内蒙古温都尔庙和巴彦敖包-交其尔蛇绿岩的元素与同位素地球化学：对古亚洲洋东部地幔域特征的限制   总被引：2，自引：5，他引：2  

黄金香赵志丹  张宏飞侯青叶陈岳龙  张本仁DEPAOLO DJ 《岩石学报》2006,22(12):2889-2900

内蒙古中部发育的三条蛇绿岩带是华北板块和西伯利亚板块之间的缝合带。本文系统研究了其中的温都尔庙和巴彦敖包-交其尔两个蛇绿岩带中变质玄武岩的元素和 Sr、Nd、Pb 同位素地球化学。苏右旗温都尔庙碱性玄武岩为轻稀土富集型;岩石具有板内和大陆裂谷区玄武岩的特征,可能代表了600Ma 左右,温都尔庙地区开始发育的新洋盆。采自苏左旗的巴彦敖包-交其尔玄武岩分为两类,一类呈现轻稀土富集型,呈洋岛玄武岩特征;另一类具有明显的 Nb、Ta 负异常,显示大洋岛弧玄武岩特征,洋岛玄武岩的存在表明古亚洲洋曾经发育洋盆,大洋岛弧玄武岩的存在表明古亚洲洋内部有大洋岩石圈之间的俯冲。将本文的古亚洲洋洋岛玄武岩与中国西南地区的特提斯洋岛玄武岩进行系统的元素和同位素地球化学特征对比表明,古亚洲洋的洋岛玄武岩显示高 U/Pb(HU)和北大西洋和太平洋省的特征,而特提斯洋岛玄武岩属于印度洋省。这些说明古亚洲洋地幔域与特提斯地幔域是两个独立的构造域,它们代表了长期演化的两个不同的地幔地球化学域。  相似文献   

磁异常数据处理方法的应用   总被引：2，自引：0，他引：2  

王郁柏 《地质找矿论丛》2006,21(Z1):149-154

文章以冀东一些铁矿区地面磁测成果为例,总结了磁异常转换、定量解释推断一些方法的应用及效果.  相似文献   

频率域电法的新进展   总被引：7，自引：6，他引：7       下载免费PDF全文

何继善 《地球物理学进展》2007,22(4):1250-1254

本文回顾了电法勘探的发展历程，分析、比较了电法勘探发展的各个阶段、各种频率域电法的优点和不足，着重介绍和论述了an序列伪随机电法具有主要频率成分丰富，各主频信号强度基本相等不随频率增高而减弱，频率间隔对数均匀、分布合理，覆盖的频率范围宽等一系列优点.不失为一种值得推广应用的新型频率域电法.  相似文献   

中国海相碳酸盐岩的储层类型、勘探领域及勘探战略   总被引：18，自引：3，他引：18  

赵宗举  范国章  吴兴宁  陈子炓 《海相油气地质》2007,12(1):1-11

中国海相碳酸盐岩有效储层成因类型主要包括古风化壳岩溶储层、礁滩储层及层状白云岩储层三大类。陆上中—古生界盆地三类储层均有分布,海上第三系盆地主要发育礁滩储层。针对我国海相油气地质特别是陆上中—古生界油气成藏的复杂性,提出应该加强对勘探及认识程度相对较低的礁滩储层形成的原生岩性-成岩圈闭油气藏的研究与勘探工作。石灰岩古风化壳岩溶储层具有强烈的非均质性,白云岩储层的含油气性比较依赖于有效储盖组合及构造圈闭。鉴于我国海相油气资源潜力巨大、勘探程度较低,故应该加强海相油气资源特别是陆上主要盆地海相油气资源及南海油气资源的研究与勘探开发,尤其要加强层序地层及岩相古地理编图等基础油气地质研究工作。  相似文献   

High Precision Time Domain Forward Modeling for Crosshole Electromagnetic Tomography     

林树海  赵立英 《中国地质大学学报(英文版)》2007,18(4):320-325

To improve the resolution of crosshole electromagnetic tomography, high precision of forward modeling is necessary. A pseudo-spectral time domain (PSTD) forward modeling was used to simulate electromagnetic wave propagation between two boreholes. The PSTD algorithm is based on the finite difference time domain (FDTD) method and uses the fast Fourier transform (FFT) algorithm for spatial derivatives in Maxwell's equations. Besides having the strongpoint of the FDTD method, the calculation precision of the PSTD algorithm is higher than that of the FDTD method under the same calculation condition. The forward modeling using the PSTD method will play an important role in enhancing the resolution of crosshole electromagnetic tomography.  相似文献   

