Geological characteristics, U-Pb age and Hf isotope of zircon in hosting intrusion for Baotuanshan Au-Cu deposit, Edong ore cluster and its geological significance

Recently discovered Baotuanshan Au-Cu deposit is located in the Baotuan Village, Shawo County, Ezhou, Hubei Province. Ore bodies occur as veins in quartz monzonite along fracture structures. This study carried on mineralogy, age and Hf isotope of the ore-hosting quartz monzonite. Au occur as visible gold inclusions in chalcopyrite and invisible gold in pyrite, and chalcopyrite is domain the primary Cu-bearing mineral. LA-ICP-MS U-Pb dating of zircon from the quartz monzonite yielded an age of 136±1Ma (MSWD=2.1, n=31) and ε_Hf(t) values are between -21.9~-7.2, suggesting that quartz monzonite was derived from the mixture of crust and mantle. Baotuanshan Au-Cu deposit may represent a period of Au-Cu mineralization. Additionally, this deposit lay on the periphery of Chengchao skarn Fe deposit, and is similar to these Au-Cu deposits/occurrences located on the peripheral of Fe deposits in the Middle-Lower Yangtze River metallogenic belt reported before. Therefore, more attention should be paid on this type of Au deposits during gold explorations, and the linkage between Fe deposits and gold deposits needs further consideration.