【作者】 唐菊兴；

【导师】 王成善；

【作者基本信息】 成都理工大学 ， 古生物学与地层学， 2003， 博士

【摘要】 众所周知，西藏玉龙铜矿是我国单个矿床规模最大、位于著名的特提斯构造—成矿域的特大型斑岩铜（钼）多金属矿床，它所属的藏东玉龙斑岩铜（钼）矿带不仅是我国重要的铜矿成矿远景区带，而且是我国铜资源的后备基地之一。 尽管自上世纪70年代末以来，众多单位的学者从不同角度的对该矿床进行研究，但对青藏高原的快速隆升与斑岩铜（钼）矿床生储盖的关系；成矿斑岩形成和侵位的动力学和热力学机制与模式问题；深部过程与壳幔物质交换及其形成的矿床系列问题；影响我国资源结构和面貌的喜山期斑岩成矿的机理和潜力问题等都缺乏可信与深入的了解，也较难解释玉龙铜矿复杂的成矿背景、元素组合、矿体组合等实际问题。然而，随着大陆动力学理论的不断完善，地球物理和地球化学资料的不断积累，已经有可能通过对玉龙铜矿成矿作用的研究，以建立大陆碰撞—高原隆升条件下玉龙型斑岩铜矿综合找矿模型以及建立特殊地质、地貌条件下的氧化富铜矿的成矿模式。为此，1995年以来，作者参加包括国家科委“95”科技攻关计划项目在内的多项攻关课题，配合地勘项目，对该矿床进行了系统的研究，取得一系列成果，不仅扩大了储量，查明了成因，而且基本解决了投入开采所需的富铜似层状氧化矿的资源量等关键问题。 本文以玉龙斑岩铜矿及其产出的昌都盆地沉积—岩浆—构造演化为主要研究对象，以研究斑岩铜矿区域成矿背景和富碱斑岩铜矿的特殊成矿作用，建立各系列矿体的定位预测模型为研究重点，建立了特殊地质、地貌条件下的氧化富铜矿的成矿模式，以及以建立在大陆碰撞与高原隆升控矿条件下玉龙型斑岩铜矿床综合信息找矿模型为切入点，从而达到对该矿床进行全面而系统的研究，为青藏高原及邻区斑岩铜矿的勘查和经济评价起到示范之目的。 玉龙铜矿是迄今为止我国矿化系列最全、成矿元素最复杂、成矿条件最独特的斑岩铜矿。矿床位于喜马拉雅构造成矿域东部的金沙江—红河斑岩型铜（钼）成矿带。 区域地球物理、区域地球化学、构造地层学、古地貌学、岩石化学、地质年代学研究表明，玉龙斑岩铜矿形成于陆—陆碰撞、陆内裂谷、陆内造山等多种构造体制从伸展背景向挤压背景的转换过程中。研究表明区域内地壳厚度较大（50～80km），具有南薄北厚特点；深部存在厚20km（60～80km深度）壳幔混合体（壳幔过渡带），软流圈厚度大（100～200km），存在软流圈上涌体，10～100km深度的持续的低速特征，反映存在软流圈的上涌和强烈的底侵作用。Cu、Ag、Au、Pb、Zn等主要成矿元素区域地球化学特征、层析分析等均印证了深部存在的北东向构造及其活跃的岩浆—流体活动，而在造山作用下，这些NE向构造处于引张状态，使得岩浆易于沿此构造带上侵，形成一系列成带的侵入岩带。 玉龙斑岩成矿带成矿年龄峰值为37.27Ma，处于早喜马拉雅阶段变形变质造山高峰期（43.04Ma）与中喜马拉雅阶段变形变质造山高峰期（28.44Ma）之间，表明它们形成于早、中喜马拉雅期陆内对冲褶皱推覆造山的间隙期，大规模岩浆侵入略滞后于早期造山，发生在两次造山高峰期之间的间造山期。 含矿斑岩富K₂O、MgO，而贫SiO₂、Fe₂O₃+FeO、MnO、CaO、Na₂O，主成矿元素Cu、Mo含量高，Co、Ag、Au、W、Pb、Zn等元素含量富集，可作为有益伴生元素。Rb、Sr、Ba含量高，Ba／Sr比值大部分接近1，Ba／Rb比值大多在1.66～5.77，Rb／Sr比值在0.19～0.67之间。稀土元素的丰度高，其中轻稀土含量明显高于重稀土，呈现左高右低的较平滑的曲线，犯u大多大于0.75。以上表明玉龙含矿岩体具有埃达克质岩的特征，属于富钾的C型埃达克岩或埃达克质岩。 对控矿构造的定量分析和解析，认为玉龙斑岩体被动侵位于一个总体向北开口的鼻状圈闭构造中，该鼻状构造为各矿体的形成提供了一个不可多得的成矿空间。成矿时期的古构造应力场恢复表明，最小主应力轴主要是NW一SE走向，与恒星错一甘龙拉背斜的轴向相一致;最大主应力轴主要为NE一SW向，它代表构造挤压力的方向。 根据各矿化体的特征，划分了五种矿体类型，并对其（斑岩型、接触带矽卡岩型、接触带角岩型、接触带矽卡岩一次生氧化氧化富集型、隐爆角砾岩型）产出特征、空间分布及变化规律等方面有了总体的把握和新的认识。其中角岩型矿体是玉龙铜矿床扩大铜储量的最重要的矿体类型。斑岩型、角岩型、隐爆角砾岩型、矽卡岩型矿体属Cu（Mo）建造型矿体，11号矿体属C^Ag一CO一-Au建造次生氧化富集型矿体，V号矿体属Cu一Co一W一Ag一Au建造次生氧化富集型矿体，其中n矿体北段Ag含量最高达104x10一“，平均51.375xl0一6，c。含量最高0.108%，平均0.042%;而v号矿体Au含量最高3.588xl0一6，c。:0.265只10一2。 各矿体的产出状态、矿石特征、矿石类型、微量元素地球化学特征、同位素地球化学特征、稀土元素地球化学特征的系统研究表明，玉龙铜矿床各矿体是同一构造一岩浆一成矿体系在时空演化过程中流体化学动力学状态和成矿元素迁移性状综合演变的产物，它们共同构成了一套完整的浅成中酸性岩浆热液系统所特有的铜矿化系列。成矿物质一部分物质来自于花岗斑岩体，另一部分物质则可能来自于三叠纪围?更多还原

