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1.
庞春勇 《矿产与地质》1995,9(5):368-374
总结了典型折矽卡岩型铜矿床同位素地质地球化学特征,认为我国矽卡岩型铜矿床成矿岩体(^87Sr/^86Sr)i一般在0.706 ̄0.710变化,岩体为幔壳混合源型。矿石铅同位素组成均匀、稳定,特别是铀铅,^206Pb/^204Pb=17.075 ̄18.100,^207Pb/^204Pb=15.337 ̄15.635,比值变化小,而^208Pb/^204Pb比值变化稍大,矿石铅源主要来自成矿岩体。矿石δ  相似文献   

2.
康滇地轴东缘铅锌矿床铅硫同位素地球化学研究   总被引:25,自引:0,他引:25  
康滇地轴东缘不同时代碳酸盐地层中铅锌矿床的铅同位素研究表明,其^207Pb/^204Pb与^208Pb/^204Pb呈良好线性关系,^207Pb/^206Pb和^208Pb/^206Pb为一常数。结合对本区床的稀土元素及成矿流体地球化学的研究,判定不同层位铅锌矿床是在同一个成矿体系同时形成的,一次成矿,其成矿年龄为245Ma;同时说明不同矿床成矿金属有相同的来源,主要来自上地幔。成矿硫以来自地层中  相似文献   

3.
论“华夏古大陆”—铅同位素研究证据   总被引:10,自引:1,他引:9  
张理刚  吴克隆 《地质论评》1994,40(3):200-208
我国东南部地区一批中生代花岗岩类岩石中长石铅同位素数据表明,至少可将该地区地壳基底岩石划分三大块体。一是武夷块体,其范围包括江-绍断裂带以南,赣江-河源断裂以东和政和一大埔断裂中,南段以西地区,它们的中生代花岗岩长石铅同位素^206Pb/^204Pb,^207Pb/^204Pb和^204Pb/^204Pb三组比值平均分别为18.226;15.620和38.725;另一块体为闽台块体,即政和一大埔断  相似文献   

4.
大厂锡石多金属硫化物矿床由两类4形矿化组成,一类为层状及似层状矿化:另一类为不规则脉状矿化,包括大脉状,细网脉状和囊状3种不同形态的矿化。这两类矿化在铅同位素的组成上有比较明显的差异,而相同形态的矿化之间大致相同。层状矿化^207Pb/^204Pb和^206Pb/^204Pb的比值较低,在同位素比值图上的数据点比较分散,且放射性同位素的含量随生成时代的变断而呈现规律性的增加。  相似文献   

5.
大别山北缘中生代火山-侵入岩的14个夺铅同位素组成表现为高的非放射性成因^204Pb,较低的^206Pb/^204Pb比值和低且相对一致的^207Pb/^204Pb比值,属于明显的低U/Pb体系,并暗示它们由具低μ值的源岩衍生的。  相似文献   

6.
东坪式金矿床铅同位素组成特征及其化探评价   总被引:2,自引:0,他引:2  
东坪式金矿床产于华北克拉通化缘深大断裂--尚义-赤城断裂的南侧,海西期水泉沟正长岩杂岩体内外接触带。矿体具有明显的分层笥,自上而下矿石类型由石英脉型向钾、硅化蚀变岩型过渡。矿床形成于燕山早期,成矿物质主要来源于正长岩杂岩体。矿石铅同位素组成与正长岩杂岩体相似,在^207Pb/^206Pb-^208Pb/^206Pb图解上,矿石、正长岩、矿石中的钾长石脉石及太古宇桑干群变质岩呈线性分布,矿石与正长岩  相似文献   

7.
粤西大沟谷钠长石岩型金矿床成矿物质来源研究   总被引:1,自引:0,他引:1  
粤西大沟谷钠长石岩型金矿床主要产于震旦系乐昌峡群呈似层状及脉状分布的钠长石岩中,钠长石岩的岩石化学成分及微量元素组成与金矿体的基本相同。黄铁矿Pb、S同位素组成可分为两组:富放射性成因铅贫^34S体系;贫放射性成因铅富^34S体系,前者与震旦系片岩的组成相似,后者为自较老富基性岩的沉积岩。  相似文献   

8.
以区域地球化学研究成果为基础,通过Pb、Sr、Nd同位素特征分析,揭示出东江口岩体群的Pb同位素特征与南泰岭东段基底具有耦合关系,而与其它构造单元则存在明显的差异,^204Pb-^207Pb/^206Pb,^204Pb-^208Pb/^206Pb图解研究表明,该岩体群为下地壳源花岗岩类,Nd同位素特征(tDN和εNd(t)表明,耀岭河群最适合于作为岩体群的主要物源。该岩体群和耀岭河群的Sr同位素存  相似文献   

9.
托云盆地晚白垩世--早第三纪碱性橄榄玄武岩Sr、Nd、Pb同位素组成表明,本区玄武岩以低Sr、Pb和相对高的Nd同位素值(^87Sr/^86Sr为0.703554 ̄0.703884;^143Nd/^144Nd为0.512838 ̄0.512904;^206Pb/^204Pb为18.0063 ̄18.4720;^207Pb/^204Pb为15.4411 ̄15.5060;^208Pb/^204Pb为37.  相似文献   

10.
内蒙赤峰红花沟金矿田矿石铅的206Pb/204Pb范围为15.47—16.49,207Pb/204Pb为14.66—15.89,208Pb/204Pb为35.92—38.48。在铅同位素演化图中呈线性排列,反映出两端元的混合,即古老的基底岩石铅与古老的多阶段演化铅的混合。中-新生代岩浆岩和太古代片麻岩等岩石铅的206Pb/204Pb为17.3—18.1,207Pb/204Pb为15.4—15.7,208Pb/204Pb为37.2—38.2,与矿石铅明显不同,表明矿石铅来源与上述岩石无关。而含透辉石斜长角闪岩的铅同位素组成与矿石铅范围一致或接近,两者间可能有成因联系。矿石铅可能主要来源于太古代基底绿岩建造之含透辉石斜长角闪岩。  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.
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   

15.
PALEONTOLOGY     
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   

16.
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   

17.
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   

18.
PETROLOGY     
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   

19.
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   

20.
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   

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