【作者】 董方浏；

【导师】 莫宣学；

【作者基本信息】 中国地质大学（北京） ， 矿物学、岩石学、矿床学， 2003， 博士

【摘要】 研究区位于西南“三江”中段，兰坪盆地南部。众所周知，兰坪盆地北部已发现众多大型、超大型矿床，而南部已知矿床的数量及规模却与其有利的成矿背景极不相称。所以，以“岩浆—流体—成矿系统”理论为指导，运用区域流体地质填图方法及其它手段相结合的综合研究方法，进行区域性的岩浆—流体—成矿系统研究，基本查明工作区的成矿条件及成矿流体的流域分布范围与规模，对该区金、铜等成矿潜力作出评价十分必要。 通过三年的野外观察和室内研究，取得如下主要成果： 1．对巍山永平矿化集中区铜金等矿床的区域成矿控矿条件进行了比较系统的研究，初步建立了本区的区域成矿模型。认为澜沧江断裂、金沙江-哀牢山断裂及盆地中轴断裂这三条岩石圈断裂是主要的控盆-控岩(岩浆岩)构造及矿集区尺度的控矿构造；盆地中以三叠系为轴的背斜构造及相关的断裂系统、盆地西南缘公郎弧形构造等是矿田尺度的控矿构造；多组断裂的交叉、层间破碎带及地层柱中的氧化还原界面是形成矿体的有利部位。大量统计表明，中生代地层、特别是晚三叠世低成熟度沉积岩是重要的矿源层。 2．测定了斑岩体的准确同位素年龄及部分成矿年龄。获得了莲花山石英二长斑岩及卓潘碱性斑岩的Ar-Ar年龄，分别为38.6Ma与36.7Ma，与整个兰坪—思茅盆地与昌都盆地及两侧的斑岩与相关火山岩一致，代表喜马拉雅运动第一幕(兰坪运动)的重要构造—岩浆—成矿事件。获得了莲花山岩体周围接触带蚀变岩中伊利石K-Ar年龄38.6Ma，参考玉龙铜矿带和哀牢山金矿带的主要成矿期(分别为30Ma左右及26Ma)，厘定本矿集区成矿年龄下限为38.6Ma，上限为20Ma，与两次重要的构造事件—兰坪运动的起始时间及哀牢山—红河断裂由左旋转为右旋的时间相当。初步认为石英二长斑岩与碱性斑岩岩浆活动对本区成矿有重要作用，既是重要的矿源和流体来源，又是驱动成矿流体循环的主要热源。研究证明，本区成矿作用与区域构造-岩浆-成矿事件及深部构造之间有很好的吻合性。 3．根据区内矿床分布规律、矿化类型及矿化特征等可划分为两个成矿带。自西向东分别是永平厂街—水泄—南涧新民中高温铜、钴成矿带，矿床类型主要有以岩浆水与盆地内大气降水混合流体为主中高温度中低盐度的热液型铜钴矿床和以中高温中低盐度的热液蚀变含铜砂岩型铜矿床；巍山紫金山—马鞍山—笔架山中低温金、砷、锑、汞成矿带，矿床类型主要有与盆地内大气降水成因有联系的低温热液型砷矿床、中高温—中低温低盐度的热液型锑矿床、中高温中低盐度的构造蚀变岩型金矿床、斑岩型金矿床及低温热液成因之脉状、似层状汞矿床和热液型似层状铜矿等。 4．对矿石和围岩岩石的微量元素、稀土元素分析及成矿流体包裹体测试研究，揭示出本区存在两个成矿流体系统。即水泄—新民—拥翠Cu-Co-Au流体子系统，紫金山—笔架山Au-Sb-As-Hg流体子系统，它们在流体元素组合、流体温度及盐度等方面有明显的不同。确定出本区成矿流体的的性质为岩浆水与盆地水不同程度的混合。进一步揭示出本矿化区成矿元素与成矿温度在平面上的分带性，西南部以Cu-Co-Au的中温-中高温成矿为主，东部及东北部以低温-低中温Au-Sb-As-Hg成矿为主，平面上的这种分带，可能也指示垂直方向的分带。 5．认为巍山永平矿化集中区具有进一步找矿的良好前景及潜力，圈定巍山紫金山背斜Au-Sb-Hg找矿靶区、巍山莲花山-朵谷Au-Cu找矿靶区、南涧新民Cu-Co-Au找矿靶区、南涧拥翠Cu-Co-Au找矿靶区，并对工作部署提出了建议。更多还原

