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西南特提斯川滇黔成矿区富锗铅锌矿床成矿理论研究新进展 总被引：2，自引：0，他引：2
川滇黔铅锌多金属成矿区位于特提斯成矿域与环太平洋成矿域交界地带的扬子陆块西南缘，并广泛分布了全球罕见的碳酸盐岩容矿的后成热液型富锗铅锌多金属矿床，其铅锌品位特高、储量大、富含稀散元素锗和贵金属银，经济价值巨大，备受广泛关注。针对制约该区深部找矿突破的成矿构造动力学背景及其响应机制、矿源—输运—聚集成矿过程、铅锌锗元素超常富集—巨量聚集成矿机制、矿床类型归属与铅锌多金属成矿系统等重大理论问题，历经20余年，通过区域地球物理剖面探测、矿田构造解析、典型矿床精细解剖及矿床地球化学、实验地球化学等系统研究，在成矿理论方面取得重要研究进展：① 提出了富锗铅锌矿形成于印支期碰撞造山过程的陆内走滑构造系统，解析并厘定了断褶构造组合样式及成矿构造体系，建立了构造分级成矿- 控矿、矿体空间定位模式；② 系统概括了矿化空间组合结构及矿床成矿规律，查明了“矿源—输运—聚集”成矿过程，揭示了铅锌共生分异机制及铅锌锗超常富集成矿机制；③ 提出了具有一定普适性的会泽型铅锌矿床新类型，建立了矿床成矿系统及流体“贯入”—交代成矿模型。在此基础上，提出了陆内走滑构造系统控矿—流体“贯入”- 交代成矿论（构造控矿—流体“贯入”成矿论）。应用该理论研发出适用于该类矿床深部勘查技术方法系列，取得了近些年来川滇黔地区一系列找矿突破和新进展。该研究进展不仅为川滇黔成矿区矿床勘查技术研发及深部找矿突破提供了理论支撑，而且将在扬子陆块西南缘乃至特提斯成矿域的类似矿床研究和找矿勘查部署中发挥重要的指导作用。 相似文献
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会泽型(HZT)富锗银铅锌矿床成矿构造动力学研究及年代学约束 总被引：7，自引：0，他引：7
川-滇-黔多金属成矿域是会泽型(HZT)富锗银铅锌矿床的主要分布区。近十年来,该类矿床成矿时代及其成矿构造动力学一直是该区研究的主要热点之一。针对铅锌矿床准确定年的难题,首次综合应用地质推断-构造变形筛分-构造古应力系统测量-同位素定年技术,提出冲断褶皱构造形成时代与矿床成矿时代一致,其主体时代为印支晚期(2.0~2.3亿年)。研究认为,该期发生的铅锌多金属成矿作用是川-滇-黔接壤区重要的地质事件,其成矿构造动力学为印支晚期特提斯洋闭合与造山作用在扬子地块西南缘前陆盆地诱发强烈的斜冲走滑,形成一系列冲断褶皱构造带,并发生流体大规模运移,在有利的构造部位形成一批大型-超大型矿床。该认识对深化川-滇-黔多金属成矿域铅锌矿床成矿模型、优选找矿标志、圈定重点找矿靶区和实现找矿突破具有现实意义。 相似文献
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川滇黔接壤区MVT铅锌矿床年代学研究进展及成矿构造背景 总被引：1，自引：0，他引：1
川滇黔接壤区处于扬子地块西南缘,经历过复杂的地质演化过程并分布有大量的大中型MVT铅锌矿床。对该区MVT铅锌矿床成矿年代学研究开展的大量工作成果显示该区至少经历过2次铅锌成矿事件,分别处于晚泥盆世-晚石炭世和中三叠世-早侏罗世。早期成矿事件与古特提斯洋的扩张(382～328 Ma)密切相关,在伸展构造环境下形成天宝山、大梁子、毛坪等矿床。晚期成矿事件与古特提斯洋闭合、印支期强烈挤压造山运动阶段(245～205 Ma)相对应,在挤压构造环境下形成会泽、茂租、金沙厂等矿床。不同地质背景下形成的矿床在控矿构造性质、矿体赋存规律等方面具有较大差别。在对川滇黔接壤区MVT铅锌矿床成矿时空分布规律总结的基础上,结合该区区域构造演化、矿床的控矿构造特征以及矿体赋存规律,探讨了该区不同时期控制MVT铅锌矿床形成的成矿构造环境。 相似文献
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MVT铅锌矿床和会泽型(HZT)铅锌矿床是全球最重要的铅锌矿床类型之一,其中大型矿床数量和铅锌金属储量均居于重要地位。基于勘查区找矿预测理论与方法,从“时间、空间、物质及其演化”四要素出发,厘定MVT铅锌矿床的成矿地质作用和成矿地质体,总结成矿结构面类型和矿化样式,概括成矿流体作用特征标志,并进一步揭示经典的MVT铅锌矿床“三位一体”的成矿规律:矿床产于前陆盆地地堑式构造带、不整合面上发育的溶塌角砾岩岩相组合、成矿正断层破碎带、区域性热卤水活动的“硅-钙面”成矿结构面中。在此基础上,综合构建经典的MVT铅锌矿床找矿预测地质模型:通过前陆盆地地堑式构造带研究确定勘查区找矿方向,通过成矿结构面研究判断矿体空间位置及其产状,硅-钙面等特征是判断矿床(体)存在的成矿流体作用标志。其勘查应用流程进一步概括为:看、查、识、厘、析、填、测、比、探、勘。该研究对同类矿床成矿规律研究和找矿预测评价具有启示意义。 相似文献
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烃类流体在MVT型铅锌矿成矿中角色与作用:研究进展与展望 总被引：1，自引：0，他引：1
MVT型铅锌矿床是最重要的铅锌矿类型之一,近百年来人们在此类矿床地质和地球化学特征、成矿物质来源、成矿物质活化、运移和沉淀机制、成矿时代和成矿动力学等方面取得了许多重要成果,其中最重要的认识就是与油气相关的烃类流体在Pb-Zn等金属元素活化、迁移和沉淀成矿中起着非常重要的作用.在综合分析前陆盆地烃类流体与MVT型铅锌矿二者之间的成因关系的基础上,系统总结了世界范围内前陆盆地MVT型Pb-Zn矿床共同特征,总结了近年来前陆盆地MVT型铅锌矿烃类流体研究成果和进展,分析表明烃类流体以什么角色、如何参与MVT型铅锌矿成矿作用是目前研究的热点问题,有关烃类流体携带Pb-Zn等金属元素能力及其参与Pb-Zn沉淀成矿机制、前陆盆地构造演化背景下流体汇聚动力学,以及油气藏破坏与Pb-Zn成矿耦合关系等是未来有待深入探讨的重要科学问题.在矿床学和矿床地球化学研究基础上,应该发挥交叉学科特色优势和研究手段,从石油地质学角度出发,研究前陆盆地构造演化过程中烃类流体形成、演化与MVT型铅锌矿成矿过程之间的耦合关系,从有机流体角度切入,探讨MVT型铅锌矿成矿物质来源、成矿作用过程和成矿机制是新的研究趋势. 相似文献
