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1.
包裹体地球化学研究表明,四川冕宁稀土矿床中存在着岩浆成因的萤石、重晶石和方解石,它们的微量元素地球化学特征与热液成因对应矿物有明显差别:岩浆成因重晶石相对富集亲石元素,贫亲硫元素;无论是岩浆成因重晶石,还是萤石均明显富集挥发分。稀土元素地球化学研究显示,不同成因萤石、重晶石在稀土元素总量、LREE/HREE、(La/Yb)N、δEu及δCe等一系列稀土元素地球化学参数上都存在明显的差异。该项研究还揭示了岩浆成因萤石、重晶石是在相对还原和酸性体系内结晶而成的。  相似文献   

2.
牛贺才  林传仙 《地球化学》1995,24(3):287-293
包裹体地球化学研究表明,四川冕宁稀土矿床中存在着岩浆成因的萤石、重晶石和方解石,它们的微量元素地球化学特征与热液成因对应矿物有明显差别:岩浆成因重晶石相对富集亲石元素,贫亲硫元素;无论是岩浆成因重晶石,还是萤石均明显富集挥发分。稀土元素地球化学研究显示,不同成因萤石、重晶石在稀土元素总量、LREE/HREE、(La/Yb)N、δEu及δCe等一系列稀土元素地球化学参数上都存在明显的差异。该项研究还  相似文献   

3.
湖南沃溪金-锑-钨矿床成因的稀土元素地球化学证据   总被引:11,自引:0,他引:11  
沃溪金-锑-钨矿床的稀土元素地球化学组成良好地反映了成矿作用的条件和过程,并为示踪矿床成因提供了有用的信息.以流体包裹体为代表的成矿溶液,以较高的稀土总量、显著的轻稀土富集和缺乏明显的铕异常为特征,代表了一种通过在碎屑沉积物柱中循环而萃取矿质的演化的海水热液.矿石相对于成矿流体(母液)富集重稀土而轻微亏损铕,反映了矿石沉淀过程中来自于海水的稀土元素掺合.同一矿层内由下往上,重稀土相对富集的程度逐渐增大而稀土总量则逐渐降低,表明随着热液化学沉淀作用的进行,海水掺合的影响逐渐增强.矿石的稀土元素组成,无论在分布模式还是在轻重稀土之间的分馏程度上,均与其他许多 Sedex型多金属矿床十分相似,暗示了这些矿床具有相似的成因机制.稀土元素地球化学特征支持矿床同生沉积成因的观点.  相似文献   

4.
通过对上库力地区萤石矿石微量元素、稀土元素地球化学特征研究,表明该地区萤石矿的微量元素表现为亏损Ti、Zr、Nb、Th,富集U、Sr、Sm,一定程度上反应了萤石矿床形成过程中源区的相似性。萤石矿的稀土元素地球化学配分模式分为轻稀土富集型及轻稀土亏损型,二者含量萤石的稀土元素总量差别较为明显,且与围岩分配模式大体一致。Eu既有正异常也有负异常,反映成矿流体既有氧化环境又有还原环境;Ce表现为弱的负异常,一定程度上反应该地区萤石成矿流体演化的一致性。综合分析研究表明,上库力地区萤石矿成因类型为为中低温热液充填型矿床,成矿物质来源为同源。  相似文献   

5.
笔者总结了福建余朋—南口地区火把山萤石矿床的地质特征, 并通过萤石的微量元素及稀土元素地球化学特征, 探讨了矿床的成因及成矿物质、流体来源。萤石矿石的微量元素及稀土元素结果显示: 火把山萤石呈中等Eu负异常及弱Ce异常, 稀土元素配分模式具有轻稀土富集型及轻稀土弱亏损的平缓型等两种曲线型式。根据萤石矿石特征、微量元素、稀土元素等特征及Y/Ho-La/Ho图解, 可知萤石存在至少三期成矿地质作用。依据M?ller的Tb/La-Tb/Ca成因判别图解, 结合常口萤石矿床的萤石及围岩的稀土元素特征, 认为火把山萤石成矿流体一方面与常口大型萤石矿床受同一成矿流体场控制, 并在有利的部位富集成矿; 另一方面, 成矿热液流体流经下峰岩组发生了淋滤、萃取、交换作用, 形成了不同地球化学特征的另一成矿期次的萤石。综合分析认为, 火把山萤石矿床为受断裂控制的大气降水成因的中低温热液充填矿床。  相似文献   

