The Coastal Cordillera in northern Chile is characterized by hosting iron-oxide-copper-gold (IOCG), iron-oxide-apatite (IOA), and porphyry copper deposit (PCD) mineralization, which are spatially and genetically associated with diverse hydrothermal alterations mineral assemblages. These assemblages can be identified through remote sensing techniques, thus defining areas of interest for mineral exploration. In this study, various spatial remote sensing methods were employed, including Red-Green-Blue (RGB) color combinations, Band Ratios (BR), Band Mathematics (BM), Spectral Angle Mapping (SAM), and Directed Principal Component Analysis (DPCA), to process data from ASTER, Landsat-9 OLI, and Sentinel-2. This approach enabled the identification of phyllic, argillic, propylitic, and advanced argillic alteration assemblages, as well as the detection of minerals such as iron oxides, ferrous silicates, and clays within the Coastal Cordillera, between 28°57′20″ and 29°13′25″ south latitude. Landsat-9 and Sentinel-2, using VNIR data, were effective for identifying iron oxides, while ASTER data, analyzed in the SWIR region, allowed for the identification of key minerals including alunite, jarosite, pyrophyllite, kaolinite, illite, muscovite, and chlorite, among others. ASTER data was particularly effective in detecting hydrothermal alterations in areas with advanced argillic, argillic, phyllic, and propylitic alterations. Sentinel-2 demonstrated superior spatial resolution for detecting iron oxide minerals compared to Landsat 9-OLI. The observed hydrothermal alterations and detected minerals are consistent with the typical mineral paragenesis of PCD, IOCG, and IOA-type deposits, validating the high probability of finding copper deposits and other associated minerals in the Coastal Cordillera, between latitudes 28°. 57′20″ and 29°13′25″ S.
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