Magnetic field and susceptibility logging in GPF3 borehole at Couy (France) between 0 and 3500 m     

A. Tabbagh  J. P. Pozzi  F. Alvarez  J. Pocachard  J. P. Martin  G. Pagès  R. Gable  F. Lebert  R. Hutin 《Geophysical Journal International》1990,101(1):81-88

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Global and Local Multiscale Analysis of Magnetic Susceptibility Data   总被引：3，自引：0，他引：3  

Maurizio?FediEmail author 《Pure and Applied Geophysics》2003,160(12):2399-2417

Geophysical well-logs often show a complex behavior which seems to suggest a multifractal nature. Multifractals are highly intermittent signals, with distinct active bursts and passive regions which cannot be satisfactorily characterized in terms of just second-order statistics. They need a higher-order statistical analysis. In contrast with monofractals which have a homogeneous scaling, multifractals may include singularities of many types. Here we describe how a multiscale analysis can be used to describe the magnetic susceptibility data scaling properties for a deep well (KTB, Germany), down to about 9000 m. A multiscale analysis describes the local and global singular behavior of measures or distributions in a statistical fashion. The global analysis allows the estimation of the global repartition of the various Holder exponents. As such, it leads to the definition of a spectrum, D(), called the singularity spectrum. The local analysis is related to the possibility of estimating the Lipschitz regularity locally, i.e., at each point of the support of a multifractal signal. The application of both approaches to the KTB magnetic susceptibility data shows a meaningful correlation between the sequence of Holder exponents vs. depth and the lithological units. The Holder exponents reach the highest values for gneiss units, intermediate ones for amphibolite units and the lowest values for variegated units. Faults are found to correspond to changes for H also when they are of intra-lithological type.  相似文献   

Improvement of lithology and saturation determined from well logging using statistical methods     

Monika Kaźmierczuk  Jadwiga Jarzyna 《Acta Geophysica》2006,54(4):378-398

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Integrated description of deformation modes in a sedimentary basin: A case study around a shallow drilling site in the Mizunami area, eastern part of southwest Japan     

Yasuto  Itoh  Kenji  Amano Naoki  Kumazaki 《Island Arc》2006,15(1):165-177

Abstract   Tectonic episodes in a sedimentary basin are described on the basis of an integrated study combining reflection seismic interpretation, drilling survey and paleomagnetism. A shallow inclined borehole penetrated a fault shown by reflection seismic and geological surveys in the Mizunami area, in the eastern part of southwest Japan. Paleomagnetic measurements were carried out on core samples successfully oriented using side-wall image logging of structural attitude. At six horizons, stable characteristic remanent magnetization (ChRM) was confirmed through thermal and alternating field demagnetization tests, which were carried by magnetite with minor amounts of high coercivity minerals, as revealed by experiments of stepwise acquisition of isothermal remanent magnetization. After correction of multiphase deformation inferred from borehole structural analysis, ChRM directions were combined with previous data and confirmed an easterly deflection reflecting the coherent clockwise rotation of the arc before the Middle Miocene. Compilation of reliable paleomagnetic data described differential rotation of the eastern part of southwest Japan raised by collision of the Izu–Bonin Arc since the Middle Miocene. The present study suggests that (i) the Mizunami area is adjacent to a highly deformed zone bounded by the Akaishi Tectonic Line (ATL), and (ii) forearc deformation of southwest Japan is localized around the ATL, which is quite different from gradual bending on the back-arc side without remarkable crustal break related to the collision event.  相似文献   

基于OpenGL的边坡数字地质编录空间查询研究   总被引：1，自引：0，他引：1  

王正培  李浩  杨彪 《测绘与空间地理信息》2006,29(6):22-24

基于影像的数字地质编录,是摄影测量、地理信息系统和工程地质等多学科技术交叉发展的成果之一,目前仍处于研究发展阶段。本文利用边坡数字地质编录结果和边坡正射影像,运用VC 和OpenGL技术,探讨实现水电工程中边坡地质编录的3维动态显示以及交互查询功能。  相似文献   

