Energize New Mexico
National Science Foundation
Mining has aided in the economic and social development of New Mexico as early as the 1500's. One of the earliest gold rushes in the West was in the Ortiz Mountains (Old Placers district) in 1828, 21 years before the California Gold Rush in 1849. Many of these mines were immediately abandoned when insufficient minerals were found, others were abandoned later when poor economics of the commodity made mining unprofitable. Miners operating on federal lands had little to no requirement for environmental protection until the 1960s and 1970s, although the dumping of mine wastes and mill tailings directly into the nation's rivers was halted by an Executive Order in 1935. Irrespective of the remarkable contribution of mining to the development of New Mexico, it has to be admitted that the after effects of mining operations in the state has resulted in thousands of abandoned/inactive mine features in 274 mining districts and prospect areas. Reclamation efforts have not examined the long-term chemical effects from these legacy mines and there is still potential for environmental effects long after remediation of the physical hazards, as found in several areas in New Mexico including Jackpile mine, Laguna subdistrict. Some of these observations only come from detailed electron microprobe studies. The purposes of this study were to characterize and determine the mineralogical and geochemical composition of waste rock piles in uranium mines in Jeter uranium mine, Ladron Mountains, Lucky Don and Little Davie uranium mines, Socorro County. Waste rock piles were sampled in order to maximize surface area coverage, ensuring statistically representative sampling, and obtaining homogeneous samples. In this study, about 100,000 ft3 volume of waste rock pile material were estimated at Jeter mine, and 32,000 ft3 volume of waste rock pile estimated at Lucky Don mine. Waste rock piles from the uranium mines have pH values 7.5-8.2. This study found elevated radioactivity from scintillometer measurements (50 times background). Backscattered electron images of samples showed pristine secondary uranium, vanadium and CaCO3 grains from Lucky Don mine samples, while uranium and vanadium grains from Little Davie samples appeared to be partially dissolved. Waste rock pile samples from all uranium mines plotted in the non-acid forming zone on the Acid Rock Drainage (ARD) classification plot. It is recommended that waste rock piles with elevated radioactivity from scintillometer should be covered. A stream sediment survey is needed to determine the leachability of uranium, vanadium and other trace elements in the environment near the uranium mines.
McLeMore, Virginia. "New Mexico Abandoned Uranium Mines Study." (2017). http://digitalrepository.unm.edu/energizenm/627