Geology, mineralogy, fluid inclusion thermometry and ground magnetic of Shahrak Magnetite-Specularite Cu-Au prospecting area, Torbat-e-Heydariyeh, Iran

The study area is located 92 Km south-east of Torbat-e-Heydariyeh and 12 Km to the north of Shahrak village in Khaf-Dorouneh volcanic-plutonic belt. Mineralization was formed in fault zones where they cross the intermediate plutonic rocks. Propylitic alteration is widespread and is the dominant type in the area. Magnetite and Specularite with variation in the amount form major portion of mineralization zones. Other primary minerals are Quartz, Calcite, Pyrite, Chalcopyrite and Chlorite. Analysis of a few samples of mineralization for Au, Cu, Pb and Zn elements using the A.A.S method. The amount of copper is 0.2 percent and gold 44 ppb. Microthermometry study of fluid inclusions in Quartz indicated temperature ranges from 160˚C to more than 430˚C and relatively high salinity for mineralization zones. Thermometry study of fluid inclusions in Quartz-Chalcopyrite veins showed Temperatures between 160˚C - 203˚C and relatively high salinity for the solution. Minimum and maximum salinity that obtained were equal to 19 and 31 percent respectively in terms of NaCl. The closest compound system for fluid inclusions was determined H2O-NaCl-CaCl2 triple system. Considering high amount of magnetite and high value of magnetic susceptibility in mineralization, ground magnetic survey was carried out which resulted to the delineation of areas of covered mineralization. Interpretation of magnetic anomalies in profiles, was indicative of the continuation of surface mineralization and increase of magnetite with depth.