102 The Philippine Journal of Science ma 



to be 27,000,000 cubic meters, 11 carrying about 50 centavos per 

 cubic meter (20 cents United States currency per cubic yard) . 



Pangasinan placer. — The Agno and Tuboy Rivers that drain 

 the Baguio and Lubang districts are very swift and carry the 

 gold for great distances before it is deposited. The result has 

 been the formation of an area of about 100 square kilometers 

 of gold-bearing gravel in Pangasinan where the country changes 

 abruptly from a precipitous mountain region to a large rolling 

 plain. The rivers upon entering this plain have taken mean- 

 dering courses, frequently changing their channels, and thus 

 depositing the gold over a large fan-like area. They also very 

 frequently overflow their banks, filling in large areas with flood 

 gold. The gold deposited is fine and frequently in the form of 

 rounded flakes. Coarser gold is found in the mountainous por- 

 tion, where smaller streams flow into the Agno and Tuboy 

 Rivers. Many such placers are worked by native miners. The 

 gravel in Pangasinan is very deep except near the mountains, 

 and contains many bowlders of all sizes wherever the river 

 channel has been. This feature has made the testing of the 

 ground a very difficult operation. 



Nueva Ecija. — Gold from the Eastern Cordillera of Luzon has 

 been distributed irregularly over a larger area than any other 

 section of the Islands, forming hundreds of square kilometers 

 of placer in Nueva Ecija, Bulacan, Rizal, and Tayabas. The 

 most interesting feature is the occurrence of platinum in this 

 placer. Some flat pieces have been found a centimeter in dia- 

 meter. Grains weighing a milligram are of common occurrence. 

 The two largest unbroken areas are found in Nueva Ecija, 

 extending eastward from the line between Cabanatuan and 

 Gapan and in Tayabas surrounding Dingalan Bay. The placer 

 in Bulacan and Rizal is found principally along stream beds. 



Ambos Camarines. — There are four sections in this district 

 where placer gold is found: 1, Mambulao; 2, Gumaus; 3, Para- 

 cale River; and 4, Maliguit. 



The Mambulao placer has not been thoroughly tested. Gold 

 is found in the gravel surrounding the bay. It is derived from 

 several large quartz veins in the San Mauricio and Robinson 

 groups, and from stringers in the schist and gneiss. 



The Gumaus placer is very different in character from the 

 other deposits in the district. The gold is found in rounded 

 grains of a clear yellow color. Very few crystals or flakes are 

 found. A large number of rich stringers, many of which con- 



" Appendix, Report of the Philippine Commission (1908), 317. 



