Investigation of copper and gold prospects using index overlay integration method and multifractal modeling in Saveh 1:100,000 sheet, Central Iran

Abstract

This study aims at prospecting copper and gold promising areas in Saveh 1:100,000 sheet, situated in Urumieh-Dokhtar magmatic belt (Central Iran). Geographic information system (GIS) is effective in recognition of probable mineral resources by collecting, processing, exploration layer weighting and integrating thematic maps. As there is no certainty in different geological phenomena, modeling and integrating information layers are used to obtain suitable results for determining potential areas. In this study, index overlay method, which is a combination of software processing and expertise knowledge, was used. The survey layers consist of the lithologic units, geophysical data, mineralization, faults and structures and alteration. For more exact survey, concentration-area (C-A) fractal modeling was applied to the map of results obtained from integration. Applying fractal model to this map, the results of the original map were prioritized and became more limited. In the end for assessing the validity of determined promising areas, the results were compared with geochemical anomaly maps of stream sediments and also field observation was performed. Areas with high exploration priority with limited extend exist in center, west and some parts of NW, conformed to granodiorite intrusives and also next priority exists in center, west, NE and NW conformed to granite, diorite, and also subvolcanic rocks respectively. These prioroties are related to fault systems. In order to perform X-ray Diffraction (XRD), Inductively Coupled Plasma - Mass Sepctrometry (ICP-MS) analyses and microscopic studies, lithogeochemical samplings were done. All investigations indicate the possibility of pyrite, chalcopyrite and galena epithermal mineralizations resulted from post magmatic fluids, and also secondary products like hematite, goethite, and malachite as a result of oxidation processes in these areas.