【作者】 罗刚；

【导师】 毛景文；

【作者基本信息】 中国地质大学（北京） ， 矿物学、岩石学、矿床学， 2010， 博士

【摘要】 滇东南位置属滇黔桂三省接壤地区,大地构造位于扬子地块西南缘与华南加里东褶皱系接合部位。该区是我国重要的多金属矿产成矿区,其大小不等规模的金矿床(点)分布,与黔桂两省的金矿床构成了有名的微细粒浸染型金矿床的“金三角”区。本文以滇南地区的微细粒浸染型金矿为研究对象,从典型矿床与成矿关系为研究切入点,以矿床—构造—流体—成矿为主线,研究区域成矿地质条件、矿床地质特征、成矿作用和成矿条件,建立矿床成因模式及找矿标志,以及找矿远景进行了预测。获得主要研究进展、成果与结论如下:1、论述了滇东南地区微细粒浸染型金矿成矿地质背景。通过研究,总结了滇东南地区微细粒浸染型金矿具有多时代、多层位等特点,比较集中产于上、中古生界及中生界三叠系,目前统计赋矿层位已达八个以上,而金矿与近东西向的断裂构造带存在着极为密切的成因联系,换句话说,近东西向张性断裂带成为金矿主要的控矿构造。2、通过对滇黔桂裂谷的演化历史的研究,揭示了裂谷的发展,为矿质的运移和沉淀提供了的空间和岩性基础,为深部含金热液向上运移提供了通道和热驱动力,也为深部的含金热液提供矿质析出的环境,并促进微量金的活化与集中。3、剖析了典型金矿床的特征,通过对矿体特征、矿石矿物的结构与组合、围岩蚀变等的研究,初步揭示了赋矿地层与构造、岩浆活动、围岩蚀变等的关系,查明了原生矿石和氧化矿石的地球化学特征和变化规律。4、基于对滇东南地区微细粒金矿典型矿床区域地质概况、矿区和矿床地质特征,尤其对矿化特征、围岩蚀变、地球化学特征等的详细研究;特别是对成矿物质及流体来源进行了分析,对热液主成矿期各阶段成矿流体组分特征和成矿物理化学条件及热力学条件进行了探讨,对该区微细粒型金矿床的形成机制进行分析,获得了相应的成果。5、通过研究,首次提出了该地区的矿床成因模式,概括为:泥盆纪至中三叠世伴随裂谷的发育和演化,以及深大断裂和岩浆活动的发展和地幔隆起,形成矿源流体贮存库,聚集了大量富含挥发份和活动元素的成矿流体;而地壳的基底和盖层起着屏障作用,使封闭于上地幔中的成矿流体与岩石圈处于强力平衡状态中;进入侏罗纪后的燕山晚期,强烈造山运动,使原有封闭的深大断裂再次复活,形成超壳深断裂,触发上地幔分异,成矿流体穿越壳—幔界面进入地壳;在强还原条件下,由于高压和蒸气的共同作用,使流体中的Au呈微粒自然金迁移;随流体交代地壳,局部或部分地壳成分加入引起部分金-硅和金-硫配合物形成并在一定范围内迁移。另一方面,这三种迁移形式又可能随流体中石英、硫化物和粘土矿物沉淀结晶所致的流体组分变化等因素作用而分解出微粒自然金,并同时分散吸附或包裹于晶出的硫化物和粘土矿物中,最终形成微细浸染型金矿床。6、基于对多年来在滇东南地区寻找到的金矿或已知金矿区的地质、物理和化学等特征,或通过各种找矿手段、找矿方法实施取得的找矿成果,以及对所获取直接和间接的找矿信息的全面总结,提出了找矿标志;依据上述成果,对滇东南地区微细粒浸染型金矿找矿远景进行预测,为在该区域内寻找金矿提供了地质依据,对实际工作有着重要的指导作用。更多还原

