Doing research, two suites of Oligocene-Miocene granitoids, one relatively oxidized (magnetite-series) and the other relatively reduced (ilmenite-series), were identified at Hired, Eastern Iran. Since Au-Sn mineralization is associated only with the relatively reduced ilmenite-series suite. It became interested to study the petrochemistry and petrophysics of these intrusive rocks. The magnetic susceptibility of the magnetite-series granitoids is greater than 300 ×10-5 SI. This suite includes meta-aluminous, medium-K to high-K series gabbros to diorites containing magnetite, hornblende and biotite. The magnetic susceptibility of the ilmenite-series granitoids are less than 60 ×10-5 SI. This suite includes meta-aluminous, high-K to shoshonitic diorites to granites, containing, biotite, muscovite and tourmaline. Both the ilmenite and magnetite series suites are strongly enriched in large ion lithophile elements (LILEs = K, Th, Rb, Ba) and depleted in high field strength elements (HFSE = Nb, Sr, Ti, Hf). Chondrite-normalized rare earth element (REE) plots indicate strong enrichments of light relative to heavy REE, with (La/Yb)N between 7-24. Ilmenite suite granitoids have pronounced negative europium anomalies. Stockwork mineralization is found within and nearby the relatively reduced ilmenite-series granites. Based on their mineral assemblages (arsenopyrite, pyrrhotite, tourmaline, pyrite, gold and quartz), the ore-bearing fluids that generated these stockwork veins was also reduced. This, and the spatial relationship of mineralization with the ilmenite suite granitoids, indicates that the ore fluids originated from reduced granitoid magmas. Hired Au-Sn deposit is a reduced-intrusion related gold system

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