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密西西比河谷型(MVT)铅锌矿床:认识与进展 总被引：14，自引：3，他引：11
MVT铅锌矿床作为一种重要的沉积型铅锌矿床类型一直受到人们的重视,近年来取得了许多重要进展,主要体现在6个方面:①MVT铅锌矿床研究范围逐渐扩大,在全世界发现了诸多相关矿床,多归为其亚类;②提出该类矿床主要分布在造山带的前陆盆地、逆冲推覆带等构造挤压环境,少数产于陆内伸展环境,改变了MVT矿床与板块构造无关的观点;③放射性同位素测年和古地磁测年技术广泛应用,获得了大量成矿年龄数据,表明MVT矿床主要形成在显生宙石炭纪—早三叠纪和白垩纪—第三纪两个时期,与地球演化史上全球尺度的板块会聚时间密切相关;④流体包裹体研究揭示了成矿流体温度主要为90~150℃,盐度w(NaCleq)为10%~30%,成矿流体具有盆地卤水特征,卤水源自近地表蒸发海水或围岩蒸发盐,同位素资料反映Pb来自地壳岩石,S来自地壳岩石或沉积物中残留的硫酸盐。成矿流体驱动机制包括构造挤压和重力驱动两种;⑤古地磁和生物化学标志物判定,单期热液活动可能持续几千到几万年,而整个矿床形成可能持续几个到十几个百万年;⑥矿质沉淀机制主要有3种:流体混合、硫酸盐还原和还原硫机制,不同成矿环境可能受不同机制控制。 相似文献
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本文对川滇黔相邻区碳酸盐岩容矿铅锌矿成矿特征进行系统总结,并对区域成矿过程进行讨论。该区碳酸盐岩容矿铅锌矿发育3种矿床类型,主要分布在泸定-荥经-汉源、雷波-金阳-巧家-会东、赫章-威宁-水城和会泽-彝良4个矿集区,震旦系和古生代地层为主要容矿层。铅锌矿形成于3个成矿期和3类构造环境:以黑区-雪区铅锌矿床为代表的喷流沉积型(SEDEX型),形成于早寒武世海底地震同生断裂环境;以会泽矿床为代表的与侵入作用有关的碳酸盐岩容矿铅锌银矿床类型(IRCH Pb-Zn-Ag型),形成于晚三叠世前陆早期局部引张环境;以大梁子和天桥矿床为代表的密西西比河谷型(MVT型),形成于前陆晚期冲断挤压环境。与世界其它地方不同,川滇黔相邻区MVT铅锌成矿作用主要发生于早侏罗世。 相似文献
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柴达木盆地西北部锶矿成矿系统研究 总被引：4，自引：0，他引：4
柴达木盆地西北部锶矿床是已知的世界上成矿时代最年轻的大陆热水沉积层控型锶矿床。区内锶矿成矿系统位于印度板块与欧亚板块碰撞带的前陆盆地内 ,其成矿作用发生在陆 -陆碰撞造山带的前缘 ;成矿构造和成矿流体对锶矿床的形成起着重要的控制作用 ;这些锶矿床是矿源场、流体场、能量场在一定时空条件下耦合的产物 相似文献
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三江特提斯复合造山与成矿作用 总被引：72，自引：4，他引：68
三江特提斯构造带作为全球特提斯构造在中国大陆最典型的发育地区,经历了复杂而完整的演化历史:从晚前寒武纪—早古生代泛大陆解体与原特提斯洋形成,经古特提斯多岛弧盆系发育与古生代—中生代增生造山/盆山转换,到新生代印度-亚洲大陆碰撞与叠加改造,完好地记录了超级大陆裂解→增生→碰撞的完整演化历史和大陆动力学过程,可谓是中国大陆构造演化的典型缩影。复合造山和叠加转换导致了三江特提斯域复杂的成矿演化,主要表现为:①在构造转换阶段,于元古代刚性基底基础上发育大量叠加改造型矿床,具有独特的金属组合(Sn-Cu,Sn-Pb-Zn,Fe-Cu等);②火山成因块状硫化物(VMS)矿床伴随特提斯岩石圈演化,连续发育于陆缘裂谷(Cu)→初始洋盆(Cu-Zn)→大洋岛弧(Cu-Zn-Pb)→弧间裂谷或弧后盆地(Pb-Zn-Ag)→弧-陆碰撞裂陷盆地(Cu-Pb-Zn)等阶段及诸环境;③特提斯阶段的岛弧型斑岩Cu矿被碰撞造山阶段的大陆型斑岩Cu矿所取代;④世界级规模的金属成矿带和巨型矿床,在新生代碰撞造山期爆发式产生。尽管已有的研究从整体上勾画出了三江特提斯域的基本构造特征和成矿面貌,但仍有许多重要问题尚未解决:①三江复合造山带构造叠加、... 相似文献
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沉积盆地中与油气密切相关的金属矿床主要包括密西西比河谷型(MVT)铅锌矿床、砂页岩型铜-铀矿床、黑色页岩中的金属硫化物矿床、沉积岩容矿的金-锑-砷-汞-铊矿床等。金属矿床与(古)油气藏在空间上的密切共生/伴生关系,暗示了二者成因上的有机联系。在许多MVT铅锌矿床和砂页岩型铜矿床中,与成矿关系密切的原油及其衍生物形成于矿化前,它们为随后的金属成矿直接提供还原硫或充当硫酸盐还原反应的还原剂。在另一些情况下,某些低温热液金属矿床,特别是Au、As、Hg、Sb、Tl矿床与油气表现出同源、同运、同聚的耦合关系,金属成矿与油气成藏同时或近同时进行。与油气具不同耦合关系的金属矿床常表现出不同的特点。与成藏和/或成矿有关的盆地流体大致可分为以碳氢化合物为主的有机流体、以含金属盐水溶液为主的无机流体以及同时富含烃类和金属组分的有机成矿流体3类,盆地中的成矿、成藏作用及其耦合关系受控于这三类流体的演化过程。沉积盆地中金属矿床与油气藏空间上密切的共生/伴生关系以及成矿、成藏过程和机理的相似性,使金属与油气矿产资源的协同勘探和综合预测成为可能。 相似文献
