Precious- and base-metal districts in Rio Arriba and Sandoval Counties, New Mexico

 Total production from Rio Arriba and Sandoval Counties is estimated at 8 million lbs of copper, 66,000 oz of gold, 284,000 oz of silver, 41,000 lbs of lead, and 1000 lbs of zinc. Five types of precious- and base-metal deposits occur in this area: placer gold, volcanic-epithermal veins, sedimentary-hydrothermal baritefluorite-galena (± copper, silver) deposits, sedimentary-copper deposits, and Precambrian vein and replacement deposits. Of these deposits, volcanic-epithermal veins in the Cochiti district and sedimentary-copper deposits in the Nacimiento Mountains district have yielded significant production and continue as viable exploration targets. Furthermore, there may be additional potential for Precambrian precious-metal vein deposits in the Bromide and Hopewell districts in the Tusas Mountains.