【作者】 文雪琴；

【导师】 王学求；

【作者基本信息】 长安大学 ， 矿产普查与勘探， 2008， 博士

【摘要】 出露区经历了人类肉眼上千年的找矿历史和一个多世纪的系统地质勘查，现要通过传统的地球化学方法找到新的矿产地的可能性越来越小，寻找新的大型矿床的最大机遇是在隐伏区。隐伏矿勘查已经成为勘查地球化学的难题和研究前沿。在此背景下，提出了“深穿透地球化学”的概念。深穿透地球化学是通过研究成矿元素或伴生元素从隐伏矿向地表的迁移机理和分散模式，含矿信息在地表的存在形式和富集规律，发展含矿信息的采集、提取与分析、成果解释技术，以达到寻找隐伏矿的目的。它的理论基础由连续的几个要素构成：元素从深部向地表的迁移机理、元素迁移到地表以后在土壤中的存在形式和富集规律、所表现的异常模式特征。元素在土壤中的存在形式和富集规律以及异常模式特征是可以观测到的，而元素从深部向地表的迁移机理问题一直存在很大争议。本文在总结前人迁移机理的基础上，针对荒漠戈壁区元素的迁移机理研究入手，选择荒漠区的典型的金、铜、铀三种类型矿区，对其地表土壤中多个层位多个粒级的样品的元素活动态分析和研究发现：钙积层对大部分元素没有“隔挡”作用，元素主要富集在钙积层的上部弱胶结层中；孔泡结皮层之下石膏层以上的(10-40 cm)弱胶结层是最佳取样层位；与矿化有关的元素富集在细粒级粘土和铁锰氧化物膜中，细粒级是深部含矿信息的最有效载体。因此，分离和提取细粒级粘土和铁锰氧化物膜可以达到有效寻找深部隐伏矿的目的。本文在对他人所建立的8种地球化学迁移模型进行系统分析的基础上，通过以上在荒漠戈壁区含矿体上方的土壤层中含矿信息的研究提出了针对干旱荒漠区的元素迁移模型—以地气流为主的多营力迁移模型。这一模型概括为：矿床本身及其围岩中存在成矿元素或伴生元素的活动态形式，包括各种离子、络合物、原子团、胶体、超微细的亚微米至纳米金属颗粒。这些元素的活动态形式可以与气泡表面相结合，并被地气流携带至地表。到达接近地表时，蒸发作用、离子扩散等因素都可参与对元素的向地表迁移。由于地表地球化学障的存在，气体所携带的元素将被卸载下来，在地表形成地球化学异常。另外，在铀矿上方的研究表明铀在干旱氧化条件下主要呈活动态的铀酰络阳离子存在，铀酰络阳离子呈纺锤状、半径大，及易被粘土表面或层间结构所吸附。细粒物质可作为盆地砂岩型铀矿地球化学勘查的有效采样介质；而在铜矿上方的研究发现，铜与金和铀的分布有些不同，铜主要富集在风化残积层中，大量的Cu被挡在钙积层的下部。也就是说钙积层是活动态Cu迁移的一个地球化学障。这些发现，对荒漠戈壁区地球化学勘查的异常解释、采样介质的选择和荒漠戈壁区迁移机理的建立都具有重要意义。最后，利用3种深穿透地球化学方法——细粒级分离技术、元素活动态提取技术和电化学提取技术，在荒漠戈壁区上对3种类型(金、铜、铀)隐伏矿进行了从区域尺度-矿区尺度-到矿体定位尺度方法的应用，发现利用细粒级分析或铁锰氧化物提取分析可以快速、经济、有效地圈定矿田所引起的区域异常，为盆地周边大型金属矿和盆地砂岩型铀矿提供找矿线索。总之，本论文通过研究含矿元素在地表的赋存形式，粒度分布和层位分布，发展完善了从样品采集、样品处理、分析测试、质量监控、数据处理、图件制作的新方法，建立我国荒漠覆盖区景观元素从深层向地表的传输和分散机理，为大面积荒漠覆盖区地球化学调查和隐伏矿产勘查提供理论与方法支撑；为创建全新的深穿透直接信息找矿理念和方法都具有重大科学意义和实际意义。更多还原

【Abstract】 Outcropping areas have been explored by naked-eye over a thousand years and explored by geological technology over a century. The biggest possibility to find the new large ore deposits is in covered areas. Exploration for buried ore deposits has become difficult.In this background the concept of ’deep-penetrating geochemistry’ has been begun to be present. The deep-penetrating geochemistry is to find the buried ore deposits by studying the migrating mechanism and dispersion patterns of mineralization elements or associated elements from ore body to the surface, the elemental forms and distribution in the regolith and development of technology of sampling and analysis in seek for buried ore body.Desert terrains in northern China are covered by widespread regolith sediments, which mask geochemical signals from ore bodies, and are major obstacles to mineral exploration. There is a critical need to study the vertical distribution of elements in the regolith, and to determine potential mechanisms for transferring elements from the ore body upwards through regolith cover to the surface, to establish appropriate sampling media and analytical methods.At the conclusion of this migration of our predecessors on the basis of the migration mechanism of elements the paper starts with a typical choice desert area of gold, copper and uranium mine—three types of its surface soil layer over multiple tablets class samples mobile element analysis and research and found: calcium plot elements not to the majority of the "screened", the main elements of plot calcium concentration in the upper layer of weak cement layer; pore foam cortex node under plaster layer above (10-40 cm) weakly cemented layer is the best sampling horizon; mineralization related elements and enrichment level in the fine-grained clay and iron-manganese oxide film, the fine-ore-bearing deep is the most effective vector information . Therefore, separation and extraction of clay and fine-grained level of iron and manganese oxide film can achieve an effective search for deep concealed ore purposes.In this thesis the migration and technology have been present as followed according to the research of mineral information over ore body based former 8 machenism of transferring:Deposits itself and associated element or its mobile forms in the mineralization, including various ions, complex atoms, colloid, sub-micron, ultra-fine to nanometer metal particles. These elements can live with the mobile form of combining the bubble surface, and was carried to the surface to air currents. When them reach close to the surface, evaporation, ion diffusion, and other factors may be involved in the relocation of elements to the surface. Because gas carried the elements geochemical barrier on the surface will be unloaded down.Using three kinds of deep-penetrating geochemical methods - Fine-separation technology, the elements of mobile extraction technology and electrochemical extraction techniques, in the desert terrains on three types (gold, copper, uranium) were concealed from the regional mine scale to mine scale - to scale methods for ore body positioning. It is found that extraction of iron-manganese oxide can be delineated ore field caused by regional anomaly rapidly, economically, effectively providing clues for prospecting the uranium deposits in basin sandstone-type and surrounding basin large ore body.These discovery, geochemical exploration anomalies explaination in desert terrains and the choice of sampling granularity and establishment of migration mechanism in desert terrains is of the great significance. By researching the forms of elements in the ore-bearing surface, particle size distribution and level of distribution this paper developed and improved sample collection, sample processing, analysis and testing, quality control, data processing, map production of a new method, build transmission mechanism for the large area covered by desert geochemical surveys and concealed mineral exploration theory and method to provide support for the creation of a new deep-penetrating direct information in China’s desert area with covered landscape elements to the surface from deep, which has the significant scientific meaning and important practical significance in building the wholly-new concept of deep-penetrating with direct information.更多还原