This deposit type is a research priority because of its economic significance and high potential for adverse environmental impact due to its high sulfide content and the low acid-buffering capacity of host rocks. Numerous examples of these deposits are found in the East, including reclaimed mine sites, abandoned mines, active mines, and sites currently in the permitting process for future production. Published studies of mine drainage chemistry from the Iron Mountain massive sulfide deposit in California have documented extreme conditions of very low pH and high heavy-metal concentrations. These extreme conditions are attributed to the unique hydrologic and climatic settings of the deposit and probably are independent of the mineral deposit type. The general strategy of current research is to use an integrated, multidisciplinary approach to understand the geologic, geochemical, and biogeochemical processes that affect the environmental behavior of these deposits and their mining wastes.
Field studies emphasize the interaction of water and rock, as mediated by biological activity.
Water sampling involves U.S. Environmental Protection Agency-approved protocols. Solid sampling includes country rocks, ores, mine drainage precipitates, solid mine wastes, soils, stream sediments, and biota. Site studies also include soil pH and geoelectrical surveys. Laboratory analysis includes a variety of techniques to determine mineralogical and chemical compositions of solids, dissolved constituents of waters, and stable isotope compositions of solids and waters. Low-temperature experimental capabilities include calorimetric and solubility studies.