BERKEY, GEOLOGICAL RECONNOISSANCE OF PORTO RICO 55 



the same locality, but such evidences are very obscure and would seem at 

 best to have very little bearing on. present prospects. 



Copper 



Some very good specimens of copper ores were seen in the possession of 

 Mr. Henry D. Sayre, of Corozal, who assured us that there were several 

 localities represented in the collection and that in no case had the real 

 value of the occurrence been determined. It was understood that exami- 

 nations have been made by engineers sent to Porto Rico in the interest of 

 American mining companies, and that some exploratory work has been 

 carried on by Porto Rican companies or groups of individuals, but so far 

 as known there is at the present time no development work being con- 

 ducted, and the possible value of these deposits has not been thoroughly 

 proven. 



Zinc, Lead and Silver 



One prospect, on which several himdred feet of underground work has 

 been done, was visited at Barrio del Carme in the Sierra de Cayey, on 

 land owned by Pablo Vasques, several miles northwest of Guayama. The 

 country rock is chiefly andesitic tuffs cut by porphyritic intrusives. A 

 quartz vein carrying sulphides, pyrites, sphalerite, galenite and chalcopy- 

 rite has been followed and there is some ore on the dump. The vein 

 vanes from a mere streak to a width of two feet. The mineralization is 

 irregular and the values are said to be chieflv in lead and silver. The 

 second-class ore is essentially mineralized tuff. The exploratory work 

 has been done in large part on side slips and streaks quite outside of the 

 vein proper. In all of this side work, there was apparently no new min- 

 eral-bearing ground discovered. The first-grade ore is heavy and the dis- 

 tribution of values is not determined. There is no doubt of the existence 

 of a real vein or of the ore in this case, but there is need of more intelli- 

 gent exploratory development along the vein proper, together with a 

 study of the possibilities of separating the chief values by some sort of 

 milling operation, before a reliable conclusion could be reached as to pos- 

 sibility of working the deposit as a mine. 



Iron 



One magnetic iron prospect was visited. This occurrence is on the 

 divide about ten kilometers west of Naguabo. It is reached by driving 

 out on the road from Naguabo toward Torres to about this distance and 

 then takino- saddle horses to the divide, a distance of about two kilometers 

 southward. On the expedition we were accompanied by Mr. Arturo 

 Gallardo. Jr., Alcalde Mmiicipal of Naguabo. 



