Mapping Rock-Forming Minerals at Daylight Pass, Death Valley National Park, California, using SEBASS Thermal-Infrared Hyperspectral Image Data

Rock-forming minerals comprise the bulk of the rocks found at the surface of the Earth. These include, amongst others, quartz, feldspars, pyroxenes, micas and carbonates, all of which possess diagnostic emission features in the thermal-infrared portion of the electromagnetic spectrum. Using established emission spectra libraries we sought to map the distribution of these minerals using aerial remotely-sensed data centered on Daylight Pass, an alluvial wash dissecting the Grapevine Mountains to the northwest and the Funeral Mountains to the southeast, both of which effectively form the northeast perimeter of Death Valley. An abundance of Late Proterozoic and Cambrian sedimentary beds of dolomite, siltstone and sandstones, in addition to low- to moderate-grade metamorphic rocks form the bulk geology of the area of study, which is largely devoid of vegetation. Thermal-infrared spatially enhanced broadband array spectrograph system (SEBASS) hyperspectral image data was collected at Daylight Pass in mid-July of 2007. Standard reflectance hyperspectral processing techniques were implemented to reduce data dimensionality and, by referencing the emission spectra of both library and laboratory-measured ground specimens, we were able to successfully map the distribution of dominant rock-forming minerals in the form of outcrops and weathering products with a high degree of confidence.