关键词: 同位素地球化学, 矽卡岩型矿床, 铜绿山, 铜铁矿床, 湖北

Abstract:

Located in the southeastern Hubei metallographic province of the MiddleLower Yangtze River FeCu metallogenic belt,the Tonglushan CuFe deposit is a typical skarn CuFe deposit in the southeastern Hubei metallographic province. The ore bodies,in the lenticular forms，occur in the contact zone between the marble of 4th 7th Members of the Lower Triassic Daye Group. The oreforming process can be divided roughly into five stages：the anhydrous skarn stage(Ⅰ)，the hydrous skarn stage(Ⅱ)，the oxide stage(Ⅲ)，the quartzsulfide stage(Ⅳ)  and the carbonate stage(Ⅴ). Ore minerals mainly  include magnetite,chalcopyrite and hematite; gangue mineral include mainly garnet, quartz and carbonate mineral. This paper mainly studied sulfur, hydrogen, oxygen,carbon, lead isotopic compositions and analyzed the indicative meaning of these isotopes to chemistry of the ore fluids and the sources of the oreforming materials and intrusions. The composition of H and O isotopes shows that ore fluids were most likely composed of magmatic water mixed with limited meteoric water at the early oreforming stage and mixed with much  meteoric water at the late oreforming stage. Sulfur and carbon isotopic data suggest that the ore forming materials were mainly derived from the deep magma and the carbon was derived subordinately from the dissolution of wall rocks or the mantle. The Pb isotopic composition of ore sulfides are stable and they are ordinary common lead. Ore lead was derived from mantle magma which was subjected to the hybridization of crust materials in the course of intruding upward.

Key words: :isotope geochemistry, skarn type deposit, Tonglushan；CuFe deposit, Hubei Province