治岭头金矿围岩蚀变特征及其意义

发布时间：2018-08-24 16:06

【摘要】：治岭头金矿位于浙江省遂昌县,是我国东南沿海的一座大型金矿床。该矿床围岩蚀变发育,类型有硅化、绢云母化、绿泥石化、黄铁矿化、方解石化和菱锰矿化。从矿体到围岩可以划分为4个蚀变带:强硅化带、弱硅化-黄铁绢英岩化带、绢云母化带和绿泥石化带。沿矿体走向,蚀变强度整体上呈波动性变化,与矿体呈透镜状产出特征一致。硅化、黄铁矿化、菱锰矿化与金矿化关系最密切,而且这些蚀变具有相似的变化趋势。绢云母化和绿泥石化与硅化的变化趋势不同,且与矿化关系不密切。另外,矿区还发育方解石化,且强度较弱。金矿化及围岩蚀变均发育在古元古界八都群变质岩中,未进入上覆中生代火山岩盖层,证明治岭头金矿成矿作用与中生代火山活动无关。定量计算结果显示:蚀变过程中Al_2O_3、TiO_2、P_2O_5为惰性组分;SiO_2、CaO、MnO、Au、Ag、Cu、Pb、Zn等为明显带入组分;Fe_2O_3、FeO、MgO、K_2O、Na_2O、Ba、Sr等为明显带出组分。根据围岩蚀变和稳定同位素分析,推断治岭头金矿原始成矿热液流体应是富含Si、Ca、Mn、Au、Ag、Cu、Pb、Zn等组分的岩浆热液,后期有大气降水的加入。
[Abstract]:Located in Suichang County, Zhejiang Province, Zhilingtou Gold Deposit is a large gold deposit along the southeast coast of China. The wall rock of the deposit is altered and developed, with silicification, sericite, chlorite, pyrite, calcite and rhodochromatic mineralization. From the orebody to the surrounding rock, there are four alteration zones: strong silicification zone, weakly silicified-yellow sericite zone, sericite zone and green-mud petrochemical zone. Along the direction of orebody, the alteration strength fluctuates as a whole, which is consistent with the lenticular characteristics of orebody. Silicification, pyrite mineralization, rhodochromatic mineralization are most closely related to gold mineralization, and these alterations have a similar trend. The trends of sericite and green mud fossilization and silicification are different, and they are not closely related to mineralization. In addition, calcite is also developed in the mining area, and its strength is weak. Gold mineralization and wall rock alteration developed in metamorphic rocks of the Paleoproterozoic Badu Group, and did not enter the overlying Mesozoic volcanic rock caprock, indicating that the mineralization of the Zhilingtou gold deposit is not related to Mesozoic volcanic activity. The results of quantitative calculation show that Al_2O_3,TiO_2,P_2O_5 is an inert component in the process of alteration, such as Sio _ 2CaO _ 2O _ (2CaO) MNO _ (2) O _ (+) _ (+) Cu _ (+) Pb _ (+) Zn, and so on. The obvious component is Fe _ 2O _ 3C _ 2O _ 3FeO _ O _ 2O _ K _ 2O _ K _ 2O _ K _ 2O _ K _ 2O _ K _ 2O _ O _ O _ O _ n, etc. Based on the alteration of the surrounding rock and the analysis of stable isotopes, it is inferred that the original ore-forming hydrothermal fluid of Zhilingtou gold deposit should be a magmatic hydrothermal fluid rich in Si,Ca,Mn,Au,Ag,Cu,Pb,Zn and other components, with the addition of atmospheric precipitation in the later stage.
【作者单位】：吉林大学地球探测科学与技术学院;国土资源部地球化学探测技术重点实验室;中国地质科学院地球物理地球化学勘查研究所;
【基金】：中国地质调查局项目(20089941) 中央级公益性科研院所基本科研业务费专项(AS2016P02)~~
【分类号】：P618.51

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