Abstract

Spectral mapping techniques were applied on shortwave infrared of advanced spaceborne thermal emission and reflection radiometer (ASTER) data for discriminating between hydrothermal alteration zones, and the identification of high potential mineralized lithologic unit associated with hydrothermal porphyry copper mineralization in the Central Iranian Volcanic Belt. In this study, shortwave infrared radiations of ASTER data were processed with spectral angle mapping, linear spectral unmixing, matched filtering, and mixture tuned matched filtering techniques. Two copper mining districts were used as reference to demonstrate the applicability of the spectral mapping techniques for spectral distinction of specific hydrothermal alteration zones such as argillic, phyllic and propylitic. The results of this study showed that spectral information can be used for generating spatial alteration mineral maps for purely virgin regions, and it can provide a cost-effective method to discriminate the new prospects for porphyry copper exploration prior to detailed and costly ground investigations.

Key words: ASTER, spectral mapping techniques, hydrothermal alteration minerals, copper exploration.