Abstract

Mesgar iron occurrence is located in northwestern part of the Central Iran, 35 km south of Gheydar. Rock units exposed in the study area consist of Miocene sedimentary and volcanic-pyroclastic rocks. Iron mineralization occurs as vein and lens-shaped bodies in and along the contacts of pyroclastic (footwall) and andesitic basalt lavas (hanging wall). Alteration is restricted to silicified and chloritized parts of ore zones. Based on mineralography, hematite is the main ore which is accompanied with minor magnetite and chalcopyrite. Quartz and chlorite are present in the gangue minerals. The ore minerals show vein, veinlet, brecciated, massive and disseminated textures. The gangue minerals represent vein, veinlet, colloform, cockade and crustiform textures. Hematite usually occurs as euhedral to subhedral bladed crystals, and occasionally shows radiate form. Field and microscopic studies indicate that iron mineralization in the Mesgar occurrence seems likely as epithermal vein mineralization.