COMPARATIVE MINERAL MAPPING IN THE COLORADO MINERAL BELT USING AVIRIS AND ASTER REMOTE SENSING DATA By Barnaby W. Rockwell First posted July 5, 2013 U.S. Geological Survey Scientific Investigations Map 3256 ABSTRACT This report presents results of interpretation of spectral remote sensing data covering the eastern Colorado Mineral Belt in central Colorado, USA, acquired by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensors. This study was part of a multidisciplinary mapping and data integration project at the U.S. Geological Survey that focused on long-term resource planning by land-managing entities in Colorado. The map products were designed primarily for the regional mapping and characterization of exposed surface mineralogy, including that related to hydrothermal alteration and supergene weathering of pyritic rocks. Alteration type was modeled from identified minerals based on standard definitions of alteration mineral assemblages. Vegetation was identified using the ASTER data and subdivided based on per-pixel chlorophyll content (depth of 0.68 micrometer absorption band) and dryness (fit and depth of leaf biochemical absorptions in the shortwave infrared spectral region). The vegetation results can be used to estimate the abundance of fire fuels at the time of data acquisition (2002 and 2003). The AVIRIS- and ASTER-derived mineral mapping results can be readily compared using the toggleable layers in the GeoPDF file, and by using the provided GIS-ready raster datasets. The results relating to mineral occurrence and distribution were an important source of data for studies documenting the effects of mining and un-mined, altered rocks on aquatic ecosystems at the watershed level. These studies demonstrated a high correlation between metal concentrations in streams and the presence of hydrothermal alteration and (or) pyritic mine waste as determined by analysis of the map products presented herein. The mineral mapping results were also used to delineate permissive areas for various mineral deposit types. DISCLAIMERS This database, identified as SIM 3256, has been approved for release and publication by the Director of the USGS. Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review.Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty, expressed or implied is made regarding the display or utility of the data on any other system, or for general or scientific purposes, nor shall the act of distribution constitute such warranty. The U.S.Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein. Any use of trade, product or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Geological Survey. Although this information product, for the most part, is in the public domain, it also contains copyrighted material as noted in the text. Permission to reproduce copyrighted items for other than personal use must be secured from the copyright owner. Note: Although the Federal Geographic Data Committee-compliant metadata files are intended to document the data set in nonproprietary form, as well as in ArcGIS and ERDAS Imagine formats, these metadata files may include some terminology specific to those software packages. DATA FILES List of files: 00ReadMe.txt SIM3256_pamphlet.pdf SIM3256_map.pdf Datafiles: img files: aster_cmb_mosaic_alteration-merge_rle.img aster_cmb_swir_mosaic_2-08_3199gf_overlapfix2.img aster_mosaic_nodata3_all_edit3-lvcld_rle.img aviris00_mosaic_1um_arcspline_utm_rgbclus_zfix_rle.img aviris00_mosaic_2um_arcspline_utm_rgbclus_zfix_rle.img cmb_fe-veg_bootcal_8scene_mosaic_02top_3-10_geofix_rgbclus_filt3focmaj_rle.img Metadata files: aster_cmb_mosaic_alteration-merge_rle.img_metadata.txt aster_cmb_swir_mosaic_2-08_3199gf_overlapfix2.img_metadata.txt aster_mosaic_nodata3_all_edit3-lvcld_rle.img_metadata.txt aviris00_mosaic_1um_arcspline_utm_rgbclus_zfix_rle.img_metadata.txt aviris00_mosaic_2um_arcspline_utm_rgbclus_zfix_rle.img_metadata.txt cmb_fe-veg_bootcal_8scene_mosaic_02top_3-10_geofix_rgbclus_filt3focmaj_rle.img_metadata.txt HOW TO OBTAIN THE DIGITAL FILES The digital files constituting the geologic map database of this report can be obtained via the Internet from the U.S. Geological Survey publications website. Go to the Web page at: http://pubs.usgs.gov/sim/3256/ and follow the directions to download the files. The main products are Portable Document Format (.pdf) maps and a pamphlet, which require Adobe Acrobat Reader for viewing. Adobe Acrobat Reader software runs on a variety of systems, and is available for download free of charge from Adobe at http://get.adobe.com/reader/otherversions/. ArcReader may be downloaded free of charge from http://www.esri.com/software/arcgis/arcreader/download for viewing additional files included in this report. The TerraGo Toolbar (http://www.terragotech.com/products/field-data-collection/terrago-toolbar), a no-cost extension for Adobe Acrobat Reader, is required for viewing geographic coordinates in the GeoPDF files. With or without the toolbar, multiple, geographically referenced map layers can be turned on and off for viewing and printing.