Investigation of the origin of Heneshk Hematitic iron deposit, Fars province using petrological, mineralogical and geochemical data

Heneshk iron deposit is located between Gushti and Heneshk villages at Safashahr, NW of Fars province. Iron mineralization occurred as massive and lenticular shapes with silica and barite veins within brownish, silicified Triassic dolomitic host. Hematite and goethite are the principal ore minerals with minor magnetite that were formed through replacement and rarely open space filling within the host. Low concentrations of P (<0.01-0.41 wt%P2O5), Ti (<0.01-0.04 wt% TiO2), Cr (<0.01 wt% Cr2O3) and V (5-16 ppm) in the ore samples, reject any magmatic origin for the studied deposit. Also, no evidence for the presence of characteristic skarn minerals have been seen in the area. Chondrite normalized REE pattern, negative anomaly of Eu and Ce, along with Co/Ni, Eu/Sm≤1 and La/Lu≥1 values, in accompany with geothermometry (200-300ºC) and textural data reveal hydrothermal characteristics for the Heneshk hematitic iron deposit. Igneous masses in the area have acted as the source of iron and heat in the hydrothermal system. Field, textural and structural observations of ore body and host rocks indicated the important role of oxidation environment in the ore deposition. In spite of very low Au and Cu concentrations in the Heneshk deposite, its Ag content is comparable to some IOCG iron deposits.