胶东中生代花岗岩与金矿关系及成矿期划分  

The relationship between Mesozoic granite,gold deposits and the division of metallogenic period in eastern Sandong

作　　者：于晓卫[1] 王来明[1] 刘汉栋[1] 张文[1] 郭瑞朋[1] 任天龙[1] 侯建华[1] 杨振毅 王立功[1] 梁太涛 YU Xiaowei;WANG Laiming;LIU Handong;ZHANG Wen;GUO Ruipeng;REN Tianlong;HOU Jianhua;YANG Zhenyi;WANG Ligong;LIANG Taitao(Shandong Institute of Geological Survey,Jinan,Shandong 250014,China;Shandong Institute of Geological Sciences,Jinan,Shandong 250013,China)

机构地区：[1]山东省地质调查院,山东济南250014 [2]山东省地质科学研究院,山东济南250013

出　　处：《地质学报》2023年第6期1848-1873,共26页Acta Geologica Sinica

基　　金：山东地勘基金项目(编号鲁勘字(2018)19号,鲁勘字(2021)18号,鲁勘字(2014)7号);山东矿保资金项目(编号鲁矿保(2020)1号);山东自然科学基金项目(编号ZR2020MD033)联合资助的成果。

摘　　要：胶东金矿集区是世界著名的黄金资源基地,截止2020年底,累计查明金矿资源量已达5400余吨。胶东地区中生代花岗岩分布广泛,岩石类型多,并与金矿关系极为密切。本文按时代+岩浆事件+岩性的划分方法,将胶东区域性广泛分布的中生代花岗岩划分为晚侏罗世玲珑期、早白垩世早期郭家岭期、早白垩世晚期伟德山期和崂山期,对上述四期花岗岩与金矿的空间展布、成矿物质来源、形成时代等关系进行了研究。金矿石硫同位素组成特征与玲珑期花岗岩、郭家岭期花岗岩的相近,特别是与玲珑期花岗岩范围重叠,金矿石铅主要为再活化的下地壳铅,即前寒武纪结晶基底铅,有幔源铅加入。金矿石的Sr-Nd同位素数据大部分与前寒武纪变质基底、玲珑期花岗岩、郭家岭期花岗岩及中生代脉岩的重叠,暗示Sr、Nd主要来自地壳源区。同位素测试结果说明胶东金矿床Au元素可能来源于胶东岩群、新太古代TTG岩、玲珑期花岗岩和郭家岭期花岗岩,主要来源于下地壳(初始为华北板块和扬子板块前寒武纪结晶基底),有壳幔相互作用的地幔物质加入。空间上,88%的金资源量赋存在玲珑期花岗岩中,7%的金资源量赋存于郭家岭期花岗岩中,伟德山期和崂山期花岗岩中金资源量仅占0.1%。时间上,晚侏罗世玲珑期、早白垩世早期郭家岭期、早白垩世晚期伟德山期和崂山期花岗岩形成时间分别为166~146 Ma、135~123 Ma、123~110 Ma、118~108 Ma,金矿成矿年龄有162~146 Ma、133~120 Ma、120~105 Ma、110~105 Ma四个区间范围,这四个金矿成矿年龄区间与四期花岗岩年龄具有较好的对应关系,成矿事件一般同步或略滞后于同源岩浆活动,即162~146 Ma成矿期对应玲珑期重熔花岗岩的侵位事件,133~120 Ma成矿期对应郭家岭期花岗岩的侵位事件,120~105 Ma的成矿期对应伟德山期和110~105 Ma矿化期对应崂山期花岗岩侵位事件,据此将The Jiaodong Gold Mine Cluster is a world-famous gold resource base.By the end of 2020,the total amount of gold resources identified reached 5400 tons.The Mesozoic granites in the Jiaodong area are widely distributed with many rock types and closely related to gold deposits.According to the division method of age+magmatic event+lithology,the Mesozoic granites widely distributed in Jiaodong region are divided into the Late Jurassic Linglong stage,the early Early Cretaceous Guojialing stage,the Late Early Cretaceous Weideshan stage and the Laoshan stage.The relationship between the above four stages of granites and gold deposits,including spatial distribution,source of ore-forming materials,and age of formation are studied.The sulfur isotope of gold ore is similar to the Linglong granite and the Guojialing granite,especially overlapping with the Linglong granite.The lead of gold ore is mainly the reactivated lower crust lead,i.e.the Precambrian crystalline basement lead,with the addition of mantle-derived lead.The data of Sr-Nd allotrope of gold ore mostly overlaps with the Precambrian metamorphic basement,the Linglong granite,the Guojialing granite and the Mesozoic vein rock,suggesting that Sr-Nd mainly comes from the crustal source area.The Au elements of the Jiaodong gold deposit may come from the Jiaodong magmatic rock group,the Neo-Archean TTG rocks,the Linglong granite and the Guojialing granite,mainly from the lower crust(initially the Precambrian crystalline basement of the North China plate and the Yangtze plate),with the addition of crust-mantle interaction mantle materials.Spatially,88% of the gold resources are hosted in the Linglong granite,7% in the Guojialing granite,and only 0.1% in the Weideshan and the Laoshan granites.In terms of time,the formation time of granite in Linglong stage of Late Jurassic,Guojialing stage of Early Cretaceous,Weideshan stage and Laoshan stage of Late Cretaceous are 166~146 Ma,135~123 Ma,123~110 Ma,118~108 Ma respectively,and the age of gold deposit is 162~146 Ma,133~120

关 键 词：中生代花岗岩 金矿 成矿期次 胶东地区 

分 类 号：P618.51[天文地球—矿床学] P588.121[天文地球—地质学]