西昆仓地区成矿地质条件与密西西比河谷型铅锌矿床成矿模式研究

【作者】 匡文龙；

【导师】 刘继顺；

【作者基本信息】 中南大学 ， 矿产普查与勘探， 2003， 博士

【摘要】 新疆西昆仑地区是我国西部待开发的重要成矿区之一，将成为我国新的矿产资源(特别是铅锌资源)基地。 本文运用区域成矿学理论从沉积(变质)建造、岩浆活动、构造演化以及区域地球物理场和地球化学场特征等方面系统地阐述了西昆仑地区(特别是奥依塔格—库尔良晚古生代裂陷盆地)的成矿地质条件。并通过系统的野外地质调查和深入的室内测试研究，对区内优势矿种——铅锌矿产进行了重点研究，获得了大量创新性成果。从矿床的地质特征和微量元素、稳定同位素、稀土元素地球化学及流体包裹体物理化学性质等方面，论证了本区以塔木、卡兰古为代表的这类层控型铅锌矿床属于密西西比河谷型铅锌矿床。在此基础上，建立了该区密西西比河谷型铅锌矿床的成矿模式和找矿模型，开展了成矿预测。取得的主要成果如下： 根据西昆仑区内的沉积(变质)建造类型、岩浆岩演化特点，结合区域构造特征，将西昆仑及邻近地区划分为5个一级构造单元，6个二级构造单元和7个三级构造单元，论证了各构造演化阶段的大地构造属性，探讨了各期构造运动对区内金属成矿作用的影响。 通过对西昆仑地区自新元古宙以来构造演化特征的分析，认为西昆仑地区最重要的成矿单元(奥依塔格—库尔良弧后裂谷盆地)是在晚古生代开始形成，到二叠纪末闭合。其所处的特殊构造位置和区内多期构造作用为铅锌等金属成矿创造了良好条件。 区域构造研究表明印度大陆的楔入是造成西昆仑地区大规模推覆构造发生的主要原因，同时也是该区在中生代以来陆内演化阶段的主要特点。这种大规模推覆和褶皱作用所引发的大规模热卤水运移、循环，特别是油田卤水与深层流体的混合导致了区内矿质的沉淀。这些新思路不仅丰富了该区成矿理论与成矿规律的研究，还将对该区正在进行的科研工作和找矿实践起到一定的指导作用。 通过矿床地质研究和成矿构造分析得出：区域性断裂及次一级断裂构造对本区铅锌矿的控制作用十分明显。铅锌矿床(点)的分布，总体上受区域性深大断裂控制；短轴背斜、穹隆构造的倾覆端、转折端是形成大而富矿体的有利构造部位；并对其中的典型矿床进行了详细的地质特征描述。这一认识不仅深化了区内铅锌矿床成矿机制的研究，而且还为今后的找矿工作指明了方向。 在卡兰古矿区，通过实地考察，总结出了区内铅、锌矿化与岩性、岩相变化带及硅化、白云石化等围岩蚀变现象密切相关的规律。新发现了“雪顶构造”、“条带状构造”等密西西比河谷型铅锌矿床证据。这些发现，对于该区铅锌矿床的厘定具有重要意义。 同位素、微量元素和稀土元素地球化学、矿物流体包裹体成分及流体物理化学性质的研究表明:区内铅锌矿床的成矿物质主要来源于前泥盆纪基底，基本上没有地慢物质和岩浆成分的参与;成矿作用主要与油田卤水和深层卤水的混合作用有关;成矿金属元素主要以硫氢配合物形式迁移;成矿流体的驱动力为构造应力和重力。 在成矿机制研究方面，根据所取得的大量测试成果，否定了本区铅锌矿床是与岩浆作用有关的“热液脉状成因”观点和“原生沉积”观点。认为塔木、卡兰古等矿床属典型的后生密西西比河谷型铅锌矿床。结合该区构造演化及成矿地质条件特征，首次建立了该区密西西比河谷型铅锌矿床的成矿模式和找矿模型。 在找矿成果方面，于卡兰古西部的卡拉塔什附近新发现了中泥盆统砂(砾)型铅锌矿。这一新的发现将对西昆仑内地区铅锌矿的找矿突破有着重大的指导意义。 在成矿预测方面，根据区域成矿学和矿床地质研究成果，结合1:5万化探异常，提出了三个成矿远景区。认为塔木一卡拉牙斯卡克、阿尔巴勒克、卡兰古一卡拉塔什是西昆仑地区3个最佳的成矿远景区，在西昆仑地区至少可以找到3个大型的密西西比河谷型铅锌矿床，并为今后找矿工作指明了方向。更多还原

