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1.
本文分三部分:(一)中国西北地区海相火山岩系特征与块状硫化物矿床的分布。介绍了我国秦岭、祁连、昆仑、阿尔泰、北山—天山各山系及东西准噶尔多时代时控火山岩石系列、岩石组合与块状硫化物矿床分布。并指出块状硫化物矿床与亚碱质钙碱系列细碧-石英角班岩岩石组合关系密切。(二)、中国西北块状硫化物矿床地质特征及其分类问题。本部分从我国西北海相火山岩地区块状硫化物矿床的岩石组分、岩石结构构造、岩体宏观特征、近矿围岩及蚀变等方面初步总结了我国西北海相火山岩地区的坎状硫化物矿床地质基本特征,并与国外同类型矿床进行类比。探讨  相似文献   

2.
大平掌铜矿位于滇西澜沧江火山岩带的中南段,矿体呈层状、似层状赋存于泥盆纪-石炭纪的一套细碧-石英角斑岩系中,矿体具明显的"上层下脉"双层结构特征,即上部为块状矿体,下部为细脉-浸染状矿体。矿床为火山岩型块状硫化物(VHMS)特征矿床。矿石的金属矿物为铜-铅-锌-金-银矿物组合为主,矿化及蚀变具明显的分带性。沿矿区北西向控岩控矿构造带南北两端及西侧具有较好的找矿前景。  相似文献   

3.
侯增谦 《矿床地质》1991,10(4):313-324
川西呷村含金富银多金属矿床是典型的黑矿型Zn-Pb-Cu-Ag矿床,其形成于与岛弧裂陷相伴的“双峰式”火山活动末期,产于岛弧裂谷带内的酸性火山岩系中。矿床由下部网脉状矿和上部块状矿组成,具“双层结构”金属分带和蚀变分带特征,矿体与喷气岩-喷气沉积岩密切伴生。成矿作用可分为四个阶段,每一阶段均形成特定的矿物共生组合。本文在已往研究基础上,拟就成矿流体的化学成分和热演变历史,探讨矿床金属分带、蚀变分带机理和成矿作用过程。  相似文献   

4.
火山成因块状硫化物矿床研究进展   总被引:3,自引:0,他引:3  
火山成因块状硫化物(VMS)矿床可形成于太古宙至现代各个地质时期.现代海底热液成矿作用是赋存于海相火山岩系中的古代VMS矿床成矿作用的再现.VMS矿床可形成于多种构造环境,但均与拉张背景有关.按照构造环境和容矿岩系将VMS矿床分为黑矿型、塞浦路斯型、别子型和沙利文型.VMS矿床的热液蚀变由下盘蚀变带和上盘蚀变带两个结构单元组成.下盘蚀变一般有两种类型:(1)不整合的蚀变岩筒,直接产在块状硫化物带的下方;(2)半整合或层控的上盘蚀变带,并可以在区域范围内展布.与下盘蚀变类似,上盘蚀变也具有蚀变岩筒和半整合的蚀变带两种类型.成矿金属主要有两种可能的来源:(1)在岩浆侵入体和浅位岩浆房之上被加热的循环海水对含矿火山岩系及下伏基底物质的淋滤;(2)深部岩浆房挥发分通过释气作用直接释放.下渗的海水是成矿流体的主要来源,同时流体包裹体和稳定同位素资料显示岩浆流体对成矿流体系统亦有较大贡献.VMS矿床具有明显的金属分带现象,其金属序列组合从下至上依次为Fe→Fe-Cu→Cu-Pb-Zn→Pb-Zn-Ba,这种金属分带的演化反应了流体的演化和块状硫化物丘的生长机制.根据成矿流体温度变化而不断演化的4阶段成矿模式可以很好的解释经典丘堆式矿床的形成过程.  相似文献   

5.
云南大平掌铜多金属矿床成矿作用   总被引:4,自引:1,他引:3  
云南大平掌矿床位于澜沧江火山岩带的中南段,左侧是澜沧江和酒房深大断裂。矿区内发育一套形成于岛弧环境的上石炭统细碧-石英角斑岩系,矿体产于流纹质火山岩中,产状与火山岩一致。矿体分2类,上部为块状矿体,下部为细脉-浸染状矿体。矿床内热液蚀变发育,特别是浸染状矿体中更强,并从矿体中心向外侧形成分带。具工业意义的Cu、Pb、Zn等元素以硫化物形式产出。S、Pb、Sr、Nd等同位素成分表明,成矿物质来源于地幔-下地壳。尽管矿体受后期构造破坏强烈,但综合研究表明,该矿床仍具有世界上绝大多数火山成因块状硫化物矿床的共同性。它与区内类似矿床的差异性,为在该区寻找火山成因块状硫化物矿床开辟了新方向。  相似文献   

6.
对铜陵地区石炭纪喷流 -沉积型 (Sedex)块状硫化物矿床成矿过程中流体运移的数值模拟 ,揭示该类型矿床底盘岩石中的流体活动和热影响范围主要局限在主排泄通道两侧较小的区域内 ;流体运移行为主要表现为海水下渗淋滤底盘岩石 ,最后汇入主排泄通道 ,与沿断裂上升热流体一道喷出海底。温度场和流场决定喷流 -沉积型块状硫化物矿床底盘岩石中的蚀变和矿化强度较弱 ,这是 Sedex型矿床底盘岩石蚀变和矿化强度不如以火山岩为容矿岩石块状硫化物矿床(VHMS型 )的原因。尽管温度场和流场的影响范围较小 ,但在铜陵地区 ,下渗海水从底盘岩石中淋滤出…  相似文献   

