Extraction of alteration minerals spectra in Angouran zinc and lead deposits using ASTER image processing

Angouran zinc-lead deposit is located in the west of Zanjan province. According to the field observation, the lithological units at this mine consist of carbonate hanging wall mainly in the form of marble and footwall schist. The purpose of this study is to detect and identify the alteration index minerals in Angouran zinc-lead deposit using ASTER sensor data using False Color Combination (FCC), Band Ratio (BR), Feature Oriented Principal Components Selection ( FPCS), and Spectral Angle Mapper (SAM). Based on these studies, the dolomite, sericite (muscovite), and chlorite alterations were detected, which corresponds to the trend of these minerals in the field visit. The best methods among the performed processes are Band Ratio (BR) and Feature Oriented Principal Components Selection (FPCS) methods, which correctly detected the area of alteration spread. The results of this study show that chlorite alteration in the form of narrow veinlets is present in the Angouran footwall schist and is limited to schists. Muscovite (sericite) was mostly found in Neogene volcanic units, while dolomite is found in Angouran marble, and to some extent in Qom Formation limestone of Neogene age. The accuracy of the results was confirmed by field observations, petrography, and XRD analysis of samples collected from the zinc and lead deposits of Angouran.