山东牟平院格庄岩体锆石U-Pb年龄及其对周缘铜钼多金属成矿的制约  

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

作　　者：邹键 唐文龙[2] 丁正江 薄军委 李志强 于森 ZOU Jian;TANG Wenlong;DING Zhengjiang;BO Junwei;LI Zhiqiang;YU Sen(No.3 Exploration Institute of Geology and Mineral Resources,Yantai 264004,Shandong,China;Tianjin Institute of Geology and Mineral Resources,China Geological Survey,Tianjin 300170,China;Shandong Exploration Bureau of Geology and Mineral Resources,Shandong 250013,Jinan,China)

机构地区：[1]山东省第三地质矿产勘查院,山东烟台264004 [2]中国地质调查局天津地质调查中心,天津0650003 [3]山东省地质矿产勘查开发局,山东济南250013

出　　处：《中国地质》2021年第3期883-899,共17页Geology in China

基　　金：国家重点研发计划课题(2018YFC0603805);中国地质调查局地质调查项目(DD20160044、DD20190155);国家自然科学基金项目(41973048)联合资助。

摘　　要：牟平院格庄岩体位于胶东东部,为燕山晚期形成的与斑岩型-矽卡岩型铜钼多金属矿床有关的岩体之一。获得院格庄岩体崖西、后野、西上寨3个单元二长花岗岩LA-ICP-MS锆石U-Pb定年结果分别为(118.10±0.66)Ma、(118.52±0.78)Ma、(118.80±0.67)Ma,皆为早白垩世晚期。岩石地球化学研究表明:岩石属于高钾钙碱性、准铝质系列(K_(2)O/Na_(2)O值为1.00~1.29、A/CNK=0.98~1.02)。轻重稀土元素分馏明显((La/Yb)_(N)=26.91~35.75),δEu=0.84~0.93,具弱负铕异常。高场强元素Nb、Ti、P元素强烈亏损,大离子亲石元素Rb、K、U富集。地球化学特征显示院格庄岩体为I型花岗岩,为壳幔同溶型花岗岩。该岩体对其周缘铜钼矿空间分布和成矿时代有显著的制约作用,具有铜钼多金属矿的成矿专属性。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(K_(2)O/Na_(2)O=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.

关 键 词：锆石U-PB测年 岩石地球化学 铜钼多金属矿床 矿产勘查工程 院格庄岩体 牟平 山东 

分 类 号：P597[天文地球—地球化学] P618.41[天文地球—地质学]