Digital map of hydrothermal alteration type, key mineral groups, and green vegetation of the southwestern United States derived from automated analysis of ASTER satellite data

Metadata Updated: November 12, 2020

Mineral groups identified through automated analysis of remote sensing data acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) were used to generate a map showing the type and spatial distribution of hydrothermal alteration, other exposed mineral groups, and green vegetation across the southwestern conterminous United States. Boolean algebra was used to combine mineral groups identified through analysis of visible, near-infrared, and shortwave-infrared ASTER data into attributed alteration types and mineral classes based on common mineralogical definitions of such types and the minerals present within the mineral groups. Alteration types modeled in this way can be stratified relative to acid producing and neutralizing potential to aid in geoenvironmental watershed studies. This mapping was performed in support of multidisciplinary studies involving the predictive modeling of mineral deposit occurrence and geochemical environments at watershed to regional scales. These studies seek to determine the relative effects of mining and non-anthropogenic hydrothermal alteration on watershed surface water geochemistry and faunal populations. The presence or absence of hydrothermally-altered rocks and (or) specific mineral groups can be used to model the favorability of occurrence of certain types of mineral deposits, and aid in the delineation of permissive tracts for these deposits. These data were used as a data source for the U.S. Geological Survey (USGS) Sagebrush Mineral-Resource Assessment (SaMiRA). This map, in ERDAS Imagine (.img) format, has been attributed by pixel value with material identification data that can be queried in most image processing and GIS software packages. Three files are included with this product: file with .img extension contains thematic image attributes and geographic projection data, file with .ige extension contains the raster data, and the file with .rrd extension includes pyramid data for fast display.

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License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Metadata Date January 28, 2019
Metadata Created Date November 12, 2020
Metadata Updated Date November 12, 2020
Reference Date(s) January 1, 2017 (publication)
Frequency Of Update notPlanned

Metadata Source

Harvested from DOI Open Data

Additional Metadata

Resource Type Dataset
Metadata Date January 28, 2019
Metadata Created Date November 12, 2020
Metadata Updated Date November 12, 2020
Reference Date(s) January 1, 2017 (publication)
Responsible Party U.S. Geological Survey (Point of Contact)
Contact Email
Access Constraints Use Constraints: Acknowledgement of the U.S. Geological Survey would be appreciated in products derived from these data. Data have been checked to ensure the accuracy of the data. If any errors are detected, please notify the originating office. The U.S. Geological Survey strongly recommends that careful attention be paid to the metadata file associated with these data. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ArcGIS and ERDAS Imagine formats, this metadata file may include some terminology specific to those software packages., Access Constraints: None
Bbox East Long -101.353107011
Bbox North Lat 42.619418381
Bbox South Lat 30.8064674067
Bbox West Long -124.696969849
Coupled Resource
Frequency Of Update notPlanned
Licence Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also contains copyrighted materials as noted in the text. Permission to reproduce copyrighted items for other than personal use must be secured from the copyright owner. This database, identified as USGS Data Release 10.5066/F7CR5RK7, has been approved for release and publication by 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 any 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.
Metadata Language
Metadata Type geospatial
Progress completed
Spatial Data Service Type
Spatial Reference System
Spatial Harvester True
Temporal Extent Begin 2000-05-01
Temporal Extent End 2007-10-01

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