Abstract
A comparative study of sulfide mine tailings from two sites near Silver City in southwest New Mexico has shown the need for environmental monitoring in a geological context. The Cyprus-Piños Altos and Cleveland deposits consist of Cu and Zn skarn mineralization in the Piños Altos Mountains of New Mexico. Primary ore minerals in both deposits include chalcopyrite, sphalerite, and galena. The Cyprus-Piños Altos Mine ceased operation in 1995 and the Cleveland Mill closed in 1950. The deposits have similar mineralogical characteristics; however, the tailings are different in terms of age, degree of oxidation and method of disposal. The Cyprus-Piños Altos tailings (CPAT) are stored in a lined, bermed impoundment. They are dominantly water-saturated and exhibit no secondary-phase formation. The grains are not cemented and show no evidence of primary-mineral dissolution. The geochemical data show a predominantly primary signature. The tailings pond water is neutral to slightly alkaline (pH from 7 to 8.3), partly as a result of processing methods. The Cleveland mill tailings (CMT) were deposited in a valley at the headwaters of an ephemeral stream. They are highly oxidized and differentially cemented. They have undergone numerous wet/dry cycles resulting in extensive oxidation. Secondary minerals predominate, and consist mainly of jarosite, goethite, hematite, and Fe-oxyhydroxides and -oxyhydroxysulfates. The pH of the stream draining the CMT is as high as 2.15. Maximum metal contents in the stream immediately downstream from the tailings are 5305 ppm Zn, 454 ppm Cu, 1.16 ppm Pb, 17.5 ppm Cd, 1.4 ppm As, and 0.01 ppm Hg.
Article PDF
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Additional information
Received: 31 October 1996 · Accepted: 21 May 1997
Rights and permissions
About this article
Cite this article
Boulet, M., Larocque, A. A comparative mineralogical and geochemical study of sulfide mine tailings at two sites in New Mexico, USA. Environmental Geology 33, 130–142 (1998). https://doi.org/10.1007/s002540050233
Issue Date:
DOI: https://doi.org/10.1007/s002540050233