胶东地区新立金矿中金矿物和载金黄铁矿成因矿物学特征及地质意义  

Genetic Mineralogy and Geological Significance of Gold Minerals and Gold-bearing Pyrites from the Xinli Gold Deposit in the Jiaodong Area

作　　者：张然 肖志斌 付超 付世兴 朱昭明 ZHANG Ran;XIAO Zhibin;FU Chao;FU Shixing;ZHU Zhaoming(Tianjin Center,China Geological Survey,Tianjin 300170,China;Geological Exploration Institute of Shandong Zhengyuan,China Metallurgical Geology Bereau,Jinan 250101,China)

机构地区：[1]中国地质调查局天津地质调查中心,天津300170 [2]中国冶金地质总局山东正元地质勘查院,山东济南250101

出　　处：《岩矿测试》2022年第6期997-1006,共10页Rock and Mineral Analysis

基　　金：国家自然科学基金项目(41802207);国家重点研发计划项目(2016YFC0600107-1);中国地质调查局地质调查项目(DD20221686)

摘　　要：山东省胶东地区西北部是该地区最重要的金矿成矿区。新立金矿是三山岛-新立成矿带的重要矿床,也是该区典型金矿之一。对新立金矿的研究已开展多年且成果较多,但在金矿物与载金矿物的矿物学特征、矿物标型特征等方面还需开展深入研究。偏反光显微镜鉴定和电子探针定量成分分析是金矿物和载金矿物研究中的主要方法,本文将两种方法相结合,对新立金矿的金矿物和载金黄铁矿的物理性质、化学成分等矿物学特征进行详细研究,并通过矿物标型特征探讨其地质意义。结果表明:新立金矿中的金矿物主要为银金矿、少量自然金和金银矿,金成色在336.2~834.9不等,平均699.8。载金黄铁矿中S含量为51.69%~53.78%,平均53.19%;Fe含量为45.69%~47.62%,平均46.52%;S/Fe值为1.99,硫略亏损。黄铁矿形态标型呈粗粒立方体形-中细粒五角十二面体形-细粒立方体形的演化趋势,反映了不同成矿阶段热液流体温度逐渐降低的演化过程;成分标型特征显示,成矿热液具有典型的中浅成、中低温特点。据此认为,新立金矿热液蚀变期存在三阶段矿化,其中第三阶段为主成矿期,且在多阶段叠加复合部位更易富集成矿。BACKGROUND:In Shandong Province,northwest of the Jiaodong area is the most important gold metallogenic area.The Xinli gold deposit is not only an important deposit in the Sanshandao-Xinli metallogenic belt,but also one of the most typical gold deposits in this area.Research on the Xinli gold mine has been carried out for years and has achieved many fruitful results,however,the mineralogical characteristics and mineral typomorphic characteristics of gold minerals and gold-bearing minerals still need to be studied further.OBJECTIVES:To investigate the mineralogical characteristics and geological significance of gold minerals and gold-bearing pyrites from the Xinli gold deposit.METHODS:Polarized light microscope identification and electron probe microanalysis were the main methods in the research of gold minerals and gold-bearing minerals.The geological significance was explored through mineral typological characteristics.RESULTS:The results show that most of the gold minerals in the Xinli gold deposit are electrum,a small amount of native gold and kustelite.The gold fineness ranges from 336.2 to 834.9,with an average of 699.8.The content of S in gold-bearing pyrite is 51.69%-53.78%,with an average of 53.19%;Fe content is 45.69%-47.62%,with an average of 46.52%;The S/Fe value is 1.99,and sulfur is depleted slightly.CONCLUSIONS:The morphological typomorphism of gold-bearing pyrites shows an evolutionary trend from coarse-grained cubic shape to medium-and fine-grained pentagonal-dodecahedral shape and then to fine-grained cubic shape,which reflects the gradual reduction of hydrothermal fluid temperature in different metallogenic stages.The compositional typomorphic characteristics indicate that the ore-forming hydrothermal solution has typical characteristics of medium hypabyssal and medium-low temperature.Therefore,it is considered that there are three stages of mineralization in the hydrothermal alteration period of the Xinli gold deposit,of which the third stage is the main mineralization period.

关 键 词：新立金矿 电子探针 金矿物 载金黄铁矿 成因矿物学 

分 类 号：P575.1[天文地球—矿物学] P578.292[天文地球—地质学]