Geology and mineralogy of the Cerrillos copper deposit, Santa Fe County, New Mexico
— Robert L. Akright

The Cerrillos copper deposit is located in the north half of section 8 and the south half of section 5, T14N, R8E in the Cerrillos Hills two mi (3 km) north of the old mining village of Cerrillos and approximately 14 mi (23 km) southwest of Santa Fe, Santa Fe County, New Mexico (fig. 1). The deposit can be reached by way of an unmaintained dirt road heading in a northerly direction from the village of Cerrillos across San Marcos Arroyo and through a narrow rocky canyon (fig. 2). The San Marcos Arroyo should be crossed with caution during the summer flash-flood season.

 

The deposit was discovered by Bear Creek Mining Company in 1959 in the course of geological, geochemical and geophysical surveys in the area (Wargo, 1964). Subsequent exploration revealed the deposit to be too small and too low grade for conventional mining and extraction techniques. The project ultimately was dropped by Bear Creek. Occidental Minerals Corporation acquired the section 8 portion of the deposit in 1973 to further evaluate the deposit and the applicability of modern insitu-leaching techniques for extraction of the copper. The project is currently on a stand-by basis.

 

Most of the geology and mineralogy of the Cerrillos deposit, as discussed in this paper, are limited to that portion of the deposit occurring in section 8. Because of different ownerships, that portion of the deposit extending into section 5 has not been explored and detailed data are not available. Approximately two-thirds of the deposit occur in section 8, with the remaining one-third in section 5. Although the section 5 portion of the deposit has not been explored, surface mapping indicates similar geology and mineralogy, and no section-line fault is postulated.