【Abstract】 The southeast of Yunnan is located the boundries of Yunnan, Guizhou and Guangxi provinces,Tectonics in the southwest margin of Yangtze Platform and the China fold system occupies a position CALEDONIAN.It’s an important area of multi-metallic minerals, ranging from different size of gold deposits (points) distribution, and Guizhou and Guangxi provinces of gold deposits constitute a well-known micro-disseminated gold deposits of the "Golden Triangle" area. In this paper, southern Yunnan region micro-disseminated type gold will be the research object, the typical deposit and mineralization will be the starting point for research, the deposit - Structure - Fluid - forming will be the main line, the studied regional mineralization geological conditions and geological mineralization features, builded the metallogenic model, prospecting indications, and prospecting was predicted. This paper acquired the main research progress, results and conclusions are as follows:1. Discussed in southeast micro-fine disseminated gold mineralization geological background. According to the research,summarized in southeast micro-disseminated gold deposits with multi-age, multi-layer characteristics, which are mainly produced in the last, Paleozoic and Mesozoic, Triassic, the current statistics ORE-BEARING reached more the eight, while the gold and near east-west faults with the existence of a very close link into the health, in other words, nearly east-west extensional faults to become a major gold ore-controlling structure.2. Through the evolutionary history of Yunnan, Guizhou rift study reveals rift development, the migration and precipitation of mineral provides the basis for the space and lithology, as the deep auriferous hydrothermal fluids migrated upward to provide a channeland thermal driving force, but also the deep gold-bearing hydrothermal mineral precipitation to provide an environment and to promote the activation and concentration of trace gold. 3. Analysis of the characteristics of a typical gold deposit, ore body through the characteristics of the structure and composition of mineral ore, rock alteration and other studies, initially revealed the stratum, and the structure, magmatic activity, the relationship between the wall rock alteration, etc. to identify the primary ore and oxide ore geochemical characteristics and variety.4. Based on the southeast Yunnan grained model deposit area geology, mining and geological features, especially mineralization, rock alteration and geochemical characteristics of the detailed study; particularly minerals and fluid into sources are analyzed, the main ore-forming hydrothermal ore-forming fluid composition of the various stages of physical and chemical characteristics and ore-forming conditions and thermodynamic conditions were discussed, the area of micro-fine gold deposit formation mechanism is analyzed to obtain the corresponding results.5. Through research, first proposed in the area of mineralization model, summarized as follows: Devonian to Middle Triassic rift with the development and evolution, as well as deep fault and magmatic activities in the development and mantle uplift, the formation of ore source fluid storage library, gathering a large number of volatile-rich ore fluid elements and activities; the crust of the basement and cover plays a barrier role, so that closed in the upper mantle and lithosphere-forming fluids in the strong state of balance; into the Jurassic After the late Yanshan Ji Luo, strong orogeny, so that the original closed deep faults were revived, and the formation of super deep faults, trigger differentiation of the upper mantle, forming fluid through the crust - mantle boundary into the crust; in strong reducing conditions , due to the joint action of high pressure and steam, the fluid nature of the Au particles were gold migration; with fluid account of the crust, local or part of the crust ingredients into the reaction part of the gold - silicon and Au - S complex formation and migration in a certain range. On the other hand, these three forms of it may move with the fluid, quartz, sulfides and precipitation of clay minerals crystal-induced changes in fluid composition factors such as the role of the natural decomposition of the gold particles, while dispersed adsorption or wrapped in crystal out sulfides and clay minerals, eventually form a micro-disseminated gold deposit.6. Based on many years in southeast Yunnan to find gold or gold mining area known geological, physical and chemical characteristics, or by means of a variety of prospecting, exploration and prospecting methods to implement the results achieved, and of the direct and indirect access to the comprehensive summary of information for mineral exploration, prospecting criteria proposed; the basis of these results, on the southeast Yunnan micro-disseminated gold prospecting forecast, look for gold in the region to provide a geological basis of the actual work has an important role in guiding.更多还原