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青海松树南沟金矿矿床地质特征 总被引：2，自引：0，他引：2
青海松树南沟金矿床位于北祁连山环太平洋型俯冲带(缝合带),产于印支～燕山期花岗闪长斑岩体及其与围岩接触带附近。通过矿床地球物理、地球化学和地质特征综合分析,认为该金矿经历了加里东期火山作用阶段和华力西-印支期岩浆侵入作用阶段,但矿床的最终形成与晚华力西—印支期陆内碰撞造山产生的大规模剪切构造—流体活动使原有成矿物质活化、迁移、富集和沉淀成矿有关,可归类为造山斑岩型金矿床,已探明储量达中型规模,具良好的成矿远景。 相似文献
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柴达木盆地北缘(以下简称柴北缘)—东昆仑地区已经勘查发现了一批造山型金矿,它们是加里东和晚华力西—印支复合造山作用的产物。通过柴北缘—东昆仑地区12处造山型金矿中流体包裹体研究发现,该区造山型金矿中发育两种不同的成矿流体:低盐度的H2O-CO2-NaCl-CH4流体和低盐度的H2O-CO2-NaCl±CH4。前者的XCH4、XCO2和XH2O分别为0.14～0.34(平均值0.24)、0.11～0.59(平均值0.34)和0.64～0.31(平均值0.42),温度变化为180～270℃,压力为180～560Mpa,是晚加里东期碰撞造山作用的产物,主要沿加里东碰撞造山带边界的上地壳底部-中地壳上部的塑性变形带大规模流动,并在本区形成了广泛的金矿化;后者的XCH4、XCO2和XH2O分别为0～0.12(平均值0.06)、0.18～0.25(平均值0.21)和0.79～0.69(平均值0.73),温度变化为280～449℃(主要在280～360℃),压力为80～230Mpa,主要与晚华力西—印支期碰撞造山作用有关,其中不少矿床还受侵入岩浆作用的影响,其沿晚华力西—印支期碰撞造山带边界的上地壳大规模流动,导致了本区造山型金矿的最终定位。上述两期成矿流体的盐度相差不大,总体变化在1.4%～11.4%(NaCl)(大部分集中于2.7%～9.1%)。压力-深度换算结果显示,本区晚华力西—印支期碰撞造山作用表现出地壳强烈隆升过程,其最大隆升幅度达12km。这说明该区大规模的造山型金成矿作用发生在地壳隆升的背景之下。 相似文献
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会泽铅锌矿是川滇黔铅锌多金属成矿区的超大型矿床之一。以该矿床铅锌成矿系统研究为主线，结合近些年来前人的主要研究成果，深入分析了印支期造山背景对铅锌多金属成矿系统的控制作用，着重讨论了成矿构造体系与成矿系统的成生联系。研究表明，受印支期（成矿期）碰撞造山背景约束，该区发生了斜冲走滑构造作用，形成NE构造带成矿构造体系，为铅锌成矿系统提供了流体“运”移和“储”存条件，构造驱动成矿流体沿会泽矿山厂、麒麟厂断褶带发生大规模“运”移，并与盖层中碳酸盐岩发生水 岩相互作用。深部流体与盆地流体混合、流体不混溶等构造 流体多重耦合作用，使流体物理化学条件改变，导致富矿流体沿三条NE向主断裂上盘背斜的层间压扭性断裂带卸载沉淀，形成NE向延伸、SE倾斜、SW向侧伏延深的雁列式柱状矿体。研究认为，斜冲走滑构造作用形成的成矿构造体系是制约该矿床“大（矿床、矿体规模大）、深（矿体延深大）、强（热液蚀变强）、带（矿物组合分带明显）”特征的主要原因，“多（共伴生元素多）”与成矿流体迁移 聚沉过程中所经过岩石的性质有关。该研究对川滇黔成矿区乃至同类矿床研究和深部勘查具有重要的理论意义和实际意义。 相似文献
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流体包裹体研究表明,滩间山矿区的金矿体是2次热液-矿化事件的叠加产物。第一次热液-矿化作用与区域上加里东碰撞造山作用有关,形成的流体属于中低温(186～250℃)、低盐度〔w(NaCleq)1.4%～7.9%〕的H2O-CO2-CH4-NaCl体系,压力变化于(4900～1800)×105Pa之间,其主要沿NW向剪切带迁移和沉淀形成金矿化。第二次热液-矿化作用与晚古生代—早中生代碰撞造山作用密切相关,产生两种不混溶流体。第一种不混溶流体属于高温的H2O-NaCl体系,可能与岩浆侵入活动有关,第二种不混溶流体为温度274～289℃,盐度w(NaCleq)1.8%～7.9%,x(CO2)=0.19～0.27,x(H2O)=0.81～0.73,压力为(2300～1100)×105Pa的H2O-CO2-NaCl体系的流体,其沿NW向剪切带内的近NS向褶皱两翼的层间破碎带流动和沉淀,并最终导致滩间山矿床内金矿体的定位。按岩压估算,第一次热液-矿化事件发生于上地壳下部,第二次热液-矿化事件发生于浅成环境,这也进一步证实了滩间山矿床的金成矿于区域晚华力西时期的隆升造山过程中。与晚加里东碰撞造山期间相比,本区晚华力西期-印支期碰撞造山过程中的最大隆升幅度达9km左右。 相似文献
