Copper Flat

Porphyry copper deposit in New Mexico, United States

Names and other identifiers

Alternate names Hillsboro
Tract name Southwest Laramide East (003pCu9008)
Site status deposit

Geographic location

Country United States
State or province New Mexico
Geographic location -107.53391547, 32.970323784
Geologic map unit -107.53391547, 32.970323784
Nearby data

Geologic information

Deposit type Porphyry copper
Age (Ma) 75Ma
Age determination method unknown
Age range 75 Ma
Age reference Singer and others (2008)
Minerals apatite, azurite/malachite, biotite, bornite, chalcocite, chalcopyrite, chlorite, chrysocolla, cuprite, epidote, fluorite, galena, magnetite, molybdenite, pyrite, sericite, sphalerite, tetrahedrite, zeolite
Associated rocks breccia, jasperoid, latite, latite porphyry, quartz monzonite, skarn, basalt, conglomerate, dolomite, limestone, mudstone, quartz monzonite porphyry, quartzite, rhyolite pyroclastics, sandstone, schist, shale, andesite flow, andesite pyroclastics
Tectonic setting continental margin
Stratigraphic age Late Cretaceous

Commodity and development information

Development status Occurrence
Major commodities Cu
Tonnage (Mt) 62Mt
Cu grade (%) 0.36%
Mo grade (%) 0.0128%
Au grade (g/t) 0.18g/t
Ag grade (g/t) 1.7g/t
Contained copper 220,000t
Gold-Moly ratio 14

Reference information

Comments 60% covered.
Study area name United States
References Dunn (1982); Long (1995); McLemore and others (1999); North and McLemore (1988); Singer and others (2008); McLemore (2008)
Site reference U.S. Geological Survey National Mineral Resource Assessment Team (2002)
Dunn, P.G., 1982, Geology of the Copper Flat porphyry copper deposit, in Titley, S.R., ed., Advances in geology of the porphyry copper deposits, southwestern North America: Tucson, University of Arizona Press, p. 313–325.
Long, K.R., 1995, Production and reserves of Cordilleran (Alaska to Chile) porphyry copper deposits, in Pierce, F.W., and Bolm, J.G., eds., Porphyry copper deposits of the American Cordillera: Tucson, Arizona Geological Society Digest 20, p. 35–68.
McLemore, V.T., 2008, Chino mine, Santa Rita district, Grant County, New Mexico, in Mack and others, Geology of the Gila Wilderness-Silver City area: New Mexico Geological Society Fall Field Conference Guidebook 59, p. 41–43.
McLemore, V.T., Munroe, E.A., Heizler, M.T., and McKee, Christopher, 1999, Geochemistry of the Copper Flat porphyry and associated deposits in the Hillsboro mining district, Sierra County, New Mexico, USA: Journal of Geochemical Exploration, v. 67, p. 167–189. (Also available at
North, R.M., and McLemore, V.T., 1988, A classification of the precious metal deposits of New Mexico, in Schafer, R.W., Cooper, J.J., and Vikre, P.G., eds., Bulk mineable precious metal deposits of the western United States: Geological Society of Nevada Symposium, Reno, April 6–8, 1987 [Proceedings], p. 625–659.
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