The mineralogic evaluation of mining sites in Wyoming using hyperspectral field and imaging systems

Two mining sites in Wyoming were analyzed to evaluate different methods of processing and interpreting data from hyperspectral field and imaging systems. This resulted in two projects being undertaken, one to compare the performance of data processing techniques on hyperspectral imagery, and the other to investigate the usefulness of field spectroscopy for identifying alteration.; The first project, located near Atlantic City, Wyoming, applied the USGS Tetracorder and the ENVI software package to AVIRIS data of the site. The results from both methods were checked against field maps and field spectroscopy data collected for the study. Several rock units in the Atlantic City image were successfully identified, including supracrustal rocks, granite and granite-peiss, and some sedimentary units. By comparing the results from each processing method, the strong and weak points of each program were identified and improvements suggested.; The Silver Crown project was undertaken to characterize alteration associated with a gold-copper ore deposit located near Cheyenne, Wyoming. This was accomplished using spectral analyses of drill hole samples and airborne spectroscopic data. Analyses of drill hole samples with reflectance spectroscopy techniques are relatively undeveloped and undocumented, so new methods had to be derived, Several alteration zones in the Silver Crown area were successfully identified by spectral analysis of cutting samples. The results suggest the spectral analysis of such samples can facilitate the geologic and mineralogic assessment of a prospect area.; Results confirm the potential of hyperspectral imaging and spectrometry as significant new tools for geologic mapping and mineral analysis. The results also indicate important limitations resulting from varying field conditions, methods of data collection, and different processing routines. Both the positive and negative results may serve as a guide to the future development and application of hyperspectral techniques and speed future users in their efforts to produce mineralogic maps and identify alteration at mining sites.