Study on the Ore-forming Materials Source of the Western Zhen'an W-Mo Ore Concentration Area in Southern Qinling Moutains
The large tungsten-molybdenum polymetallic ore concentration area in the western of Zhen'an,Shaanxi Province is located in the north of the southern Qinling tectonic belt,where faults,joints and complex intermediate-acid intrusions are closely related to skarn type and quartz vein type tungsten-molybdenum mineralization.Although certain exploration and research achievements have been made in the study area,it is still unclear which period of magmatic activity in the complex massif is related to mineralization.That is,the source of ore-forming materials is still unclear,which restricts the further exploration and prospecting.On the basis of the basic geological study of the deposit,related magmatic rock samples were collected for geochemical testing and zircon U-Pb isotope dating,sulfide mineral for sulfur isotope analysis,and molybdenite for Re-Os isotope dating.Based on the spatio-temporal relationship between complex massif and tungsten-molybdenum mineralization,it is considered that the Tianwan unit of Lanbandeng rock mass,Wangjiaping concealed rock mass and granitic fine-grained dike are rich in SiO2,and the Mg#and the total REE content are low.The REE distribution curve shows obvious tetrad effect with strong negative Eu anomaly,and the magmatic differentiation crystallization degree is high.Zircon U-Pb isotope ages of Jiujianwu unit of Lanbandeng rock mass and Wangjiaping concealed rock mass are(222.7±2.6)Ma and(201.6±4.7)Ma,respectively.The Re-Os isotope model ages of molybdenite in Qipangou tungsten deposit and Jiangkou molybdenum deposit are(199.7±3.9)Ma and(198.7±3.9)Ma,respectively.The sulfide mineral δ34S of tungstan-molybdenum deposit ranges from 3.6‰ to 10.2‰.The source of ore-forming materials should be the acid intrusion formed in late stage between 190 Ma and 200 Ma,which is represented by Tianwan unit of Lanbandeng rock mass,Wangjiaping concealed rock mass and granitic dike.
tungsten-molybdenum ore concentration areaore-forming material sourcecomplex rock masswestern area of Zhen'ansouthern Qinling
NETL
NSTL
万方数据
