【作者】 胡斌；

【导师】 陈国达； 戴塔根；

【作者基本信息】 中南大学 ， 矿产普查与勘探， 2002， 博士

【摘要】 滇西澜沧江成矿带是我国西南一条重要的岩浆—变质—构造活动带，大地构造位置极为独特。地质构造复杂，地层发育齐全，岩浆活动频繁，不同程度的变质作用，矿产资源丰富，有大量的金属矿点分布，是矿化集中区，同时也是我国重要的贵金属和有色金属成矿带之一，对本带的研究具有重大的地质意义。 本区处于冈瓦纳超级古壳体与劳亚超级古壳体的汇聚带，可划分为三个壳段：①兰坪—思茅壳段，出露有苍山—哀牢山早元古代原始陆壳变质基底、安定—藤条江古生代蛇绿混杂岩带、维西—绿春印支裂谷、兰坪—思茅中生代边缘裂陷、澜沧江印支火山弧，澜沧江汇聚接合带：②昌宁—盂连壳段，出露有澜沧—西盟中新元古代至古生代早期变质基底地层、昌宁—孟连晚古生代大陆边缘裂谷系、柯街—南定河汇聚接合带；③保山壳段，出露有崇山中新元古代—古生代早期变质基底、保山陆架裂陷、怒江汇聚接合带。 作为南亚壳体、中亚壳体和东亚壳体过渡域的—部分，本区经历了多次壳体边界离散、汇聚过程，其演化史如下：①晚泥盆—早三叠世，伴随早古生代超级壳体裂解，本区于晚泥盆—早石炭世拉裂—离散形成占位地槽，由此产生了澜沧江过渡际—这一特殊的大地构造特征，成为该带重要的成矿背景条件；石炭—二叠纪为主离散、分裂期，发育有拉斑系列—钙碱性系列—钾玄岩系列岩石组合；晚二叠纪末期，火山弧顶部发育浅海及海陆交互相火山碎屑沉积；至早三叠世，全区缺失下三叠统沉积，这说明古澜沧江地槽在晚二叠至早三叠间封闭；②中、晚三叠世，此期间澜沧江构造带再度经历离散和汇聚的过程，形成火山岩带，三个壳段完全接合，本区进入整体演化阶段；③晚三叠世末期至今，经过短暂的地台阶段，接着全区进入地洼阶段，本区经过块断构造控制的持续缓慢的均衡沉降，下陷成裂陷盆地，大面积沉降史到喜山运动期结束。第三纪末，南亚壳体与欧亚超级壳体汇聚接合，本区全部地层发生强烈褶皱及大规模逆冲推覆构造。 受本区演化史的影响，本区铜多金属矿受澜沧江过渡际构造成矿的宏观控制，具有同位多期，多系列的特点，在三个主要演化阶段有着不同的成矿系列：①晚泥盆—早三叠世，在其裂陷早期有碱性玄武岩式矿床形成，在裂陷晚期有蛇绿岩式矿床，包括细碧角斑岩式矿床；②中、晚三叠世，包括裂陷早期的基性火山岩式矿床、裂陷中期的中酸性火山岩—次火山岩式矿床和热水沉积(含铜)菱铁矿以及褶皱带期产于碳酸盐岩和碎屑岩中的Sb、Hg、As、Au热液矿床；③晚三叠世末期至今，本区开始进入地洼阶段，主要形成中、新生代红层铜矿以及与中酸性岩浆活动有关的系列矿床。此外，本区成矿还有如下特点：①矿产分布与构造—岩浆—热活动带一致；②成矿后的改造作用十分强烈。 由于本区经历了壳体(段)边界的多次离散与汇聚过程，形成了三个主要含矿层、三个主要的成矿系列以及众多的矿床类型式，从而构成了本区“多因复成”式的区域成矿模式。 本文首次对澜沧江中北段中生代浅变质岩系开展了矿物、岩石、地球化学、原岩恢复、构造、成矿等方面的详细研究，在雪山河地区测制了“雪山河变质岩群”的标准剖面，提出了关于雪山河变质岩群的新认识，并通过其原岩恢复，得出了澜沧江印支期火山弧带在此未中断的重要结论。 综上所述，笔者在重新分析前人资料的基础上，根据成矿带的成矿系列、典型代表矿床成矿模式等方面特点，综合建立了该带铜多金属矿综合找矿模型，认为澜沧江成矿带具有良好的有望找到大中型铜矿床的成矿远景及找矿条件。更多还原

