244 The Philippine Journal of Science me 



and is very highly Impregnated with iron sulphides. The sur- 

 face exposed to the air decomposes very rapidly and allows 

 of excessive erosion. 



The upper rock has been very heavily silicified in altering, and 

 masses of a quartzose material are common. It shows a great 

 network of little veinlets or stringers of quartz which are the 

 results of a secondary infiltration into cracks and crevices, sug- 

 gesting dehydration of a large mass rather than dynamic causes. 

 These little veinlets of stringers are usually an indication of 

 gold values. 



Wherever the veins are wider, they present a banded structure 

 of quartz and a bluish white kaolin known by the natives as 

 "pitoc." A fibrous variety of gypsum, white in color and with 

 a shiny luster, and fibers that are usually curved and transverse 

 to the veins alternate at times with the kaolin. It is an indica- 

 tion of rich gold values and is very closely observed by the Igorots. 

 Several kilograms of gold are said to have been removed from 

 a single pocket in the gypsum. 



Exposed in the slide are several rather prominent veins, which 

 have been worked for gold by the Igorots. The most prominent 

 of these, the Palidan and Cadangan veins, have produced the 

 greatest amount of gold within the past few seasons. The gold 

 occurs free in the ore in rather fine particles. The ore is very 

 similar in color to the iron sulphide and is distinguished with 

 difficulty by any one not well acquainted with it. The natives 

 who have been handling the ore since childhood recognize the 

 free gold at a glance, the rapidity with which they judge a 

 piece of ore being almost unbelievable. 



The mining season at Palidan lasts from one to six months, 

 and from 40,000 to 80,000 pesos' worth of gold is recovered 

 from the ground in that time. The miners start work imme- 

 diately after one rainy season and continue until the next, when 

 the ground becomes subject to slides and consequently dangerous. 

 About two hundred men, women, and children are actively em- 

 ployed in the work. Of these, the majority are women, the rest 

 are children, and a small number are men. 



The method of working is that used in other countries 

 known as "booming." In the smaller veins and in the begin- 

 ning of the Palidan slide, dams have been built across gullies 

 to form reservoirs, which are allowed to fill either with 

 rain water or water from a small creek. As soon as the reser- 

 voir is full, the gate is opened and the flood of water is allowed 

 to tear away the overburden from the vein. Between washings 