【Abstract】 West Kunlun Mountain Region in Xinjiang(China) is one of the most important metallogenic regions in west China, it will become a new base for mine resource especially for Lead-Zinc mine prospecting.Regional sedimentary (metamorphic) formation, magmatite, tectonic evolution, geophysics field characteristics and regional geochemistry condition have been analysised in order to expound the metallogenic Geological Condition about West Kunlun Mountain Region brilliantly in this paper. Especially considered that Oytage-kurliang fissure basin, as a very important polymetal metallogenic belt in West Kunlun Mountain Region, is the key of the paper. The author chose Lead-Zinc deposits in Oytage-kurliang fissure basin as a main target to research. After detail field inspecting, combined with the deep indoor research result, the author regarded that those deposits, which districted in West Kunlun Mountain Region(such as Tamu, Kalangu), are belong to Mississippi Valley Type Lead-Zinc deposits. Based on all of these, the metallogenic model of these Mississippi valley type lead-zinc deposits have been built up. The regional metallogenic regular pattern and exploration model had been summarized. At last, the dissertation gave a revaluating of Long-rang prospect for Mississippi Valley type lead-zinc deposits in West Kunlun Mountain Region, proposed three long-range prospecting. From all of these researching, some important achievements are acquired as follow:According to the sedimentary (metamorphic) formation, magmatite, tectonic evolution, the geotectonic units of West Kunlun Mountain Region and it’s adjacent area are divided into 5 first order units, and subdivided into 6 second-order units, on the basis of these, 7 third-order units are divided in order to show those important polymetal metallogenic belt clearly. The relationship between plate tectonic movement and ore-forming process was revealed.Based on the analysis about the main characteristics of West Kunlun Mountain Region’s tectonic evolution stage since the late Proterozoic Era, the author put forward that Rodinia super-continent’s merging and dissociation had a profoundly influence during the West Kunlun Mountain Region ’s tectonic evolution phase. Oytage-kurliang fissure basin was formed in the end of Permian, it’s special tectonic place and special tectonic evolution process supplied favourable conditions to the polymetal metallogenical course in this .Referring himself to some geophysics information, the author made a suggestion that the Indio Continent’s jamming together with Europ-Asian Continent was the main force of West Kunlun Mountain Region’s grand scale napping and the main characteristics of the regional evolution, pointed out that it was the grand napping and folding that caused grand scale hot brine’s moving and cycling, especially the oil field brine blending with deeply fluid that leaded the metallogenic material to precipitate. This new idea not only enriched the metallogenic theory and the metallogenic law’s researching, but also gave a guide to the mining respecting and mining scientific research on West Kunlun Mountain Region .After studying on the deposits’ geological character and metallogenic tectonic, Some development have been achieved in the relation between the West Kunlun Mountain Region’s regional tectonic and Lead-Zinc’s metallogenic process. The author regarded that the regional rifts and the second scale rifts had an obviously control function during the metallogenic process of Lead-Zinc deposits in West Kunlun Mountain Region. All of those Lead-Zinc deposits’ character,which distributed around the big rifts nearly such as Tamu, Kalangu, Teklyke, had been described detail to readers. This work not only deepened the Lead-Zinc deposits’ metallogenic machine and metallogenic process’ researching but also pointed out a way for the West Kunlun Mountain Region region’s mining respecting.Based on the detail field inspecting information, the law of Lead-Zinc mineralization had been concluded. It shows that the Lead-Zinc mineralizatio更多还原