beaches of perfectly rounded 

 gravel of sizes suitable for use without reduction in road build- 

 ing. The pebbles are of hard metamorphic rocks, and while 

 they tend to assume flat rather than spherical forms, they should 

 make a superior road metal. 



ARTESIAN WATER 



Only a few wells have been drilled on Caramoan Peninsula, 

 but the drilling campaign which the Bureau of Public Works 

 is carrying on will ultimately extend to this region, and the 

 possibilities of obtaining artesian water should be considered. 



The metamorphic and igneous rocks on Caramoan Peninsula 

 will probably be found to be comparatively dry. If no water 

 is obtained from the first or second test-well in these formations, 

 no more wells should be drilled into them. The tertiary sedi- 

 mentaries have been shown by experience elsewhere to be usually 

 barren of artesian water. Therefore they will probably also be 

 dry in Caramoan Peninsula. The volcanic tuffs and flows on 

 the north coast may possibly yield artesian water, but they 

 off"er little promise; in general, they are too close-grained to 

 yield strong flows. 



There remain the alluvial deposits and the Isarog tuffs and 

 agglomerates. Both these formations are undoubtedly water- 

 bearing and with proper care should be made to yield potable 

 water from comparatively shallow wells. The Isarog formation 

 may contain mineralized water at places and may require deeper 

 wells than the alluvium. The alluvium on which Caramoan lies 

 should receive attention when wells are drilled for that town. 

 It should be saturated above the sedimentary floor on which it 

 rests, and a series of shallow wells should meet the requirements 

 of this town. If they do not, there is little hope of obtaining 

 water, because the underlying sedimentaries are almost certainly 

 not water-bearing. Likewise the areas of alluvium overlying 

 the metamorphic rocks should be tested in advance of the meta- 

 morphics themselves. 



The prospects for artesian water are fairly good, then, at the 

 towns of Caramoan, San Jose, Sabang, Lagonoy, Goa, and Ti- 

 nambac ; but elsewhere, except within alluvial areas or the Isarog 

 Volcanic formation, artesian water will probably not be obtained. 



