【作者】 周涛；

【导师】 戴塔根； 徐文炘；

【作者基本信息】 中南大学 ， 国土资源信息工程， 2009， 博士

【摘要】 论文以成矿系列理论为指导,在对香花岭锡多金属矿区资料收集和综合分析前人研究成果的基础上,以野外地质调查为基础,以地质综合分析法、矿物学研究分析法、岩石学研究分析法、地球化学研究分析法、地质热力学研究法以及流体包裹体研究法为主要手段,针对前人研究较为薄弱的成矿物理化学条件、成矿物质来源、成岩机制、成矿机理、矿床成因及成矿模式进行了探索性的研究。通过研究,取得的主要成果如下:①根据香花岭矿区岩浆岩岩石学和岩石化学特征、微量元素及稀土元素地球化学特征,得出本区花岗岩造岩元素K/Na+K和Al₂O₃/K₂O+Na₂O+CaO指标值分别为0.39～0.45和0.54～0.69,ACF为“S”型区域,初始锶同位素组成为0.7824,而Nd模式年龄为负值,显示区内花岗岩是壳幔混合作用的产物。岩体具有高硅、适度富碱、贫钙镁铁的特点,富含钨锡等成矿元素及锂和氟等挥发组分。②对香花岭矿区主要类型的岩石和金属矿物进行了微量元素测定,获得与锡矿化有关的硫化物都具有富砷、钨、锡和贫硫的特点。③首次通过对矽卡岩形成物理化学条件的研究,获得本区矽卡岩阶段成岩温度为430℃～570℃,成岩压力为1000×10⁵Pa,Xco₂为0.22～0.02。由于流体温度下降和H₂O参与流动,使得晚期矽卡岩成岩流体温度下降,XCO₂下降。在温度为570℃时,logfo₂为-24.8～-20.2;在温度为430℃时,logfo₂为-26.0～-16.2。④首次通过对云英岩—锡石—硫化物、锡石—石英—硫化物、硫化物以及萤石—碳酸盐岩阶段的流体包裹体温度和盐度的测定,获得云英岩—锡石—硫化物和锡石-石英-硫化物阶段成矿温度为300℃～350℃,盐度为3.85～6.9wt%NaCl;硫化物阶段成矿温度为200℃～270℃,盐度为0.53～6.4wt%NaCl;萤石—碳酸盐岩阶段成矿温度为85℃～178℃,盐度为0.2～4.5 wt%NaCl。⑤首次通过热力学计算获得各个阶段氧逸度、硫逸度、pH值,并确定了锡、铜、铅、锌的迁移形式和能力。⑥对矿体硫化物进行硫和铅同位素测定,获得溶液的δ³⁴S_∑S与磁黄铁矿硫同位素组成相近约等于0±3‰,δ³⁴S_∑S值小,表明热液硫是岩浆来源,方铅矿铅同位素线性排列,暗示出铅可能是多来源的。⑦通过对矿区地质特征、成矿地质条件、地球化学特征、成矿物质来源、成矿作用、矿化型式以及成矿物理化学条件的分析,总结了香花岭矿区的矿床成因以及成矿模式,认为香花岭锡多金属矿成矿物质主要来源于岩浆,矿床成因类型包括花岗岩体内及其边部产出的与钠长岩化有关的高温气液型Nb、Ta矿床、花岗岩体与碳酸盐岩内接触带产出的与矽卡岩化有关的中高温矽卡岩型Sn、Be矿床、花岗岩体与碳酸盐岩外接触带产出的与矽卡岩化有关的中高温锡石硫化物矿床以及围岩中产出的与硅化、萤石化、青磐岩化有关的中低温热液型铅锌银矿床,整体构成与燕山期岩浆活动有关的广义岩浆热液型锡多金属成矿系列。更多还原