【Abstract】 The district studied is located in the southern portion of Lanping basin in the middle of Sanjiang area. As we know, lots of large and supper-large deposits have been discovered in the northern part of Lanping basin. However, the deposits known so far in both quantity and size in south part of the basin are not adequate with respect to its favorable metallogenic settings. Therefore, it is essential to evaluate the metallogenic potential of Copper-Gold of this area by conducting a systematical research on the regional magma-fluid-metallogenic system. A combinational method of regional fluid geology mapping combined with other methods under the instruction in the theory of "magma-fluid-metallogenic system" has been employed to find out the mineralization condition and potential including the size of distribution area of ore-forming fluid.The main progress after three years field investigating and indoor research work are summarized as follows:1. A regional metallogenic model has preliminarily been established on the basis of systematical studies on the regional metallogenic condition and control factors of copper-gold deposits at Weishan-Yongping mineralization district. The author suggests that the three lithosphere-scale faults, Lancangjiang fault, Jinshanjiang-Ailaoshan fault and axis fault in the middle of the basin, are the main geological structures that control the formation of basin, magmatism and metallogenic congregate district. The anticline structure with an axis of Triassic strata and the related fault system within the basin, and Gonglang arch-shaped folding structure in the south of the basin are the geological structure controlling the formation of ore fields. Junctions of two or more faults with different orientation, interlayer cataclastic structural zone and oxidation-reduction (Redox) boundary were the favorable position for the formation of ore bodies. A great deal of statistic data illustrates that the Mesozoic strata, especially the Upper Triassic immature sediments, are presumably an important source of ore-forming metals.2. 38.6Ma and 36.7Ma isotopic ages of quartz-monzonite-porphyry in Lianhuashan and alkaline porphyry in Zhuopan have respectively been obtained. Those results are consistent with the ages of the porphyries in both Lanping-Shimao basin and Changdu basin related igneous rocks, representing the first episode (Lanping movement) of tectonics-magmatism-metallogenic event during the Himalayan movement. K-Ar age of an illite from alteration rock in the contact zone around Lianhuashan porphyry is 38.6Ma. With referencing to the main metallogenic period of Yulong copper metallogenic zone and of Ailaoshan gold metallogenic zone, it is suggested that the time of formation of deposits in the district studied is probably in a period of time from 38.6Ma at earliest to 20Ma at latest. This time is equivalent to the origination time of two important tectonic events, i.e., Lanping movement and the turning point when Ailaoshan-Red river fault turned from sinisteral into dextral. It is argued that the magmatic activities of quartz-monzonite-porphyry and alkaline porphyry presumably played an essential role in mineralization of this district, that is, the porphyry system could be important sources of both ore-forming metals and ore-forming fluids, as well as a thermal engine that drived cycling of metallogenic fluids. The research shows that mineralization fitted well with the regional tectonic-magmatic- metallogenic events and deep structure in this district.3. Based on distribution of deposits and types and characteristics of mineralization, twomineralization zones could be divided. From west to east they are Yongpingchangjie-Shuixie-Nanjianxinmin middle-high temperature copper-cobalt mineralization zone and Zijinshan-Maanshan-Bijiashan middle-low temperature Au-As-Sb-Hg mineralization zone. The types of deposits in the former are high -middle temperature and middle-low salinity hydrothermal copper-cobalt deposits, and high -middle temperatur更多还原