Primary analysis for enhancing the iron oxide and alteration minerals, using ETM+ data: a case study of Kuh-e-Zar gold deposit, NE Iran

Different types of iron oxides deposits have been identified along the Khaf – Dorouneh volcanic and plutonic belt in north east of Iran. Kuh-e-Zar is one of these ore deposits known as Fe- oxide gold deposit. The main purpose of this paper is to detect and discriminate the iron oxide minerals in this area based on the ETM+ data. Data processing has been done by ENVI (Environment for Visualizing Images) software. Color Composites, Band Ratios, Principal Components (PC) analysis were used to delineate the associated zones of hydrothermal alteration and iron oxide minerals. Based on both field observations and the results of this satellite data processing, the area covered by secondary iron oxide (hematite, goethite and limonite mainly in soil) was enhanced very good, but the primary iron oxides (specularite) which are very fine grain and have a linear structure (mainly in mineralized veins) are not very clear in detail in these images.