Gold Metallogenis Of The Huaishupin Deposit In The Xiong'ershan-waifangshan Region: Constraints On Traditional And Non-traditional Isotopes

The Huaishuping gold deposit located in the Xiong'ershan region,southern margin of north China craton.The Xiong'ershan region is one of the important gold ore-concentrated area.It has been so controversial about source of ore forming material and fluids,especially the source of gold.In this paper,we revealed the basic geological characteristics,structural controls,ore texture and structure of the Huaishuping gold deposit by field observation,microscopic observation.Based on traditional and non-traditional stable isotopes testing and analysis,we determined the property of the ore-forming mineral sources and fluids into;proposed the ore-formation processes.The stratums in the mining area are composed of Mesoproterozoic Xiong'er Group and Cenozoic.Ore-controlling structures are mainly NE-trending and NW-trending faults.The mineralization can be divided into three stages:?1?Pyrite-orthoclase stage is characterized by coarse pyrites,and pitted surface appearance in the pyrite.?2?Quartz-polymetallic sulfide stage,main ore minerals composed of pyrite,chalcopyrite,gold,galena,sphalerite,molybdenite and quartz.?3?Carbonate stage is characterized by vein type and veinlet disseminated type ore.By Fe isotope study,we propose Fe is from remelted mantle magma in the early mineralization,and enriched heavy Fe isotope.The value of?⁵⁶Fe is variable in the main mineralization,Fe is from the mix of magma and stratum.Sulfur isotopes show that S has multiple sources,and we think S comes from magma in the early mineralization,has a mix source of magma and stratum in the gold mineralization.It shows that ore forming fluids were derived mainly from the mix of magmatic and stratigraphic source in the previous study.In conclusion,the ore-formation processes of the Huaishuping gold deposit:In late Jurassic to middle Cretaceous,intracontinental subduction from southern margin of north China craton to north Qinling has caused a series of NE-trending and NW-trending structures in shallow strata,in the meantime,the intracontinental subduction make some meterials of lower crust remelt,then these metarials come up to the upper crust and formed granites,brought aboudant magmatic fluids which contain a lot of gold,eventually formed gold deposit in the favorable environment.