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驼路沟喷气沉积型钴(金)矿床的地质-地球化学 总被引：19，自引：3，他引：16
驼路沟矿床是容矿于震旦－寒武纪富钠火山－沉积岩系中的钴（金）矿床。矿床地质－地球化学特征,矿体的产态,矿石结构构造以及金属矿物的标型表明,驼路沟钴（金）矿床主要与震旦－－寒武纪海底喷气沉积成矿作用有关,在加里东和晚华力西－印支碰撞造山过程中,喷气沉积型矿体被构造改造,并导致金在局部地段进一步富集。元素地球化学研究揭示,Au,As,Pb,Cu,Zn,Mo,Co是圈定含矿层的化探异常元素组合,而Co-Ni-Au-Pb-Mo-As组合异常可以指示矿体。建议在矿床勘查的初期注意可能出现于喷气沉积成矿中心附近的铜钴矿。 相似文献
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江南造山带(湖南段)金矿成矿规律与资源潜力 总被引：1，自引：0，他引：1
扬子地块—华夏地块经历武陵期—雪峰期增生造山-碰撞造山形成江南造山带,构成统一的华南板块,进入板内演化阶段。本文从构造-岩浆作用-沉积建造角度,结合地质年代学、古地磁、岩相古地理分析,加里东运动、印支运动属陆内作用,造就了加里东期、印支期两次主要的金矿成矿事件。湖南雪峰山—幕阜山(俗称“金腰带”)加里东期和印支晚期金矿床分区成带产出,构成一条复合型造山型金矿带。区域性构造导矿、次级构造交汇或叠加控矿明显;矿石普遍发育条带状构造,属韧性剪切递进变形的产物。通过对区域成矿背景、金矿成矿理论,金矿床(体)地质特征,结合同位素地球化学、地质找矿成果及深部验证情况等多方面研究表明该成矿带深部找矿潜力巨大,2000 m以浅金远景资源量有望达到3000 t。 相似文献
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造山型金矿形成于汇聚板块边缘,俯冲增生或碰撞造山体制,是现代矿床学研究的热点之一。西准噶尔地区有几十个造山型金矿,但其究竟形成在洋壳俯冲增生造山过程还是洋盆闭合后的碰撞造山过程,尚不清楚。本文系统总结了西准噶尔地区造山型金矿的时空分布及地质、地球化学特征,发现它们主要赋存于达拉布特断裂西北侧,可分为安齐(包括哈图金矿)和萨尔托海(包括萨Ⅰ金矿)两个成矿带;成矿作用受控于达拉布特走滑断裂引发的区域变质变形事件,矿体主要赋存于中晚石炭世变质火山沉积岩或蛇绿岩中,发育NaCl—H_2O—CO_(2 )±CH_(4 )±N_2流体包裹体体系,成矿温度为170～380℃,成矿流体主要为变质热液,晚期为大气降水热液;成矿同位素年龄为271～300 Ma,已有资料显示西准噶尔地区存在多期次俯冲增生作用,并于晚石炭世—早二叠世消减完毕。而造山型金矿广泛发育的达拉布特西北侧古洋盆闭合于308～328 Ma,此后为大陆碰撞造山体制,因此西准噶尔造山型金矿形成于大陆碰撞造山体制,适合于碰撞造山成岩成矿和流体作用模式。晚石炭世—早二叠世,达拉布特地区陆—陆或弧陆碰撞过程中,大规模的韧脆性剪切变形及区域变质事件导致地层及围岩中不稳定组分发生变质活化,形成含矿变质流体,流体向上运移至韧—脆性转换带内形成了西准噶尔造山型金矿成矿系统。 相似文献
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江南造山带湖南段为一重要的金成矿带,目前关于带内金矿形成的时代背景存在较大争议。本文基于区域成岩成矿年代学、矿床(区)地质特征、矿床成因和流体来源、区域构造演化背景等多方面资料,对带内各主要金矿区的成矿时代逐一进行详细解析,以此为基础重新厘定了区域金矿成矿地质事件及其时代,并探讨了各成矿事件的构造背景,初步形成以下认识。江南造山带湖南段主要发生了加里东期、印支晚期和燕山期等3期金成矿事件。加里东期金矿成矿年代为430～410 Ma(志留纪后期),产于同期雪峰冲断带的中段-西南段和东段东部、湘中-湘东南构造岩浆带的东北部等3个地区,各区赋矿地层分别为板溪群、冷家溪群、冷家溪群,前两个地区的成矿与加里东运动变质变形和构造活化作用有关,后一个地区的成矿与志留纪后期花岗质岩浆活动提供热能和流体有关。印支晚期金矿成矿年代为227～202 Ma(晚三叠世),主要分布于同期雪峰冲断带东南缘构造岩浆隆起带,与后碰撞花岗质岩浆活动的热能和热液驱动有关。燕山期金矿成矿年代为152～130 Ma(晚侏罗世—早白垩世初),主要分布于同期雪峰冲断带东南部构造岩浆隆起带的东部,与伸展环境下的花岗质岩浆活动有关。 相似文献
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[摘 要]温泉钼矿床的形成与西秦岭造山带印支期碰撞造山事件和岩浆活动密切相关。西秦岭温泉钼矿床成因及成矿过程的研究成为揭示印支期秦岭造山带构造体制转换与大规模成矿关系的关键,对发展秦岭造山带印支期成矿理论和印支期花岗岩的成矿潜力评价以及找矿勘探都具有重要意义。本文在前人对温泉钼矿床区域地质和矿床地质研究的基础上,对该矿床的矿床地质-地球化学特征做了进一步的综合研究,结果表明温泉钼矿床成矿物质来源于花岗岩浆气水热液,成矿与印支晚期花岗质岩浆结晶分异过程中产生的岩浆热液活动密切相关;温泉钼矿床具备岩浆热液型矿床的地质特征,其成矿过程为:晚三叠世秦岭造山带发生由挤压向伸展转变的构造体制转换引起下地壳发生熔融形成富含Mo的花岗质岩浆,岩浆在结晶过程中冷凝分异出的成矿流体经充填和交代作用而使Mo 富集形成矿床 相似文献
