Writers : Esfandiarpour, A.; Malekzadeh Shafaroudi, A.; Heidarian Shahri, M. R
Refference : 2nd National Symposium of Iranian Society of Economic Geology
Publishing Year : 1390

Abstract :

Neyshabour Turquoise Mine is one of the oldest turquoise mine in the world and its history goes back to 4000 years ago. The mine is located in 55 km north west of Neyshabour city. The Gharduom tunnel prospect area is situated in north and northeast of Turquoise mine. Geology of the area include intermediate volcanic rocks with andesite to trachyte in composition and subvolcanic diorite porphyry that intensely altered. Mineralization which is observed in both volcanic and intrusive bodies includes primary and secondary stages. Primary mineralization appeared in three forms as stockwork, disseminated and hydrothermal breccias which include specularite, magnetite, pyrite, chalcopyrite and bornite. Secondary mineralization consist of turquoise, chalcocite, covellite, hematite and goethite. The diorite porphyry and hydrothermal breccias could be the source rocks of the disseminated and stockwork mineralization in the area. Geochemical exploration of stream sediment shows anomalies of Cu, Zn, Ni, Co elements. Based on lithogeochemical studies, ranges of element content is Cu (ppm)= 8-3222, Zn (ppm)=1-332, pb (ppm)= 3 -71, Mo (ppm)= 8 -58, Co(ppm)=1 -75, Ni (ppm)=1-36, Ag (ppm)=1-241, Bi (ppm)=18-67 and Au (ppb)=3-20. The highest anomaly is related to Cu in hornblende trachyte with high silicified alteration.

Subject List : Geochemical Exploration