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1.
向文帅  赵凯  张紫程 《地质学报》2021,95(4):1284-1291
厄立特里亚Augaro金矿床产于努比亚地盾新元古代变质火山岩中,矿体主要赋存于片理化安山岩内,受北北东向断裂与近东西向次级断裂控制.对矿床主要含金石英脉型矿石与蚀变岩型矿石进行碳氢氧硫同位素研究显示,成矿流体的δDw-H2O范围为-68.7‰~-49.4‰,δ18 Ow-H2O范围为-1.9‰~4.9‰,δ13 CV-...  相似文献   

2.
西岔、金厂沟金矿床属于层控破碎带蚀变岩型金矿,其成矿时代为印支至燕山早期.地层岩石中元素含量及其演化资料表明,本矿床成矿物质来源具双重性,即有来源于地层,也可能有部分来自岩浆岩.稳定同位素研究结果为:西岔金矿床δ~(34)S=1.9%—7.4‰,金厂沟金矿床δ~(34)S=3,2‰—5.1‰,二矿床硫同位素组或基本相近,表明硫源相似;δ~(18)Ο_(H_2o)=5.3‰—6.4‰; δ~(13)C=—6.1‰.流体包裹体研究表明,成矿流体主要为氯化物水型.成矿温度集中于142—290℃.由此推断矿波水可能是岩浆水与大气降水的混合水.矿液中的碳可能来源于地层.  相似文献   

3.
黑龙江争光金矿地质地球化学研究   总被引:10,自引:0,他引:10  
通过氢、氧、铅同位素和流体包裹体测试,结合争光金矿床的地质、微量元素、稀土元素地球化学特征研究,表明争光金矿为岩浆低温热液矿床.成矿物质主要来源于地层,矿化类型为蚀变岩型和石英脉型.成矿流体为岩浆水、变质水和大气降水的混合液.δD值为-63‰~-85‰,δ18O水值为-0.2‰~-7.0‰,主成矿阶段温度为133~276℃.  相似文献   

4.
辽宁小佟家堡子金矿床成矿流体特征及来源讨论   总被引:1,自引:0,他引:1  
小佟家堡子金矿床地处辽宁青城子矿田东南部,为一大型蚀变岩型矿床。矿床产于辽河群大石桥组三段白云石大理岩中,矿体呈层状、似层状产出。矿床由热液叠加改造作用形成,历经石英-黄铁矿、石英-碳酸盐两个阶段。流体包裹体研究表明,该矿床成矿流体属中低温、低盐Na Cl-H2O型体系热液。碳氢氧同位素地球化学的研究表明,石英-黄铁矿阶段成矿流体氧同位素δ18O组成在15.2‰~18.4‰,碳同位素δ13CV-PDB组成在-7.4‰~-13.2‰,氢同位素δD组成为-89.3‰~-92.2‰,反应该阶段成矿流体主要来自岩浆水并伴有少量的大气降水。石英-碳酸盐阶段成矿流体氧同位素δ18O组成在17‰~17.8‰,碳同位素δ13CV-PDB组成在-12.3‰~-13.5‰,氢同位素组成δD为-87.7‰~-90.4‰,表明该阶段成矿流体主要来自大气降水。  相似文献   

