NEW APPLICATIONS OF REMOTE SENSING TO MINERAL EXPLORATION

Twenty years of field and laboratory measurements in the reflected and emitted portions of the electromagnetic spectrum have developed comprehensive spectral libraries for extracting geologic information remote sensing data. Software programs have reached maturity and permit the multi-dimensional nature of spectral data to be analyzed on relatively inexpensive computer systems. A variety of new sensor/platform systems have been developed that can adequately measure the natural spectral variability of most surface materials.

Within the last decade improvements in sensors have allowed the detection and mapping of tens of spectral end-members from measurements of mineralized terrains. These improvements have enabled geoscientists to, not only identify diagnostic minerals, but to also develop information on the variations in composition of specific minerals. Multiband thermal sensors have demonstrated that gross differences in silicate mineral content of most rock types can be mapped on the basis of generalized variations in thermal emittance. Preliminary analysis of ASTER data from Terra-1 has shown promise for mapping 1:250,000 scale variations in silicate mineral content in areas that have low vegetative surface cover. The Spatially Enhanced Broadband Area-Array Spectrograph System (SEBASS), developed by Aerospace Corporation, has shown potential for detecting and mapping discrete thermal emittance variations related to specific minerals found in common mineral deposits.

In the last few years a number of promising commercial sensor/platform technologies (Probe-1, HyMap and HyperSpecTIR) have become available to geoscientists. A number of these advanced technologies are being considered for flight on spaceborne platforms. Graduate students and faculty of the Arthur Brant Laboratory for Exploration Geophysics at the University of Nevada, Reno have been evaluating these technologies in the Virginia City and Steamboat Hills areas near Reno, Nevada, and in the Aurora-Bodie mining districts of Nevada and California. This paper discusses these new developments in applications of geologic remote sensing to mineral exploration.