Using SWIR Bands from ASTER for Discrimination of Hydrothermal Altered Minerals in the Northwest of Iran (Se-Sanandaj City); A Key for Exploration of Copper and Gold Mineralization

摘要

We used SWIR bands from ASTER sensor data for mineral explorations in the west of Iran in Kurdistan Province in the southeast of Sanandaj city. The wavelength of SWIR bands is situated between 1.6-2.43 ?m. In these range, hydroxides minerals which have been produced by hydrothermal alteration have a good absorption compared to lower or upper wavelengths. Based on PCA and Band Ratios (BR) methods and so comparing reflectance-wavelength curves with NASA/JPL standard curves, we distinguished two Propylitic and Phyllic alteration zones; in Propylitic zone is rich in chlorite and epidote minerals and Phyllic zone is rich in white mica and kaolinite minerals. These 2 alteration zones are important for copper and gold mineralization in this part of Iran. In the last decade some gold mineralizations such as Kervian and Dashkasan have been explorated in the northwest and northeast of study area respectively.