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The Tethyan domain from China to Iran hosts many important sediment-hosted Pb–Zn deposits but most have been poorly documented. This study summarizes the salient features of these deposits and discusses the type of ore, tectonic setting, and important ore controls, on the basis of new geological observations and previous publications. The Tethyan domain is characterized by the young and extensive Himalayan–Tibetan and Zagros orogens that formed through collisions between the India/Arabia and Eurasia continents since the Late Cretaceous or early Cenozoic. Abundant Mississippi Valley-type (MVT) and subordinate clastic-dominated (CD, also known as SEDEX) Pb–Zn deposits occur in this domain, including in central and eastern Himalayan–Tibetan orogen in China, the Indian passive margin in southern Pakistan, and various tectonic units of Iran. Economically important deposits contain 0.1–21 Mt Pb + Zn and have total metal resources of ∼75 Mt with ∼48% being oxidized ores. All major deposits known in this domain are MVTs (i.e., the Jinding, Huoshaoyun, Mehdiabad, and Angouran deposits).Mississippi Valley-type Pb–Zn deposits occur in continental-collision-related fold-and-thrust belts and forelands, where deposits are mostly located on the margin of the Eurasian continent, with some in the Indian and Arabian continental margins. Clastic-dominated Pb–Zn deposits occur in central Iran and southern Pakistan, hosted by deep-water siliciclastic sequences of the early Cambrian rifted continental margin of Gondwana and the Jurassic passive continental margin of India, respectively. The youngest mineralized rocks and ages constrain that some important MVT deposits (e.g., the Jinding, Chaqupacha, and Angouran deposits) were formed after a main phase of regional compression, during a regional, large-scale strike-slip or crustal-extension stage in a continental collision setting. In sense of lithologic structure, important ore controls for MVT deposits include evaporite diapir structure, carbonate/evaporite dissolution–collapse structure, pre-existing barite, and porous dolostone. Much of the primary sulfide ore in this domain has been oxidized by supergene processes. This is particularly pronounced in the newly discovered Huoshaoyun deposit, where almost all sulfides have been oxidized to smithsonite and cerussite. An understanding of tectonic setting, ore controls, and supergene processes is essential in exploring for MVT deposits in this domain. 相似文献