5.
争光浅成低温热液型金矿床位于大兴安岭成矿带北段,是多宝山矿集区内的一个重要矿床。文章通过流体包裹体和C_H_O_He_Ar同位素的系统研究,对该矿床成矿流体和矿床成因进行了深入探讨。矿床成矿作用可划分为4个主要阶段:石英_黄铁矿阶段(成矿前阶段)、石英_多金属硫化物阶段(主成矿阶段)、方解石_(石英)_多金属硫化物阶段(主成矿阶段)和方解石阶段(成矿后阶段)。流体包裹体研究表明,争光金矿床主要发育富液相流体包裹体。石英_黄铁矿阶段、方解石_(石英)_多金属硫化物阶段和方解石阶段流体包裹体的均一温度分别介于116~243℃(集中于150~170℃)、129~294℃(集中于140~160℃)和130~155℃(集中于130~150℃);w(NaCleq)分别介于0.9%~10.1%、1.2%~13.8%和2.7%~8.7%。成矿流体具有低温、低盐度、相对还原的特征,属H_2O_Na Cl体系。石英_黄铁矿阶段成矿流体的δD和δ18O分别为-127‰~-110‰和-5.9‰~0.6‰,蚀变围岩的δD值和δ18O值分别为-118‰~-108‰和6.3‰~7.9‰。方解石_(石英)_多金属硫化物阶段和方解石阶段方解石的δ~(13)C分别为-5.3‰~-2.0‰和-2.9‰~-2.2‰,δ18O分别为7.7‰~9.3‰和9.9‰~13.5‰。黄铁矿流体包裹体的~3He/~4He、~(40)Ar/~(36)Ar和~(40)Ar*/4He比值分别为1.75~3.06 Ra、683~1295和0.30~0.63。综合流体包裹体特征和稳定同位素组成,认为成矿早阶段成矿流体为大气降水与围岩发生水_岩反应后的演化水。随着成矿作用的进行,成矿流体变为大气降水与岩浆水的混合水,但仍以大气降水为主导。成矿流体与贫H_2S的流体混合和硫化物沉淀的共同作用可能是该矿床金沉淀的主要机制。  相似文献   

6.
胶东是我国最重要的黄金产地,也是全球成矿晚于赋矿围岩近2Ga的巨型金矿集区之一。大尹格庄金矿床位于胶西北招平断裂中段是区域内典型的超大型蚀变岩型金矿床也是胶东金矿集区内最大的金银伴生矿床。本研究在详实的野外地质调查和岩相学观察基础上对不同成矿阶段的石英中流体包裹体进行碳、氢、氧同位素测试和计算。大尹格庄金矿床热液成矿过程可分为四个阶段:黄铁矿-绢云母-石英阶段(Ⅰ阶段)、石英-黄铁矿阶段(Ⅰ阶段)、石英-多金属硫化物阶段(Ⅲ阶段)和石英-方解石-黄铁矿阶段(Ⅳ)。氢-氧同位素组成表明,Ⅰ阶段流体的δD为-84.4‰~-68.4‰,δ~(18)O为2.04‰~7.36‰;Ⅱ阶段流体的δD为-78.6‰~-69.8‰,δ~(18)O为0.3‰~4.2‰;Ⅲ阶段流体的δD为-81.4‰~-72.0‰,δ~(18)O为-3.47‰~-1.25‰。随着成矿作用进行,δ~(18)O逐渐降低。流体包裹体的碳-氧同位素分析表明,δ~(13)C和δ~(18)O分别随成矿作用的进行降低和升高。两种测试获得的氧同位素变化趋势不同,可能是由于前者是通过石英单矿物氧同位素计算得到的流体包裹体中水的氧同位素而后者测定的是流体包裹体中CO_2的氧同位素。综合分析表明,大尹格庄金矿床成矿流体主体为变质水;成矿作用过程中,断裂带强烈构造变形诱发次生包裹体的形成导致氢氧同位素组成向中生代大气水漂移。  相似文献   

7.
江苏观山铜铅金矿是典型的高硫型浅成低温热液矿床。本文通过对观山铜铅金矿床氢、氧、碳、硫同位素组成的研究,探讨成矿溶液中水、碳、硫的来源以及成矿溶液的演化。同位素测定显示石英流体包裹体水的δD=-90‰~-70‰,δ18O水=-8.9‰~-1.1‰;热液方解石流体包裹体水的δD=-90‰~-81‰,δ18O水=0.1‰~2.3‰。氢氧同位素组成说明成矿流体主要为与围岩进行过水岩反应的循环大气降水,不排除有少量岩浆水的加入。黄铁矿与黄铜矿矿石的δ34SV-CDT=5.8‰~9.9‰,平均值为7.6‰,表明该矿成矿过程中的S很可能是沉积岩来源的硫与岩浆岩来源硫的混合。矿床中可见较多的重晶石等硫酸盐矿物,这种高价态硫的矿物的存在显示其成矿溶液具有富集34S的特征,加上成矿过程中流体的沸腾导致H2S等气体大量逸出和残余岩浆流体富集34S,使得沉淀的黄铁矿、黄铜矿等硫化物同样具有富集34S的特征;热液方解石碳同位素δ13C方解石=-4.1‰~6.1‰,平均为δ13C方解石=1.3‰,显示其中的C主要来源于流体对流循环过程中对基底岩石中碳酸盐地层的溶解。  相似文献   