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Continental China is a mosaic of numerous tectonic blocks, which amalgamated from Neoarchean to Cenozoic broadly coeval with the cycles of global supercontinents such as Kenorland, Columbia, Rodinia, Gondwana, and Pangaea. By reviewing the long-lasting geological evolution in the different tectonic blocks, it reveals that more than two episodes of tectonic events, including accretionary and collisional orogeny, and dismantling, as well as mantle plume, occurred successively or simultaneously within a single tectonic belt. This is called superimposed orogeny in this study. Examples of the dominant types of superimposed orogeny in China include: (1) Cenozoic continental collision superimposed on Paleo- to Mesozoic accretionary orogeny in the Tibet and Sanjiang orogenic belts; (2) Reactivation of Paleozoic accretionary orogen in later Mesozoic oceanic subduction in the eastern part of Qinling–Qilian–Kunlun and Central Asian orogenic belts; (3) Mesozoic oceanic subduction under the paleo-suture in the South China Block; (4) Mesozoic demantling along the Paleo- and Neoproterozoic, and Paleozoic sutures in the eastern part of North China Craton; and (5) mantle plume rising through metasomatized lithospheric mantle or stagnant oceanic slab in the Emeishan large igneous province. A comprehensive review of the spatial-temporal distribution of ore deposits and their salient features shows that the superimposed orogeny has exerted significant control on metallogeny in China. The giant porphyry and skarnore deposits, as well as orogenic gold deposits were preferentially formed along previous tectonic suture, craton margin, and arc during later orogenesis due to the remobilization of previously enriched metals. Superimposed orogeny has reworked the lithospheric structure with concomitant granitoid-associated metallogeny. The mixing of magmas from juvenile lower crust, ancient lower crust, and middle crust, which tends to induce the different mineralization of Cu–Au, Mo, and