Geochemistry of Oxygen and Carbon Stable Isotopes in Non-Sulfide Zn-Pb Deposits, Case Study: Chah-Talkh non-Sulfide Zn-PbDeposit (Sirjan- South of Iran)

Submitted: Jul 19, 2013; Accepted: Sep 3, 2013; Published: Sep 11, 2013 Abstract: The study of isotopic ratios of oxygen and carbon has gained importance to determine the origin of ore bearing fluids, carbon origin and also to determine the formation temperature of non-sulfide lead and zinc minerals. In order to determine the origin of fluids and carbon existing in zinc carbonate minerals in Chah-Talkh deposit, initially the amounts of changes of O and C in various zinc minerals in important deposits 18 13 SMOW PDB of Iran and the world were studied and then by comparing these values in Chah-Talkh deposit with other deposits, the origin of fluids responsible for the ore forming, carbon and formation temperature of Chah-Talkh deposit was determined. The range of changes of O in smithsonite mineral in non-sulfide lead and 18 SMOW zinc deposits varies from 18.3 to 31.6 per mil and O in hydrozincite mineral varies from 7.8 to 27 per mil. 18 SMOW Due to the impossibility of smithsonite sampling from Chah-Talkh deposit (due to being fine-grained and dispersed), hydrozincite minerals which have high isotopic similarities with smithsonite are used for isotopic analysis of carbon and oxygen. The range of changes of O in hydrozincite mineral of Chah-Talkh deposit 18 SMOW varies from 7.8 to 15.15 per mil which places in the domain of metamorphic water. The extensiveness of O changes in Chah-Talkh indicates the role of at least two fluids in the formation of nonsulfide minerals. 18 SMOW The formation temperature of non-sulfide minerals (hydrozincite) in Chah-Talkh deposit is obtained at 70 to 85°C which indicates the role of metamorphic fluids in the formation of deposit. Complete weathering of sulfide minerals to a depth of 134 meters confirms the role of rising metamorphic fluids in the formation of nonsulfide minerals. The C values of Chah-Talkh deposit are set in the range of atmospheric CO and carbonate rocks 13 PDB 2 which the existence of atmospheric CO indicates the role of atmospheric fluids and the existence of carbonate 2 carbon-rock is indicative of the role of metamorphic fluids in the precipitation of nonsulfide Zn minerals.