7.
川西呷村含金富银多金属矿床是典型的黑矿型Zn-Pb-Cu-Ag矿床,其形成于与岛弧裂陷相伴的“双峰式”火山活动末期,产于岛弧裂谷带内的酸性火山岩系中。矿床由下部网脉状矿和上部块状矿组成,具“双层结构”金属分带和蚀变分带特征,矿体与喷气岩-喷气沉积岩密切伴生。成矿作用可分为四个阶段,每一阶段均形成特定的矿物共生组合。本文在已往研究基础上,拟就成矿流体的化学成分和热演变历史,探讨矿床金属分带、蚀变分带机理和成矿作用过程。  相似文献   

8.
根据地质和同位素地球化学特征,建立了铜陵地区赋存于石炭系地层底部的块状硫化物矿床的成因模型;该类型矿床的形成主要与石炭纪海底热水活动有关,属喷流-沉积型(SEDEX)块状硫化物矿床;下伏古生代地层是重要的成矿金属源区,海水硫酸盐是硫化物成矿的主要硫源。成矿热流体循环的动力学数值模拟揭示。该类型矿床底盘岩石中的流体活动和热影响范围主要局限在主排泄通道两侧较小的区域内;温度场和流场决定以沉积岩为容矿岩石的喷流.沉积型块状硫化物矿床底盘岩石中的蚀变和矿化强度不如以火山岩为容矿岩石的块状硫化物矿床。伴随强大深部热流的张性同生断裂是控制喷流一沉积型块状硫化物矿床形成与分布的关键因素。海西期扬子板块北缘的张性构造体制为该时期喷流一沉积型块状硫化物矿床的形成提供了有利的地球动力学环境。  相似文献   

9.
云南澜沧老厂矿床形成于滇西南昌宁-孟连晚古生代裂谷早期,是一个在我国具有重要典型意义的火山成因块状多金属硫化物矿床。本文基于作者的工作,并结合前人的一些研究成果,较系统地总结了老厂矿床的容矿火山岩系、矿床结构、矿体形态、矿石结构构造、矿物组合、蚀变分带等方面的特征,进而通过与火山成因块状硫化物矿床的描述性模式及其主要类型的对比,探讨老厂矿床的典型性。  相似文献   

10.
新疆阿舍勒铜锌型硫化物矿床地质地球化学分带性研究任秉琛(西安地质矿产研究所,西安710054)关键词矿床地质分带,元素地球化学分带,新疆阿舍勒矿床新疆阿舍勒铜锌型硫化物矿床为产于中泥盆世酸性火山岩层中的海底喷气沉积火山成因块状硫化物矿床,属Large...  相似文献   

11.
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.  相似文献   

12.
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.  相似文献   

13.
Robert L. Linnen   《Lithos》2005,80(1-4):267-280
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.  相似文献   

14.
15.
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).  相似文献   

16.
正20141520 Bo Ying(Key Laboratory of Metallogeny and Mineral Assessment,MLR,Beijing 100037,China);Liu Chenglin Saline Spring Hydrochemical Characteristics and Indicators for Potassium Exploration in Southwestern and Northern Tarim Basin,Xinjiang(Acta Geoscientica Sinica,ISSN1006-3021,CN11-3474/P,34(5),2013,p.594-602,5 illus.,3 tables,28 refs.)  相似文献   

17.
正20141243Chen Ge(Hangzhou Research Institute of Petroleum Geology,PetroChina,Hangzhou 310023,China);Si Chunsong Study on Sedimentary Numerical Simulation Method of Fan Delta Sand Body(Journal of Geology,  相似文献   

18.
正20142599Chen Sanming(Guangxi Key Laboratory of Concealed Deposits Exploration,Guilin University of Technology,Guilin541004,China);He Yuzhou Block Model and Reserves Estimation of Panzhihua Iron Deposit Based on 3D Geological Modeling(Journal of Guilin University of Technology,ISSN1674-9057,CN45-1375/N,33(4),2013,p.610-615,9illus.,1table,15refs.)  相似文献   

19.
正20140594 Bai Daoyuan(Hunan Institute of Geology Survey,Changsha 410016,China);Zhong Xiang Faults in the Jingzhou Basin and Their Tectonic Settings(Geotectonica et Metallogenia,ISSN1001-1552,CN44-1595/P,37(2),2013,p.173-183,6illus.,59refs.)Key words:basin evolution,tectonic setting,South China In the Upper Paleozoic and Jurassic se-  相似文献   

20.
正20141912Cao Hui(State Key Laboratory for Continental Tectonics and Dynamics,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)Gravitational Collapse and Folding during Orogenesis:A Comparative Study of FIA Trends and Fold Axial Plane Traces(Geology in China,ISSN1000-3657,CN11-1167/P,40(6),2013,p.1818-1828,9illus.,35refs.,with  相似文献   

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