Geochemical Characteristics And Ore-forming Potential Of The Kekebieketi Mafic Complex,Xinjiang

The Kekebieketi rock mass is located at the junction of fuyu county and qinghe county in xinjiang,about 30 kilometers southeast of the Kalatongke large copper and nickel ore.Its geotectonic position is located at the junction of junggar plate and Siberia plate,and in the Ertix metallogenic belt.This rock mass is lower degree of exploration and research currently.This paper intends to know its rock formation age,diagenetic environment,original magma character and magmatic evolution process by study the petrology,petrochemistry,geochronology,geochemistry,geophysics of Kekebieketi rock mass.And then discussing the mineralizing potential of it.The main research results are as follows:Through geological studies,it was showed that Kekebieketi rock mass is dominated by basic rock.The main are composed of pyroxenite,gabbro and a small amount of diorite.The petroliferous lithofacies is pyroxenite.There are pyrite and chalcopyrite in pyroxenite lithofacies.Mineralization styles are dominantly star-like veinlet-disseminated and veinlet.The distribution of rock mass is controlled by NNE and NE fault.The petrochemistry research of Kekebieketi rock mass shows that it is mainly of iron basic rock,the m/f ratio is between 0.8 and 2.0.Microelement analysis result showed that it is relative loss compatible elements(Cr,Co,Ni)and High field strength elements(Nb,Ta,Zr,Hf,Th),enrichment of large ionic lithophile elements(Ba,U,K,Pb,Sr).?REE=49.90~148.02,the fractionation degree between the light and heavy rare earth is strong,and the internal fractionation degree in light and heavy rare earth is low.The rare earth distribution curve shows the right type of light rare earth concentration.The sulfur isotope test results show that there is no crustal sulfur in the rock mass,combined with petrochemistry study result,the rock mass has been subjected to the crustal material mixing slightly;The main fractional crystallization of Kekebieketi rock mass is orthopyroxene,and there are also a few monoclinal pyroxene and plagioclase.Its Mg# value is 0.47 ~ 0.73,It is indicated that Kekebieketi rock mass is the product of the proper evolution of the primary magma.Estimated results show that MgO accounts for 8.22% of the primary magma,this paper conclude that there are olivine-based crystallization in deep magma chamber.The results of La-ICP-MS zircon U-Pb date shows that the age of Kekebieketi gabbro and diorite was 330.3 + 0.76 Ma and 328.9 + 0.61 Ma respectively,formed in the middle carboniferous,the post-collisional extension settings.By contrasting with typical ore deposits(It's mainly for the Kalatongke ore deposits.),This paper considers that Kekebieketi rock mass has the potential to find the magmatic copper nickel sulfide deposit,and the prospecting direction should be placed in the search of the deep buried ultrabasic rock mass.Large scale geochemical survey results of study area shows that Au,Ag,As,Pb,Ba geochemical anomalies have directive function to the search of deep buried orebody.