GEOLOGICAL, GEOCHEMICAL AND MINERALOGICAL INVESTIGATION OF JANJA INTRUSION RELATED AND SKARN (AU-AG-CU-PB-ZN) DEPOSIT (SOUTHEAST OF NEHBANDAN, IRAN)

Iran is a resource able country and hosts a variety of ore deposits that have been, are, or have potential to be mined. These deposit types include porphyry Cu and Cu-Mo-Au, skarn, vein-type, volcanogenic massive sulfide (VMS), Manto-and etc. However, the porphyry and epithermal deposits of Iran have better known in the Urumieh–Dokhtar Magmatic Arc (UDMA), but recently new explorations in southeastern Iran, especially in Sistan and Baluchestan province indicate a high potential of this province for porphyry and epithermal mineralization. The Janja deposit area is located in southwestern Iran, north of Sistan and Baluchestan province and about 70 km southeast of Nehbandan. This area according to the tectonic and structural map of Iran is a part of East Iranian ranges (Sistan suture zone) and Mirjaveh-Birjand gold belt. Lithological outcrops of Janja area consist Late Cretaceous – Paleocene sedimentary rocks ( Sefidabeh flysch formation) which are cut by Paleocene-Miocene diorite, quartz diorite, granodiorite, subvolcanic intrusions and Neogene diabasic dikes Intrude of plutonic rocks into sedimentary hosts cause contact metamorphism, skarn and also intrusion related Au- Ag- Cu- pb-Zn mineralization. Mineralization is occurred in quartz and siliceous vein with breccia, vein-veinlet, vuggy, disseminated and comb texture and mineral paragenesis includes pyrite, chalcopyrite, galena, sphalerite, gold, malachite, azurite, cerussite, pyrolusite, iron oxides and hydroxide. In the Janja deposit area, hydrothermal fluid process develops a variety of alteration, such as sericitization, propylitic, silicification .

Filed observation such as host rock, mineralogy, alteration, texture and structure and laboratory studies suggest that the Janja (Au-Ag-Cu-Pb-Zn) mineralization show a close relationship with the skarn and oxidized intrusion related types .