8.
林旺金矿床是滇黔桂地区典型的复合型金矿床之一,具有层位控矿和断裂控矿的双重特点,为揭示矿床成矿流体的性质和来源,对两类矿体中主成矿阶段的石英进行了流体包裹体岩相学观察、显微测温和氢氧同位素测试分析。结果表明:两类矿体中的石英流体包裹体以水溶液包裹体为主,其次是CO_2-H_2O包裹体,水溶液包裹体的均一温度范围为134℃~394℃,盐度w(NaCl_(eqv))范围为1.05%~10.98%,密度范围为0.79~0.94g/cm~3。石英中流体包裹体水的δD_(H2O)范围为-71‰~-57‰,石英的δ~(18) O_(V-SMOW)范围为21.7‰~26.5‰,计算得到流体的δ~(18)O_(H2O)范围为11.7‰~16.5‰,表明成矿流体来源于混合的变质水。成矿流体总体属于中低温、低盐度、中低密度的流体,具有的典型卡林型金矿床的成矿流体特征。  相似文献   

9.
甘肃礼县李坝大型金矿床成矿地质特征及成因   总被引:24,自引:4,他引:24       下载免费PDF全文
文章以成矿地质条件、矿床地质特征为基础,通过Ar—Ar年龄测定、稳定同位素测试和地层含金性分析等,研究了李坝金矿床的成因。研究表明,李坝金矿床与中川花岗岩在时间、空间和成因上关系密切。含金石英脉Ar—Ar法、Rb-Sr法和Pb—Pb法年龄为210~171.6Ma,与中川岩体年龄(177~229Ma)吻合。包裹体水的δD-74‰~-83‰,δ^18O水9.51‰~11.72‰,成矿流体水为岩浆水和大气降水的混合水。花岗岩提供了部分成矿物质来源,含矿热液通过F1导矿构造进入F3、F12等容矿断裂破碎带沉淀成矿。  相似文献   

10.
新疆东天山红石金矿床成矿流体和成矿物质来源示踪   总被引:7,自引:4,他引:7  
红石金矿床是新疆东天山康古尔塔格金矿带中的代表性矿床之一,本文对其进行了比较系统的流体包裹体和稳定同位素研究。流体包裹体研究结果表明,红石金矿床的成矿流体为中低温、低盐度、中低密度的富 CO_2流体。石英氢同位素组成δD_(SMOW)为-104‰~-63‰,石英氧同位素组成δ~(18)O_(石英)为13.8‰~15.5‰、δ~(18)O_水为-1.7‰~6.1‰。方解石碳同位素组成δ~(13)C_(PDB)为-3.5‰~-2.7‰,方解石氧同位素组成δ~(18)_(PDB)为-28.9‰~-26.5‰、δ~(18)O_(SMOW)为1.1‰~3.5‰。H、O、C 同位素组成特征指示红石金矿床成矿流体主要起源于深部,后期混合有大气水。黄铁矿硫同位素组成δ~(34)S 为-11.5‰~3.8‰,集中于0.4‰~3.8‰,平均值为1.73‰,指示了成矿物质中的硫具有接近陨石硫的深源特征。红石金矿床的成矿作用可概括为富含成矿元素的深源流体在区域剪切构造作用下沿剪切系统不断向上运移,逐渐与浅部流体混合并与围岩发生交代蚀变作用,由于物理化学条件的改变,成矿元素最终在剪切扩容空间中富集成矿。  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.
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   

13.
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   

14.
HYDROGEOLOGY     
正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level  相似文献   

15.
正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),  相似文献   

16.
17.
正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-  相似文献   

18.
正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-  相似文献   

19.
正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)  相似文献   

20.
GEOCHEMISTRY     
正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861  相似文献   

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