胶东邓格庄金矿成矿流体、成矿物质来源与矿床成因  

Ore-forming fluids,sources of materials in the Denggezhuang gold deposit,Jiaodong Penisula and implications for ore genesis

作　　者：薛建玲[1] 李胜荣[2] 庞振山[1] 陶文[1] 孙文燕[3] 陈辉[1] 张运强[4] XUE JianLing;LI ShengRong;PANG ZhenShan;TAO Wen;SUN WenYan;CHEN Hui;ZHANG YunQiang(Development and Research Center of China Geology Survey, Beijing 100037, China;Chinese University of Geosciences, Beijing 100083, China;Chinese Academy of Geological Sciences, Beijing 100037, China;Institute of Regional Geology and Mineral Resources Survey in Hebei Province, Lanfang 065000, China)

机构地区：[1]中国地质调查局发展研究中心,北京100037 [2]中国地质大学,北京100083 [3]中国地质科学院,北京100037 [4]河北省区域地质矿产调查研究所,廊坊065000

出　　处：《岩石学报》2018年第5期1453-1468,共16页Acta Petrologica Sinica

基　　金：国家自然科学重点基金项目(41230311);中国地质调查局项目(DD20160052)联合资助

摘　　要：邓格庄金矿是胶东牟平-乳山成矿带第二大石英脉型金矿床,其空间产出受断裂构造、荆山群变质地层和岩浆活动联合制约。对不同类型蚀变岩和不同阶段金脉体流体包裹体研究表明:包裹体可划分为液相包裹体(Ⅰ)、气相包裹体(Ⅱ)、含液体CO_2包裹体(Ⅲ)和含子矿物包裹体(Ⅳ)四类。从热液蚀变期到主成矿期,包裹体的种类增多,数量增多,主成矿期可见Ⅲ和Ⅳ型包裹体。激光拉曼探针分析结果显示成矿流体的气相成分类型包括CO_2-CH_4-H_2O、CO_2-H_2O、CO_2-CO_2和CO_2-CH_4四种,以CO_2为主,H_2O次之,主成矿期出现了少量的CH_4,成矿流体总体属CO_2-H_2O-NaCl体系。成矿流体完全均一温度变化范围为177～361℃,峰值240～280℃;盐度为1.7%～16.3%NaCleqv,密度变化范围为0.65～0.97g/cm^3;表明该矿床属于中低温、中低盐度、中低密度热液脉型矿床,成矿流体为酸性、弱酸性,且富含CO_2、CH_4等还原性质的热液体系。从热液蚀变期到成矿期各个阶段成矿温度、盐度、密度总体显示降低趋势。邓格庄金矿石英的δD值为-87.6‰～-80.7‰,δ18O_(H_2 O)值为5.87‰～7.49‰;δ13C_(V-PDB)值为-3.6‰～0.7‰,δ18O_(V-SMOW)值为1.3‰～9.1‰;δ34S值的变化范围在8.4‰～10.8‰之间;表明成矿流体来源于深部流体,以岩浆水为主,少量的大气降水参与了成矿过程。流体包裹体及C-H-O-S同位素研究,并结合地质特征,表明邓格庄金矿是与白垩系岩浆岩有关的,受断裂构造控制,并以大面积钾长石化为特征标志的中温岩浆热液型矿床,充填作用和混合作用可能是金矿成矿物质大规模沉淀的机制。The Denggezhuang gold deposit is currently the second largest quartz vein gold deposit in the Muping-Rushan gold belt in Jiaodong Penisula. Its spatial occurrence was jointly controlled by the NS-trending Jinniushan fault,the metamorphic strata of the Paleoproterozoic Jingshan Group and the Early Cretaceous magmatic activities in the region. The characteristics of the fluid inclusions from different altered wallrocks and gold ores show that the inclusions can be divided into four types： liquid inclusions（ Ⅰ）,volatile inclusions（ Ⅱ）,liquid CO2-rich inclusions（ Ⅲ） and daughter mineral-rich inclusions（ Ⅳ）. From the early hydrothermal alteration to main metallogenic stages,the inclusion types and quantities increase with inclusions of type Ⅲ and type Ⅳ being frequently observed in the main metallogenic stages. The results of Laser Raman spectra study show that the volatile phases have four types： CO2-CH4-H2 O,CO2-H2 O,CO2-CO2 and CO2-CH4. The main gas is CO2; the second is H2 O. A small amount of CH4 occurs in the inclusions of the main metallogenic stages. We suggest that the ore-forming fluid belongs to a CO2-H2 O-NaCl hydrothermal system. The homogenization temperatures range from 177 to 361℃,peak value from 240 to 280℃; the salinities range from 1. 7% to 16. 3%NaCleqv and the densities range from 0. 65 to 0. 97 g/cm^3. The pressures of the inclusions of type Ⅲ range from 102 to 376 MPa; The values of δD,δ^18 O（H2 O）,δ^13 CV-PDB,δ^18 OV-SMOWand δ^34 S are-87. 6‰ --80. 7‰,5. 87‰ - 7. 49‰,-3. 6‰ - 0. 7‰,1. 3‰ -9. 1‰ and 8. 4‰ - 10. 8‰. These results indicate that the quartz veins of the Denggezhuang gold deposit formed in a hydrothermal environment with medium-low temperature,medium-low salinity,and medium-low density. From the hydrothermal alteration phase to the mineralization phase,the temperature,salinity and density gradually decreased. The ore-forming fluid was derived mainly from magmatic water,and a small amount of meteoric water involved int

关 键 词：胶东 邓格庄 流体包裹体 碳氢氧硫同位素 矿床成因 石英脉型金矿 

分 类 号：P618.51[天文地球—矿床学]