兰坪-思茅盆地砂页岩中铜矿床同位素地球化学   总被引：33，自引：5，他引：28  

刘家军  李朝阳  潘家永  胡瑞忠  刘显凡  张乾 《矿床地质》2000,19(3):223-234

兰坪－思茅中新生代盆地中的铜矿床,主要产于同砂岩、粉砂岩和页岩组成的含盐红色碎屑岩建造中。对矿床的同位素组成研究表明：成矿溶液主要来自大气降水,矿蚀变作用是在水／岩比值较低的体系中进行的;铅来自赋矿的沉积与基底岩石的混合;硫、碳和硅则具有多来源的特性。矿床地质特征和同位素组成特点表明,所研究的铜矿床与典型砂页岩型铜矿床存在显著差异,而与一些地热区的矿化作用相似。说明研究区砂页岩中的铜矿床具有特殊的  相似文献   

广东庞西洞银金多金属矿床成因探讨   总被引：8，自引：0，他引：8  

张乾  潘家永 《广东地质》1994,9(1):12-21

  相似文献   

砂砾岩型铅锌矿床的地质特征、时空展布规律及形成机制          下载免费PDF全文

张乾 《地质与勘探》1988,(8)

讨论了砂砾岩型铅锌矿床的形成环境及其地质特征,概述了该类矿床的成矿时代及其空间分布规律;分析了矿床成因的地下水搬运模式、热卤水成矿模式等;建议在古生代以前的古陆边缘及不整合面之上寻找海相砂岩型矿床,在中生代以后的内陆盆地边缘的碎屑岩建造中寻找陆相砂砾岩型矿床。  相似文献   

中国SEDEX型矿床成矿流体硼、硅、氦-氩同位素组成研究评述     

祝朝辉  张乾  朱笑青  何玉良 《矿物岩石地球化学通报》2006,25(3):279-284

SEDEX型矿床成矿流体的研究是矿床地球化学研究的重要课题之一。正确识别系统中不同的流体来源及其混合过程,是深刻理解SEDEX型矿床形成演化的关键。系统总结了国内几个典型的SEDEX型矿床同位素研究成果,认为B和Si同位素是根据SEDEX型矿床独特的矿物组合而提出的一种示踪方法,对矿床成因和沉积环境示踪效果理想;He、Ar同位素则因为在地壳和地幔储库中有极不相同的组成,是理想的幔源流体示踪剂。鉴于SEDEX型矿床含有电气石、黄铁矿、硅质岩等特殊的矿物与岩石组合,B、Si、He-Ar同位素可能更适合SEDEX型矿床矿化流体来源研究,并指出其理论发展的薄弱之处。  相似文献   

A simulating experiment on the geochemical variation trend at the initial period of meteoric waters converting to underground waters and ore fluids     

ZHU Xiaoqing 《中国地球化学学报》2005,24(4):306-315

Experimental studies were undertaken on leaching of sedimentary rocks （ dolomite and sandstone） and Hg, Sb ores by distilled water under the condition of a completely open system （room temperature and room pressure）. The aim is to find whether the halogen elements or metal elements first enter the solution at the early stage of meteoric waters converting to groundwaters and ore fluids, and, at the same time, to understand how and when they enter distilled water solutions from the rocks. The experimental resuhs have shown that F and Cl began to enter the fluids in the initial period of thirty days. With increasing leaching duration, the amounts of the elements that entered the fluids increased steadily. During the period from 120 days to 150 days the amounts increased more drastically, followed a slow increase. It is found that the capability of Cl entering the solutions is much greater than that of F. Hg and Sb were found not to have entered the solutions till 120 days later. During this period of time the pH value of the solutions began to drop. As for Hg and Sb ores, Hg and Sb began to enter the solutions on the 60th or 90th day, greatly ahead of schedule, but the two metallic elements in the rock samples began to enter the solutions 150 days later. Relatively speaking, Hg is more easily leached out than Sb from the rocks. In some rock samples, Sb could be detected in the solutions at the end of the experiment. However, Cu, Pb and Zn had not been detected in the leaching solutions from the beginning to the end of the experiment. In the whole leaching process the pH value of the solutions tend to decrease slowly from 7.1 at the beginning to 6.5 at the end. That is to say, in the interaction between pure water and rock the halogen elements in the rocks were preferentially leached out and then entered the fluids. With increasing water/rock reaction duration and amount of halogen-group elements in the solution and with decreasing pH value of the solution, some active metallic elements began to release in small amounts. This experimental result can explain the source and mechanism of volatile components and trace metals in underground waters. Meanwhile, as for those ore deposits produced by ore fluids derived from meteoric waters, the experimental result is also helpful to the understanding of the geochemical variation trend at the initial stage of conversion of meteoric waters to ore fluids.  相似文献   

