The chronological constraint of Jixinling fault and its implication for metallogenic potential in Wulong gold deposit, Liaodong peninsula, China

Wulong gold deposit is a typical quartz vein-type ore deposit formed in the Early Crataceous in Liaodong peninsula, similar in many aspects to the Linglong-type gold deposit in Jiaodong area.The gold deposits in Jiaodong area mainly occurred in the NE trending fault.However, most of orebodies in the Wulong deposit are controlled by the NW and N-S trending fault.The study of the NE trending fault are limited within the Wulong deposit and their ore-potential are still unclear.Geological survey were conducted for Jixinling fault, and chronology study of dikes and hydrothermal muscovite in the fault were also carried out.Jixinling fault, being brittle, experienced multi-stage of structural motion, was intruded by lamphoryrye dikes, muscovite-bearing quartz veins and diorite dikes sequentially.U-Pb dating of the zircons from the lamprophyre and the diorite yields ²⁰⁶Pb/²³⁸U mean age of 132.1 ±1.7 Ma and 112.9 ±1.4 Ma, respectively.The hydrothermal muscovite gives a ⁴⁰Ar/³⁹Ar plateau age of 126.8 ±0.51 Ma.It is indicated that, Jixinling fault was formed before 132 Ma, and magma and hydrothermal motion occurred in the fault during 132~113 Ma.The Jixinling fault fracturing, the intrusion of dikes and veins were probably correlated to the NNW-SSE compression in the earlier time of Early Crataceous, NW-SE/NWW-SEE extension in the middle of Early Crataceous, respectively.Jixinling fault was formed in a lower order than NE trending fault in Jiaodong area, with less structural intensity, smaller fracture zone and alteration range.The further exploration for NE trending faults of Early Crataceous gold systems in Liaodong peninsula should focus on low-angle faults with higher order, and more attention should be paid to the area where the faults' attitude switches suddenly for the NE trending faults in the Wulong orefield.