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1.
扬子地台震旦纪海水碳同位素的变化 总被引：15，自引：1，他引：15
本文测定了湖北宜昌三峡剖面震旦系海相碳酸盐岩样品的碳同位素组成。研究表明：震旦纪扬子区海水的δ＾１３Ｃ值显示出大幅度变化，南沱冰期δ＾１３Ｃ为低值（－４‰）；陡山沱早期δ＾１３Ｃ值迅速上升，达到５－６‰，陡山沱期δ＾１３Ｃ值一般在０－５‰之间；灯影期δ＾１３Ｃ值较平稳，一般在２．０－３．４％之间，导致震旦经水δ＾１３Ｃ值大幅度变化的原因主要是由于以疑在和近岸为藻类等光合作用的海洋植物群体为主体的大 相似文献
2.
日本本州岛中部的远野砂岩型铀矿区地层由中新统下部的湖相沉积岩（１８￣２２Ｍａ）和上部的海相（１５￣１６Ｍａ）沉积岩组成。方解石和黄铁矿是该地层中的主要成岩蚀变产物。湖相和海相的方解石和黄铁矿的特征差别很大。湖相沉积物中方解石的δ＾１３Ｃ值低（－１９‰￣－６‰ＰＤＢ），而海相地层中的δ＾１３Ｃ值高（－１１‰￣＋３‰）。这意味着海相碳酸盐在上部海相沉积岩上所起的作用较大，下部湖相地层中方解石的碳既来源 相似文献
3.
中国东部橄榄岩包体和榴辉岩中CO2流体包裹体的碳同位素组成 总被引：9，自引：0，他引：9
应用阶段段加热技术,对中国东部新生代玄武岩中的橄榄岩包体和大别造山带超高压榴辉岩进行了裹体ＣＯ２的碳同位素组成测定,结果表明,榄岩的δ＾１３Ｃ值变化较大,从－２２．８％到＋０．７‰到＋４．６‰,同样明显不同于前人报道的低δ＾１３Ｃ值（－３０‰２０～－２０‰）特征,大别造山带榴辉岩的δ＾１３Ｃ变化从－１８．５‰到＋４．６‰,同样明显不同于前人报道的低δ＾１３Ｃ值（－３０‰～－２０‰）特征。榴辉;岩的 相似文献
4.
结合碳酸盐岩层序地层分析，首次系统测定了马平组碳，氧同位素值，并对其演化规律与层序地层的关系进行了探讨，研究结果表明：马平组内δ＾１３Ｃ，δ＾１８Ｏ值变化范围分别是－２．５６‰～＋３．８９‰和－８．１６‰～－６．０２‰（ＰＤＢ）准层序为δ＾１３Ｃ值向上逐渐减小，海进体系域（ＴＳＴ）和高水位体系域（ＨＳＴ）内δ＾１３Ｃ值分别呈增加和减小的趋，层序界面处δ＾１３Ｃ，δ＾１８Ｏ值均表现为负异常，控制层序 相似文献
5.
云南兰坪三山—白身坪铜银多金属成矿富集区的碳氧同位素地球化学 总被引：9，自引：0，他引：9
研究区的碳氧同位素组成表明,矿化灰岩和细晶灰岩的δ＾１３Ｃ为正值,其δ＾１８Ｏ值变化于－６．４‰～－２１‰之间;而绝大多数矿石中碳酸盐矿物的δ＾１３Ｃ为负值,只有少数为正值,与其对应的δ＾１８Ｏ值为－１２．３‰～－１２．５‰。根据δ＾１３Ｃ－δ＾１８Ｏ图解分析,区分出了３种不同类型的碳同位素：（１）三叠纪海洋生物碳;（２）海相碳酸盐的碳与热卤水中碳的过渡类型;（３）深部热卤水中ＣＯ２的碳。研究发现 相似文献
6.