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Mississippi Valley-type lead–zinc deposits through geological time: implications from recent age-dating research 总被引：11，自引：0，他引：11
David L. Leach Dwight Bradley Michael T. Lewchuk David T. Symons Ghislain de Marsily Joyce Brannon 《Mineralium Deposita》2001,36(8):711-740
Remarkable advances in age dating Mississippi Valley-type (MVT) lead-zinc deposits provide a new opportunity to understand how and where these deposits form in the Earth's crust. These dates are summarized and examined in a framework of global tectonics, paleogeography, fluid migration, and paleoclimate. Nineteen districts have been dated by paleomagnetic and/or radiometric methods. Of the districts that have both paleomagnetic and radiometric dates, only the Pine Point and East Tennessee districts have significant disagreements. This broad agreement between paleomagnetic and radiometric dates provides added confidence in the dating techniques used. The new dates confirm the direct connection between the genesis of MVT lead-zinc ores with global-scale tectonic events. The dates show that MVT deposits formed mainly during large contractional tectonic events at restricted times in the history of the Earth. Only the deposits in the Lennard Shelf of Australia and Nanisivik in Canada have dates that correspond to extensional tectonic events. The most important period for MVT genesis was the Devonian to Permian time, which corresponds to a series of intense tectonic events during the assimilation of Pangea. The second most important period for MVT genesis was Cretaceous to Tertiary time when microplate assimilation affected the western margin of North America and Africa-Eurasia. There is a notable paucity of MVT lead-zinc ore formation following the breakup of Rodinia and Pangea. Of the five MVT deposits hosted in Proterozoic rocks, only the Nanisivik deposit has been dated as Proterozoic. The contrast in abundance between SEDEX and MVT lead-zinc deposits in the Proterozoic questions the frequently suggested notion that the two types of ores share similar genetic paths. The ages of MVT deposits, when viewed with respect to the orogenic cycle in the adjacent orogen suggest that no single hydrologic model can be universally applied to the migration of the ore fluids. However, topographically