Geology, mineralogy, and fluids inclusion studies in Shadan copper- gold deposit, Southern Khorasan

Shadan copper-gold deposit is located in nearly 65km Southwest of Birjand. The area is a part of eastern margin tertiary volcano-plutonic belt in Lut Block. The oldest units in this area are tertiary andesite, tuff, rhyolite, and rhyolitic tuff. The units are intruded by late Eocene–Oligocene Shadan subvolcanic, granite, and granodiorite intrusion rocks. The rocks are again overlined by Quaternary deposits. Shadan mine is considered as Cu-Au porphyry in which mineralization was controlled by tectonic strictures. The deposit is hosted by dacite, rhyodacite and micro granodiorite subvolcanic rocks which are mainly associated with potassic, sericitic, argillic and propylitic alterations. Mineralization mostly occurs as disseminated, stockwork, veins and veinlets in host rocks. The paragenesis in veins and veinlets includes quartz, chalcopyrite, pyrrhotite, magnetite, hematite and covellite, gold, iron-hydroxide and rare abundances of other minerals. Gold grains are between 1-150μm in diameter commonly occurring within the quartz and in some places occur in