Pb–Zn–W–Sn deposits respectively, was considered to generate a wide variety of combinations of metal species. The superimposed orogeny caused the overlapping of diverse genetic types of deposit formed in different tectonic periods in the same tectono-metallogenic belt. The stratiform ore deposit, including BIF, VMS, SEDEX, or sedimentary sulfide layers, formed from Neoarchean to Paleozoic, were modified by later mineralization, resulting in the enrichment of the various metal species and enhancement of ore resources. This study brings up the concept of composite metallogenic system to summarize the regional metallogeny driven by superimposed orogeny. The composite metallogenic system was dominantly characterized by the multi-episodic and diverse mineralization concomitant with one or more features, including mineralization evolved from the previous metal enrichment, later overlapping or modification on previous ore belt, and diversifying of metal species derived from reworked lithosphere. 相似文献
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复合造山和复合成矿系统:三江特提斯例析 总被引：30，自引：26，他引：4
提出复合造山定义,认为复合造山指多期次造山以及其它类型壳幔过程(裂谷作用、地幔柱活动、克拉通减薄等)在同一构造带先后发生或者多类型过程同时同位发生的地质事件;复合造山是大洋闭合-大陆拼贴过程的必然演化结果、地质历史时期普遍存在的地质过程,其具有不同属性板块拼接、多条蛇绿岩套与岛弧带并列、构造格架继承与改造、物质活化与循环运动以及构造体制转换突出等特征;复合造山带成矿时代长,类型多样,金属富集强度大,大型矿集区集中。复合成矿系统指在特定时-空域中,不同时期多种成矿作用或者同一时期不同成矿作用复合形成的成矿系统。复合成矿表现为成矿物质继承改造或成矿作用融合交叉,导致成矿元素多幕式富集,成矿空间广,成矿强度大,成矿概率增加。复合成矿系统分为多期复合和同期复合两类。复合造山驱动了复合成矿系统的形成,其是中国区域成矿典型特色。复合造山和复合成矿系统在特提斯构造带最为典型,中国西南三江造山带是典型解剖区。构建了古生代与中生代原-古-中-新特提斯洋闭合引发的增生造山和新生代印度-欧亚大陆汇聚导致的碰撞造山过程,厘定了增生造山海底喷流型Cu-Pb-Zn-Ag、增生-碰撞造山岩浆热液型CuMo-Sn-W、碰撞造山盆地卤水-岩浆热液型Pb-Zn-Ag-Cu和碰撞造山斑岩-矽卡岩型Au-Cu-Mo四类典型复合成矿系统。 相似文献
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胶东中生代动力学演化及主要金属矿床成矿系列 总被引：8，自引：4，他引：4
胶东处于古特提斯和太平洋两大成矿域的结合部位,经历了强烈的中生代构造岩浆活动和重要金属矿床成矿作用。本文通过对中生代各期岩浆活动背景、典型矿床成因类型的分析判别,结合区域地质构造特征,总结提出胶东中生代成岩成矿动力学演化主要受扬子板块、华北板块碰撞造山作用和古太平洋板块俯冲作用影响,并可划分为晚三叠世陆陆碰撞造山期,中侏罗世被动陆缘向活动陆缘转换、地壳增生期,早白垩世早期地壳增生向垮塌转换期,早白垩世中期岩石圈大规模拆沉、壳幔强烈作用期,早白垩世晚期陆缘弧俯冲作用期,和晚白垩世早期弧后岩石圈强烈伸展期六个演化阶段,分别对应着区域~205Ma、160~155Ma、135~125Ma、125~115Ma、115~100Ma、100~90Ma等六期主要金及多金属成矿作用;形成的贵金属及有色金属矿床具有较为明显的时空分布规律,大致包括6个矿床成矿系列,分为9个亚系列和16个矿床式。自西向东,可划分出莱州西部、招远-平度、栖霞-蓬莱-福山、胶莱盆地东北缘、牟平-乳山、文登-威海、荣成等7个贵金属、有色金属成矿区(带)。区内造山型金矿仍是找矿的重点,斑岩型有色金属矿床可望取得突破,中低温热液脉型多金属矿床应受到充分重视。 相似文献
