Zircon U-Pb dating of the Yuangezhuang pluton in Muping of Shandong Province and its constraints on mineralization of Cu-Mo deposits

The Yuangezhuang Pluton located in the east of Jiaodong area,is formed in the late Yanshanian and is one of the granites associated with Cu-Mo polymetallic deposits hosted inporphyry and skarn. LA-ICP-MS zircon U-Pb dating of Yaxi unite,Houye unite and Xishangzhai unite from the Yuangezhuang monzonitic granite yields (118.10±0.66) Ma,(118.52±0.78) Ma,and (118.80±0.67) Ma respectively,indicating the Late Epoch of Early Cretaceous. The results of petrochemistry indicate the pluton is belong to high-K calc-alkaline serie (K₂O/Na₂O=1.00-1.29,A/CNK=0.98-1.02). The results of trace elements are characterized by dramatic fractionation between light REE and heavy (REE(La/Yb)_N=26.91~35.75 unapparent Eu anomalies (δEu=0.84-0.93),enriched in LILE (i.e. Rb,K,U) and loss in HSFE (i.e. Nb,Ti,P). The geochemical characteristics indicate the Yuangezhuang pluton is an I type granite,crust-mantle syntectic granite. The pluton has strong constrain on spatial distribution and metallogenic epoch of Cu-Mo deposits.