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1.
吉林夹皮沟成矿带金成矿作用与太古宇变质岩系、幔源岩浆活动、韧性剪切带密切相关。成矿流体以地幔流体为主,成矿物质主要来源于地幔,地幔活动形成的韧性剪切带及其伴生的次一级断裂构造不仅是成矿流体的运移通道,而且是矿体就位的有利空间。论述了新立屯-马家店、大朝阳沟地区具有金矿成矿的基本地质条件-太古宇变质岩系广泛分布,幔源岩浆、韧性-脆性构造活动强烈;金矿化体(石英脉)受韧性剪切带两侧的次一级断裂控制,质  相似文献   

2.
胡平  周阳 《吉林地质》2013,(4):35-36,42
夹皮沟地区地处吉林省东南部,是我国比较重要的金成矿带之一。本文介绍了该区的地层、构造、岩浆岩,特别是那些沿着环形构造发育的韧性剪切带与金成矿关系密切。阐述了金矿形成的三个基本条件——太古宇变质岩系、剪切体系的构造破碎蚀变带以及幔源岩浆活动,根据上述条件指出找矿远景区——新立屯—马家店地区和大朝阳沟地区。  相似文献   

3.
吉林夹皮沟断裂带动力系统碰撞,叠加及金矿床形成   总被引:10,自引:0,他引:10       下载免费PDF全文
动力系统是金成矿作用研究的关键,它控制金矿床产生的始终,运用成矿动力系统思想把夹皮沟区地壳演化和金成矿为三大阶段和三大构造带,(1)太古一元古宙克拉通隆-滑动力系统边缘矿化带,太古宙克拉通隆起,元古宙沉积物拉伸滑断,矿矿动力系统在克拉通周边形成韧性剪切带,金受到初步富集;(2)海西俯冲动力系统南缘矿化带,西伯利亚板块与中朝板块间大陆拉张和碰撞,正反动力系统产生超壳断裂和金矿化;(3)中生代叠加构造岩浆动力系统成矿带,中生代太平洋板块俯冲,反动力系统产生超壳断裂和金矿化;(3)中生代叠加构造岩浆动力系统成矿带,中生代太平洋板块俯冲,反动力系统产生超壳断裂和金矿化;(3)中生代叠加构造岩浆动力系统成矿带,中生代太平洋板块俯冲,郯庐断裂滑称及区域NNE与NW向共轭控矿等多级动力系统叠加,岩浆活动和幔源流体上升及金元素进一步富集等夹皮沟金矿床最终形成,成矿预测范围由原变质岩区进入夹皮沟断裂带上及两侧俯近中生代花岗岩区。  相似文献   

4.
邵军 《地质与资源》1999,8(4):229-235
地幔活动是岩石圈构造活动的动力学基础,是上地壳发生地质作用——区域变质作用、成岩成矿作用——所需要的深源物质、能量乃至流体的主要来源形式.吉林省东南部地区的麻粒岩相区域变质作用、幔源岩浆的侵入-喷发活动以及深部构造活动等特征表明,该地区曾有太古宙末期和中生代两个地幔活动高峰期.夹皮沟大型金矿田的金矿成矿作用与地幔活动有密切的成因联系.成矿作用主期与地幔活动的高峰期相对应.稳定同位素研究显示成矿物质、成矿热液主要来源于地幔.地幔活动引起携带大量热流体和丰富的成矿元素的幔源物质上侵,并且在下地壳重熔过程中活化、萃取了围岩中成矿物质而形成成矿流体;伴随地幔活动形成的深大断裂构造、大型韧性剪切带不仅是成矿流体运移的通道,而且为成矿物质沉淀提供了有利空间.  相似文献   

5.
以南天山中段萨恨托亥-大山口成矿带内控矿韧性剪切带为例,对韧性剪切带的金成矿作用进行了初步探讨.通过对地质体的构造变形特点、变形演化过程的分析表明,韧性剪切带的构造属性控制了金矿的产状及规模,金矿化阶段与韧性剪切带的变形演化过程密切相关.矿化类型、矿化强度及矿化方式受韧性剪切带发展阶段制约,剪切带内物质组分迁移变化揭示出韧性剪切带与金在剪切带内的迁移富集、沉淀成矿的内在联系.韧性剪切带成矿作用是南天山成矿带中段重要的金矿成矿作用.  相似文献   

