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黔东北沿河大竹园萤石矿赋存于下奥陶统桐梓组及红花园组碳酸盐岩内,受NW向断裂构造控制。该类萤石矿床在黔东北及渝东南一带广泛分布。本文对该萤石矿床的萤石单矿物及围岩进行了微量元素及稀土元素地球化学分析,结果显示萤石的微量元素仅Pb、Zn、Co、Ni等元素含量相对较高,Rb、Sr、Ta、Zr、Nb、V、Cr、U、Th、Hf等元素含量仅为地壳值的0.01~0.05倍。稀土元素含量很低(∑REE=2.35×10–6~4.80×10–6),相对富集轻稀土元素(LREE/HREE=3.12~6.33),具有Eu正、负异常(δEu=0.59~1.59)和Ce负异常(δCe=0.80~0.96)。萤石与赋矿围岩具有相近的微量元素配分型式,均明显亏损Nb、Zr、Hf等元素,富集Ba、U、Sr等元素。萤石与赋矿碳酸盐岩都具有轻稀土相对富集、重稀土相对亏损,明显右倾的REE配分型式。综合分析认为该萤石矿的成矿物质Ca主要来源于碳酸盐岩围岩;而碳酸盐岩围岩的F元素含量很低,结合萤石的微量元素及δEu、δCe值特征,暗示形成萤石的成矿流体经过了深部演化,成矿物质F可能主要来自深部富F地层。 相似文献
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闽北浦城羊角尾萤石矿产于侏罗系梨山组火山碎屑岩中的断裂破碎带内, 对其地质矿产特征和矿石、围岩及矿区内黑云母正长花岗岩的岩石地球化学特征进行了研究。羊角尾萤石矿矿石∑REE为65.17×10–6～125.87×10–6, 重稀土相对富集, δEu和δCe无明显异常; Ni、Cd、Pb和As等中低温微量元素相对地壳富集。围岩梨山组火山碎屑岩轻重稀土分馏不明显, Eu负异常明显, Sm/Nd值与萤石接近, 微量元素相对地壳的含量曲线趋势与萤石基本一致。黑云母正长花岗岩则显示轻稀土富集、重稀土亏损, Eu正异常和Ce负异常的特征, Sm/Nd值远小于萤石矿。结合稀土微量元素特征及矿床成因判别图解, 认为羊角尾萤石矿的主要成矿物质来源为梨山组火山碎屑岩。成矿流体在形成后经历了长期的演化, 在此过程中与围岩发生了充分的水岩反映, 使Ca、F、REE等重新活化, 最终在构造破碎带就位沉淀形成矿体, 矿床成因类型为中-低温热液充填型。羊角尾萤石矿的矿床成因研究表明晚侏罗世火山-沉积岩系是区域萤石矿成矿的重要物源基础, 在区域找矿工作中应重点关注。 相似文献
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张厝萤石矿是福建邵武地区典型萤石矿床之一, 萤石矿体赋存于晚侏罗世似斑(少斑)中细粒(细粒)正长花岗岩的断裂构造中, 矿体产状严格受断裂控制。本文对萤石矿石及围岩的微量元素及稀土元素进行了系统分析。微量元素分析结果显示: 亏损高场强元素Nb、Zr及大离子亲石元素Sr、Ba, 富集高场强元素U、Hf、Ti和大离子亲石元素Rb。萤石和围岩稀土配分曲线具有相似同步性, 因此认为研究区萤石的成矿物质来源是相同的, 物源具有相似性。萤石矿稀土元素分布模式为右倾的轻稀土富集型, Eu处出现一个明显“V”形, 表现为负Eu异常、Ce弱正异常, 表明其形成于还原环境中。通过Tb/Ca-Tb/La关系图分析, 说明该萤石矿为热液充填型萤石矿床。综合分析, 认为该萤石矿的成矿物质F和Ca主要来源于热液对围岩的淋滤和萃取, 成矿热液主要来源于大气降水。 相似文献
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额尔古纳地区拥有丰富的萤石矿资源,萤石矿的产出严格受断裂构造控制,成矿类型为中低温热液充填型,成矿时代为燕山中晚期及华力西中期.区内萤石矿多分布于石炭系及侏罗系酸性-中酸性岩浆岩及其接触带上,区域断裂系统派生的北东、北西和北北西向次级断裂是萤石矿的有利赋矿部位.区内的F元素在下白垩统白音高老组、上侏罗统满克头鄂博组、中... 相似文献
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贵州戈塘金矿储量大、品位高、成矿环境特殊,具有“层位和岩溶不整合面”双重控矿的典型特征,含矿岩系中发育多种(硅化、构造)角砾岩、低温热液矿物(雄黄、雌黄、辉锑矿和萤石等)和围岩蚀变矿物组合,热液成矿期可分为主成矿期—黄铁矿阶段和成矿晚期—萤石阶段.通过对单矿物(黄铁矿和萤石)及含矿岩系各岩石(层位)微量元素含量、Co/Ni和Th/U值、稀土元素和硫同位素(黄铁矿、辉锑矿)组成特征的系统研究.初步认为戈塘金矿具有正常海水沉积特征,矿石层位形成于海相贫氧还原环境,初始成矿物质可能与峨眉山玄武岩浆活动有关,但后期深部物质为金的进—步富集成矿贡献也较为明显. 相似文献
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拉拉IOCG矿床萤石的微量元素地球化学特征及其指示意义 总被引：1，自引：0，他引：1
康滇地区元古宙拉拉IOCG矿床中有与铜、钼矿化密切相关的萤石产出,其中,变质期有萤石(I)和萤石(II)2个世代萤石产出,前者与鳞片状辉钼矿共生,后者与条带状辉钼矿共生;热液期萤石(III)呈脉状穿插含变质期萤石的矿石;萤石的微量元素记录了成矿流体来源方面的重要信息。通过ICP-MS方法分析矿床中2期萤石样品的微量元素组成,运用微量元素含量、比值及蛛网图探讨微量元素特征、成矿流体来源及性质。结果表明:变质期萤石中各微量元素含量有一定的变化范围,热液期中各微量元素含量比较稳定,元素在萤石中的含量主要由元素在原始流体中的含量及元素本身性质所决定。结论认为:1变质期萤石(I)和萤石(II)为同源流体不同阶段演化产物,成矿流体来自于围岩,为具有高F-,Cu,Mo和Y含量的低p H值海水相流体,活动范围有限,没有发生大规模流动或迁移;2热液期萤石(III)与变质期萤石不同源,成矿流体由大气降水或地下水渗透淋滤围岩形成,为具有低F-含量的高p H值大陆淡水相流体,可能发生较远距离的渗入性流体流动或迁移。 相似文献