driven models best explain most MVT districts. The migration of MVT ore fluids is not a natural consequence of basin evolution; rather, MVT districts formed mainly where platform carbonates had some hydrological connection to orogenic belts. There may be a connection between paleoclimate and the formation of some MVT deposits. This possible relationship is suggested by the dominance of evaporated seawater in fluid inclusions in MVT ores, by hydrological considerations that include the need for multiple-basin volumes of ore fluid to form most MVT districts, and the need for adequate precipitation to provide sufficient topographic head for topographically-driven fluid migration. Paleoclimatic conditions that lead to formation of evaporite conditions but yet have adequate precipitation to form large hydrological systems are most commonly present in low latitudes. For the MVT deposits and districts that have been dated, more than 75% of the combined metal produced are from deposits that have dates that correspond to assembly of Pangea in Devonian through Permian time. The exceptional endowment of Pangea and especially, North America with MVT lead-zinc deposits may be explained by the following: (1) Laurentia, which formed the core of North America, stayed in low latitudes during the Paleozoic, which allowed the development of vast carbonate platforms; (2) intense orogenic activity during the assembly of Pangea created ground preparation for many MVT districts through far-field deformation of the craton; (3) uplifted orogenic belts along Pangean suture zones established large-scale migration of basin fluids; and (4) the location of Pangea in low latitudes with paleoclimates with high evaporation rates led to the formation of brines by the evaporation of seawater and infiltration of these brines into deep basin aquifers during Pangean orogenic events. 相似文献
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贵州普定五指山地区铅锌矿床成矿模式 总被引：1，自引：1，他引：0
黔西北五指山铅锌矿集区是川滇黔接壤铅锌成矿域的重要组成部分之一,近年已探明多个大中型铅锌矿床,提交铅锌金属资源储量超250万t,实现了地质找矿的重大突破。文章对区内典型矿床的地质、地球化学等资料进行综合分析,并与邻区及MVT矿床进行比较。研究结果显示,本区矿体主要赋存于上震旦统灯影组和下寒武统清虚洞组白云岩中,呈层状、似层状和陡倾斜脉状产出,断控和层控特征明显。矿石自然类型为原生硫化矿型,主要金属矿物由闪锌矿和方铅矿组成。矿床形成受构造、层位及岩性、沉积岩相等因素的约束,构造是必要条件和主要控矿因素,灯影组和清虚洞组鲕状白云岩是有利赋矿层位和容矿岩性,局限-半局限的台地-泻湖相沉积为有利沉积岩相条件。成矿物质具有混合特征,其中成矿金属Pb、Zn等主要来源于基底岩石,而矿化剂C和S则分别来自赋矿海相碳酸盐岩及其内的蒸发膏岩。成矿流体属于与右江盆地演化有关的低温中低盐度盆地卤水,矿体是富金属流体在早燕山期区域挤压向伸展转换的动力学背景下卸载,与富硫流体混合的产物,成矿过程与MVT矿床相似。五指山地区铅锌矿床成矿模式的建立,有望推动区内找矿新突破,并为邻区铅锌成矿预测提供理论指导。 相似文献
15.
