Foliation fields and 3D cartography in geology: Principles of a method based on potential interpolation   总被引：4，自引：0，他引：4  

Christian Lajaunie  Gabriel Courrioux  Laurent Manuel 《Mathematical Geology》1997,29(4):571-584

A modeling method that takes into account known points on a geological interface and plane orientation data such as stratification or foliation planes is described and tested. The orientations data do not necessarily belong to one of the interfaces but are assumed to sample the main anisotropy of a geological formation as in current geological situations. The problem is to determine the surfaces which pass through the known points on interfaces and which are compatible with the orientation data. The method is based on the interpolation of a scalar field defined in the space the gradient in which is orthogonal to the orientations, given that some points have the same but unknown scalar value (points of the same interface), and that scalar gradient is known on the other points (foliations). The modeled interfaces are represented as isovalues of the interpolated field. Preliminary two-dimensional tests carried-out with different covariance models demonstrate the validity of the method, which is easily transposable in three dimensions.  相似文献   

三维任意形体高密度电阻率法数值模拟方法     

杨文强 《物探化探计算技术》1997,19(3):270-273,278

为研究高密度电阻率法对各种三维地电体的反映规律，本文介绍了正演程序编制的方法并给出了计算实例。  相似文献   

相山铀矿田成矿作用的地球化学模拟   总被引：4，自引：0，他引：4  

周文斌  史维浚 《地球化学》1997,26(5):62-70

相山铀矿田是我国最大的火山岩型热液铀矿田，在地质地球化学和高温高压实研究的基础上，利用地球化学模式程序ＥＱ３／６模拟了成矿热水溶液的形成过程和减压排泄区铀成矿作用。计算机模拟结果表明，通过大气降水与碎斑熔岩相互作用，可以形成富含Ｆ和ＳｉＯ２等矿化剂的含铀热水溶液；由于铀以ＵＯ２Ｆ＾３和ＵＯ２（ＣＯ３（＾２－３等配合形式存在，非常稳定，即使在深部强还原环境中仍能能够迁移；酸性和碱性环境，尤其是强酸性  相似文献   

树轮年代学的若干进展   总被引：60，自引：10，他引：60       下载免费PDF全文

邵雪梅 《第四纪研究》1997,17(3):265-271

树轮年代学是一门研究树木木质部年生长层，以及利用年生长层来定年的科学。由于树轮不仅是一种定年工具，它本身还可提供树轮生成时的环境要素信息，为一种环境变化的代用资料。在全球变化特别是在过去全球气候变化研究中，树轮年代学受到愈来愈广泛的重视，在近期内取得了长足的、惊人的进展。本文仅在树轮长年表的建立，树轮年代学生物基础研究──模式研究，利用树轮对环境要素变化的研究，以及树轮的图像分析等几个与环境变化研究相关的方面和本学科目前研究热点的若干进展，予以概要的论述。  相似文献   

Numerical modeling of 3-D terrain effect on MT field   总被引：1，自引：0，他引：1  

Shizhe Xu  Baiyao Ruan  Hui Zhou  Leshou Chen  Shiwen Xu 《中国科学D辑(英文版)》1997,40(3):269-275

Using the boundary element method, the numerical modeling problem of three-dimensional terrain effect on magnetotelluric (MT) field is solved. This modeling technique can be run on PC in the case of adopting special net division. The result of modeling test for 2-D terrain by this modeling technique is basically coincident with that by 2-D modeling technique, but there is a great difference between the results of 3-D and 2-D modeling for 3-D terrain. Project supported by the National Natural Science Foundation of China.  相似文献   

Assimilating data into open ocean tidal models     

Gennady A. Kivman 《Surveys in Geophysics》1997,18(6):621-643

The problem of deriving tidal fields from observations by reason of incompleteness and imperfectness of every data set practically available has an infinitely large number of allowable solutions fitting the data within measurement errors and hence can be treated as ill-posed. Therefore, interpolating the data always relies on some a priori assumptions concerning the tides, which provide a rule of sampling or, in other words, a regularization of the ill-posed problem. Data assimilation procedures used in large scale tide modeling are viewed in a common mathematical framework as such regularizations. It is shown that they all (basis functions expansion, parameter estimation, nudging, objective analysis, general inversion, and extended general inversion), including those (objective analysis and general inversion) originally formulated in stochastic terms, may be considered as utilizations of one of the three general methods suggested by the theory of ill-posed problems. The problem of grid refinement critical for inverse methods and nudging is discussed.  相似文献   

Prediction of the measured response of a scaled soil-pile-superstructure system   总被引：1，自引：0，他引：1  

N. Makris  T. Tazoh  X. Yun  A.C. Fill 《Soil Dynamics and Earthquake Engineering》1997,16(2):113-124

The validity of the Winkler foundation model is investigated by predicting the experimentally measured displacement transfer functions and strain spectra of a single pile embedded in a sandbox and supporting a single-degree-of-freedom superstructure. The foundation-superstructure system is a scale model and was subjected to shake table excitations. The distributed springs and dashpots of the Winkler foundation model are frequency dependent and the calibrated model predicts satisfactorily the displacement transfer function at different depths for both fixed- and free-tip pile conditions. On the other hand, the pile-axial-strains are substantially underestimated when expressed in terms of the second derivative of the computed elastic line of the pile. It is shown that a much more dependable prediction is achieved when pile-axial-strains are expressed in terms of the inertial forces acting along the pile-superstructure system.  相似文献   

泌阳碱矿形成的地球化学模拟研究   总被引：2，自引：0，他引：2       下载免费PDF全文

文冬光  曾建华 《地球科学》1997,22(1):69-73

泌阳碱矿过去一直被认为是原生沉积矿床。通过综合分析泌阳凹陷的地质、石油地质、碱矿地质和水文地质条件，从不同方面论证泌阳碱矿不太可能属于原生沉积矿床。利用地球化学模拟技术，从理论上模拟了泌阳碱矿的形成过程，提出了一种水－岩相互作用成矿模式，并用大量的事实支持了这种观点。  相似文献   

宁南深层岩溶地下水系统三维数值模拟   总被引：2，自引：0，他引：2  

李向全  侯新伟  张莉 《地球科学进展》2004,(Z1)

宁南“南北古脊梁”岩溶裂隙水系统的储水空间以岩溶裂隙为主,岩溶水的空间分布明显受南北向大型断裂构造控制。根据水动力场和水化学场特征,划分了3个相对独立的岩溶水子系统。通过三维数值模拟计算,确定了马渠—洪河岩溶水子系统天然资源量和可开采资源量,为本区的地下水合理开发利用提供了科学依据。  相似文献   

工程岩体三维构模中钻孔数据处理方法   总被引：1，自引：0，他引：1  

李卫兵  刘斌  何满潮  徐能雄 《吉林大学学报(地球科学版)》2004,(Z1)

原始数据处理是工程岩体三维构模中存在的主要困难之一。从三维构模的角度,将工程岩体按几何特征抽象为4种结构单元类型。钻孔数据是描述工程岩体的重要原始数据,具有多尺度性。针对这个特点,提出钻孔数据纵向概化准则,解决工程岩体多尺度显示问题;根据地质学的地质数据解译方法,结合岩层层状分布的特点,提出层处理方法对钻孔数据进行概化处理,确定工程岩体所对应的结构单元类型,创建工程岩体结构单元三维构模数据,建立由钻孔数据所得到的工程岩体三维模型。  相似文献