地球物理联合反演研究综述

地球物理联合反演由于使反演问题的非唯一性得到有效限制而越来越受到人们的重视。本文概述了联合反演的发展现状及实现的方法，并讨论了其发展趋势及其局限性，指出地球物理联合反演是地球物理数据分析的理想工具，而非线性联合反演方法则是地球物理联合反演发展的方向。     

高斯平面坐标换算到测区平均高程面上的方法

依据高斯投影原理，提出了一种在高斯平面与任决高程平面间进行坐标转换的方法，并设计了相应的计算软件。     

综合气体地球化学测量

本文在综合大量资料的基础上,总结了气体地球化学的发展历史,对有关综合气体测量在发展过程中出现的一些术语,阐述了一点浅见,介绍了综合气体测量的采样方法、理论依据,提出了综合气体测量的发展方向。     

Recovering magnetic susceptibility from electromagnetic data over a one-dimensional earth

While the inversion of electromagnetic data to recover electrical conductivity has received much attention, the inversion of those data to recover magnetic susceptibility has not been fully studied. In this paper we invert frequency-domain electromagnetic (EM) data from a horizontal coplanar system to recover a 1-D distribution of magnetic susceptibility under the assumption that the electrical conductivity is known. The inversion is carried out by dividing the earth into layers of constant susceptibility and minimizing an objective function of the susceptibility subject to fitting the data. An adjoint Green's function solution is used in the calculation of sensitivities, and it is apparent that the sensitivity problem is driven by three sources. One of the sources is the scaled electric field in the layer of interest, and the other two, related to effective magnetic charges, are located at the upper and lower boundaries of the layer. These charges give rise to a frequency-independent term in the sensitivities. Because different frequencies penetrate to different depths in the earth, the EM data contain inherent information about the depth distribution of susceptibility. This contrasts with static field measurements, which can be reproduced by a surface layer of magnetization. We illustrate the effectiveness of the inversion algorithm on synthetic and field data and show also the importance of knowing the background conductivity. In practical circumstances, where there is no a priori information about conductivity distribution, a simultaneous inversion of EM data to recover both electrical conductivity and susceptibility will be required.     

闽西北地区隐爆作用与火山岩型铀矿化

隐爆角砾岩体对火山岩型铀矿化的控制作用已为实践所证明，并引起高度重视。本文阐述了闽西北地区隐爆角砾岩形成的时空条件、与围岩的关系、分带性及其鉴别要素。以实例说明隐爆角砾岩体对铀矿化起控制作用的３种主要形式，指出了寻找隐爆角砾岩体的方法。     

地籍测量中的RTK技术和其它技术

RTK技术是GPS发展的最新技术 ,已经开始应用于测量的很多方面。主要论述了GPSRTK在地籍测量中的相关技术 ,并且将其与地籍测量中的其他技术进行了一些比较 ,提出了将GPSRTK与全站仪结合进行地籍测量的基本观点。     

航空物探平剖图自动绘制的可视化处理

简要介绍了航空物探平面剖面图的自动绘制方法,给出了绘制中对一些问题的处理方法;重点介绍了彩色渐变填充着色、彩色渐变渲染着色等几种可视化处理方法,并提出了着色中渐变度、透明度概念及应用方法。     

大厂矿区坑道磁测找矿试验

大厂矿区一条长1．5km的运输巷道内进行了高精度磁测找矿试验，并进行了地质钻探验证。结果表明：在将局部磁性干扰压抑后，所获相对磁异常是可以取得找矿效果的。     

高坪-吉心段公路喀斯特工程地质综合勘察

以沪蓉国道主干线湖北省高坪-吉心段的喀斯特地质勘察工作为例，探讨喀斯特地区公路工程地质综合勘察的基本方法。在喀斯特地区运用遥感和地理信息技术技术、地质测绘、综合物探以及地质钻探等勘察手段，通过综合分析各种勘探成果，能够较准确地查明可溶岩的分布、喀斯特形态类型、分布规律、控制因素以及喀斯特水的赋存、分布和运移规律等，并根据不同的喀斯特地貌提出了有针对性的处理对策。通过不断的实践和经验总结。针对喀斯特工程地质问题合理运用综合工程勘察方法，能做出科学的分析评价，可以适应喀斯特区公路建设的需要，并且供今后在喀斯特地区修建公路时参考和借鉴。     

Image processing of 2D resistivity data for imaging faults

A methodology to locate automatically limits or boundaries between different geological bodies in 2D electrical tomography is proposed, using a crest line extraction process in gradient images. This method is applied on several synthetic models and on field data set acquired on three experimental sites during the European project PALEOSIS where trenches were dug. The results presented in this work are valid for electrical tomographies data collected with a Wenner-alpha array and computed with an l₁ norm (blocky inversion) as optimization method. For the synthetic cases, three geometric contexts are modelled: a vertical and a dipping fault juxtaposing two different geological formations and a step-like structure. A superficial layer can cover each geological structure. In these three situations, the method locates the synthetic faults and layer boundaries, and determines fault displacement but with several limitations. The estimated fault positions correlate exactly with the synthetic ones if a conductive (or no superficial) layer overlies the studied structure. When a resistive layer with a thickness of 6 m covers the model, faults are positioned with a maximum error of 1 m. Moreover, when a resistive and/or a thick top layer is present, the resolution significantly decreases for the fault displacement estimation (error up to 150%). The tests with the synthetic models for surveys using the Wenner-alpha array indicate that the proposed methodology is best suited to vertical and horizontal contacts. Application of the methodology to real data sets shows that a lateral resistivity contrast of 1:5–1:10 leads to exact faults location. A fault contact with a resistivity contrast of 1:0.75 and overlaid by a resistive layer with a thickness of 1 m gives an error location ranging from 1 to 3 m. Moreover, no result is obtained for a contact with very low contrasts (1:0.85) overlaid by a resistive soil. The method shows poor results when vertical gradients are greater than horizontal ones. This kind of image processing technique should be systematically used for improving the objectiveness of tomography interpretation when looking for limits between geological objects.