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. Marbin exploration area is situated in Urumieh-Dokhtar magmatic belt. Marbin index is located in the east of Zefreh fault within central part of Zefreh pull apart basin. The composition of Eocene subvolcanic and volcanic units of this area is rhyolite to dacite. The spectral of sericite, epidote, calcite and chlorite minerals in this area have been recognized by using the Spectral angle mapper (SAM). Finally with combination of spectral of index minerals in phyllic and propyllitic alteration zone with field observations, petrograghy and geochemical analysis, the alteration zones map in Marbin area have been prepared. As a result, phyllic and propylitic alterations as well as silicification are index alterations in this area. Based on litho-geochemical analysis, high contents of Mo/Cu and occurrence of hydrothermal alterations besides other evidences, 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.

Keywords

• hydrothermal alteration mapping
• remote sensing
• sam method
• mo porphyry
• marbin index
• zefreh