Alamogordo to Orogrande mining district and Oliver Lee Memorial State Park. Third-day road log
Virginia McLemore, James Tabinski, James Mclemore, and Geoffrey Rawling
The third-day trip proceeds south from Alamogordo to the Orogrande mining district in the Jarilla Mountains, also known as the Jarilla, Brice, and Silver Hill district. It is northwest of the small community of Orogrande, which is Spanish for “big gold.” Turquoise was probably first mined from the district by Native Americans before the 1880s. The Jarilla Mountains consist of a core of granodiorite surrounded by monzonite. A large number of granodiorite, monzonite, andesite, and diabase dikes and sills cut the larger intrusions as well as the surrounding sedimentary rocks, the Pennsylvanian Panther Seep through Permian Hueco Formations (Seager, 1961; Strachan, 1976). The limestones and shales adjacent to parts of the intrusions have been metamorphosed to three types of skarns: pyroxene-scapolite-garnet adjacent to granodiorite, epidote-garnet-calcite adjacent to monzonite porphyry, and pyroxene-scapolite-garnet-epidote-calcite adjacent to dikes, monzonite, and granodiorite. Total production from the district from 1879–1966 is estimated as 16,500 oz Au, 50,000 oz Ag, 5.7 million lbs Cu, and 158,000 lbs Pb (McLemore et al., this volume). In 1916, 6,656 short tons of tungsten ore was produced from the district (Finlay, 1922). Total iron ore production was approximately 260,000 short tons. Today we are going to examine one of the skarn deposits (Three Bears mine), a turquoise mine, and a placer gold mine. The final stop will be at Oliver Lee Memorial State Park, located along the base of the Sacramento Mountains. Here the geology of the Paleozoic and Pennsylvanian rocks of the escarpment can be examined up close along the Dog Canyon Trail. There will also be opportunity to visit the Oliver Lee Ranch house.
Note: The full-text of all Fall Field Conference road logs are only available in print.
- McLemore, Virginia; Tabinski, James; Mclemore, James; Rawling, Geoffrey, 2014, Alamogordo to Orogrande mining district and Oliver Lee Memorial State Park. Third-day road log, in: Geology of the Sacramento Mountains region, Rawling, Geoffrey; McLemore, Virginia T.; Timmons, Stacy; Dunbar, Nelia, New Mexico Geological Society, Guidebook, 65th Field Conference, pp. 95-108.