Delineation of hydrothermal alteration zones for porphyry systems utilizing ASTER data in Jebal-Barez area, SE Iran

Abstract

The Urumieh-Dokhtar Magmatic Belt (UDMB) is the host of many Iranian Cu porphyry deposits. The southern part of this belt, in the Jebal-Barez area, has been less investigated due to the mountainous and rough topography as well as some security confrontations. Porphyry deposits are associated with hydrothermal alteration zones, which can be mapped using the remote sensing data such as Advanced Space borne Thermal Emission and Reflection Radiometer (ASTER). The aim of this study was to identify and detect the alteration zones associated with porphyry systems using ASTER data in Jebal-Barez area, SE Iran. For this reason, seven scenes of ASTER level-1B data which cover the Jebal-Barez area, were pre-processed and then processed by band ratio, false color composite and Spectral Angle Mapper (SAM) methods. The result indicated the presence of extensive phyllic and argillic alteration zones. The argillic alteration is surrounded by border zones of propylitic alteration. Also, a massive granitoid intrusion in NW of the studied area was detected by SAM method and the color composite of 4, 6, and 8 bands of ASTER as a completely altered area (SF area) which strongly needs more detailed exploration and field inspections.