西南三江特提斯造山带中新生代沉积盆地中(沱沱河、玉树、昌都和兰坪-思茅地区)发育包括金顶超大型铅锌矿床在内的一系列以沉积岩容矿的Pb-Zn-Ag-Cu贱金属矿床,构成长达千余千米的青藏高原东缘贱金属成矿带。作为大陆碰撞环境成矿谱系的重要矿床类型,加强这些矿床的理论研究对提高和完善大陆碰撞造山成矿理论和指导找矿勘查等具有重要意义。已有研究表明这些Pb-Zn-Ag-Cu矿床的分布受盆地形成后新生代大型逆冲推覆-走滑构造控制,其容矿岩石和成矿作用特征与SEDEX和MVT矿床存在明显的差异,矿床成矿流体表现出多来源混合的特征,成矿与深部过程密切相关。尽管取得重要进展,但由于缺乏高精度年代学数据制约,成矿动力学背景及其与碰撞造山的时空联系存在较大争议。一些矿床的研究显示复合成矿迹象,但是复合成矿过程与深部驱动等问题仍不清楚。近年来我们以兰坪和昌都盆地的Pb-Zn-Ag多金属矿床和Cu多金属矿床为重点研究对象,系统开展了成矿年代学、成矿流体源-运-储系统和复合成矿机制以及深部过程对成矿制约等方面研究。结果表明,兰坪盆地西缘Cu(Mo)多金属矿床主要形成于48～58Ma,兰坪和昌都盆地Pb-Zn-Ag多金属矿床主要形成于27～33Ma。成矿流体表现出明显的多来源混合的特征,主要存在三种类型:1)变质流体与盆地卤水或大气降水复合成矿,以金满-连城Cu矿床为代表; 2)盆地卤水与大气降水复合成矿,以金顶Pb-Zn矿床为代表; 3)盆地卤水和岩浆流体复合成矿,以拉诺玛Pb-Zn-Sb矿床为代表。兰坪盆地西缘Cu矿床主要形成于新生代印度-欧亚大陆主碰撞挤压阶段,与成矿密切相关的变质流体可能来源于陆-陆碰撞俯冲引起的高压变质。Pb-Zn矿床主要形成于印度-欧亚大陆晚碰撞构造转换环境,构造挤压和造山隆起驱动盆地流体迁移,同期的岩浆活动主要为成矿提供热驱动力或成矿物质。 相似文献
16.
The Tethyside orogen, a direct consequence of the separation of the Gondwanaland and the accretion of Eurasia, is a huge composite orogenic system that was generated during Paleozoic–Mesozoic Tethyan accretionary and Cenozoic continent–continent collisional orogenesis within the Tethyan domain. The Tethyside orogenic system consists of a group of diverse Tethyan blocks, including the Istanbul, Sakarya, Anatolide–Taurides, Central Iran, Afghanistan, Songpan–Ganzi, Eastern Qiangtang, Western Qiangtang, Lhasa, Indochina, Sibumasu, and Western Burma blocks, which were separated from Gondwana, drifted northwards, and accreted to the Eurasian continent by opening and closing of two successive Tethyan oceanic basins (Paleo-Tethyan and Neo-Tethyan), and subsequent continental collision.The Tethyan domain represents a metallogenic amalgamation across diverse geodynamic settings, and is the best endowed of all large orogenic systems, such as those associated with the Cordilleran and Variscan orogenies. The ore deposits within the Tethyan domain include porphyry Cu–Mo–Au, granite-related Sn–W, podiform chromite, sediment-hosted Pb–Zn deposits, volcanogenic massive sulfide (VMS) Cu–Pb–Zn deposits, epithermal and orogenic Au polymetallic deposits, as well as skarn Fe polymetallic deposits. At least two metallogenic supergroups have been identified within the eastern Tethyan metallogenic domain (ETMD): (1) metallogenesis related to the accretionary orogen, including the Zhongdian, Bangonghu, and Pontides porphyry Cu belts, the Pontides, Sanandaj–Sirjan, and Sanjiang VMS belts, the Lasbela–Khuzdar sedimentary exhalative-type (SEDEX) Pb–Zn deposits, and podiform chromite deposits along the Tethyan ophiolite zone; and (2) metallogenesis related to continental collision, including the Gangdese, Yulong, Arasbaran–Kerman and Chagai porphyry Cu belts, the Taurus, Sanandaj–Sirjan, and Sanjiang Mississippi Valley-type (MVT) Pb–Zn belts, the Southeast Asia and Tengchong–Lianghe Sn–W belts or districts, the Himalayan epithermal Sb–Au–Pb–Zn belt, the Piranshahr–Saqez–Sardasht and Ailaoshan orogenic Au belts, and the northwest Iran and northeastern Gangdese skarn Fe polymetallic belts. Mineral deposits that are generated with tectonic evolution of the Tethys form in specific settings, such as accretionary wedges, magmatic arcs, backarcs, and passive continental margins within accretionary orogens, and the foreland basins, foreland thrust zones, collisional sutures, collisional magmatic zones, and collisional deformation zones within collisional orogens.Synthesizing the architecture and tectonic evolution of collisional orogens within the ETMD and comparisons with other collisional orogenic systems have led to the identification of four basic types of collision: orthogonal and asymmetric (e.g., the Tibetan collision), orthogonal and symmetric (Pyrenees), oblique and symmetric (Alpine), and oblique and asymmetric (Zagros). The tectonic evolution of collisional orogens typically includes three major processes: (1) syn-collisional continental convergence, (2) late-collisional tectonic transform, and (3) post-collisional crustal extension, each forming distinct types of ore deposits in specific settings. The resulting synthesis leads us to propose a new conceptual framework for the collision-related metallogenic systems, which may aid in deciphering relationships among ore types in other comparable collisional orogens. Three significant processes, such as breaking-off of subducted Tethyan slab, large-scale strike-slip faulting, shearing and thrusting, and delamination (or broken-off) of lithosphere, developed in syn-, late- and post-collisional periods, repsectively, were proposed to act as major driving forces, resulting in the formation of the collision-related metallogenic systems. Widespread appearance of juvenile crust and intense inteaction between mantle and crust within the Himalayan–Zagros orogens indicate that collisional orogens have great potential for the discovery of large or giant mineral deposits. 相似文献
17.
