随县-马鞍山地带地壳与上地幔结构及郯庐构造带南段的某些特征

本义利用1979-1981年中国科学院地球物理研究所在随县-马鞍山所做的人工源地震探测的资料,采用二维射线追踪来拟合地震波的走时和振幅,取得了该地带的地壳与上地慢速度结构.结果表明,该地带地壳厚度为32-37km,莫霍面起伏变化显著.地壳速度的横向变化甚为强烈,地壳中部存在低速层.在巢湖以西宽数10km的范围内,地壳结构与其它地方明显不同,上地壳速度明显偏高,莫霍面上隆并有间断;在其两侧,明显可见有两条深断裂.结合其它地球物理场特征及大地构造概况,对结果进行分析,认为郯庐构造带南段被两条深断裂所夹,构造带宽度可达数10km,并在地质历史时期曾有过地幔物质上涌.     

地层压力和大直径套管抗挤压力计算

介绍了上覆地层压力和粘土吸水膨胀对套管挤压以及大直径管受外挤力失稳破坏的计算方法。解决了现场遇到的实际问题。     

华北地区人工地震测深震相与地壳结构研究

主要讨论了华北地区人工地震测深中的４个（Ｐ＿ｇ，Ｐ＿ｃ，Ｐ＿ｍ，Ｐ＿ｎ）常规震相以及它所反映的构造和物性特征，这些震相反映了地壳上地幔不同层位的构造形态以及速度和速度梯度结构在纵横向的变化。还重点研究了华北地区的奇异震相以及反映在构造上的特殊性和重要意义，一些剖面局部区域的某些震相显示在视速度、振幅和出现区间等方面的异常，反映了该区域在构造上的特殊性，而这些特殊性往往与地震的孕育、发生以及矿产资源的潜在构造背景有着密切的关系     

天水地区大地电磁测量及深部电性结构

天水地区的大地电磁测量结果表明，在４３ｋｍ左右的深度上普遍存在高导层，这可能是壳幔过渡带的反映。岩石圈厚度大约９５－１１０ｋｍ。在天水太京附近可能存在一条大型近东西向地壳－岩石圈构造带，在秦安以北的叶堡和陇城附近可能也存在一条近南北向的大型地壳－岩石圈构造带，它们都是不同构造单元的分界线。１６５４年天水８级大震可能与深部热异常引起的热应力有关。     

TWO DIMENSIONAL FINITE ELEMENT-BOUNDARY ELEMENT COUPLING MODEL OF MAGNETOTELLURIC SOUNDING

This paper describes how to apply the boundary element method to solve 2-D magneto-telluric sounding problem and then couple the BEM with finite element method to deal with inhomogeneous geological structure and its relation to regional stress regime. The BEM is able to calculate precisely the derivative of field variables. Such a new approach can more flexibly than others set up the upper boundary condition of the air region. Two practical examples are given. One is the study of topographical effect on the MT fields using boundary element method. There is an inverse relationship between the change of apparent resistivity and the topographical variation. The other is a coupled model of a basin in Nei Monngol Autonomous Region. A lower resistivity zone must exist in the crust and should be thicker below the central portion of the basin. This seems to agree with the regional stress regime changed from extension in Mesozoic to compression in Cenozoic     

山东五莲七宝山金铜矿控矿因素及找矿方向

五莲七宝山金铜矿床赋存于隐爆角砾岩筒中 ,与次火山岩关系密切。火山机构受NE ,NW向断裂联合控制。根据隐爆角砾岩筒的地质标志 ,结合对物、化、遥等资料的综合分析认为七宝山地区还有较好的找矿前景     

