Piedras Verdes

Porphyry copper deposit in Sonora, Mexico

Names and other identifiers

Tract name Western Mexican Basin and Range and Laramide Southwest (003pCu3006x)
Site status deposit

Geographic location

Country Mexico
State or province Sonora
Geographic location -109.012326059, 27.162810118
Geologic map unit -109.012326059, 27.162810118
Nearby data

Geologic information

Deposit type Porphyry copper
Age (Ma) 60Ma
Age determination method Re-Os
Age range ~60 Ma
Age reference Singer and others (2008)
Minerals actinolite, azurite/malachite, biotite, chalcocite, chalcopyrite, chlorite, chrysocolla, copper, cuprite, epidote, goethite/limonite, hematite/specularite, jarosite, molybdenite, muscovite/sericite, neotocite, pyrite, tourmaline
Associated rocks mafic volcanic tuff
Tectonic setting continental margin
Stratigraphic age Paleocene

Commodity and development information

Development status Past Producer
Tonnage (Mt) 288Mt
Cu grade (%) 0.37%
Contained copper 1,100,000t
Gold-Moly ratio -9999

Reference information

Comments Total reserves and resources; location at center of 2008 pit outline as reported by Swendseid and others (2008). Exposed. Elongate deposit (4 km long by 500 m wide). Mineralization in Triassic-Jurassic metasediments and various intrusive phases of a Laramide granodiorite porphyry. Alteration: argillic-propylitic.
Study area name Mexico
References Barton and others (1995); Minjárez-Sosa and others (2002); Singer and others (2008); Swendseid and other (2008); Dreier and Braun (1995); Sillitoe (1976)
Site reference Hammarstrom and others (2010)
Barton, M.D., Staude, J.-M.G., Zürcher, L., and Megaw, P.K.M., 1995, Porphyry copper and other intrusion-related mineralization in Mexico, in Pierce, F.W., and Bolm, J.G., eds., Porphyry copper deposits of the American Cordillera: Tucson, Arizona Geological Society Digest, v.20, p.487–524.
Dreier, J.E. and Braun, Eric, 1995, Piedras Verdes, Sonora, Mexico—A structurally controlled porphyry copper deposit: Arizona Geological Survey Digest, v. 20, p. 535–543.
Minjárez-Sosa, Ismael, Montño-Jiménez, T.R., Ochoa-Granillo, José, Grijalva-Noriega, F.J., Ochoa-Landín, L.H., Urbina-Herrera, Saúl, Guzmán-Espinosa, J.B., and Mancilla-Gutiérrez, A.A., 2002, Carta geológico-minera, Ciudad Obregón G12-3, Sonora, Chihuahua: Servicio Geológico Mexicano, 1 sheet, scale 1:250,000.
Sillitoe, R.H., 1976, A reconnaissance of the Mexican porphyry copper belt: Institutions of Mining and Metallurgy Transactions, Section B—Applied Earth Science, v. 85, p. B170–B189.
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 http://pubs.usgs.gov/of/2008/1155/.
Swendseid, T.J., Welhener, H., Gray, M., and Hanks, J., 2008, Technical report for the Piedras Verdes copper project, March, 2008: Technical report prepared for Frontera Copper Corp., 235 p.