Wood textures in Jinman copper deposit in western Yunnan and their genetic implications   总被引：2，自引：0，他引：2  

刘家军  李朝阳  张乾  潘家永  刘玉平  刘显凡  刘世荣  杨伟光 《中国科学D辑(英文版)》2001,44(6):545-554

Jinman vein copper deposit in western Yunnan occurs in a salt-bearing red clastic rock formation composed of sandstone, siltstone and shale. Wood texture is considerably developed in the ores. The metallic minerals making up the wood textures mainly include pyrite, chalcopyrite and bornite. Studies on the samples and examination of their micrographs and electron micrographs have confirmed that they belong to xenoxylon, reflecting that the ore-hosting rock series is the product of sedimentation in the terrestrial environment. Organic geochemistry and sulfur and carbon isotopic composition data indicate that the formation of the deposit is substantially related with underground hot brines and biological processes.  相似文献   

金属矿床的卤素元素异常及其形成机理——以粤西茶洞银金矿床为例     

张乾  邵树勋等 《地质地球化学》2001,29(1):1-6

金属矿床中卤素元素参与了金属元素的活化，迁移互沉淀成矿的全过程，然而，除F能作为萤石和云母类矿物的组成部分有时富集于矿石中外，Cl,Br,I很难在矿石中富集。在成矿过程中尤其在成矿孤后期，它们能在矿体上部形成范围较广的卤素扩散晕，在茶洞矿床，这种上部扩散晕范围可达200米，其中以I扩散范围最大，Br扩散晕在距矿体50－130米的范围内最明显，Cl扩散晕在距矿体30－110米范围内最明显，卤素元素的这种变化特点，一方面可用来解释成矿热液的演化过程，另一方面可用来作为勘查深部隐伏矿体的地球化学标志，成矿流体中卤素元素与金属元素的配合物着成矿条件的改变而不断被破坏，金属元素作为硫化物等矿物的组成部分沉淀下来，随着热液蚀变的发生和进行，部分瞄卤素元素被带入蚀变带，大部分仍残留在流体相，在成矿的后期，和残余热液一道，以排泄和渗透等方式，在矿体上方或残余热液流经的途中形成大范围的异常。  相似文献   

内蒙古白云鄂博矿区元古代非造山岩浆岩及其对成矿的制约     

王一先  裘愉卓  高计元  张乾 《中国科学D辑》2003,(Z2)

白云鄂博矿区广泛分布着元古代非造山岩浆岩。主要岩性是粗面岩、镁铁钠闪石-长石岩、钾质流纹岩、英安岩、流纹岩、石英斑岩和中长玄武岩,并有大量高钾辉绿岩脉(墙)出露。这些非造山岩浆岩来源于地幔,它们的ε_(Sr)(t)值都较低,ε_(Nd)(t)主要集中在4.52～5.88,钕模式年龄T_(DM)~(Nd)集中在1.54～1.92 Ga。它们的Nd同位素组成和钕模式年龄都与矿石一致,意味着成矿物质来源于这些岩浆岩。这些岩浆岩的锆石U-Pb年龄为1.8 Ga年左右。各种研究结果表明矿床是与非造山岩浆岩有关的热液交代白云鄂博群的产物。  相似文献   

改造成矿作用的定义、类型及特点     

张乾 《矿物岩石地球化学通报》1997,(2)

改造成矿作用的定义、类型及特点张乾（中国科学院地球化学研究所，贵阳５５０００２）关键词改造成矿作用改造型矿床类型划分成矿特点改造作用作为一种重要的地质作用，是涂光炽六七十年代经过大量的研究，于８０年代正式提出的成矿作用术语。改造成矿作用从根本上解决了...  相似文献   

粤西金、银矿床成矿规律探讨     

潘家永  张乾  张宝贵  张玉学  邵树郧 《矿床地质》1996,15(3):257-266

粤西是我国华南的主要金、银矿床集中医，医内金矿床与银（金）多金属矿床具有相间排列的分布规律，即从南到北分为以下5个矿带：廉江地区银（金）多金属矿带、高州-信宜金矿带、罗宁-云浮银（金）多金属矿带、德庆-清远金矿带、连山地区银（金）多金属矿带。本文从区域地层、岩浆岩及成矿作用等方面对粤西金、银矿床区域分布规律进行了探讨，认为影响金、银矿床分布的主要因素是不同区域地层、岩浆岩Au、Ag含量的差异及金矿床与银（金）多金属矿床成矿作用的差异。  相似文献