共查询到20条相似文献，搜索用时 62 毫秒
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《地质科技情报》1986,(1)
文章根据激电法理论、国内外二十多年的应用经验和方法近十来年的新进展,总结出激电法的三大优点:1.能寻找各种结构的金属矿;2.干扰因素较少且有可能识别和去除;3.具有较大的探测深度和克服低阻覆盖层影响的能力.文章简述了频域激电法近十来年的几项重大进展:1.相位激电法的广泛应用;2.多频激电测量去耦技术的发展;3.谱激电法的提出及其在理论和实验研究方面的新成就;4.视复电阻率近似公式的发展和面极化体视复电阻率物理模拟不可行性的提出.文章根据激电法的优点、方法的新进展又潜力认为,在寻找深埋金属矿的普查和详查阶段,它可以而且必须作为一种主要电法勘探方法投入使用.但是,应当改变我国以时域纵向中梯装置激电测量为主的传统工作方法与技术.普查时应主要投入频域偶极装置激电法.对发现的激电异常可应用谱激电法识别其性质.在对有意义的异常进行详查时可视情况选用普通的激电法.文章认为,频域激电法今后应着重研究以下五个方面问题:1.岩(矿)石低频特性;2.谱激电法的方法理论;3.视复电阻率的数值模拟;4.视复电阻率谱的自动反演;5.用面极化体进行视复电阻率物理模拟的可行性. 相似文献
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经过在测区进行双频中梯测量,圈定了4个激电异常,综合测区岩石的电性、物性特征,对异常进行了推断和解释。根据所测量的视幅频率和视电阻率结果分析,双频激电法完适应于云南地形起伏较大的地区,并能取得良好的地质效果。 相似文献
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通过频率域激电法在已知矿区实际观测结果,发现在第四系覆盖厚度较大的地区视频散率和激电相位参数存在严重的电磁耦合现象,电磁耦合的干扰湮没了激电效应异常。通过多项式法的视频散率校正和双频相位法的激电相位校正,分离出激电效应异常,且异常范围和形态特征与地下隐伏矿体对应的较好,取得了明显的应用效果。同时根据实际电磁耦合校正工作体会,指出频率域激电法中电磁耦合校正应注意的一些关键技术问题。 相似文献
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以时间域中梯装置激发极化、偶极—偶极装置相位激电测深和可控源音频大地电磁测深在内蒙古乌尼克吐铅锌矿试验结果为例,验证综合电法在寻找矽卡岩型铅锌矿床中的作用及找矿效果。试验结果表明,在激发极化普查测量中应注意供电电极与异常体之间相互关系,否则会产生虚假异常;在勘查区岩矿石电性条件较好的情况下,激发极化面积测量基本能够反映出异常源平面分布情况。在矿(体)与围岩之间的电阻率差异不明显的条件下,较相位激电测深,可控源音频大地电磁测深基本能够推断出矿体的空间赋存位置。所以,时间域中梯装置激发极化与可控源音频大地电磁测深的电法组合在有色金属矿产勘查中可以发挥更大作用。 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