【Abstract】 The Lancangjiang metallogenic belt in Western Yunnan is an important magmatic, metamorphic and tectonic mobile zone of Southwestern China, whose geotectonic location is very unique. It is characterized by complex geological structures, perfectly developed strata, frequent magmatic activities, various degrees of metamorphism, rich ore resources and lots of metal deposits, thus formed a centralized zone of mineralization and also constituted one of the important metallogenic belts of noble and nonferrous metal deposits. That is why the researching on geology for this belt is of great significance.Geotectonically, the belt lies in the junction of Gondwana paleao-super梒rustobody with Laurasia paleo-super-crustobody, which can be subdivided into three segments:(1) The Lanping -Simao area, which includes the Cangshan - Ailaoshan Paleoproterozoic continent-genetic metamorphic basement, the Anding-Tengtiaojiang Paleozoic ophiolitic melange belt, the Weixi-LUchun Indosinian rift valley, the Lanping-Simao Mesozoic marginal collapse belt, the Lancangjiang Indosinian volcanic arc and the Lancangjiang converging-connection belt.(2) The Changning-Menglian area, which consists of the Lancang-Ximeng Mesoproterozic, Neoproterozic and Early Paleozoic metamorphic basement stratum, the Changning-Menglian Late Paleozoic continental marginal rift system and Kejie-Nandinghe converging-connection belt.(3) The Baoshan area, which outcrops the Chongshan Mesoproterozic, Neoproterozic and Early Paleozoic metamorphic basement, Baoshan continental shelf rift and Nujiang converging-connection belt .As a part of the transitional domain of South Asia crustobody, Central Asia crustobody and East Asia crustobody, the zone has undergone the process of splitting and amalgamation time after time in its evolution history. The tectonic evolution history in this region is summarized as follows:(1) Late Devonian-Early Triassic stage: With the fragmenting of Early Paleozoic super ?crustobodies, the zone was split and formed gap geosynclinal region called the Lancangjiang Transitional Field (LTF) which is an important and special advantage of mineralization in this region during Late Devonian-Early Carboniferous Epoch. The Carboniferous-Permianperiod was the main period of splitting, and in which there existed rock梐ssemblage belts of tholeiitic series, calc梐lkaline series and alkali basaltic series. At the top of the Late Permian series, the neritic or paralic pyroclastic sediments were formed on the top of volcanic arc. For the sediments of lower Triassic series doesn’t exist in whole area, the Lancangjiang paleo梘eosyncline was closed during the Late Permian桬arly Triassic Epoch.(2) Middle桳ate Triassic stage.- When the process of splitting and amalgamation of the Lancangjiang tectonic zone took place again in this period, volcanic rocks belt was formed and the three crustosections converged completely in the end. At the same time, the evolutionary process of the three crustosections as a whole was beginning in this region.(3) Late Triassic final stage to this day: After the transient platform stage, the whole area turned into diwa stage at the end of the Late Triassic Epoch. With the continuous equilibrium sedimentation of the whole area controlled by block faulting, this area became a sag basin and the sag lasted to the Himalayan movement period. At the end of Tertiary, as South Asia crustobody was sutured to Eurasia super梒rustobody, lots of folds and large reversed nappes in all strata was formed in this area.Influenced by its tectonic evolution, copper梡olymetal ores in the belt which are broadly limited by the LTF tectono梞etallogenesis are characterized by multi-stage and multi-series in the same sites. In its three main evolution stages, there are different metallogenetic series in this area.(1) During Late Devonian桬arly Triassic Epoch, the alkali梑asalt梙osted deposits were formed in the early splitting period, and the ophiolite series梙osted deposits including the spilite梜eratophyre series梙osted deposits formed in the更多还原