Thermal infrared exploration in the Carlin trend, northern Nevada
Experimental Thermal Infrared Multispectral Scanner (TIMS) aircraft data have been acquired for the Rodeo Creek NE 7 1/2 minute quadrangle, Eureka County, northern Nevada, covering the Carlin gold mine. A simple model has been developed to extract spectral emissivities for mapping surface lithology and alteration based on the physical properties of geologic materials. Emissivity-ratio images were prepared that allow generalized lithologic discrimination, identification of areas with high silica content, and the first reported detection of the carbonate secondary reststrahlen feature. Together with thermal-inertia images, they permit identification of areas of subtle lithologic variation not shown on conventional geologic maps. Emissivity-ratio spectra extracted from the data compare favorably with modeled laboratory spectra and establish for the first time the link among theory, measured physical properties, and color-composited TIMS images. Identification of previously unknown silicification in the Tertiary volcanic rocks and mapping of a silicified structure and possible extensions in alluvium indicate that TIMS data can be a valuable tool for detecting subtle alteration associated with mineralization, particularly in less accessible or less well-known areas.
Citation Information
Publication Year | 1990 |
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Title | Thermal infrared exploration in the Carlin trend, northern Nevada |
DOI | 10.1190/1.1442773 |
Authors | K. Watson, F.A. Kruse, S. Hummer-Miller |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Geophysics |
Index ID | 70016228 |
Record Source | USGS Publications Warehouse |