6.
以南天山中段萨恨托亥-大山口成矿带内放韧性剪切带为例,对韧性剪切带的金成矿作用进行了初步探讨。通过对地质体的构造变形特点、变形演化过程的分析表明,韧性剪切带的构造属性控制了金矿的产状及规模,金矿化阶段与韧性剪切带的谱形演化过程在。矿化类型、矿化强度及矿化方式受韧性发带发展阶段制约,剪切带内物质组分迁移变化揭示出韧性剪切带内的迁移富集、沉淀成矿的内在联系。韧性剪切带成矿作用是南天山成矿带中段重要的金  相似文献   

7.
陕西周至马鞍桥金矿床地质特征及成因分析   总被引:4,自引:3,他引:4  
阐述了马鞍桥金矿区的地层、构造、岩浆岩特征,总结了金矿床矿体、矿石及化学成分的基本特点,分析了围岩、剪切构造带、中酸性岩体与金矿化的关系,认为马鞍桥金矿的成矿物质来源于围岩泥盆系罗汉寺岩群,成矿作用严格受脆性剪切变形变质带控制,剪切同期中酸性岩浆活动为含矿热液上升迁移和富集成主矿体提供了必要的热能。含矿热液与韧性剪切变质岩之间交代作用的强度是导致金的沉淀和富集形成金矿体的关键。矿床为韧性剪切带蚀变岩型金矿。  相似文献   

8.
通过研究小秦岭金矿田构造控矿和构造赋矿特征,总结了成矿与韧性剪切带的关系,肯定了小秦岭金矿为韧性剪切带控制的矿床。成矿的同位素年龄表明,同一矿床中同韧性剪切带成矿作用和后韧性剪切带成矿作用往往同时存在,矿床普遍具有叠加改造成矿的特征。区内成矿流体组分与地幔流体组成相似,成矿流体的H、O、S、C、He、Ar同位素组成显示其初始来源为地幔。由于区内后期剥蚀少,从而使主要矿体得到了保存。韧性剪切带型金矿矿化带深度往往相当大,甚至大于矿化带长度。近年来的接替资源勘查工作证明中深部矿体的存在,因此,小秦岭金矿深部具良好找矿前景。  相似文献   

9.
永兴金矿区所发现的金矿化体受北东向韧性剪切带控制,矿化体类型有含金糜棱岩型、含金石英脉型和含金硅化角砾岩型。由于成矿作用的多期性,导致矿床类型的多样性。中晚太古界地层,特别是晚太古界夹皮沟岩群三道沟岩组为本区金矿的主要初始矿源层,在后期断裂构造、岩浆活动等成矿作用下金元素进一步迁移富集成矿,基本构成地层、构造、岩浆岩三位一体的成矿模式。由于成矿作用的多期性和矿床类型的多样性,拓宽了该区找矿的思路,即在寻找石英脉型金矿的同时,应注意其它类型金矿的寻找。  相似文献   

10.
朱永峰 《矿床地质》2004,23(4):509-519
文章总结了产在克拉通和古生代造山带中、受韧性剪切带控制的金矿的重要研究成果。通过对比这两类金矿的地质特征及其成矿作用发生的大地构造背景,探讨形成韧性剪切带型金矿的成矿环境与成矿机制。大型韧性剪切带型金矿一般就位于剪切带的脆一韧性转换位置,成矿作用一般不受围岩性质和变质程度的控制。剪切带既是成矿流体的通道,又是金的沉淀场所。克拉通中韧性剪切带型金矿的成矿模式有两类:同构造成矿和构造期后成矿,前者认为变质流体沿韧性剪切带迁移,最终在剪切带中沉淀形成矿床;后者则强调发生在韧性剪切带形成之后的地质过程如岩浆活动等对成矿作用的贡献。  相似文献   

11.
Jun Deng    Liqiang Yang    Bangfei Gao    Zhongshi Sun    Chunying Guo    Qingfei Wang    Jianping Wang 《Resource Geology》2009,59(2):140-152
The Jiapigou gold belt, one of the most important gold-producing districts in China, is located in the northern margin of the North China Craton (NCC). The tectonic evolution of the gold belt is closely related to the Siberian Plate (SP) in the north, Yangtze Craton (YC) in the south and Pacific Plate in the east. In order to investigate the nature of the tectono-fluid-metallogenic system, the authors investigated the relationships among the tectonic regimes, fluid evolution and metallogenesis. This paper examined the corresponding spatial–temporal relationship between the ore-controlling tectonic regime and hydrothermal fluid evolution in the Jiapigou gold belt. There are two types of gold mineralization: disseminated ores that are distributed within the NW-trending main ductile shear zone and gold-bearing quartz veins and minor disseminated ores that are distant to the ductile shear zone. The fluid inclusions in quartz contain a large amount of CO2. Metamorphic fluids of middle to high temperatures and pressures and meteoric waters of low temperatures and pressures mixed together during mineralization. A proposed ore-forming model is as follows: in the pre-ore phase, the collision of SP and NCC resulted in the NS-trending compression of the ore belt. This formed the NE-trending and NW-trending shear faults and EW-trending folds. During the ore-forming phase, the collision of YC and NCC resulted in dextral shearing of the NW-trending Jiapigou fault and the NE-trending Green faults. High-pressure fluids caused by the compression flowed into the dilatant zone. This may have caused both phase separation of CO2-bearing fluids and the mixing of meteoric waters, metamorphic waters and magmatic source fluids and finally resulted in the disequilibrium of the ore fluids and precipitation of ore minerals.  相似文献   

