Mapping Hydrothermal Alteration Zones Associated with Copper Mineralization using ASTER Data: A Case Study from the Mirjaveh Area, Southeast Iran

In this research, ASTER satellite images and the combined algorithm of band ratios with the method of logical operators with the determination of the threshold limit based on ground, laboratory and experimental studies have been used in order to highlight hydrothermal alterations. Image transformation techniques such as specialized band ratio and principal component analysis are used to map lithologic units and alteration minerals. Supervised classification technique, i.e. Spectral Angle Mapper (SAM) is applied to detect subtle differences between index alteration minerals associated with actual copper localities in the region. The results show that the integration of image transformation techniques and supervised classification of ASTER data with field studies and geochemical exploration is highly effective in targeting new copper mineralization prospects. Copper mineralization is found in siliceous veins that strike from north-south to northeast-southwest across the region. Remote sensing evidence supports the presence of propylitic and argillic alteration, which can be useful for searching for copper-gold type deposits. Kaolinite and pyrophyllite play a role in identifying arzilic alteration zones, and muscoite, epidote and chlorite minerals are very important in identifying pyropilitic and phyllic areas and in mineral exploration. Based on remote sensing processing, according to the detection of various alterations (phyllic, pyrophyllite and argillic) in this area, possible copper mineralization was detected in the central part of the studied area. The approach used in this research provides a quick and cost-effective means of initiating comprehensive geological and geochemical exploration programs in the study area and elsewhere in similar areas.