【作者】 叶珂；

【导师】 杨斌；

【作者基本信息】 中南大学 ， 矿物学、岩石学、矿床学， 2009， 硕士

【摘要】 本论文运用成矿系统和多因复成成矿的理论和方法,探索天马山硫金矿床及其外围地区的矿床地质地球化学、控矿构造系统及构造地球化学特征,以确定该矿床的成矿模式和找矿靶位优选,取得以下成果：(1)利用美国陆地卫星LANDSAT-7ETM数据,对铜陵地区约1500 km2范围的泥化、铁化和混合蚀变异常信息进行了提取。根据遥感蚀变的分布特征,结合成矿地质条件分析,在铜陵地区圈定找矿远景区11处。(2)野外地质调查表明,天马山和黄狮涝矿床岩层节理的特点相似,其中走向295°-320°的横节理特别发育。据天马山赋矿岩层中2组共轭剪节理产状得出的控矿断裂系统形成的应力场的分布为,σ1(最大主压应力)：290°∠70°；σ2(中间主应力)：130°∠20°；σ3(最小主压应力)：38°∠7°。在该应力场作用下,天马山矿床主要容矿构造呈张性正断层性质,反映了天马山地区在燕山期构造活动的特点。(3)铜陵矿集区矿石硫同位素组成以富重硫为特征,硫的来源主要与海水硫及地层中膏盐硫的热还原有关,反映了区域性热水沉积作用的存在。铜陵地区矿床铅同位素样品主要集中分布在造山带和上地壳铅同位素演化线附近,显示铅的来源与造山带环境有关,并有大量来自上地壳的浅源铅参与。氢氧同位素分析显示,天马山及其外围地区成矿流体具混合流体特征,大气水、地下水及变质水参与明显。(4)天马山及其外围地区铜、金成矿具有层控性、变化性及多世代性特征,成矿作用主要经历石炭纪海底热水沉积成矿作用和燕山期岩浆—热液成矿作用2个关键的成矿地质事件。早期矿体的诱导作用和热液对流系统中成矿金属元素及硫、碳等物质的大规模的循环是成矿的关键。(5)利用空间分析方法和信息统计单元方法对天马山及其外围地区进行了数字矿床空间信息成矿预测模型的研究。根据预测单元计算结果,结合地质分析,圈定了14个找矿靶区。(6)据天马山—黄狮涝测区构造地球化学异常空间分布,结合多元统计分析,判断测区内金矿的最佳近矿成矿指示元素组合为Au-Ag-As,矿体旁侧及外围成矿指示元素组合为Sb-Hg。测区内铜矿的最佳近矿成矿指示元素组合为Cu-Mo-Bi。结合地质分析,在天马山—黄狮涝测区共圈定找矿靶位5处。更多还原

【Abstract】 According to the theory and method of ore forming system and polygenetic compound mineralization, this thesis tries to investigate geology and geochemistry, ore-controlling structural system, tectono-geochemistry, and remote sensing geology so as to establish the mineralizing model and find out prefered targets for Tianmashan sulphur-gold deposit and the neighboar area, with the resulths as follows:(1)The LANDSAT-7ETM’s remote sensing data are used to extract the information of the argillization, ferrugination and mixture alteration anomaly in the 1500 km2 area in Tongling. Eleven prospecting areas were outlined based on the distribution characteristics’ alteration and minerogenetic conditions.(2)It is shown, from field survey, that the features of cleavages in the host roucs are similar in Tianmashan and Huangshilao deposit. Charaterised by good development of the transverse joints with strike 295-320°. The distribution stress field of ore-controlling fault system, obtained from 2 sets of conjugate shear joints in the ore-hosted rocles in Tianmashan:σ1(Maximum major pressure stress):290°∠70°;σ2(intermediate principal stress): 130°∠20°;σ3(Minimum major pressure stress):38°∠7°.Because of this pressure stress, the main ore structures of Tianmashan deposit is strike-slip tensile normal faults, indicating the feature of the Tianmashan’s tectonism feature during Yanshan Period.(3)The sulfur isotope of the ores is rich in S34 in Tongling ore concentration area. There are some relation between the genesis of sulfur and those for general sea waters as well as the thermal recovery of gypsum-bearing sulfur in stratum. All of these indicate the presense of terrestrial hot water sedimentation. The Pb isotope of samples are distributed along the the boundaries of upper crustal and orogenic fields showing that the source of Pb is related to the orogenic belt’s environment, and part of Pb coming from supracrust participates in this process. The analyses of isotopic characteristics of H and O display that the metallogenic fluid has the characteristic of mixed liquid, and the meteoric water, groundwater, metamorphic water involved obviously.(4)The Cu and Au mineralizing in Tianmashan and its neighbor area shows the characteristic, of layer-control, variability and multi-generation. The metallogenesis has experienced submarine hot water deposition in Carboniferous and magmatic-hydrother deposition in the period of Yanshan. The metallogenetic key that the induction of early orebody and the large-scale circulation of metallic elements as well as S, C in thermal fluid system.(5)The methods of spatial analysis and information statistics, are used to build a forecasting model of mineralizing with information of digital deposit space for Tianmashan and its neighbor area. According to the calculating results of predicting unit and analysis of geology,14 targets areas are proposed.(6)Based on the spatial distribution of tectono-geochemical anomalies in testing zone of Tianmashan and Huangshilao and multivariate statistical analysis, it is suggested that the best mineralizing indicator element combination is Au-Ag-As for gold near the orebody in testing zone,the best mineralizing indicator element combination is Sb-Hg for gold beside the orebody and its neighbor area, and that the best mineralizing indicator element combination is Cu-Mo-Bi for copper near the orebody in testing zone. According to the information mentioned above and analysis of geology,5 areas targets in the testing zone air localised.更多还原