青藏高原东北缘海原弧形构造区地壳电性结构探测研究

对青藏高原东北缘海原弧形构造区（105deg;～107deg;E，36deg;～37.5deg;N）的5条大地电磁测深剖面进行处理分析和二维反演，得到研究区内东西宽约160 km、深约60 km范围的地壳电性细结构. 结果表明: 研究区呈现南西——北东的带状分布特征. 由南西——北东可分为6个电性区块，依次为西吉盆地(Ⅰ)、西、 南华山隆起(Ⅱ)、兴仁堡-海原盆地(Ⅲ)、中卫-清水河盆地(Ⅳ)、中宁-红寺堡盆地(Ⅴ)和鄂尔多斯西缘带(Ⅵ). 各区块在平面上呈北西撒开、 南东收缩的ldquo;扫帚状rdquo;形态；弧形构造区弧顶附近构造完整、规模大，自弧顶向北西、南东两端构造规模逐渐减小. 地表到深度10 km左右，西、南华山隆起和鄂尔多斯西缘带呈高阻特性，西吉、兴仁堡-海原、中卫——清水河和中宁-红寺堡4个盆地的电阻率较低且呈盆地凹陷形状. 其中兴仁堡-海原盆地电性基底最深，显示为南西深北东浅的ldquo;簸箕状rdquo;起伏形态. 研究区发育不连续的壳内低阻带，与该区中、强震活动密切相关. 1920年海原大震区存在明显的电性结构差异，震区南西侧和上部区域为相对高阻，北东侧和下部区域为相对低阻.      

苏北地区大地电磁测深采集方法技术研究

根据苏北地区大地电磁勘探环境特点进行了电极距长度、磁场位置和采集时长的试验工作，确定了大地电磁测深勘探技术参数设置下限，电极距长度不能小于50m，采集时间要大于8h，磁距应控制在2km范围内。     

江西安远路迳金伯利质煌斑岩筒研究——一种新型的幔源碱性超基性岩

路迳岩筒属火山通道相,由金伯利质煌斑岩、角砾岩、角砾凝灰岩组成,富含幔源橄榄岩包体、普通辉石巨晶和岩球。造岩矿物是橄榄石、斜方辉石、单斜辉石、角闪石和金云母,深源特征指示矿物有镁铝榴石、铬透辉石、铬尖晶石和镁钛铁矿。岩石化学组成超低SiO2,低MgO,高Al2O3,富碱,富挥发组分。轻稀土元素富集,相容元素贫化,不相容元素明显富集。岩浆起源深度约85km。其中：岩体产状,富含包体、巨晶和岩球,岩石结构和构造,矿物组成,岩石化学组成超低SiO2、富碱、富挥发组分等特征与金伯利岩相似;但岩石化学组成高Al2O3,低MgO,K2O低于Na2O,REE和LREE/HREE偏低,部分微量元素的亏损或富集,金云母成分富TiO2,富TFeO,贫MgO,镁铝榴石、铬透辉石、铬尖晶石和镁钛铁矿的Cr2O3含量偏低,岩浆起源深度较浅,均与金伯利岩有重大差异,而更接近煌斑岩类。研究认为,是幔源岩浆岩的一种新类型,岩石名称界定为金伯利质煌斑岩。     

2D magnetic resonance tomography applied to karstic conduit imaging

Karstic conduits play a crucial role for water supply in many parts of the world. However, the imaging of such targets is generally a difficult task for most geophysical methods. Magnetic Resonance Sounding (MRS) is a geophysical method designed for imaging of water bearing structures. Initially, MRS was developed for characterizing horizontally stratified aquifers. However, when applying a 1D MRS measuring setup to the imaging of 2D–3D targets, the size of which may be much smaller than the loop, the accuracy and the lateral resolution may not be sufficient. We have studied the possibility of simultaneously processing several MRS aligned along a profile to perform a Magnetic Resonance Tomography (MRT). This work emphasizes the gain of resolution for 2D–3D imagery of MRT versus the interpolation of 1D inversion results of MRS along the same profile. Numerical modelling results show that the MRT response is sensitive to the size and location of the 2D target in the subsurface. Sensitivity studies reveal that by using the coincident transmitting/receiving (TX/RX) setup and shifting the loop around the anomaly area, the depth, section and position of a single karstic conduit with a size smaller than the MRS loop size can be resolved. The accuracy of the results depends on the noise level and signal level, the latter parameter being linked to the depth and volume of the karstic conduit and the water content in the limestone matrix. It was shown that when applying MRT to the localization of 2D anomalies such as karstic conduits, the inclination of the geomagnetic field, the orientation of the MRT profile and the angle of crossover of the conduit by the MRT profile must be taken into account. Otherwise additional errors in interpretation should be expected. A 2D inversion scheme was developed and tested. Both numerical and experimental results confirm the efficiency of the developed approach.