新疆和田火烧云铅锌矿的发现,标志着我国铅锌找矿在西昆仑甜水海地区取得了重大突破,区内目前已发现铅锌矿床（点）29处,其中铅锌矿中型矿床7个、大型矿床2个、超大型矿床1个。通过收集整理区内最新的矿产地质勘查成果资料,对该区带内铅锌矿的成矿特征、找矿前景进行系统分析与总结,将区内铅锌矿床划分为密西西比河谷型(MVT)和沉积喷流型(SEDEX) 2个大类和4个具体类型,认为它们的成矿过程分别与区域大地构造演化、区域断裂活动及同沉积断层-喷流沉积活动密切相关,在矿体形态、矿石矿物、矿石结构构造等矿化特征及成矿模式方面均有明显差异。火烧云式是受中侏罗统龙山组上段灰岩-白云岩沉积层位控制的沉积喷流型铅锌矿,化石山式是受中侏罗统龙山组铁锰质沉积层位控制的沉积喷流型铅锌矿,多宝山式是受断裂构造控制的碳酸盐岩建造中的MVT型铅锌矿,元宝岭式是受北东向左行张扭性断裂控制的碎屑岩建造中的MVT型铅锌矿。 相似文献
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19.
扬子准地台为大型克拉通碳酸盐发育的地区，从震旦系到中三叠统为典型盖层沉积，其中许多地层中不乏碳酸盐沉积。新中国建国以来，在其周边及其隆起边缘的碳酸盐地层中，陆续发现了许多层控铅锌矿床。近几年来，随着地质大调查的开展，又发现一批很有希望的铅锌矿化集中区。笔者总结了这些铅锌矿床的地质特征，并将这些矿床与国外的MVT矿床进行对比，探讨它们的矿质来源、成矿溶液、成矿机制和成矿控制因素等。 相似文献
20.
地质界面对桂中凹陷区铅锌矿床的控制意义 总被引：6，自引：0，他引：6
桂中凹陷大地构造条件特殊, 其北为桂北台隆, 与扬子地台接壤, 其西与右江再生地槽连接, 其东和南与大瑶山隆起相连.在区域性范围内, 广西大部分铅锌矿床分布于桂中凹陷的边缘.其中, 河池-南丹成矿带几十个大-中型和特大型铅锌铜矿床位于凹陷的西部及西北部边缘, 在凹陷的东南部和东部边缘有武宣-象州成矿带的几十个大-中型和特大型铅锌铜矿床, 在凹陷的南、北和东南、东北部边缘地带则连续分布着宾阳、贵县、锡基坑、北山、泗顶等若干个大-中型铅锌铜矿床.在矿区范围内, 铅锌矿体主要产于不整合面附近、多组断裂的交汇部位、岩体的周围、沉积岩相变带、不同岩性接触面等.不论在宏观的区域范围内, 还是在微观的矿区范围内, 矿床的成矿作用和分布明显受到地质界面的控制, 其主要特征与美国MVT铅锌矿床相似.地质界面是地球内部能量集中、汇集、传递、转化和释放的地带, 是地球物质变化、活化、迁移和沉淀富集的部位, 也是成矿作用发生的场所.桂中凹陷与周边地质构造单元接合处的地质界面是“ MVT型”铅锌矿床形成的有利地段. 相似文献