我国煤的稳定同位素组成特征 总被引：2，自引：0，他引：2
总结了煤及其煤化作用产物稳定同位素地球化学研究成果。煤的δ＾１３Ｃ值主要在－２２．５‰～－２５．５‰之间，中值为－２４．４‰。煤化作用及地质年代影响极微，但煤岩显微组分对δ＾１３Ｃ值有明显影响，壳质组含量增加，煤的δ＾１３Ｃ值变轻。煤的热模拟演化产物δ＾１３Ｃ值；甲烷在液态烃产出峰值处有最烃的碳同位素组成，液态烃与煤有相似的δ＾１３Ｃ值，其族组分中烷烃部分随温度增高，δ＾１３Ｃ值有变重的趋势。煤的 相似文献
7.
长坑金银矿床方解石的δ＾１３Ｃ值为－３．２３‰，方解石和石英的δ＾１８Ｏ和８．６４‰－１８．６１‰和９．６０‰－１３．０‰，其范围与其它卡林型金矿相似。结合大本模式的理论分析，认为成矿热液的部碳同位素组成可大致取为－２‰－１７‰，即碳主要来自地层中的沉积碳酸盐，部分来自有机碳。 相似文献
8.
深源流体—老王寨金矿床含矿流体来源的一种可能性 总被引：6，自引：1，他引：6
老王寨金矿床含矿流体是一种富含矿化剂Ｃｌ＾－、ＣＯ２和Ｓ＾２－的高温高压深源流体。石英中流体包裹体的δ＾１８ＯＨ２Ｏ值在＋６．９１‰￣＋１１．７６‰之间，δＤＨ２Ｏ值为－６８．１０‰￣－１０１．１０‰之间，辉锑矿的δ＾３４Ｓ值为－０．１５‰￣－１．０３‰，方解石的δ＾１３Ｃ值为－０．３４‰￣－３．１２‰。研究结果表明，这种流体既不是岩浆热液也不是大气降水，而是一种深源流体。 相似文献
9.
天然气碳同位素部分反序与乙烷碳同位素特征的模拟研究 总被引：4，自引：1，他引：3
通过煤系源岩热模拟烃类气地球化学研究,结合源岩自然演化形成天色气的研究,认为煤原岩在热演经进行中,随化程度增高δ＾１３Ｃ１值从轻变重,δ＾１３Ｃ２变化较小,在低演化阶段一般为－２８‰±（Ｒｏ＝０．４５％～０．５６％）,当源岩进入生烃门限阶段δ＾１３Ｃ２值一般为－２６‰～２３‰左右。且随热演化程度增高进一步变重,但一般不大于－２０‰。烃类气碳同位素系列４ 部分反序现象,不仅仅是不同成因天然气混源特征 相似文献
10.
一个未成熟褐煤抽提物中，高等植物生源化合物的同位素值在全煤碳同位素组成（δ１３Ｃ值－２７．０‰）的±２‰范围内，表明相似成煤植物对这些化合物的贡献，或者其成煤植物经历过相似的生物合成分馏效应。所检测的萜烃类按同位素差异分为两组：二萜类（δ１３Ｃ值－２５．０±１．４‰）和倍半萜类（δ１３Ｃ值－２５．９±１．５‰）平均较全煤样富集１～２％。１３Ｃ，而奥利烷－乌散烷－羽扇烷型衍生物（δ１３Ｃ值－２９．０±０．８‰）平均比全煤样减少１～２‰１３Ｃ。Ｃ１５～Ｃ３５正烷烃δ１３Ｃ平均值－３２．４±０．６‰，据此表明Ｃ１７～Ｃ２２和Ｃ２２～Ｃ３３正烷烃的同位素值与上述平均值没有明显差异。与全煤样相比较，该煤样抽提物的藿烷衍生物１３Ｃ值则减少８～３４‰，标志在成煤过程中甲烷的细菌循环起着作用。 相似文献
11.
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
12.
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
13.
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
14.
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
15.
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.
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