Extracting clay minerals with emphasis on Bentonite in Eastern Iran, using Landsat 8 and ASTER images

The prospecting area is located in the eastern part of Iran. Aster and Landsat 8 satellite images were processed with different spectral analyses techniques to detect the clay representing the alteration zones, with emphasis on bentonite occurrences in the study area. Band ratio (BR), Spectral Angle Mapper (SAM), Mixture Tuned Matched Filtering (MTMF), Principal Component Analysis (PCA), Spectral Feature Fitting (SFF), and Least Square Fit (LS-Fit) techniques were performed to show the promising areas for clay mineral. Band ratios of 6/7, 6/5, and 4/2 from Landsat 8 OLI imagery and 4/6, 5/6, 5/8, from ASTER were used to enhance clay alterations. The results obtained from the supervised classification using the SAM algorithm for minerals from US Geological Survey spectral library (USGS) have been compared with the results of Jet Propulsion Laboratory (JPL) spectral library. The Sequential Maximum Angle Convex Cone (SMACC) algorithm also performed to detect same minerals. Comparing the different analyzing satellite image based on ASTER data indicate all methods generate relatively similar results for clay mineral. Although all methods generate relatively similar results, the SAM method seems to be the best fit with geological evidences to generate reliable promising areas for clay mineral in this area. Based on this study, around 100 km2 of the total studied area was selected as suitable for more exploration and ground survey.