| 兰坪盆地演化与多金属大型矿集区形成耦合关系研究 |
| 其他题名 | Coupling Relationship Between Evolution of Lanping Basin and Formation of Large Ore-Assembly District of Polymetallic Deposits, in Western Yunnan
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| 李志明
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| 2003
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| 学位授予单位 | 中国科学院地球化学研究所
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| 学位授予地点 | 中国科学院地球化学研究所
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| 学位名称 | 博士
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| 学位专业 | 地球化学
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| 关键词 | 盆地演化
多金属大型矿集区
成矿作用
藕合关系
兰坪中新生代盆地
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| 摘要 | 滇西兰坪中新生代盆地是我国著名“三江”构造带的重要组成部分，盆地内矿产资源丰富，金顶超大型铅锌多金属矿床及其周围的铜多金属矿床构成了我国西南地区重要的多金属大型矿集区之一。本文重点研究了兰坪中新生代盆地的演化、矿集区的成矿作用以及盆地演化与矿集区形成的藕合关系；同时对盆地上三叠统三合洞组的沉积环境以及盆地沉积岩源区构造背景和物源属性也进行了分析。研究结果表明：上三叠统三合洞组的沉积环境属浅海局限台地相，沉积时古海水的温度介于26.7℃-32.1℃，反映上三叠统三合洞组沉积时兰坪盆地处于炎热的热带区；盆地沉积岩源区构造属被动大陆边缘环境和大陆岛弧环境，原始物源来自上地壳，以长英质岩石为主，兰坪中新生代盆地属典型的大陆型盆地；盆地演化经历了三个原型盆地即裂陷盆地（T2-J1）、坳陷盆地（J2-K1）和走滑盆地（E-N）的演化过程，三个原型盆地的形成和演化明显受特提斯洋演化和印度板块与欧亚板块碰撞作用的制约；矿集：区内矿床的成矿物质源自地壳（盆地基底和盆地地层）、成矿流体为盆地热卤水：沥自盆地生油岩地层的有机质参与了成矿作用；矿集区矿床形成时间为56Ma左右或3OMa左右，两时间分别与印度板块和欧亚板块发生碰撞和后续的强烈挤压阶段的时间相一致；中新生代兰坪盆地演化过程也是多金属大型矿集区形成的过程。在裂陷和坳陷盆地演化阶段是大型矿集区形成的预备阶段，形成了成矿物质、成矿流体和成矿流．体通道及矿石堆积场所；走滑盆地演化过程中，强烈的构造活动等使区内成矿能量快速积聚，同时进一步富集成矿物质、成矿流体进一步汇聚以及形成成矿流体的运移通道和矿石堆积的场所，在印度板块和欧亚板块发生碰撞时和后续的强烈挤压阶段分别发生成矿作用，最后形成多金属大型矿集区。 |
| 其他摘要 | The Lanping Mesozoic-Cenozoic Basin in western Yunnan is an important part of famous "Sanjiang"(Tri-river) structure zone in our country. Mineral resources abound in it. Jinding largest-scale Pb-Zn polymetallic deposit and copper polymetallic deposits around it become one of important polymetallic large ore-assembly district in southwest of China. Evolution of the Lanping Mesozoic-Cenozoic Basin, mineralization of large ore-assembly district, and coupling relationship of both have been studied emphatically in this paper; meanwhile, sedimentary environment of the Upper Triassic Sanhedong Formation, tectonic setting and nature of provenance for sedimentary rocks of basin have been analyzed. The results of this paper show: (1) The Upper Triassic Sanhedong Formation deposited in limited carbonate platform sedimentary environment of shallow marine; the temperature of paleo-sea water is mainly from 26.7 ℃-32.1 ℃, which indicates Lanping Basin located in the hot tropics during formation of the Upper Triassic Sanhedong Formation. (2) The provenance tectonic setting of sedimentary rocks from the Lanping Basin are represented by passive continental margin and continental island arc and the original source rocks were all derived from the upper continental crust, with felsic rocks dominant. So the Lanping Basin is a typical continental-type basin. (3) The evolution of Lanping Basin have undergone three different prototype basins' evolution, i.e. rift basin (T2-J1), depression basin (J2-K1) and strike basin (E-N). (4) Ore-forming materials of deposits in large ore -assembly district were derived from crust (mainly from basement and stratum of basin); ore-forming fluids were hot brine of basin dominant and the organic matter from source rocks of basin stratum has involved in mineralization; and mineralization epoch of deposits was about 56Ma or 30Ma, which are compatible with the times of collision of Indian plate and Eurasian plate and late strong compression stage respectively. (5) The evolution process of the Lanping Mesozoic-Cenozoic basin was the formation process of polymetallic large ore -assembly district; the ore-forming materials and fluids, the path of ore-forming fluids migration and the space for ore deposition were formed during the evolution of rift basin (T2-J1) and depression basin (J2-K1); the energy of ore-forming was accumulated rapidly by strong structure activities during the evolution of strike (E-N), and the the ore-forming materials and fluids, the path of ore-forming fluids migration and the space for ore deposition were formed further; and during the times of collision of Indian plate and Eurasian plate and late strong compression stage, mineralization occurred respectively and the polymetallic large ore -assembly district was formed finally. |
| 页数 | 104
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| 语种 | 中文
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| 文献类型 | 学位论文
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| 条目标识符 | http://ir.gyig.ac.cn/handle/352002/3646
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| 专题 | 研究生_研究生_学位论文
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推荐引用方式
GB/T 7714 |
李志明. 兰坪盆地演化与多金属大型矿集区形成耦合关系研究[D]. 中国科学院地球化学研究所. 中国科学院地球化学研究所,2003.
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