Remote sensing of geothermal-related minerals for resource exploration in Nevada

Abstract

We use remote sensing data from a variety of satellite and airborne instruments to characterize mineral and thermal properties as surface indicators of geothermal resources in Nevada. We generally use satellite data as a reconnaissance tool to target higher resolution airborne data collections. Spectral data are collected from field surface locations and samples to validate remote identifications and refine mineral maps. Spectral validation is done using an ASD portable spectrometer (0.4–2.5μm) in both field and lab configurations. We also have a Thermo/Nicolet Nexus 6700 FTIR spectrometer and shared use of a Designs and Prototypes FTIR field instrument for thermal infrared data collection. Past work has identified sinter, tufa, travertine, argillic hydrothermal alteration minerals, evaporites, vegetation concentration near springs, and thermal anomalies as indicative of resource potential and structural controls on fluid pathways. Our methodology places mineral maps into GIS databases with other geologic information to make comparisons and site assessments. We recommend target areas for subsequent exploration including shallow temperature measurements, detailed geologic mapping, and structural analyses. This paper reviews over a decade of remote sensing geothermal exploration in Nevada and summarizes the common and unique features identified by our surveys.