中亚成矿域斑岩铜（钼）矿带的认识与建立   总被引：4，自引：0，他引：4       下载免费PDF全文

李 明周圣华  胡庆雯田培仁 《中国地质》2007,34(5):870-877

对中亚成矿域斑岩铜(钼)矿带的认识,起源于哈萨克斯坦滨巴尔喀什—伊犁火山侵入岩带的划分和地球物理场的确认。尤其是对哈萨克斯坦—准噶尔环状磁力异常带的厘定,奠定了中亚成矿域斑岩铜(钼)矿带的地球物理基础和与哈萨克斯坦—准噶尔地块外缘火山-侵入岩带的耦合关系,最终建立起哈—中—蒙中亚成矿域斑岩型铜(钼)矿带的雏型。  相似文献   

局部角度域波传播步进算法研究   总被引：2，自引：2，他引：2       下载免费PDF全文

高静怀  周艳辉  毛剑  陈文超  吴如山  李幼铭 《地球物理学报》2007,50(1):248-259

本文从非均匀介质中波动方程出发，提出了基于一般标架的相空间（局部角度域）波传播的步进算法. 该方法在构造单程波的步进算法时,在选择标架或正交基等方面有更大的自由度. 我们以不随频率及深度变化且具有变尺度特性的Gabor_Daubechies紧标架为例，给出了单程波传输算子的具体形式及相应的波场步进算法；详细讨论了基于Gabor_Daubechies标架的传输算子的高频渐近展开问题，得出了在高频、小传输步长条件下传输算子的近似解析表达式，并给出使用条件. 通过模型算例，比较了精确传输算子与高频近似传输算子用于非均匀介质中波传播的结果，说明在一定条件下由两者得出的波场几乎是相同的.  相似文献   

Transient analysis of wave propagation in non‐homogeneous elastic unbounded domains by using the scaled boundary finite‐element method     

Mohammad Hossein Bazyar  Chongmin Song 《地震工程与结构动力学》2006,35(14):1787-1806

The scaled boundary finite‐element method has been developed for the dynamic analysis of unbounded domains. In this method only the boundary is discretized resulting in a reduction of the spatial dimension by one. Like the finite‐element method no fundamental solution is required. This paper extends the scaled boundary finite‐element method to simulate the transient response of non‐homogeneous unbounded domains with the elasticity modulus and mass density varying as power functions of spatial coordinates. To reduce the number of degrees of freedom and the computational cost, the technique of reduced set of base functions is applied. The scaled boundary finite‐element equation for an unbounded domain is reformulated in generalized coordinates. The resulting acceleration unit‐impulse response matrix is obtained and assembled with the equation of motion of standard finite elements. Numerical examples of non‐homogeneous isotropic and transversely isotropic unbounded domains demonstrate the accuracy of the scaled boundary finite‐element method. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

3D viscous-spring artificial boundary in time domain   总被引：7，自引：1，他引：7  

刘晶波  杜义欣  杜修力  王振宇  伍俊 《地震工程与工程振动(英文版)》2006,5(1):93-102

After a brief review of studies on artificial boundaries in dynamic soil-structure interaction, a three-dimensional viscous-spring artificial boundary （VSAB） in the time domain is developed in this paper. First, the 3D VSAB equations in the normal and tangential directions are derived based on the elastic wave motion theory. Secondly, a numerical simulation technique of wave motion equations along with the VSAB condition in the time domain is studied. Finally, numerical examples of some classical elastic wave motion problems are presented and the results are compared with the associated theoretical solutions, demonstrating that high precision and adequate stability can be achieved by using the proposed 3D VSAB. The proposed 3D VSAB can be conveniently incorporated in the general finite element program, which is commonly used to study dynamic soil-structure interaction problems.  相似文献   

Indian Ocean-MORB-type isotopic signature of Yushigou ophiolite in North Qilian Mountains and its implications   总被引：10，自引：0，他引：10  

HOU Qingye  ZHAO Zhidan  ZHANG Hongfei  ZHANG Benren  CHEN Yuelong 《中国科学D辑(英文版)》2006,49(6):561-572

Many researchers have focused on the tectonic evolution of North Qilian Mountains (NQM) since the 1970s[1―7]. However, the tectonic affinity of the an- cient oceanic mantle in early Paleozoic remains in de-bate. Three general explanations for it have been pro- posed. The first one suggests that the ancient ocean was a part of Proto-Tethys, and the tectonic evolution of NQM should be regarded as a portion of the562 Science in China: Series D Earth Sciences Tethyan tectonic domain[1]. …  相似文献