【Abstract】 It is well known that Yulong copper deposit, situated in the Tethys Tectonic-Metallogenic domain, is the largest porphyry Cu (Mo) polymetallic deposit in our country. And Yulong porphyry Cu (Mo) ore belt, east Tibet, is an important copper prospecting zone, and one of the Cu metal resource reserve regions of our country.Numerous specialists and scholars have studied the deposit through various ways and views since the end of 1970s. But we still lack of credible and general understanding on the relation between quick plateau uplift and the forming-reserving-covering of the deposit, the problem about the models and mechanisms of dynamics and thermodynamics of the mineralization porphyry forming and emplacement, the problem of mineralization series formed in deep process and exchange between the crust and the mantle, and the problem of mineralization potentiality and mechanism of the porphyry in the Himalayan period which have an effect on the resource structure and resource situation of our country. And it is difficult to define the practical problem about the complicated mineralization setting, element association and ore body series. However, with unceasingly perfecting of the theory of continental dynamics and unceasingly accumulating geophysical and geochemical formation, it is possible to study the metalization of the Yulong Cu deposit, to build up a synthetical information ore-finding model for Himalayan porphyry copper deposit with the continent collision and plateau uplift controlling ore forming, and to build up a metallogenic model of porphyry-skarn oxidized copper ore body in such unique geological and geomorphologic conditions. So from 1995, the author has taken part in some projects sponsored by former National Planning Department, National Science Department, the Ministry of Land and Resource (former Ministry of Geology and Minerals) and Tibetan Geology Bureau. Exploration work and research projects of various levels have been carried out corporately by the Sixth Geology Team of Tibetan Geology Bureau and Chengdu University of Technology. Throughsystematic study, some progresses have been acquired, which have not only enlarged the reserve of the deposit and found out the mineralization genesis, but also basically resolved the key problem about the reserve of the oxidized copper ore body which will be mined in the first stage.So, this thesis takes Yulong porphyry copper deposit and sedimentary-volcanic-tectonic evolution of Changdu basin where the deposit occurs as study subject, and centers around the specific mineralizing process of alkaline porphyry Cu deposits and regional metallogenic background of porphyry copper deposits. It builds up a location prediction model of all series ore bodies, and metallogenic model of porphyry-scarn oxidized copper ore body in such unique geological and geomorphologic conditions, and also builds up a synthetical information ore-finding model for Himalayan porphyry copper deposit with the continent collision and plateau uplift controlling ore forming by studying Yulong deposit comprehensively and systematically.So far as we know, the Yulong porphyry copper deposit, situated in the Jinshajiang-honghe porphyry Cu (Mo) ore belt in the east Himalayan tectonic-metallogenic domain, has the most thorough mineralization series, most complex mineralization elements, and most uniquemetallogenetic condition among the porphyry deposits.By region geophysics, region geochemistry tectonic-stratigraphic, paleo-geomorphologic, lithochemical, geochronological study, it has been pointed out that the Yulong copper deposit has undergone several tectonic settings transforming from continent collision, continental rifts development to inland orogeny. The crust of the area is thick with the thickness of 50 to 80 km, and the northern is thicker than the southern. There is an admixture of the crust and the mantle whose thickness is 20 km and depth from 60 to 80 km. There are some up-flowing bodies of asthenosphere whose thickness is from 100 to 200 km. The evidences o更多还原