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本文将晚古生代以来苏门答腊火成岩划分出四个岩浆-构造旋回或岩浆活动期次(海西期、印支期、燕山期和喜山期),并讨论其板块构造背景。结果表明:分布于西苏门答腊地体海西期酸性侵入岩属于碰撞后地壳的火山弧I-型花岗岩带,其火山岩为大陆拉张带(初始裂谷)中的安山.玄武岩系列,而分布在东苏门答腊地体的大多数酸性侵入岩具有s-型花岗岩的性质。印支期西苏门答腊地体侵入岩为I-型花岗岩,属于火山弧花岗岩。印支期碰撞后板内岩浆活动带(廖内群岛-班加岛-勿里洞岛)的侵入岩以含锡s-型花岗岩为特色。燕山期以后的深成岩-火山岩活动的岩石类型和分布特征,受大陆拉张带(初始裂谷)及其相邻的洋岛的控制。燕山早期细碧岩属于陆缘裂谷火山岩。喜山期火山岩属于陆缘火山弧,其中橄榄玄粗岩落在洋岛玄武岩与洋中脊玄武岩(MORB)交界线附近。 相似文献
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《International Geology Review》2012,54(6):1110-1112
The supposed specific distinction of the lower Pleistocene elephants, Elephas Müst Pavlova of eastern Europe and E. trogontherii Pohlig of western Europe, cannot be supported, as shown by evidence adduced by the author; the former is therefore relegated to the synonymy of the latter.—C. E. Ray. 相似文献
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文章详细介绍了平面与多面体相交的算法。讨论了多面体的描述,建立查找表、扫描、跟踪等方法,以及平面与多面体多次相交情况的处理。文章还介绍了直线与多面体相交的算法。 相似文献
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I. J. SMALLEY 《Sedimentology》1967,8(1):27-33
At the moment of deposition an ideal sediment has certain topological properties. The diagenetic process is driven by the reduction of surface area and this process is considered in relation to the topological properties. The connectivity and genus increase as cementation occurs and in some systems may decrease again. Relations between genus, density, depth of burial and time are considered for a sand-sandstone system. 相似文献
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一、前言笔者在分析我国某一盆地的一个钻井剖面的样品中;以及在第三纪、三叠纪、二叠纪、奥陶纪、寒武纪和震旦纪碳酸盐岩和其它地层中,发现了一种新的有机色素。它主要存在于含氧、氮和硫的非烃馏分中。纯化合物呈橙红色。在硅胶薄板上很稳定,长期暴露于空气中其颜色仍清晰不变,是普遍存在于天然地质样品中的一种色素物质,在石油勘探上有着实际和理论意义。因此,引起笔者的注意。对它进行了多种测试和研究。 相似文献
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TM极化时,当测点越过界面时视电阻率均发生变化,基底较深时能放大界面附近的异常,当基底较深、频率较高时,高阻一侧相位低于45°,低阻一侧相位高于45°。TE极化时,只有基底为高阻时越过界面时视电阻率才发生变化,当基底为高阻且频率较高时,相位在界面两侧发生变化。通过岩脉时若相位无变化,岩脉是窄的。 相似文献
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一个已埋藏的古造山带探讨 总被引:2,自引:1,他引:2
本文从研究磨拉石与造山带的关系入手,分析了扬子板块东缘志留系磨拉石的沉积学特征和物质成分特点,进而推测出在磨拉石堆积区东侧(相当于现代长江口外)有一条近南北向的古造山带,该造山带始形成于奥陶纪末,现在已被剥蚀并被深埋于地下。这对重新认识华南大地构造演化及古生代油气分布规律都是很有意义的。 相似文献
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钻孔桩基础的一个失败实例 总被引:2,自引:1,他引:1
列举了一个显然是按照正常施工过程步骤成桩的败例。以对整个成桩过程全面调查和详细试桩结果为基础,对该桩质量所存在的问题作了深入细致分析。提出了改进挖斗体结构、改善无循环钻孔灌注桩成孔工艺,对混凝土各个环节质量控制手段也提出建议。 相似文献
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Soumyajit Mukherjee 《International Journal of Earth Sciences》2012,101(2):503-503
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Kahasa. J. (ed) IY84: Quorrrriury of South Afrierrco and Antarctic Penusula A. A. Balksma. Rotterdam. 相似文献
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钍和铀的地球化学性质比较相似,但也有差异,这就使钍、铀矿化作用既相互联系,显示共生性,又相互区别,表现分带性。本文探讨了某钍铀混合矿床的钍、铀分带性。文中应用数理统计所得结果与地质分析基本一致,并阐述了钍、铀分带富集与蚀变岩石演化的本质联系。 相似文献
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A. P. S. SELVADURAI 《国际地质力学数值与分析法杂志》1996,20(5):351-364
The present paper examines the elastostatic problem pertaining to the axisymmetric loading of a rigid circular foundation resting on the surface of a non-homogeneous elastic half-space. The non-homogeneity corresponds to a depth variation in the linear elastic shear modulus according to the exponential form G(z)=G1+G2e-ζz. The equations of elasticity governing this type of non-homogeneity are solved by employing a Hankel transform technique. The mixed boundary value problem associated with the indentation of the half-space by the rigid circular foundation is reduced to a Fredholm integral equation which is solved via a numerical technique. The numerical results presented in the paper illustrate the influence of the near-surface elastic non-homogeneity on the settlement of the foundation. 相似文献
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Gunnar Grendstad 《GeoJournal》1999,47(3):463-475
The existence of culture is far less contested than the ways in which one can conceptualize, theorize and measure it. Grid-group
theory is a typological contribution to the field of political culture. It identifies one dimension of individuality (grid)
and one dimension of social incorporation (group). Combined, these dimensions demarcate four omnipresent and interdependent
cultures - hierarchy, egalitarianism, individualism and fatalism - each of which interlocks a social pattern with a type of
cultural bias. The overall political cultural configuration of a country is determined by the given combination of the four
cultures, each of whose size can be measured by the number of adherents. The estimated configurations of twelve European countries
are obtained by analyzing two waves of the World Values Study in 1981 and 1990 (N=34,858). The results show that egalitarianism
is dominant in the Nordic countries and the Netherlands, whereas fatalism is dominant in Great Britain, Ireland and southern
Europe. Further analysis confirms the hypothesized correspondance between egalitarianism and Inglehart's concept of postmaterialism,
both of which, in turn, are related to proenvironmental concern.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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在厚第四纪地层中进行勘探施工,最常见且最难以处理的孔内事故钻具下钻受阻,导致经常出现岔孔等孔内事故,对钻探施工影响很大。本文运用现代钻探理论,结合现场事故处理经验等资料,分析论证了在钻进和停钻时地层、泥浆和钻具等因素对钻孔孔径的影响,并对此问题的处理了探讨。 相似文献
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《Boreas: An International Journal of Quaternary Research》1985,14(3):241-241
Book reviewed in this article:
Delcourt, Paul A., Delcourt, Hazel R. & Webb, Thompson 1984: Atlas of Mapped Distributions of Dominance and Modern Pollen Percentages for Important Tree Taxa of Eastern North America 相似文献
Delcourt, Paul A., Delcourt, Hazel R. & Webb, Thompson 1984: Atlas of Mapped Distributions of Dominance and Modern Pollen Percentages for Important Tree Taxa of Eastern North America 相似文献
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