Determination and mapping of hydrothermal alteration zones in exploration Marbin area (North of Zefreh) by remote sensing, field observations and petrology investigations

Abstract

In this research, the altered and non-altered zones in Marbin exploration area has been determined by VNIR and SWIR wavelengths processing of ASTER satellite images and by False Color composite and band ratio methods. The Marbin exploration area lies in the Urumieh-Dokhtar magmatic belt. The Marbin index is located in the east of the Zefreh fault within the central part of the Zefreh pull apart basin. Rhyolite to dacite are the predominant rock types of the Eocene subvolcanic and volcanic units of the area under study. The spectral of sericite, epidote, calcite and chlorite minerals in this area have been recognized using the Spectral angle mapper (SAM). Finally, with combination of spectral of index minerals in phyllic and propyllitic alteration zones with field observations, petrograghy and geochemical analysis, the alteration zones map in Marbin area have been prepared. As a result, the phyllic and the propyllitic alterations as well as the silicification are index alterations in this area. Based on litho-geochemical analyses, the high Mo/Cu contents, the occurrence of hydrothermal alterations in combination with several other evidences, we concluded that the Marbin index can be introduced as a porphyry deposit with Mo anomaly. This could be indicative of the potential of this area for the molybdenum mineralization in detailed exploration phase. © 2019, University of Isfahan.