Metamorphic rocks of the Sanandaj-Sirjan zone host the Muteh gold mining district. The gold occurrences are in northwest-striking and northeast-dipping normal faults crosscutting the regional ductile pattern of the host rocks. This faulting is possibly related to a Tertiary extensional uplift event. The hydrothermal alteration assemblage quartz-muscovite-pyrite-carbonate-albite overprints the metamorphic assemblage. Gold is associated with pyrite.Fluid inclusion data suggest that gold deposition is related to mixing between a regional C0₂-bearing saline fluid and a dilute fluid, possibly of meteoric origin.