Aquatic ecosystems in Central Colorado are influenced by mineral forming processes and historical mining

摘要: Stream water and sediment toxicity to aquatic insects were quantified from central Colorado catchments distinguish the effect of geologic processes which result in high background metals concentrations historical mining. Our sampling design targeted small underlain by rocks a single lithology, allowed development biological geochemical baselines without complication multiple rock types exposed catchment. By accounting for sources environment, we able between environmental effects caused mining weathering different mineralized areas. Elevated metal not restricted mined catchments. Impairment communities also occurred unmined influenced Schmidt is Mendenhall post doctoral fellow research ecologist, U.S. Geologic Survey, Mineral Resource Science Center, Denver, CO 80225; Fort Collins Collins, 80521. Church, Fey, Wanty, Verplanck, San Juan, DeWitt, Rockwell, Klein are geologists, geochemists, geospatial scientists, all with Geological P.O Box 25046, MS 973, 80225. Clements Mitchell ecotoxicologists, both State University–Fish, Wildlife, Conservation Biology Department, Email: tschmidt@usgs.gov; schurch@usgs.gov; defy@usgs.gov; rwanty@usgs.gov; plverplanck@usgs.gov; csanjuan@usgs.gov; edewitt@usgs.gov; barnabyr@usgs.gov; tklein@usgs.gov; willc@cnr.colostate.edu; kmitchel@warnercnr.colostate.edu. hydrothermal alteration. Hydrothermal alteration style, deposit type, important determinants quality community structure. Weathering porphyry Cu-Mo occurrences resulted (median toxic unit (TU) = 108) (TU 1.9) that exceeded thought be safe ecosystems 1). Metalsensitive virtually absent streams draining (1.1 individuals/0.1 m). However, 0.1, 0.5 sediment, respectively) presence metalsensitive (204 m) polymetallic vein indistinguishable unaltered respectively; 201 In quartz-sericite-pyrite altered deposits, 8.4) 3.1) degraded more (36 than 0.4) 1.7) propylitically deposits. The approach taken this study distinguishes mineral deposits on can used accurately quantify environment.