Detection of Alteration Zone with Multispectral ASTER Data in Ghabaghloujeh Gold Deposit (Kordestan, Iran)

摘要

Ghabaghloujeh gold deposit is located in the Sanandaj-Sirjan Zone and is hosted by NE-trending ductile shear zones and younger brittle fractures. The hydrothermal alteration zones are fairly developed within and around the lenticular intrusive body. Since the vegetation coverage is low, multispectral remotely sensed data of ASTER employed to extract the alteration zones; which might vector mineralized zones with mapping of sericitization, chloritization, silicification, and ferrugination, which are product of the chemical interaction between the bedrock minerals and minerals of the solutions. Each alteration is characterized by significant minerals related to these kinds of alterations such as alunite (K/Na), muscovite, kaolinite, illite, chlorite, goethite, hematite, jarosite, calcite, and quartz. Spectral Angle Mapper was applied to map the distribution of hydrothermally altered rocks associated with the possible mineralization. The overall result and comparison with the extensive field works showed that the hyperspectral remotely sensed data are the best tool, and multispectral data are one of the best tools to map the altered rocks.