Santo Niño Group

Porphyry copper deposit in Benguet, Philippines

Names and other identifiers

Alternate names Santo Niño
Tract name Luzon Arc (Central Cordillera segment) (142pCu7301b)
Included sites Southwest, Ullman, Suluakan
Site status deposit

Geographic location

Country Philippines
State or province Benguet
Geographic location 120.655557829, 16.490279
Geologic map unit 120.655557829, 16.490279
Nearby data

Geologic information

Deposit type Porphyry copper
Age (Ma) 9.47Ma
Age determination method K-Ar whole rock
Age range 9.47 ±0.25 Ma
Age reference Imai (2002)
Minerals azurite/malachite, biotite, bornite, calcite, chalcopyrite, chalcocite, chlorite, epidote, gold, kaolinite, magnetite, molybdenite, muscovite/sericite, pyrite
Associated rocks andesite porphyry, breccia, dacite porphyry, conglomerate, andesite, diorite, diorite porphyry, quartz diorite, quartz gabbro, volcaniclastics
Tectonic setting island arc
Stratigraphic age Miocene

Commodity and development information

Development status Past Producer
Major commodities Cu, Mo, Au, Ag
Tonnage (Mt) 286Mt
Cu grade (%) 0.35%
Mo grade (%) 0.008%
Au grade (g/t) 0.2g/t
Ag grade (g/t) 1.7g/t
Contained copper 1,000,000t
Gold-Moly ratio 20

Reference information

Comments Mined by open-pit 1972–1981. Exposed.
Study area name East and Southeast Asia
References Apostol (1974); Bryner (1969); Divis (1983); Govett and Hale (1967); Imai (2001); Imai (2002); Imai and others (1992); MMAJ-JICA (1977); Motegi (1977); Philippines Mines and Geosciences Bureau (1986); Sillitoe (1997); Sillitoe and Gappe (1984); Singer and others (2008); Takenouchi (1980); Tarkian and Koopmann (1995)
Site reference Hammarstrom and others (2014)
Apostol, E.L., 1974, Porphyry copper deposits in Baguio district, Luzon, Philippines: Geological Society of the Philippines Journal, v. 28, no. 2, p. 32–43.
Bryner, Leonid, 1969, Ore deposits of the Philippines—An introduction to their geology: Economic Geology, v. 64, p. 644–666. (Also available at
Divis, A.F., 1983, The geology and geochemistry of Philippine porphyry copper deposits, in Hayes, D.E., ed. The tectonic and geologic evolution of Southeast Asia seas and islands—Part 2: Washington, D.C., American Geophysical Union, Geophysical Monograph 27, p. 173–216.
Govett, G.J.S., and Hale, W.E., 1967, Geochemical orientation and exploration near a disseminated copper deposit, Luzon, Philippines: Institutions of Mining and Metallurgy Transactions, Section B—Applied Earth Science, v. 76, p. B190–B191.
Imai, Akira, 2001, Generation and evolution of ore fluids for porphyry Cu-Au mineralization of the Santo Tomas II (Philex) deposit, Philippines: Resource Geology, v. 51, no. 2, p. 71–96. (Also available at, Akira, 2002, Metallogenesis of porphyry Cu deposits of the Western Luzon arc, Philippines—K-Ar ages, SO3 contents of microphenocrystic apatite and significance of intrusive rocks: Resource Geology, v. 52, no. 2, p. 147–161. (Also available at 10.1111/j.1751-3928.2002.tb00127.x.)
Imai, A., Muyco, J.D., Domingo, E.G., Almeda, R.L., Villones, R.I., Yumul, G.P., Jr., Damasco, F.V., Baluda, R.I., Malihan, T.D., Datuin, R.T., Punongbayan, R.S., Listanco, E.L., and Santos, R.A., 1992, Porphyry copper and gold mineralization in the Philippines, in Kojima, Satoru, and Hase, Hirokazu, eds., Mineral deposits of Japan and the Philippines: Nagoya, Japan, Society of Resource Geology, 29th IGC Field Trip Guide Book, v. 6, p. C36-1–C36-30.
MMAJ-JICA, 1977, Report on geological survey of northeastern Luzon, Phase III: Metal Mining Agency of Japan (MMAJ) and Japan International Cooperation Agency (JICA), Tokyo, 280 p.
Motegi, M., 1977, Porphyry copper deposits in Philippines—Their tectonic setting and present status of development: Mining Geology, v. 27, p. 221–230.
[Philippines] Mines and Geosciences Bureau, 1986, Geology and mineral resources of the Philippines, v. 2—Mineral resources: Manila, [Philippines] Mines and Geosciences Bureau, 446 p.
Sillitoe, R.H., 1997, Characteristics and controls of the largest porphyry copper-gold and epithermal gold deposits in the circum-Pacific region: Australian Journal of Earth Sciences, v. 44, p. 373–388. (Also available at
Sillitoe, R.H., and Gappe, I.M., Jr., 1984, Philippine porphyry copper deposits—Geologic setting and characteristics: Committee for Co-ordination of Joint Prospecting for Mineral Resources in Asian Offshore Areas (CCOP), CCOP Technical Publication 14, 89 p.
Singer, D.A., Berger, V.I., and Moring, B.C., 2008, Porphyry copper deposits of the world—Database and grade and tonnage models, 2008: U.S. Geological Survey Open-File Report 2008-1155, [45] p. and digital data, accessed December 31, 2013, at
Takenouchi, S., 1980, Preliminary studies on fluid inclusions of the Santo Tomas II (Philex) and Tapian (Marcopper) porphyry copper deposits in the Philippines: Mining Geology Special Issue, no. 8, p. 141–150.
Tarkian, M., and Koopmann, G., 1995, Platinum-group minerals in the Santo Tomas II (Philex) porphyry copper-gold deposit, Luzon Island, Philippines: Mineralium Deposita, v. 30, p. 39–47. (Also available at