共查询到20条相似文献，搜索用时 54 毫秒
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在1.0、2 .0GPa和873～12 2 3K的温压条件下,借助于12 6 0阻抗增益相位分析仪测定了叶蜡石的电导率,并用阻抗谱原理分析了其微观导电机制。实验结果表明:样品的电导率对频率具有很强的依赖性;电阻率随着温度的升高而减小,电导率随着温度升高而增大,logσ与1/T之间符合Arrenhius线性关系;叶蜡石在1.0GPa和2 .0GPa的压力下脱水温度分别为10 74K和110 1K。根据本次获得的电导率实验结果并结合前人对滑石族所做的工作,得出了与前人不同的结论:滑石族矿物脱水电导率曲线出现了转折点。 相似文献
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在1．0～4．0GPa和1073～1423K及不同的氧分压条件下，借助YJ-3000t紧装式六面顶高压设备和Sarltron-1260阻抗／增益-相位分析仪，就位测定了斜方辉石的电导率。氧逸度控制由Ni＋NiO、Fe＋Fe3O4、Fe＋FeO和Mo＋MoO2四种固态氧缓冲剂完成的。实验结果表明：①在所选择的频率范围内（10^-1～10^6Hz），复阻抗对频率有很强的依赖性;②随着温度（T）升高，电导率（σ）增大，logσ与1／T之间符合Arrenhius关系； 相似文献
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高温高压和控制氧逸度条件下透辉石电导率的各向异性实验研究 总被引：2，自引：0，他引：2
在1.0～4.0GPa 和1073～1373K 及控制氧分压条件下,借助于 YJ-3000t 紧装式六面顶固体高压设备和1260阻抗/增益-相位分析仪,就位测定了沿着不同晶轴方向的透辉石的电导率。氧逸度控制是由 Ni+NiO 固体缓冲剂完成的。实验结果表明:(1)在选择的频率范围,无论从复阻抗的模与频率还是从相角与频率关系上,部可以看出复阻抗对频率具有很强的依赖性;(2)随着温度升高,阻抗降低,电导率增大,Logo 与1/T 之间符合 Arrenhius 线性关系式;(3)随着压力升高,[001]方向的透辉石电导率降低,活化焓和指前因子亦随之减小,并首次获得了透辉石中主要载流子的活化能和活化体积分别为1.80±0.04eV 和0.035±0.015cm~3/mol;(4)在2.0GPa 下按照[001]、[100]、[010]的顺序,样品的电导率和指前因子降低,活化焓依次升高,高压下的透辉石电学性质存在各向异性;(5)小极化子导电机制可为透辉石在高温高压下的导电行为提供合理的解释。 相似文献
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北祁连玉石沟蛇绿岩形成于晚震旦世的SHRIMP年龄证据 总被引：45，自引：5，他引：45
玉石沟蛇绿岩位于青藏高原东北缘的北祁连山中部 ,由地幔橄榄岩、堆晶辉长岩、辉绿岩、枕状熔岩以及夹杂在其中的硅质岩组成。地幔橄榄岩主要是方辉橄榄岩 ,其主要氧化物成分较为单一 ,具 L REE富集、Eu亏损的 U形 REE配分模式 ,亏损强不相容元素 ;枕状熔岩具典型 MORB特征 ,在构造判别图解上位于 MORB和 IAT区域 ,指示蛇绿岩可能形成于类似于洋中脊的构造环境 ,并受到火山弧岩浆作用的影响。堆晶辉长岩具明显的 Eu正异常 ,其锆石离子探针 (SHRIMP) 2 0 6 Pb/2 38U加权平均年龄为 5 5 0± 17Ma,Th/U值为 0 .5 3～ 1.85 ,大于0 .2 3,为岩浆成因锆石 ,其年龄代表辉长岩的成岩时代 ,推断玉石沟蛇绿岩形成于晚震旦世。 相似文献
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内蒙古西乌旗阿拉坦高勒含钒钛磁铁矿的辉长岩岩体主要由中--粗粒的狭义辉长岩、角闪辉长及橄榄辉长岩、细粒辉长岩和辉绿岩等复合而成。不同钻孔岩心的主量、微量和稀土元素分析结果研究发现,Al2O3 含量为14. 5% ～ 19. 65%,K2O + Na2O 含量为3. 03% ～ 4. 7%,P2O5 含量为0. 11% ～ 1. 04%,总体上,主量元素具有高铝、低碱、不均匀富磷的特点,属于里特曼指数σ ＜ 4 的钙碱性系列岩石。( La /Yb) N 为1. 40 ～ 6. 54,( Gd /Yb) N 为1. 38 ～ 2. 09,表现为轻稀土富集的右倾型,表明岩浆来源于地幔物质的低程度部分熔融。辉长岩δEu 为0. 53 ～ 1. 18,Eu 元素异常的不同表现形式和相似的微量元素配分特点,一方面揭示了不同岩石类型具同源性特点,另一方面结合岩相学研究,也为该岩体历经岩浆分离结晶--多期脉动侵位--流体叠加成矿的成因机制提供了地球化学依据。 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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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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Muriel Rocher Stéphane Baize Stéphane Jaillet Edward Marc Cushing Yannick Lozac&#x;h Francis Lemeille 《Comptes Rendus Geoscience》2003,335(8):701-708
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
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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
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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
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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
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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
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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
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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