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D. Rickard 《Mineralium Deposita》1999,34(5-6):417-421
Phanerozoic metallogenesis in Europe displays divergent characteristics which may be related to the variable nature of the
three great European Phanerozoic orogens: Caledonian, Variscan and Alpine. These reflect different geodynamic processes. The
Caledonian orogen resulted from the interaction of essentially oceanic with continental lithosphere, whilst the Variscan and
Alpine orogens evolved mainly from continent-continent collisions with the involvement of a series of smaller oceanic basins.
Each major stage of the orogenic processes is characterised by a typical metallogeny. The occurrence of subduction-related
processes in the Caledonian orogeny gave rise to extensive VHMS deposition with characteristic Zn:Cu ratio signatures. The
relative lack of abundance of metal-rich, Andean-type porphyry-type mineralisation remains unexplained, unless present erosional
levels have prevented the preservation of such deposits. Continent-continent collisions do not appear to result in extensive
mineralisation unless elevated heat flows result, possibly as a result of lithospheric delamination at the peak collisional
stage. The development of late stage and peri-orogenic sedimentary basins are characterised by extensive Pb-Zn-Ba-F mineralisation
as expressions of basinal fluid flow of regional dimensions. 相似文献
15.
青海省东昆仑地区晚古生代—早中生代火山活动与区域构造演化 总被引：43，自引：1，他引：42
从沉积建造分析入手,通过对区内晚古生代—早中生代火山岩组合的构造属性识别,认为区内晚古生代—早中生代构造演化是一个连续的过程,它奠定了该区的基本构造格局,也是金与铜多金属矿产的主要成矿时期;晚古生代—早中生代发育的双岩浆弧是在同一动力学机制下不同阶段形成的造山岩浆弧：陆缘的钙碱性岩浆弧和陆内的高钾钙碱性岩浆弧。晚古生代—早中生代构造岩浆旋回可以划分为２个阶段,早期的俯冲造山阶段形成了与蛇绿岩有关的火山岩类和弧火成岩类,晚期的大洋闭合和碰撞造山阶段则形成了钾玄岩系列火山岩。 相似文献
16.
造山带热结构对大陆碰撞带的形态大小、构造式样、岩浆活动和变质作用具有重要控制作用。然而,热结构对碰撞成矿作用的控制还不清楚。本文概述比利牛斯、阿尔卑斯、加里东、扎格罗斯、青藏高原和华力西等全球主要碰撞带的热结构与成矿系统发育特征,对比各个造山带内不同矿床类型成矿温度变化,探讨热结构对碰撞成矿的控制作用。研究表明,碰撞带主要发育盆地流体有关的密西西比河谷型铅锌矿床、变质流体有关的造山型金矿床和岩浆热液有关矿床(斑岩铜矿床、云英岩型钨锡矿床和岩浆热液有关的铌钽锂铍矿床等)。其中,前两者在大多数碰撞带内均有发育,代表了大陆碰撞成矿作用的基本类型。这些矿床的成矿温度在热碰撞带比较高而在冷碰撞带则偏低。岩浆热液有关矿床一般只出现在比较热的碰撞带内,这些热碰撞带的温度压力条件有很大区域在湿固相线以内,热扰动能够造就地壳发生部分熔融形成含矿岩浆。 相似文献
17.
