Document Type : Original Research Paper
Authors
1 Associate Professor, Department of Earth Sciences, Faculty of Natural Sciences, Tabriz University, Tabriz, Iran
2 Ph.D. Student, Department of Earth Sciences, Faculty of Natural Sciences, Tabriz University, Tabriz, Iran
3 Professor, Department of Earth Sciences, Faculty of Natural Sciences, Tabriz University, Tabriz, Iran
4 M.Sc., Department of Earth Sciences, Faculty of Natural Sciences, Tabriz University, Tabriz, Iran
Abstract
The Khalifehlu Cu-Au deposit is located ~7 km North of Khoramdareh, in the central part of the Tarom magmatic zone. Rock units exposed in the area consist of volcanic, subvolcanic and intrusive rocks, which are associated with Eocene tectonics and Magmatism. Volcanism started with large-scale andesitic-trachyandesitic lavas and pyroclastics; continued by rhyolite domes, and culminated by a quartzmonzonite porphyry. Copper-gold mineralization at the Khalifehlu is intimately associated with the breccias and veins. The highest grade and most extensive mineralization occurs in silicic veins. Two stages of mineralization are identified at the Khalifehlu area that progressed from regional breccia (phase 1 from stage 1) to Au- bearing silicic- sulfide vein- veinlet (phase 2 from stage 1) to oxide-dominant breccias (phase 1 from stage 2) to specularite vein- veinlet (phase 2 from stage 2). Gold occurs with sulfide minerals as disseminations, as well as in the veins and breccia cemented during phase 2 from stage 1. The wall–rock alteration in the Khalifehlu deposit exhibits a clear concentric zoning pattern. The vuggy quartz and argillic alteration are spatially and closely associated with high-grade gold mineralization, and are mainly developed along veins and in breccias. Propylitic alteration is widespread around the ore bodies. Pyrite, chalcopyrite, bornite, covollite, chalcocite, hematite and native gold are present in the ores. The ore minerals show disseminated, vein-veinlet, replacement, fibrous and breccia textures. We suggest near-surface emplacement of volatile-rich quartzmonzonite porphyry, followed by extensive brecciation and hydrothermal alteration-mineralization. The geology, alteration, and mineralization in the Khalifehlu deposit is similar to high-sulfidation type epithermal deposits.
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