Geochemical and structural studies of the Hossein-Abad Zn-Pb ore deposit (Markazi Province)

Hosein-Abad Jurassic slate and phyllite-hosted Zn-Pb ore deposit is located in the northern Irankuh- Ahangaran metallogenic belt. Structural investigations document the study area was structurally controlled by a northward-steeply dipping Hossein-Abad reverse fault zone with thickness of 20 meters where it cuts through the Jurassic-Cretaceous units and effected mineralization. Main mineralization of sphalerite, galena and subordinate pyrite, and minor chalcopyrite have been occurred in form of brecciation, vein-veinlet, and replacement textures as epigenetic mineralization. The main alteration minerals are quartz, siderite, calcite, dolomite, sericite, and chlorite. Geochemical investigations decipher active continental margin and anomalously enrichment of Pb and Zn for the metamorphosed Jurassic host rock. Pb, Zn, S, Cu, Ag, and As elements have the genetic relationship with the deposit. The Zn/Cd ratio in sphalerite range from 37 to 581. The Pb-Pb isotope modeling age analysis of galena suggests the remobilization of Pb from Upper Triassic-Lower Jurassic strata as most possible source. The overall ranges of homogenization temperatures and salinities of fluid inclusions range from 100 to 305 ℃ and from 10.5 to 13.3 wt. % NaCl, respectively. The Hossein-Abad reverse fault caused fault related E-W trending hanging wall anticline and foot wall-syncline, respectively. The drag folds are faded out outward of E-W trending reverse fault zone and turned to its NW-SE origin structural trend. Furthermore, the breccia- type mineralization is dominantly occurred and distributed along the Hossein-Abad reverse fault zone and clearly fade out far from fault zone.