Petrography and geochemistry of igneous rocks and antimony mineralization in Lakhshak, northwest of Zahedan, southeastern Iran

The Lakhshak Sb index is located in the northwest of Zahedan in the Sistan suture zone. The geological units of the area include metamorphosed flysch (garnet schist, actinolite schist, phylite, mylonite), granitoid pluton, acidic and basic dikes, mineralized and un-mineralized silicic veins. According to the geochemical studies, Lakhshak igneous rocks are calc-alkaline, high-K calc-alkaline and shoshonitic, metaaluminous rocks which are belong to the volcanic arc, and collisional and post-collisional tectonic settings. The studied igneous rocks are characterized by LREE and LILE enrichment relative to HREE and HFSE. Enrichment of Pb and depletion of Zr, Nb and Y are more consistent with melts generated from the lower crust. In the Lakhshak area, the Sb mineralization mainly occurs as quartz-stibnite veins in type-like rocks and is associated with silicic, argillic and phyllic alterations.