RECONNAISSANCE OF MINDANAO AND SULU : III. 379 



methods. Since his yisit to this country an American miner has brought 

 some rich ore to Manila which he states comes from a fairly wide lode 

 which could be worked by the ordinary mining methods. The natives 

 probably have worked here for centuries. In speaking of the native 

 methods of mining, Goodman says that in four days of mining and one 

 day spent in cleaning up the sluice, a native miner, assisted by his wife 

 and two male helpers, washed approximately 7.5 cubic meters of gravel, 

 cleaning up therefrom 260 grams of gold for which they received 15.60 

 pesos (7.80 dollars, United States currency), equivalent to about 3.08 

 pesos per cubic meter. This is extremely rich ground. I have marked 

 the principal localities where gold has been found on the map accom- 

 panying this paper and have added Goodman's report as an appendix, 

 to my own.^ 



A letter from Eeverend Francisco de P. Sanchez to the Eector of 

 the Ateneo S. J., in Manila, dated May 16, 1887, gives some geological 

 notes on Surigao, but as later writers have covered the territory more 

 fully, I shall merely cite the reference.^" 



THE CAGATAN DISTRICT. 



There now remains to be considered the district of Cagayan. This 

 is an irregular defined area, bounded on the west by Iligan Bay, on 

 the north by Makahalar and Hingoog Bays and on the south by the up- 

 land country of the Cotabato district. A stretch of unknown country 

 extends to the east of this district through which Ickis had traveled and 

 concerning which he made notes just before his death. The district is 

 marked physiographically by a very limited coastal plain, a rough but not 

 very elevated interior, and a number of rivers, the Cagayan, Iponan, and 

 Tagoloan, which head on the divide close to the Pulangui Eiver. The 

 country rock consists largely of sedimentaries and a schist formation 

 partially overlain by andesite. I shall refer tlie reader to my transla- 

 tion of Abella's report of 1877 for a detailed account of this district.^^ 

 This report deals with the liigh- and low-level placers of the Iponan, 

 Cagayan, and Tagoloan Elvers. According to Abella, the country rock 

 is largely a chlorite in which small stringers of quartz-bearing gold occur. 

 These stringers are too small to be worked per se, but the concentrates 

 which have been deposited along the rivers already named can be worked. 

 The natives have worked these placer deposits probably for ages and have 

 become so skillful that they are able to tell at just what depth they will 

 get values. The work is fairly crude, and, briefly, is as follows: 



A pit is dug until the formation termed dugcalon is reached. This consists 

 of a yellow clay containing pebbles of quartz and erupted rock, some of great 



' In the last year there has been renewed activity in gold mining near Surigao 

 and exceptionally fine samples of placer gold have been obtained. 

 ^"Cartas de los PP. de CompaHIa de Jesus, Manila, (1887), 251. 

 "Mill. Resources P. I. Bur. Set., Div. Min. (1910), 62-71. 



