B-54 Natural Acid Rock Drainage Associated with Hydrothermally Altered Terrane in Colorado

Is pristine mountain water always clean and pure? Can streams unaffected by human activities and livestock influences be unfit for human consumption, or fish? A new study by the CGS has some surprising answers. The study examines specific areas in Colorado that have naturally poor surface-water quality due to the area’s geology.

The report identifies a number of streams in eleven different headwater areas of Colorado where surface water is acidic and has high concentrations of metals upstream of any significant human impacts.

Through detailed geologic mapping, the study characterized the type and intensity of hydrothermal alteration and correlated the geology with surface-water chemistry. Many of the areas exhibiting intense hydrothermal alteration also contain historic mine sites. Frequently, acid rock drainage from natural sources and mine sites combine to cause severe downstream water quality problems. In these situations it is important to distinguish the natural, or background water quality so that realistic cleanup goals for water quality can be set.

Book, 112 pages, 2 plates. B-54

Author: J.T. Neubert, J.P. Kurtz, D.J. Bove, and M. A. Sares
Status: In Print
Year: 2011

$18.00

33 in stock