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前河金矿控矿构造主要为发育在区域性卢氏-潘河-马超营断裂北侧的近东西向断裂构造,按断裂间的相互关系、蚀变矿物及其共生组合特征,划分出6次构造活动并相应划分出6个矿物生成阶段。以硅化、绿帘石化、绢云母化、绿泥石化等为标志的第二至第五阶段为成矿阶段。碎裂岩带是矿体的主要控矿构造类型;受节理控制的矿体多分布于控矿断裂的两侧。在断裂带中Ag、Cu、Pb、Zn、Mo、Ni等元素含量普遍增高。沿断裂微量元素的含量有一定变化,在矿区东段Ag、Cu、Pb、Zn含量相对增高,而Bi、Mo、Cr、Co、Ni等在西段较高。Ag、Cu、Pb、Zn等多集中分布在矿体上部;而Bi、Mo、Cr、Co、Ni等主要集中分布在矿体的中下部。据此认为东段目前所出露的矿体是整个矿体的中上部,而西段是整个矿体的中下部。故应注意在东段下部的找矿。 相似文献
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为进一步明确内蒙古喀喇沁旗地区萤石矿床的成因,为该区下一步萤石矿找矿勘查工作提供参考,在系统总结研究区萤石矿床地质特征及分布规律的基础上,通过分析典型萤石矿床围岩和萤石的微量元素及稀土元素地球化学特征,探讨萤石矿床的成因及成矿物质来源。结果表明,喀喇沁旗地区萤石矿中萤石的Cu、Pb和Zn含量较低,轻稀土元素略富集,稀土元素总量相对较低,说明该区萤石矿成矿流体为岩浆期后热液成因的可能性较小; 萤石矿与赋矿围岩的球粒陨石标准化稀土元素配分曲线相似且同步,当围岩为黑云母二长花岗岩时,萤石及围岩与华南黑云母的球粒陨石标准化稀土元素配分曲线一致,表明萤石中的稀土元素可能主要来源于被破坏了的黑云母,说明这类萤石成矿物质主要来源于地下热水流体对围岩的淋滤和萃取。结合研究区北部林西地区萤石矿床H-O、S同位素研究成果,认为喀喇沁旗地区萤石矿属于有大气降水参与的热液脉状充填型成因类型。 相似文献
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Emily Keeble David I. Whiteside Michael J. Benton 《Proceedings of the Geologists' Association. Geologists' Association》2018,129(2):99-119
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
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Gilles Serge Odin 《Comptes Rendus Geoscience》2002,334(6):409-414
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
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The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts 总被引：4，自引：0，他引：4
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
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Emmanuel Skourtsos Daniel Vachard Alexandra Zambetakis-Lekkas Rossana Martini Louisette Zaninetti 《Comptes Rendus Geoscience》2002,334(12):925-931
Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931. 相似文献
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正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.) 相似文献
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正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.) 相似文献
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正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.) 相似文献
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正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus., 相似文献
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正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an 相似文献
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正20141266Fan Chaoyan(Guangdong Provincial Key Laboratory of Mineral Resources and Geological Processes,Guangzhou 510275,China);Wang Zhenghai On Error Analysis and Correction Method of Measured Strata Section with Wire Projection Method(Journal of 相似文献