332 SMITH. 



Altogether, there are only nine stamps dropping at the present time, 

 two mills having been badly crippled in the fall of 1909. However, two 

 new mills are about to begin operations. 



In the mining district of Masbate the country rock is largely andesite, 

 in old, worn-down volcanic stocks. The andesite is cut by a system of 

 northwest and southeast quartz veins, one of which is over-^meters wide. 

 The ore is oxidized to a much greater extent than is the case in Benguet, 

 but is only partially free-milling. This ore also contains large amounts 

 of manganese oxide. There are four principal companies in this district, 

 but not one in the producing stage at the present time. Some dredging 

 was attempted in this district, but for various causes it was unsuccessful. 



Other promising regions are near Cabua and in Nueva Ecija, Luzon; 

 the Cagayan-Muniqui-Pigtao district, Mindanao ; the Surigao Peninsula, 

 Mindanao; the Island of Catanduanes; Pangasinan Province, Luzon; 

 and Mindoro Island. 



The gold mined in 1909 amounted to 495,194 pesos. 



Silver. — Some silver is found in all the gold districts, usually alloyed 

 with gold. Native silver has been encountered in Benguet in small 

 quantities. Practically all the lead is argentiferous. The production in 



1908 was 2,750 pesos (1,375 dollars United States currency). That for 



1909 was not estimated separately. 



Copper. — Copper has been found in the form of arsenates and sulphides 

 in the Mancayan-Suyoc district of the Mountain Province, Luzon, as 

 native copper in Masbate, the Camarines, and the Island of Jolo. The 

 best known deposit is that in the Mancayan-Suyoc district. Eveland 20 

 writes the following concerning this deposit: 



In view of the fact that the entire region, with the exception of the one ore 

 body of the Mancayan mine, is in an early stage of development, it is impracticable 

 to treat the ore deposits in detail. It seems to be fairly conclusive, however, that 

 the general type of vein in the district is a narrow quartz lead, carrying metallic 

 sulphides, in some cases of copper, and generally with gold associated in a free 

 state. These veins are in the Mancayan diorite which underlies the entire 

 district. With the advent of the "trachyte" flow, metamorphic changes have 

 taken place and the nature of the country rock is altered to a considerable degree. 



Eecent development work has shown this deposit to be rather in the 

 nature of a stockwork, and it appears to me to be more extensive than 

 was thought to be the case. 



Lead and zinc- — Lead and zinc are associated in some of the Cama- 

 rines deposits. Argentiferous lead occurs in many localities, principally 

 in Cebu and the Island of Marinduque. In Cebu it is of the nature of 

 a stockwork in an andesite flow. 



Iron. — Iron ore in the form of hematite, magnetite, and limonite, 



20 Bull, P. I., Min. Bur. (1905), No. 4, 53. 



