Improved Automated Identification and Mapping of Iron Sulfate Minerals, Other Mineral Groups, and Vegetation using Landsat 8 Operational Land Imager Data, San Juan Mountains, Colorado, and Four Corners Region

First posted February 24, 2021 For additional information, contact: Director, Geology, Geophysics, and Geochemistry Science CenterU.S. Geological SurveyBox 25046, MS-973Denver, CO 80225-0046 Multispectral remote sensing data acquired by the Landsat 8 Operational Land Imager (OLI) sensor were analyzed using a new, automated technique to generate map of exposed mineral vegetation groups in western San Juan Mountains, Colo., Four Corners Region United States. Band ratio results combined into displayed Boolean algebra. New analysis logic has been implemented exploit coastal aerosol band OLI identify concentrations iron sulfate minerals. These may indicate presence near-surface pyrite, which can be potential nonpoint source acid rock drainage. Zoned occurrences minerals areas surrounding down gradient known sources pyrite have mapped this technique. They show high correlation with jarosite-bearing assemblages, as airborne imaging spectrometer supporting field verification surveys. Mapping occurrence produced weathering oxidation hydrothermally altered rocks also provide an important indicator genetic environment alteration associated deposit type. The methodology is being employed rapidly cost-effectively maps large regions States support U.S. Survey resource mineral-environmental assessments. This map, includes ERDAS IMAGINE thematic raster format release, attributed pixel value group classification data, queried most image processing GIS software packages.