Abstract:
Digital data and images gain from satellites are appropriate tools for geological studies specially in lithology and mineral exploration. In this research, to separation and detection of minerals and lithologic units, using ETM+ digital data from Landsat satellite, a region at 65 kilometers in the west of Isfahan and south of Tiran city was selected because of weak botanic cover and litological diversity. After initial processes in images, two multivariable statistical methods were used: Optimum Index Factor (OIF) and Crosta. OIF method, were used for selection of compositions contain most spectral information about minerals and rocks. Then, classification was applied to mentioned compositions and accuracy of different classifications in separation of Minerals and rocks were determined. Results of this method shows that because of existence of dense botanic cover in side of Zayandeh Rud river in region's image, using high OIF compositions, although leaded to satisfactory separation of botanic cover data class and water from rocks data class, but it was not effective in separation of minerals and rocks. Crosta method, based on principle components analysis using ETM+ 6bands, was done and components those contain information about minerals and rocks were specified. Results showed that this method reveals PC3 component of amphibole minerals in Green Stons and PC5 for clay minerals.
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