12.
吉林省夹皮沟金矿成因研究   总被引:1,自引:0,他引:1  
李碧乐  金巍 《世界地质》1998,17(1):22-25
吉林省夹皮沟金矿区金矿赋存在夹皮沟北西向韧性带内,控矿构造为叠加在韧性剪切带之上的脆性构造。中生代中酸性脉岩为成矿期脉岩,且与黄泥河花岗岩岩基有着密切的成因联系。成矿物质主要来自岩浆分异,金丰度值高的暗色岩类提供部分矿质。  相似文献   

13.
枣子沟金矿位于同仁-夏河-岷县金成矿带,矿区赋矿地层为三叠纪中统古浪堤组下段细碎屑岩及灰岩,并发育大量闪长质脉岩。矿体既产于地层中,也出现在脉岩或其接触带中,但其产状均严格受NE、NW及近SN向3组断裂构造控制,控矿构造为高角度的张剪性及旋扭性断裂。热液成矿期可划分为黄铁矿-石英阶段,黄铁矿-毒砂-(闪锌矿-方铅矿-黄铜矿-辉银矿-绢云母-绿泥石-)石英阶段,辉锑矿-石英-方解石阶段及石英-方解石阶段。围岩蚀变类型主要为硅化、方解石化及绢云母化。环境扫面电镜及电子探针测试数据表明,金呈显微可见金存在于矿物裂隙和粒间隙中或以纳米不可见金捕获在载金矿物中。成矿期不同硫化物金的质量分数均高出检测限,其范围为0.003%~0.658%,平均值为0.257%。枣子沟金矿床具有卡林型金矿床的典型特征。氢氧同位素数据显示成矿流体主要来自大气水,硫同位素数据则表明硫主要来自沉积地层。其成矿过程可能为深切割断裂导通地下水,在深部被加热循环萃取围岩中成矿物质,并在浅表张性断裂中充填交代围岩,致使成矿物质沉淀富集成矿。金的迁移形式可能存在AuH3SiO04、Au(HS)2-、H2Au(Sb,As)S02和HAu(Sb,As)S3-等多种迁移方式。成矿早阶段可能以金硅络合物的解体为主,成矿晚阶段则可能是硫氢(锑)络合物发生解体,致使金与硫化物同时沉淀,以显微纳米金的形式包含在硫化物中。  相似文献   

14.
内蒙古西口子-八道卡地区岩金成矿特征   总被引:1,自引:1,他引:1  
西口子-八道卡地区大地构造位置处于额尔古纳地块北部.区内出露变质岩系为古元古界新华渡口群和新元古界震旦系加疙瘩群.侏罗纪中-酸性岩浆岩活动强烈.基底断裂构造呈近东西向,在侏罗纪形成一系列左行的压扭性北东向断裂构造及伴随的北西向、近南北向张性断裂.金矿化体呈脉状、透镜体状发育在变质岩系、黑云二长花岗岩体的破碎蚀变带内或变质岩系与石英闪长岩的接触部位,受左行压扭性北东向断裂构造与北西向、近南北向张性断裂构造的联合控制.金矿化类型为蚀变岩型和石英脉型,金矿化与硅化、黄铁矿化、绢英岩化关系密切.地球化学研究表明金矿化与黑云二长花岗岩、石英闪长岩关系密切,成矿物质主要来源于地壳深部或地幔,成矿热液属富碱质的、具有弱还原性质的岩浆热液.依据区内金矿成矿作用特点,总结了金矿找矿标志.  相似文献   