A simple digital filter for the geophysical excitation of nutation     

Aleksander Brzeziński 《Journal of Geodesy》2007,81(6-8):543-551

A simple digital filter is derived for application to studies concerning geophysical excitation of nutation. Attention is focused on the inverse solution, i.e., inferring the excitation function from the time-series of the celestial pole offsets observed by very long baseline interferometry (VLBI). Filter properties are discussed by comparing its transfer function with that of the original differential equation of nutation. An excellent agreement in both the amplitude and phase response is shown at frequencies between −5 and + 5 cycles per year, which is the frequency band with expected geophysical signals. The difference appears at higher frequencies, leading to a spurious oscillation produced by the filter. This undesired effect is considered and the algorithm enabling its removal is described.  相似文献   

Subsurface electrical imaging of anisotropic formations affected by a slow active reverse fault, Provence, France   总被引：4，自引：0，他引：4  

F. Nguyen  S. Garambois  D. Chardon  D. Hermitte  O. Bellier  D. Jongmans   《Journal of Applied Geophysics》2007,62(4):338-353

In seismic hazard assessment studies, near-surface geophysical prospecting is increasingly used to help in identifying active faults and to constrain seismic deformation parameters (fault offset, recurrence…). In the current study, electrical tomography was used (1) to locate the Trévaresse slow reverse fault (Provence, SE France), the source of the most important seismic event recorded in the 20th century in France and (2) to test electrical tomography's ability to detect faults and tectonic deformation in a complex geological environment. Our study is supported by a detailed geologic and geomorphic field study. In the investigated area, where the geology is made of a succession of folded marl and limestone layers, electrical images are strongly influenced by electrical macro-anisotropy which plays a critical role in this survey, depending on the investigation scale. When resolution (i.e. the smallest target that can be resolved) is larger than the layer thickness (at depth and/or for large electrode spacing), inversion is unable to retrieve the real structure. To successfully interpret these electrical images, in terms of tectonically induced dip variations, we constrain field data interpretation by comparing measured and inverted electrical data with synthetic modelling results and geological data. The synthetic models were hypothetical coarse geological structures determined on the basis of geological/geomorphologic information (e.g. outcropping layers). For shallow depths, when the resolution is smaller or equal to the anisotropy scale, an electrical tomogram yields straightforward interpretation of the subsurface structure. Coupled with numerical modelling, electrical results successfully helped in positioning a trench for fault characterization.  相似文献   

中国大陆科学钻探工程主孔100～2 000 m 岩心自然伽马测量及其地质意义   总被引：1，自引：0，他引：1       下载免费PDF全文

陈世忠  杨经绥  张泽明  刘福来  李天福  邱海峻牛一雄王文先徐海军 《中国地质》2005,32(2):239-248

中国大陆科学钻探工程使用石油大学研制的岩心地面伽马测量仪对主孔2000m岩心进行了连续测量，并记录峰、谷的伽马值及其对应的岩性、构造和矿化等特征。通过系统测量，建立了主孔2000m自然伽马值剖面，发现榴辉岩具有较低的伽马值，并从榴辉岩→角闪岩→花岗片麻岩，伽马值逐渐增大。伽马值与变质岩的岩性具有明显的对应关系。并从放射性元素U、Th和K含量的角度来看岩石中放射性元素的变化规律，探讨这些元素变化的成因，指出变质基(中)性岩原岩反映的岩浆岩成因，不同于变质泥质沉积岩；岩石高Th／U比值与岩石曾经经历了近地表环境有关。主孔深变质岩自然伽马测量的系统研究对主孔岩心深度归位、探讨岩石成因和区域岩石圈热状态和大地构造演化具有重要的作用。  相似文献   

面向对象分析与建模技术在开发多井评价软件系统中的应用   总被引：2，自引：0，他引：2  

邵才瑞  关丽  张福明 《物探化探计算技术》2005,27(1):84-88

面向对象的分析(OOA)和建模技术(OMT)为摆脱软件危机提供了分析和建模手段,是目前软件开发中的主流建模方法。传统结构化软件开发模式在某种程度上限制了国内地球物理软件的开发速度和水平。这里以测井资料多井解释系统的面向对象分析和建模为实例,阐述了面向对象建模的技术思路及其特点,为高质、高效地开发易于扩充和维护的大型地球物理应用软件系统提供了建模实例。  相似文献   

应用电测井曲线计算地层水矿化度   总被引：4，自引：0，他引：4  

朱命和 《物探与化探》2005,29(1):31-33

在豫东地区进行水源地和供水管井勘探中,应用电测井曲线在含水层上的幅值与矿化度的相关性,建立回归曲线,计算地层水矿化度含量,为水井施工提供了可靠的资料,在成井中起到了关键作用。  相似文献