东昆仑祁漫塔格早中生代大陆地壳增生过程中的岩浆活动与成矿作用 总被引：1，自引：0，他引：1
东昆仑祁漫塔格地区位于青藏高原北缘,为典型的大陆边缘增生造山带,经历了漫长的古生代—早中生代增生造山过程,其中以早中生代岩浆活动与成矿作用最为发育。文章系统总结了区内早中生代侵入岩分布及成因,对与其相关矿床地质、成矿流体特征及成矿物质来源进行分析,进一步探讨了祁漫塔格地区早中生代大陆地壳增生过程中的壳幔混合岩浆活动与成矿作用的关联。研究结果认为,中二叠世—早三叠世以俯冲阶段的侧向增生为主,中-晚三叠世以碰撞-后碰撞阶段的垂向增生为主,与成矿有关的岩浆岩主要为中-晚三叠世石英闪长岩、花岗闪长岩、二长花岗岩、正长花岗岩、花岗斑岩等,以I型、A型花岗岩为主,且多见暗色包体,Sr-Nd-Hf同位素组成表明其源于古陆壳物质的重熔,有地幔物质的参与,由地幔底侵古老陆壳,幔源基性岩浆与壳源花岗质岩浆发生不同程度混合作用而形成。与该时期岩浆活动关系密切的主要为斑岩型铜钼矿床、矽卡岩型铁多金属矿床、层控矽卡岩型铅锌矿床、与碱性花岗岩有关稀有金属矿化等。成矿时代集中于248~210 Ma,成矿流体主要来源于岩浆热液,成矿物质具有壳幔混合来源,区内中-晚三叠世大陆垂向增生过程中的壳-幔岩浆混合作用为区域大规模金属成矿提供大量热能、成矿流体及成矿物质。 相似文献
18.
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
19.
《International Geology Review》2012,54(6):523-538
The Qinling orogen extends 1650 km E-W and has a width of 95-255 km. It has a long evolutionary history of ～3.02 Ga and a mineralization history of approximately 2.5 Ga. There are more than 400 mineral deposits of Au, Ag, Pb, Zn, Sb, Hg, Mo, W, Fe, Ni, Mn, rare elements, REE, U, V, P, As, Ba, Sr, Ti, Al, pyrite, gypsum, trona, halite, glauberite, mirabilite, blue asbestos, fluorite, rock crystal, mica, vermiculite, graphite, kyanite, andalusite, talc, fireclay, and K-feldspar in the Qinling orogen and adjacent areas. The deposits were formed in six tectono-minerogenic cycles and have been grouped into 21 regional minerogenic series. The metallogeny of the Qinling orogen is closely associated with the tectonic evolution of the orogen, and most of the ore deposits were formed in two important metallogenic periods: (1) Middle Proterozoic to Early Paleozoic, which was characterized by spreading and rifting-related minerogenetic processes; during this period, the minerogenic series are directly associated with basic-ultrabasic magmatism and marine volcanism resulting from spreading-rifting and deep faulting; (2) Mesozoic, when mineralization was controlled by intracontinental subduction and postorogenic relaxational taphrogenesis or extension; the minerogenetic series are associated with intermediate-acid magmatism and terrestrial volcanism. Gold is one of the most important ore-forming commodities in the Qinling orogen. Over 80% of those gold deposits were formed in the Mesozoic and Cenozoic and are related genetically to magmatism, terrestrial volcanism, and alluvial sedimentation. Most gold deposits in the Qinling orogenic belt are of hydrothermal origin. The Dashui-type gold deposits may be a new category of high-sulfi-dation epithermal gold deposits hosted by carbonate rocks of the Upper Paleozoic and Triassic in the southwestern part of the Qinling orogen. Shuangwangtype gold deposits in the middle of the Qinling orogen are characterized by low-grade (but large in terms of tonnage) ores hosted by brecciated and banded albitites, which are thought to have been formed by Yanshanian (late Mesozoic) magmatic-hydrothermal fluids injected into the Devonian sedimentary rocks. Carlin-type, quartz vein-type, and placer-type deposits also are important in this continental orogenic belt and adjacent areas. 相似文献