6.
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   

7.
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   

8.
论570矿床稀土元素特征及地球化学演化   总被引:1,自引:0,他引:1  
本文对570矿床新鲜岩石、蚀变岩石的稀土元素进行了地球化学研究。稀土元素特征表明,矿区基底花岗岩的成因类似华南改造型花岗岩;火山岩可能是基底变质深熔作用形成;次花岗斑岩与火山岩同源。在弱酸性-中性热液蚀变(赤铁矿化和水云母化)过程中,稀土元素的变化不大,仅表现为稀土总量有所增减;而碱性蚀变(碱交代和碳酸盐化)则一方面表现出稀土总量的变化,另一方面轻、重稀土的分馏程度也有变化。矿石中稀土总量,特别是重稀土含量普遍升高,这一特征可以作为铀成矿的指示标志。  相似文献   

9.
本文对570矿床新鲜岩石、蚀变岩石的稀土元素进行了地球化学研究。稀土元素特征表明,矿区基底花岗岩的成因类似华南改造型花岗岩;火山岩可能是基底变质深熔作用形成;次花岗斑岩与火山岩同源。在弱酸性一中性热液蚀变(赤铁矿化和水云母化)过程中,稀土元素的变化不大,仅表现变稀土总量有所增减,而碱性蚀变(碱交代和碳酸盐化)则一方面表现出稀土总量的变化,另一方面轻,重稀土的分馏程度也有变化。矿石中稀土总量,特别是  相似文献   

10.
杨忠琴  赵磊  贺永忠  安亚运  盘应娟 《贵州地质》2016,33(3):199-204,198
为了研究沿河县萤石矿成因,主要针对研究区内具代表性的水田坝和丰水岭两个矿床地质特征进行研究,并运用等离子质谱(ICP-MS)对稀土元素进行了系统分析。研究结果表明,围岩的稀土总量、轻稀土和重稀土的含量远高于萤石矿石,但是萤石的稀土配分型式与围岩相似。根据Moller等(1976)的Tb/Ca_Tb/La关系图,结合矿体特征和区地质背景研究,认为该区萤石矿为热水(热卤水)再造沉积岩(或矿床)。  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.
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   

15.
China, as many other parts of the world, has a serious shortage of water resources. In China, there is a total amount of 2.8×10^12 m3 of freshwater, but that is only 2000 m3 per capita, which is about one quarter of the world average. Thereforc, seawater desalination engineering is of great significance to the nation.  相似文献   

16.
正Dear Authors and Readers:First of all,on behalf of the new Editorial Board,I would like to express our sincere appreciation for your continuing support of our journal.This journal,founded in 1922,is the oldest geological journal in China.As the flagship journal of the  相似文献   

17.
正The Wulashan-Hademengou gold ore district in Baotou city,Inner Mongolia,is a further newly discovered super-large gold metallogenic belt in northern China.The accumulated proven gold metal amount is 84.46 t,with an average grade of3.53 g/t and a gold metal amount of 63.16 t,with an average grade of 3.30 g/t.The potential reserves are over 100 t.  相似文献   

18.
正Since the first discovery of the excellent performance of nickel-bearing iron alloys in 1889,scientists have developed3000 more kinds of nickel alloys,which still have an enormous market demand at present.However,the scarcity of global nickel ore resources has restricted economic development.In recent years,experts from the Institute of Multipurpose Utilization of Mineral Resources have studied the comprehensive utilization technique of low-grade nickel ores from  相似文献   

19.
正Professor Shu received his undergraduate training in Paleontology at Peking(Beijing)University in1964–1969,obtaining his Master's degree at Northwest University(Xi’an)and Ph.D.in China University of Geosciences(Beijing);he was Visiting Scholar at the Smithsonian Institution,Washington,D.C.,USA in 1988,Humboldt Research Fellow at University of Bonn in 1988–1989,at University of Wuerzburg,Germany in 1994–1995,and Visiting Scholar at Cambridge University,UK  相似文献   

20.
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