RECONNAISSANCE OF SOUTHEASTERN LUZON. 477 



between Bulan and Magallanes show the character of tlie deposit and 

 exhibit some bedding. Inland, the plain is aggraded by detrital ma- 

 terials. Bulusan Volcano M'as nndonbtedly tlie soiirce of nuich of the 

 tuff and pnmice. 



MINERAL RKSOURCES. 



No new mining localities liave been discovered in southeastern Luzon 

 during recent year.s, but since American occupation considerable de- 

 velopment work has been done and prospecting has been carried on at 

 nearly every place concerning which there M'ere either records or tradi- 

 tions of economic deposits. 



The history of gold mining in tiie L'aracaie-Mambulao district covers 

 a long period and contains much of the glamour that usually is found 

 in the accounts of the wealth of old Spanish mines. Most of the recent 

 locations on lodes include old workings. Similarly, the jSTalasvetan local- 

 ity and Catanduanes Island have been investigated and prospected as 

 a result of information oljtained from the inhabitants. However, tbe 

 jjlacer locations are not confined to the ground where gold was formerly 

 n'ashed by the natives, since present dredging methods make it ])ossible 

 to obtain values from areas which could not be worked by them. 



The present mining enterprises are the result of new energy and 

 larger capital, and the future development is dependent upon the intro- 

 duction of further capital. The natives worked only the free gold. 

 Future mining jnust take into consideration the sulphide ores. 



The history of coal mining compiled by Burritt mentions practically 

 all of the localities where coal deposits are known to-day. The presence 

 of oil-seeps was known by the inhabitants of Tayabas Peninsula and 

 they collected small quantities to burn for lights, but prospecting by 

 means of drills was never attempted by them. 



The geologic relations of the economic deposits have been discussed in 

 a former chapter. The following is a brief resume of the condition 

 of development of the resources. 



Gold. — According to the statistics published by the division of mines, 

 Bureau of Science, the gold production in 1907 was 100 ounces, in 

 1908 it was 3,470 ounces, and in 1909, 7,333 ounces. Practically all 

 of the production for 1907 was obtained by panning, but during the last 

 two years the increase has been from the dredges. 



Silver. — No mining is carried on for silver, but some is obtained al- 

 loyed with the gold which is produced, and the lead ores in some of the 

 veins of the Paracale-Mambulao district are silver bearing. 



Copper. — Native copper (tumbaga) is found in the placer deposit at 

 Calbornay. It has been described by Rinne. but his wi-itings arc not 



106090 4 



