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کلیدواژهها
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Keywords: active tectonics, thrust-folding, uplift, faults, ASTER, OLI8, lineament, alteration pattern, porphyry Cu, erosion level, NW of Iran
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چکیده
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Abstract—The Kighal and Bormolk porphyry copper deposits (PCDs) are known subeconomic deposits and are ~10 km south of Sungun, the world-class copper mine in NW Iran. The deposits are located in the Azerbaijan plateau, within Alborz, Zagros, and Caucasus Mountain ranges, having undergone active tectonics, including uplift and thrust-folding from the Cimmerrian Orogeny. The sub-economic nature of the Kighal and Bormolk deposits, despite their relatively close distance and age and lithologic similarity to those of the Sungun deposit, has been discussed. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Landsat 8 Operational Land Imager (OLI) imagery were used to map alteration patterns and lineaments associated with these deposits. In order to discriminate alteration minerals of the deposits in comparison with those in the Sungun deposit, the ASTER image was processed using False Color Composite (FCC), Band Ratio (BR), Principal Component Analysis (PCA), Minimum Noise Fraction (MNF), and Mixture-Tuned Matched-Filtering (MTMF) techniques, which recognize seven alteration types in the Kighal‒Bormolk area and three types in the Sungun area, including its more intense alteration systems. The results were verified by field observations, mineralogical, and X-ray diffraction (XRD) studies. Also, lineament extraction of DEM and Landsat 8 OLI data by Envi 5.1, Geomatica, ArcGIS 10.6, and Rockworks 16, displayed a lower density of fault intersections in the Kighal‒Bormolk area. Additionally, NW‒SE trending lineaments of the Sungun deposit, which is in accordance with most of the valuable porphyry copper deposits in Iran, are taken into account.
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