四川省甘孜—理塘金矿成矿带成矿模式与开发模式研究

【作者】 夏廷高；

【导师】 孙传敏；

【作者基本信息】 成都理工大学 ， 矿物学、岩石学、矿床学， 2006， 博士

【摘要】 甘孜-理塘断裂带分布于四川西部，大地构造上位于青藏高原东部松潘-甘孜造山带与义敦岛弧造山带的交界部位。近年来断裂带上相继发现了嘎拉、雄龙西、阿加隆洼等金矿床，显示了成矿带寻找金矿的巨大潜力。 本文以构造-区域地质地球化学背景-成矿作用-开发利用为研究主线，就甘孜-理塘断裂带区域地质、地球物理、地球化学背景开展了详细的研究，发现成矿带Au、Mn、Cr、Ni、Co、V、Ti丰度值均低于地壳克拉克值，Cu、Mo、Ag、Ba、W丰度值略近于地壳克拉克值，Hg、Sb、As、Bi、Pb、Zn、B、Sn丰度值高于地壳克拉克值，曲嘎寺组中Au平均丰度值高于区域克拉克值，而图姆沟组则低于区域克拉克值，砂岩、板岩及千枚岩中Au的含量≥3.00×10^-9，高于区域克拉克值；Au、As、Sb、Hg在区内上三叠统曲嘎寺组地层中含量相对较高；Au、As、Hg、Sb复合异常是指示微细浸染型金矿存在的最佳有效异常。 在系统的野外地质调查基础上，就断裂带上嘎拉金矿、雄龙西金矿和阿加隆哇金矿床成矿地质条件、成岩成矿作用和控矿因素进行了系统的研究；深入探讨了嘎拉金矿、雄龙西金矿、阿加隆洼金矿的矿床地质特征、矿石矿物组合、围岩蚀变、控矿因素、矿床地球化学特征；系统分析了金矿石的矿物学、岩石学、微量元素和稀土元素地球化学特征；归纳了成矿带典型金矿的矿床地质特征和成矿模式。雄龙西金矿床的成因类型属地下（卤）水溶滤形成的微细浸染型金矿。阿加隆沣金矿为断裂带控制的变质中基性火山岩为容矿围岩的浅成中低温热液型会矿床。嘎拉金矿为脆-韧性剪切带蚀变火山岩-硫化物型金矿床。 本文系统分析了断裂带地质、地球化学条件与典型金矿床的成生联系，首次提出了甘孜-理塘金矿成矿带的概念，指出成矿带上成矿作用是多期次的，不是简单的一次作用的结果，赋矿围岩主要以沉积岩、变质中基性火山岩为主。以此为基础，开创性地建立了区域金矿成矿模式，指出了甘孜-理塘断裂带的发生、发展和岩浆成岩作用和变质作用是成矿带金矿形成的最主要控矿因素，所派生的次级断裂和构造则成为主要的导矿和容矿空间。成矿带上金矿床的主成矿期为燕山晚期-喜马拉雅早期。 在金矿床中金的物相分析结果基础上，针对研究区金矿床金的赋存状态的复杂性，有针对性地分别对金矿床氧化矿石、半氧化矿石和原生矿石进行了单样、组合样的浮选、重选试验，以及浮选、重选的条件试验；开展了不同粒级、不同选液下的工业选冶试验，获得了相应的一系列工业指标，绘制了不同试验的工艺流程图，并在此基础上，系统地提出了成矿带上不同金矿石类型的开发模式，为该区难选金矿石或质量较差金矿石的利用提供了技术支撑，为本次研究的一项重大突破，在某些方面（如金精矿细菌氧化氰化试验）填补了国内的空白。更多还原

【Abstract】 Ganzi-Litang Fracture Zone, in Western Sichuan Province, was situated tectonically in boundary area between the giant Songpan-Ganzi Orogenic Belt and Yidun Island Arc. From north to south, Gala gold deposit, Xionglongxi gold deposit and Ajialongwa gold deposit have been discovered and explored along the fracture zone in recent years, and also great gold potential has been prospected.This PhD thesis, mostly focused in tectonics, faults, regional geo-chemistry, mineralization and exploitation for gold deposits along the fracture zone, and it researched on regional geological setting, geo-physics, geo-chemistry in detail. On the one hand, the contents of the following elements Au、Mn、Cr、Ni、Co、V、Ti in different geological units such as stratigraphy or magmatite were lower than the crust Clark value, and the values of the elements Cu、Mo、Ag、Ba、W were near to the crust Clark value. On the other hand, the components of the elements Hg、Sb、As、Bi、Pb、Zn、B、Sn were conspicuously higher than crust Clark value. It was important for the gold deposit that the stratigraphy of Upper Triassic Qugashi Formation was characterized with higher value of Au than crust Clark value. But the value of Au in rocks of Tumugou Formation of Upper Triassic is lower than crust Clark value. However, the value of Au in sandstone, slate and phyllite of the strata is above 3.00×10^-9 and obviously higher than regional value. Finally, the thesis concludes that the area with a mixing geo-chemical anomaly of Au、As、Hg、Sb is the best place to metallogenetic predicting area for fine-desseminated gold deposit.Based on the careful investigation in the field, the thesis has devoted most of the time in studying on the following aspects, such as, geological conditions to mineralization, lithogenesis and metallogenesis, controlling factors for ore forming, and geo-chemical characters of ore deposits. The thesis has also researched on geological characters, mineral assembly of ore-rocks, alteration of host-rocks, characters of geo-chemistry, respectively, of the different gold deposit as Gala deposit, Xionglongxi and Ajialongwa deposit. The results of systematically analyzing on mineralogy, petrology, components of trace element and rare earth element, have proposed to this PhD thesis to the establishment of the geological characteristics and metallogenetic models of gold deposits along Ganzi-Litang fracture zone.Xionglongxi gold deposit was considered to be an epithermal fine-disseminated gold deposit （or sedimentary-rock-hosted gold deposit） controlled by fault. Regional deep-fault is the main pathway for rain water and deep earth paleo-geothermal fluids, subsidiary inter-layer fracture zone is the ore depositing structure for the ore-body. The fault tectonite, such as metamorphic feldspar quartzose sandstone and tuffaceous sandstone, was the main host rock, and slate was the main shielding layer in the deposit.更多还原