206 ^'ic Philippine Journal of Science ms 



bridge." At this point a stream from the west joins the Chico 

 through a fine box canon in soHd andesite. The cross section 

 is about like that reproduced in the diagram (fig. 5). 



Above the box caiion the valley widens out, affording a very 

 considerable impounding area. This valley does not appear to 

 be particularly populous, so there ought not to be much diflficulty 

 in persuading the people to move to other sites. The dam would 

 be located within a few meters of the main road into Bontoc, and 

 Igorots could efficiently perform all the labor, as they are already 

 skilled in rock work. 



METALS 



Mountain Province, of course, has one, presumably, very valu- 

 able mineral asset in the well-known Mancayan copper deposits. 

 As these have long since received attention from geologists " 

 and engineers, there is no need of describing them here. 



Northward there are indications of copper, but these are 

 in the Cordillera Central and not eastward, where most of my 

 work was carried on. I neither saw nor heard of any copper 

 deposits in the Polis Range. 



Gold. — Eastward from Bontoc, at a point about 4 kilometers 

 distant, granite is encountered, and this continues for several 

 kilometers. As already outlined, this formation extends north- 

 ward at least as far as Balbalasan. On the western side of 

 this, toward Talubin, I came across several large quartz lodes, 

 outcrop samples of which were assayed, but gave only "traces" 

 of gold. However, as these were only "grass root" samples, 

 it is not conclusive that values are not to be found in the lodes 

 farther from the surface. One of these lodes is about 30 meters 

 wide, striking about north and south, and is nearly vertical. I 

 merely mention these as possibilities for the prospector to look 

 into. The Igorots have never, as far as I could learn, found 

 any free gold in the Bontoc region. It is my opinion, on the 

 other hand, that a granite intrusion like this one will ultimately 

 be found to have caused the deposition of some minerals of 

 value near it. I should not omit to mention that there is more 

 or less iron-stained quartz in Fidelisan Valley near the Sagada 

 Mission sawmill, which has attracted more or less attention from 

 prospectors. Samples taken by me from the face of the ledge 

 gave only a "trace." It is said that the gravel in the ancient 

 banks of this stream about 60 meters above the gorge carries 



='Eveland, A. J., This Journal, Sec. A (1907), 2, 207. 



