Geochemistry of surface water in alpine catchments in central Colorado, USA: An example of sampling scale versus detail
Wanty RB, Verplanck PL, Fey DL, Church SE, San Juan CA, Swigert VA. Geochemistry of surface water in alpine catchments in central Colorado, USA: An example of sampling scale versus detail. USGS. Denver, CO
The U.S. Geological Survey is conducting a study of surface-water quality in the Rocky Mountains of central Colorado. Sampled media include stream water, sediment, and biofilm coatings on streambed rocks. At selected sites, aquatic macroinvertebrates are being collected. This paper focuses on the streamwater chemistry. The dominant regional feature affecting water quality in central Colorado is the Colorado Mineral Belt (CMB), a northeast-trending zone hosting many polymetallic vein and replacement and porphyry Mo deposits that were mined from the mid-1800’s to the present. The influence of the CMB is seen in lower surface-water pH (less than 5), and higher concentrations of SO4 2- (greater than 100 mg/L) and siderophile and chalcophile metals such as Fe (greater than 1 mg/L), Cu (greater than 0.01 mg/L), Zn (greater than 0.1 mg/L), and Cd (greater than 0.001 mg/L). At local scales, effects of individual rock units on water chemistry are subtle but discernible, as shown primarily by concentrations of major lithophile elements or ratios between them.
- Type
- Published Report
- Authors
- Wanty, Richard; Verplanck, Philip; Fey, David; Church, Stanley; San Juan, Carma; Swigert, Valerie
- Publisher
- USGS
- Units
- ROMO
- Keywords
- biofilm coatings, Sediment, stream water, Surface Water Quality