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Regional hydrothermal alteration mapping using Landsat-8 data

This study presents the applicability of recently launched Landsat-8 data for hydrothermal alteration and lithological mapping. Sar Cheshmeh copper mining district in the southeastern part of the Urumieh-Dokhtar volcanic belt, SE Iran has been selected as a case study. Several Red-green-Blue (RGB) color combination images and specialized band ratios were developed. Band ratios derived from image spectra (4/2, 6/7, 5 and 10 in RGB) allows the identification of altered rocks, lithological units and vegetation. Fieldwork and laboratory analysis verified the image processing results. Thermal infrared bands of Landsat-8 significantly improved the quality and availability of thermal infrared remote sensing data for lithological mapping. The achievements of this investigation should have considerable implications for geologists to utilize Landsat-8 OLI/TIRS data for geological purposes in the future.