IDENTIFICATION AND MAPPING OF FERRIC-OXIDE AND OXYHYDROXIDE MINERALS IN IMAGING SPECTROMETER DATA OF SUMMITVILLE, COLORADO, USA, AND THE SURROUNDING SAN-JUAN MOUNTAINS

Fe3+ bearing minerals and poorly crystalline mineraloids can host pern icious trace metals released by mining activities. Such mineral phases are readily detectable in imaging spectrometer data such as is collec ted by NASA's Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). Laboratory measured reflectance spectra of fluvial sediment samples g athered downstream from the Summitville mining district in southwest C olorado, U.S.A., have been compared with AVIRIS data collected over Su mmitville and the surrounding San Juan mountains. Spectra from the AVI RIS image cubes over Summitville match with the laboratory measured re flectance of several Fe3+ bearing mineral phases including a ferrihydr ite produced in an acid water environment.