15.
广西新坪金矿地处大瑶山多金属成矿带六岑矿田,矿体主要受新坪复式背斜和近东西向的断裂破碎带控制,赋存于寒武系黄洞口组砂岩、砂泥岩中。石英流体包裹体数据显示,成矿流体为中温低盐度低密度含CO2的流体;流体中阳离子以Na+、Ca2+、Mg2+、K+为主,阴离子以Cl-为主。氢氧同位素分析表明,成矿流体中水可能主要来源于岩浆,并叠加有变质水,且不排除有少量大气水加入的特征;矿石硫化物的硫同位素组成范围较窄,多为距离零轴很近的负值,推断可能是深源硫与地层硫的混合。根据本次分析及结合前人研究表明,Au来源具有多源性,主要来源于寒武系地层,但区内深源岩浆岩也有提供Au的可能性。据以上分析,结合前人对该地区矿床成因的研究,初步认为新坪金矿属于变质-岩浆热液叠加成矿。  相似文献   

16.
The Jiapigou gold belt (>150 t Au), one of the most important gold-producing districts in China, is located at the northeastern margin of the North China Craton. It is composed of 17 gold deposits with an average grade around 10 g/t Au. The deposits are hosted in Archean gneiss and TTG rocks, and are all in shear zones or fractures of varying orientations and magnitudes. The δ34S values of sulfide from ores are mainly between 2.7?‰ and 10?‰. The Pb isotope characteristics of ore sulfides are different from those of the Archean metamorphic rocks and Mesozoic granites and dikes, and indicate that they have different lead sources. The sulfur and lead isotope compositions imply that the ore-forming materials might originate from multiple, mainly deep sources. Fluid inclusions in pyrite have 3He/4He ratios of 0.6 to 2.5 Ra, whereas their 40Ar/36Ar ratios range from 1,444 to 9,805, indicating a dominantly mantle fluid with a negligible crustal component. δ18O values calculated from hydrothermal quartz are between ?0.2?‰ and +5.9?‰, and δD values of the fluids in the fluid inclusions in quartz are from ?70?‰ to ?96?‰. These ranges suggest dominantly magmatic water with a minor meteoric component. The noble gas isotopic data, along with the stable isotopic data, suggest that the ore-forming fluids have a dominantly mantle source with minor crustal addition.  相似文献   

17.
The Sanshandao Au deposit is located in the famous Sanshandao metallogenic belt, Jiaodong area. To date, accumulative Au resources of 1000 t have been identified from the belt. Sanshandao is a world-class gold deposit with Au mineralization hosted in Early Cretaceous Guojialing-type granites. Thus, studies on the genesis and ore-forming element sources of the Sanshandao Au deposit are crucial. He and Ar isotopic analyses of fluid inclusions from pyrite(the carrier of Au) indicate that the fluid inclusions have 3 He/4 He=0.043–0.21 Ra with an average of 0.096 Ra and 40 Ar/36 Ar=488–664 with an average of 570.8. These values represent the initial He and Ar isotopic compositions of ore-forming fluids for trapped fluid inclusions. The comparison of H–O isotopic characteristics combined with deposit geology and wall rock alteration reveals that the ore-forming fluids of the Sanshandao Au deposit show mixed crust–mantle origin characteristics, and they mainly comprise crust-derived fluid mixed with minor mantle-derived fluid and meteoric water during the uprising process. The ore-forming elements were generally sourced from pre-Cambrian meta-basement rocks formed by Mesozoic reactivation and mixed with minor shallow crustal and mantle components.  相似文献   

18.
This paper deals with characteristics of silicon isotope compositions and siliceous cathodolumines-cence of host rocks, ores and hydrothermal silicified quartz of the Carlin-type ore deposits in the Yunnan-Guizhou-Guangxi triangle area. The study shows that primary silicified quartz is nonluminescent but quartz in host rocks andsecondary silicified quartz are luminescent by the action of cathode rays. Correspondingly, silicon isotope composi-tions of host rocks, ores and hydrothermal quartz veins are clearly distinguished. In strata from the Middle Triassic tothe "Dachang" host bed, δ~(30)Si of the host rocks ranges from 0.0‰-0.3‰, while that of primary ore-forming silici-fied fluids from -0.1‰ to -0.4‰, in the Upper Permian and Lower Carboniferous strata and Indosinian diabasehost beds, δ~(30)Si of the host rocks is from -0.1‰ to -0.2‰ and that of the primary silicified quartz veins from 0.3‰-0.5‰. This pattern demonstrates the following geochemical mineralization process: primary ore-forming sili-ceous fluids migrated upwards quickly along the main passages of deep-seated faults from mantle to crust and en-tered secondary faults where gold deposits were eventually formed as a result of permeation and replacement of thesiliceous ore-forming fluids into different ore-bearing strata. This gives important evidence for the fact that ore-forming fluids of this type of gold deposits were mainly derived from upper mantle differentiation and shows goodprospects for deep gold deposits and geochemical background for large and superlarge gold deposits.  相似文献   

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