【Abstract】 Taking the mineralize serial theory as guidance,through the materials collection of Xianghualing Sn-polymetallic mining areas and the comprehensive analysis of the former research results,the thesis make the exploratory research on the basis of the outdoor geological survey.The main analytic methods includes the comprehensive approach,mineralogical approach,petrological approach,geochemical approach,geological thermodynamics and fluid inclusion approach aiming at the ore-forming physicochemical conditions,the ore-forming materials source,the rock-forming mechanism,the metallogenic mechanism,the ore deposit genesis and metallogenic model.The main achievements are made as follows:①According to petrological and petrochemical characteristics of magmatic rocks,microelements and REE geochemiscal characteristics of Xianghualing mining area,we draw the conclusion that the rock-forming elements of granite K/Na+K and Al₂O₃/K₂O+Na₂O+CaO’s index value are 0.39—0.45 and 0.54—0.69 respectively,ACF is "S" type area,it is 0.7824 that the constituent of initial strontium isotope,and the age of Nd mode is the negative value, demonstrated that the granite in this area are the products of crust-mantle mixing. The rock bodies have the characteristics of high silicon,rich alkali,containing calcium magnesium iron,rich in tungsten Sn mineralize element and volatilize components of lithium and Fluorine etc.②Determine the microelements to the rock of the main type of mining area and metal minerals in Xianghualing mining areas,getting the characteristics that the sulphides related to Sn mine all have rich arsenic,tungsten,Sn and poor sulphur.③Through the research on the physicochemical conditions of the formation of the skams for the first time,the results show that the rock-forming temperature is 430℃—570℃,the pressure of rock-forming is 1000×105Pa, XCO₂ is 0.22-0.02.Because of the drop of the fluid temperature and the participation and flow of H₂O,the rock-forming temperature and the XCO₂ of the later skarns fluid drops.When the temperature is 570℃,the logfo₂ varies from-24.8 to -20.2.When temperature is 430℃,the logfo₂ varies from -26.0 to -16.2.④On measuring the temperature and salinity of inclusions in greisen-cassiterite-sulfides,cassiterite-quartz-sulfides,sulfides and fluorite-carbonate metallogenetic stages for the first time,the main results show that the data of mineralization temperature and salinity are respectively 300℃—350℃and 3.85—6.9wt%NaCl in greisen-cassiterite-sulfide, cassiterite-quartz-sulfide stage;200℃—270℃and 0.53—6.4wt%NaCl in sulfide stage;85℃—178℃and 0.2—4.5 wt%NaCl in fluorite-carbonate stage.⑤The thesis gain the results of oxygen fugacity,sulfur fugacity,pH in every stages via thermodynamic calculation for the first time,and estimate the transfer model and capability of Sn,Cu,Pb,Zn.⑥It can draw the conclusion thatδ³⁴S_ΣS in solution has an approximate content（0±3‰）with S isotope of pyrrhoSne by measuring S and Pb isotope of sulfide in ore bodies,a lower value shows S in hydrothermal fluid is origin from magma;Linear array of Pb isotope in galenite suggests that Pb may be multisources.⑦According to geological characteristics of mineral area,geological conditions of mineralization,geochemical characteristics,material sources of mineralization,mineralization patterns,as well as physical and chemical conditions of mineralization,it summarize the mineralization pattern and genesis of ore deposit of Xianghualing mining areas,considering that mineralization materials in this deposit mainly come from magma,genesis patterns of deposit include high-temperature gas-liquid Nb、Ta deposit related to albitization laying in or on the edge of granite rock bodies,median-high temperature Skarn Sn,Be deposit related to skarnized laying at the inner contact-belt of granite and carbonate rock bodies;median-high temperature cassiterite -sulphide mineral deposit related to skamized laying at outer contact-belt of granite and carbonate rock bodies and median-low temperature hydrothermal liquid Pb-Zn-Ag deposit related to silicification,fluorite, propylitization laying in wall rocks;Series of generalized magma- hydrothermal liquid type Sn-polymatellitic related to magmatic activity in Yanshan period as a whole.更多还原