胶东郭家岭序列北截杂岩体SHRIMP锆石U-Pb年代学、岩石学、地球化学特征及构造意义  

SHRIMP U-Pb zircon geochronology,petrology,geochemical characteristics and tectonic significance of Beijie complex of Guojialing sequence in Jiaodong Peninsula

作　　者：迟乃杰 韩作振 单伟 刘传娥 熊玉新 舒磊 李增胜 郭广军 马祥县 CHI Naijie;HAN Zuozhen;SHAN Wei;LIU Chuan′e;XIONG Yuxin;SHU Lei;LI Zengsheng;GUO Guangjun;MA Xiangxian(Key Laboratory of Gold Mineralization Processes and Resources Utilization of Ministry of Natural Resources,Shandong Key Laboratory of Mineralization Geological Processes and Resources Utilization in Metallic Minerals,Shandong Institute of Geological Sciences,Jinan,Shandong 250013,China;College of Earth Science and Engineering,Shandong University of Science and Technology,Qingdao,Shandong 266590,China;Shandong Provincial Geo-mineral Engineering Exploration Institute,Jinan,Shandong 250014,China)

机构地区：[1]山东省地质科学研究院自然资源部金矿成矿过程与资源利用重点实验室,山东省金属矿产成矿地质过程与资源利用重点实验室,山东济南250013 [2]山东科技大学地球科学与工程学院,山东青岛266590 [3]山东省地矿工程勘察院,山东济南250014

出　　处：《山东科技大学学报（自然科学版）》2021年第5期30-42,共13页Journal of Shandong University of Science and Technology(Natural Science)

基　　金：山东省级地质勘查委托项目(鲁勘字(2019)8号,鲁勘字(2020)7号);山东省自然科学基金项目(ZR2019PD019);自然资源部金矿成矿过程与资源利用重点实验室开放课题(kfkt201810)。

摘　　要：胶东地区大规模金成矿作用与中生代构造、岩浆活动关系紧密,如郭家岭期岩浆杂岩体与该区域大规模的金成矿期存在较好的时间耦合性。本研究以郭家岭期北截杂岩体中发育的两期花岗闪长岩为研究对象,开展岩相学、全岩主微量元素地球化学及SHRIMP锆石U-Pb年代学研究。北截杂岩体两期花岗闪长岩均为似斑状结构,但二者的基质粒度表现出显著的差异性,其中较早一期(132.9±1.2)Ma花岗闪长岩中基质为中粗粒结构,而较晚一期(129.7±1.1)Ma花岗闪长岩中基质呈中细粒结构;前者具有高钾钙碱性特征,后者属中钾-高钾钙碱性系列,二者均表现出准铝质至弱过铝质特征。两期花岗闪长岩的主量元素具良好的线性关系,表明二者为同源岩浆演化的结果。此外,早期就位岩体与晚期岩体的微量元素特征存在轻微差异,且岩浆物质来源显示为壳幔混源,说明胶东地区中生代发育的岩浆杂岩体以持续构造活动为基础,存在长期活动的岩浆房,不同时期的同源岩浆具有轻微的演化程度差异。Large-scale gold mineralization in Jiaodong area is closely related to Mesozoic tectono-magmatic activity.For example,there is a good time coupling between Guojialing magmatic complex and the large-scale gold mineralization period in this area.In this paper,two stages of granodiorites in Beijie complex of Guojialing sequence have been studied in terms of petrography,major and trace element geochemistry of the whole rock and SHRIMP zircon U-Pb chronology.Both of the granodiorites in Beijie complex show porphyritic texture,but their granularity of the matrix minerals is significantly different.The granodiorite of the earlier stage(132.9±1.2)Ma is of medium-coarse structure while the granodiorite of the later stage(129.7±1.1)Ma is of medium-fine structure.The former has the characteristics of high K calc-alkaline while the latter belongs to the middle K to high K calc-alkaline series.Both of them show quasi-aluminous to weak peraluminous characteristics.There is a good linear relationship between the major elements of the two granodiorites,indicating that the two granodiorites are the results of homologous magmatic evolution.In addition,there are slight differences in the characteristics of trace elements between the two stages of granodiorites,and the source of magmatic material is crust-mantle mixed source.This indicates that the Mesozoic magmatic complex developed in Jiaodong area is based on continuous tectonic activity,that there are long-term active magma chambers,and that the homologous magmas in different periods have slight differences in evolution.

关 键 词：郭家岭序列 北截杂岩体 SHRIMP锆石 岩浆演化 构造环境 

分 类 号：P597[天文地球—地球化学]