胶东地区早白垩世周官高镁闪长岩体年代学、地球化学特征及其构造意义  

Geochronology,Geochemical Characteristics and Tectonic Implications of Early Cretaceous Zhouguan High-Mg Diorite Rock Mass in the Jiaodong Peninsula

作　　者：王斌 宋明春[3] 刘志宁 李健 董磊磊 张艺多 蒋雷 王润生 董小涛 刘家良 Bin WANG;Mingchun SONG;Zhining LIU;Jian LI;Leilei DONG;Yiduo ZHANG;Lei JIANG;Runsheng WANG;Xiaotao DONG;Jialiang LIU(Ministry of Natural Resources Technology Innovation Center for Deep Gold Resources Exploration and Mining,No.6 Geological Team of Shandong Provincial Bureau of Geology and Mineral Resources,Weihai 264209,Shandong,China;College of Earth Sciences,Jilin University,Changchun 130061,Jilin,China;Hebei Key Laboratory of Strategic Critical Mineral Resources,College of Earth Sciences,Hebei GEO University,Shijiazhuang 050031,Hebei,China;School of Resources and Environmental Engineering,Shandong University of Technology,Zibo 255000,Shandong,China;School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100080,China;Shandong Institute of Geophysical and Chemical Exploration,Jinan 250013,Shandong,China)

机构地区：[1]山东省地质矿产勘查开发局第六地质大队(山东省第六地质矿产勘查院),自然资源部深部金矿勘查开采技术创新中心,山东威海264209 [2]吉林大学地球科学学院,吉林长春130061 [3]河北地质大学地球科学学院,河北省战略性关键矿产资源重点实验室,河北石家庄050031 [4]山东理工大学资源与环境工程学院,山东淄博255000 [5]北京科技大学土木与资源工程学院,北京100080 [6]山东省物化探勘查院,山东济南250013

出　　处：《黄金科学技术》2024年第5期798-812,共15页Gold Science and Technology

基　　金：国家自然科学基金NSFC-山东省联合基金项目“胶东深部金矿断裂控矿机理”(编号:U2006201);河北省人才项目“冀北地区金成矿系统及深部找矿技术”(编号:HBQZYCXY0010);山东省地矿局科技攻关项目“胶西北断裂系统及其与金成矿关系”(编号:KY202208)和“伟德山期侵入岩岩浆演化与多金属成矿作用”(KY202209)联合资助。

摘　　要：胶东地区是我国最重要的金矿集区,金矿床的时空分布与晚中生代花岗岩类密切相关,其中早白垩世伟德山期花岗岩侵位时间与大规模金成矿时间一致,是重要的成矿期地质体。隶属于伟德山期花岗岩的周官岩体与金成矿时空关系密切。选择周官岩体作为研究对象,系统开展了岩石学、锆石U-Pb同位素测年和全岩地球化学研究工作。结果表明:周官岩体侵位时代为(119.4±1.1)~(118±1.0)Ma,与金成矿同期;岩体具有低硅、高镁和富钠,以及相对高的Cr、Ni、Co、Sc含量、Sr/Y比值和明显贫化的Zr含量特征,Mg#值介于55.83~59.26,表现为高镁闪长岩特征。岩石属高钾钙碱性系列,为高镁闪长岩类,岩浆源于富集岩石圈地幔的部分熔融,并混染了部分地壳物质;周官高镁闪长岩体和伟德山期花岗岩的岩浆侵位导致地壳浅部发生剧烈隆起,形成伸展构造,为成矿流体运移、成矿物质富集和矿体定位提供了良好通道和有利空间。The Jiaodong region represents the most significant gold ore cluster in China,with the temporal and spatial distribution of gold deposits being closely associated with Late Mesozoic granites.The emplacement timing of the Early Cretaceous Weideshan granite aligns with the epoch of large-scale gold mineralization,marking it as a crucial geological body for ore formation.The Zhouguan rock mass,a constituent of the Weideshan granite,exhibits a strong spatial and temporal correlation with gold mineralization.Based on comprehensive studies encompassing systematic petrology,zircon U-Pb isotope dating,and whole rock major and trace element geochemistry,the Zhouguan rock mass was emplaced during the late Early Cretaceous period,specifically between(119.4±1.1)Ma and(118±1)Ma.This emplacement coincided temporally with gold mineralization events.The rock mass is characterized by low silicon(Si),high magnesium(Mg),and rich sodium(Na)content,along with relatively elevated concentrations of chromium(Cr),nickel(Ni),cobalt(Co),and scandium(Sc),as well as a high Sr/Y ratio and significantly depleted zirconium(Zr)content.These rocks are classified within the high-potassium calc-alkaline series and are identified as high-Mg diorite.The magma is derived from the partial melting of the enriched lithospheric mantle and incorporates some crustal materials.The emplacement of magma in the Zhouguan rock mass and Weideshan granite induced significant uplift of the shallow crust,leading to the formation of a series of extensional structures.These structures facilitated the migration of ore-forming fluids and created favorable conditions for fluid enrichment and orebody formation.

关 键 词：周官高镁闪长岩体 锆石U-PB测年 地球化学特征 富集岩石圈地幔 胶东半岛 

分 类 号：P618.51[天文地球—矿床学]