胶西北地区谢家沟金矿岩脉U-Pb年龄及其对成矿时限的制约  

U-Pb age of post-ore dykes in the Xiejiagou gold deposit and its constraints on ore-forming age,Northwest Jiaodong,China

作　　者：姚晓峰[1] 程志中[1] 杜泽忠[1] 刘坤 鲍兴隆 李少华 YAO Xiaofeng;CHENG Zhizhong;DU Zezhong;LIU Kun;BAO Xinglong;LI Shaohua(Development and Research Center,China Geological Survey/Technical Guidance Center for Mineral Resources Exploration,Ministry of Natural Resources,Beijing 100037,China;Shandong Land and Mining Group Co.,Ltd.,Ji’nan 250013,Shandong,China;Jintingling Mining Industry Co.,Ltd.,Zhaoyuan 265400,Shandong,China)

机构地区：[1]中国地质调查局发展研究中心/自然资源部矿产勘查技术指导中心,北京100037 [2]山东地矿集团有限公司,山东济南250013 [3]招金集团金亭岭矿业公司,山东招远265400

出　　处：《地质通报》2020年第8期1153-1162,共10页Geological Bulletin of China

基　　金：国家重点研发计划项目课题《深部矿产资源三维找矿预测评价示范》(编号:2017YFC0601506);《华北克拉通辽东/胶东重要成矿区带金多金属矿深部预测及勘查示范》(编号:2018YFC0603806)。

摘　　要：胶西北地区是中国最大的金矿集区之一,金资源储量超过4500 t,金矿床受三山岛、焦家、招平3条断裂带及其分支断裂控制明显。谢家沟金矿位于招平断裂带的西侧,与区域上产于招平主干断裂的大尹格庄、夏甸等矿床不同,该矿床产出于主干断裂带的下盘,矿体与次一级的北北东向、北北西向断裂构造关系密切。基于坑道中发现的石英闪长玢岩和花岗闪长岩岩脉切割矿化蚀变现象,对2套岩脉进行U-Pb定年,获得其结晶年龄分别为118.0±1.1 Ma和118.4±0.9 Ma,确定了谢家沟金成矿作用的时间下限,指示区域上金成矿作用在118 Ma基本结束。推测区域成矿与郭家岭岩体形成之后、伟德山岩体形成之前的闪长类岩体关系密切。The northwest Jiaodong peninsula is one of the largest gold ore concentration areas in China,in which gold resource reserves exceed 4000 tons.Most of the deposits in the area are controlled by Sanshandao,Jiaojia and Zhaoping faults.The Xiejiagou gold deposit is located in the west and the footwall of Zhaoping fault,controlled by NWW-and NEE-secondary faults,which is different from the feature of the deposits which occur in Zhaoping fault such as Dayinggezhuang and Xiadian.Based on the phenomenon of existence of two kinds of dike,i.e.,quartz diorite porphyry and granodiorite,which cut though mineralization and alteration in the tunnel,the authors conducted LA-ICP-MS U-Pb dating for the dikes.It is found that the U-Pb ages are 118.0±1.1 Ma and 118.4±0.9 Ma respectively,which suggests that the lower limit age of mineralization is 118 Ma in the Xiegagou gold deposit,and gold mineralization in northwest area of Jiaodong peninsula had been mainly completed by 118 Ma.It is inferred that regional mineralization was more probably related to diorite type intrusives between the formation of Guojialing and Weideshan intrusives.

关 键 词：胶西北 谢家沟 金矿 LA-ICP-MS锆石U-PB测年 

分 类 号：P618.51[天文地球—矿床学] P597[天文地球—地质学]