胶东大尹格庄金矿成矿流体时空演化及矿床成因:来自流体包裹体、成矿元素和H-O-S-Pb同位素证据  

Ore genesis and vertical variations of ore-forming fluids in the Dayingezhuang gold deposit,Jiaodong Peninsula:Constraints from fluid inclusions,ore forming elements,and H-O-S-Pb isotopes

作　　者：严子清 石文杰[1] 张鹏涛 王勇军 邵玉宝 黄鑫 宋宇 谭俊[1] 王治华 YAN Ziqing;SHI Wenjie;ZHANG Pengtao;WANG Yongjun;SHAO Yubao;HUANG Xin;SONG Yu;TAN Jun;WANG Zhihua(School of Earth Resources,China University of Geosciences(Wuhan),Wuhan 430074,China;Ecological Geology Brigade of Jiangxi Geological Bureau,Nanchang 330030,China;Shandong Coalfield Geological Planning Investigation Institute,Jinan 250104,China)

机构地区：[1]中国地质大学(武汉)资源学院,武汉430074 [2]江西省地质局生态地质大队,南昌330030 [3]山东省煤田地质规划勘察研究院,济南250104

出　　处：《地质科技通报》2024年第2期156-174,共19页Bulletin of Geological Science and Technology

基　　金：国家自然科学基金项目(42273067);山东省部省协议地质勘查项目“山东省烟台市牟平区将军石-曲河庄断裂带深部金矿普查”(鲁勘字[2022]32号)。

摘　　要：大尹格庄金矿位于招平成矿带中段,是胶东地区典型的构造蚀变岩型金矿床,储量达到超大型规模,但关于该矿床的成因类型尚存在较大争议。在详细野外地质调查的基础上开展了该矿床成因和成矿流体纵向变化特征研究。流体包裹体研究表明,成矿流体为中温、低盐度、中低密度的H_(2)O-CO_(2)-NaCl±CH_(4)体系。从成矿早期到晚期各阶段(Ⅰ~Ⅳ阶段)均一温度和盐度逐渐降低,密度逐渐增加。氢氧同位素组成显示成矿流体早期以岩浆水为主,后期有大气降水的混入,主成矿阶段可能存在流体沸腾作用;黄铁矿硫铅同位素组成表明成矿物质来源于深源壳幔混合岩浆。成矿过程和背景总体与胶东其他金矿床类似,形成于克拉通破坏环境。浅部与深部流体和物质组成的对比研究表明,在垂向纵深范围内成矿流体性质、金银成矿强度和金成色稳定一致,金沉淀具有宽泛而稳定的环境,指示大尹格庄金矿床深部仍然具有很大的成矿潜力和找矿空间。[Objective] The Dayingezhuang gold deposit in the middle of the Zhaoping metallogenic belt represents a typical altered-rock type deposit with a giant Au reserve of 283 tons on the Jiaodong Peninsula.The genetic type of the deposit is still controversial.[Methods] Based on detailed field observations,ore genesis and variations in ore-forming fluids from different depths were investigated in this study.[Results] Fluid inclusion studies show that the ore-forming fluids formed an H_(2)O-CO_(2)-NaCl±CH_(4) system with moderate temperature,low salinity,and moderate-low density.Furthermore,the temperatures and salinities decrease gradually from the early to late mineralization stages(Ⅰ-Ⅳ),but the opposite occurs at densities.Hydrogen and O isotopic compositions show that the ore fluids were dominated by magmatic water in the early stage,with subordinate meteoric water input during the late stages.Fluid boiling occurred possibly during the main mineralization stages.Sulfur and Pb isotopes of pyrite indicate that the ore-forming materials were derived from deep crust-mantle mixed magma.Overall,the mineralization process and tectonic setting are similar to those of the other Jiaodong gold deposits in a craton-destruction environment.[Conclusion] Comprehensive comparisons of ore fluids,Au and Ag contents,and gold fineness between shallow and deep ores show that ore fluids and mineralization intensity are consistent throughout the deposit.Gold precipitation has a broad and stable environment,indicating the great potential for mineral exploration in deep spaces.

关 键 词：流体包裹体 H-O-S-Pb同位素 金成色 矿床成因 深部找矿 成矿流体 大尹格庄 

分 类 号：P618.51[天文地球—矿床学]