Detecting areas of high-potential gold mineralization using ASTER data

Remote sensing plays an important role in mineral exploration. One of its proven applications is extracting and locating alteration zones that are related to gold deposits. In this study, surface reflectance data derived from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery are used to map hydrothermal alteration zones for gold exploration. A band ratio derived from the image spectra (4/8, 4/2, and 8/9 in RGB) and a mineral extraction method based on n-dimensional spectral feature space have been developed, and tested against other conventional methods, and known auriferous alteration zones. Spectral signatures used to construct the new band ratio are validated by a field study of the Abu-Marawat area in the Eastern Desert of Egypt. Results indicate that the method is promising for identifying alteration zones and is a useful tool for gold exploration in similar areas elsewhere.