合成平面波数据的Rytov近似叠前深度偏移

作者把Berkhout(1992)提出的合成平面波技术应用于线性Rytov近似叠前深度偏移，提高了波动方程叠前深度偏移的计算效率。通过在Marmousi模型数据试验，我们认为在达到基本相同成像效果的条件下，利用合成平面波技术的波动方程叠前深度偏移相对于基本共炮集数据的波动方程叠前深度偏移可提高计算效率约10倍。     

柴达木盆地CXQ构造油气化探特征及找矿预测

通过在CXQ构造上进行的油气化探结果表明深部拥有油气活动，结合地质构造综合评价认为它具有形成构造圈闭油气藏的条件。为下一步勘探提供了地球化学依据。     

地震勘探在山东蓬家夼金矿深部预测中的应用

在分析了石油地震与金属矿地震不同点的基础上，简介了地震勘探方法的基本原理，并通过在山东蓬家夼金矿的实际应用，得到了理想的效果，为隐伏矿床的精确定位预测提供了十分重要的地球物理资料。     

小秦岭西段驾鹿金矿田矿物地球化学特征及找矿标志

本文在总结驾鹿金矿田有关石英脉主要金属矿物地质产状、物性特征的基础上，系统对比性研究了蚀变岩和石英脉两类金矿床中产状、粒级、晶形、破碎程度不同的各世代黄铁矿中微量元素的含量、组合、比值特征及演化和不同世代撤离铅矿、地表褐铁矿、软锰矿的含金性，建立了两类金矿的找矿矿物学标志。     

矿物成因族的演化及其地质找矿信息

基于对胶东、晋北寒武纪变质岩系、超基性岩、基性岩、花岗岩类、火山岩类、硅铁建造铁矿、金矿蚀变带内 1 1个不同地质产状的 34个角闪石、 2 51个绿泥石、 60个黑云母单矿物的提纯 ,矿物的共生组合、物理性质、化学成分、X光衍射分析、热分析、红外吸收光谱分析、双矿物地质温度计、矿物压力计的测定 ,提出了角闪石、绿泥石、黑云母矿物成因族的地壳物质演化、成岩成矿作用、变质岩原岩恢复、地层对比、变质相、蚀变带的演化规律和地质找矿信息。     

New imaging method for seismic reflection wave and its theoretical basis

Some new imaging formulas for seismic reflection wave and their theoretical basis are given. Phenomena of wave propagation should be characterized by instantaneous spectrum and expressed by complex function of three variables (time, space and frequency) in mathematics. Various physical parameters of medium are also complex functions of two variables (space and frequency). The relationship between reflection coefficient of medium and spectrum of reflected wave is given. Multi-reflection and filter of formations are considered in inversion formulas. Problems in classical convolution model and wave equation are illustrated. All these inversion formulas can be used to image underground medium by wavelet transform and method of “3-basic colors”. Different colors mean different media.     

Evaluation of density in layer compaction using SASW method

SASW test, which is non-intrusive and rapid in the field application, was used to evaluate the layer density in the roller compaction without performing the complicated inversion process. The concept of normalized shear wave velocity was introduced to minimize the effect of confinement in the density evaluation. SASW test was performed to determine the shear wave velocity of the layer, and the free–free resonant column (FF–RC) test was adopted to determine the correlation between the normalized shear wave velocity and density of the site, which is almost unique independent of confinement. Testing and data reduction procedures of both tests were briefly discussed and an evaluation procedure of the field density was proposed by effectively combining in-situ shear wave velocity determined by the SASW test with the correlation between the normalized shear wave velocity and the density determined by the FF–RC test. Finally, the feasibility of the proposed method was verified by performing a field case study at Hoengsung road construction site. Field densities determined by the proposed method matched well with those determined by sand cone tests, showing the potential of applying the proposed method in the field density evaluation.     

Scattering of seismic waves by cracks in multi-layered geological regions: II. Numerical results

The mechanical model for plane strain, time-harmonic seismic wave propagation problems in cracked, multi-layered geological regions with surface topography and non-parallel interfaces was described in the first part of this work. Here, this model is used to investigate the response of such a region to the presence of traveling elastic waves generated by a seismic source. The computational methodology that was developed in the first part is based on a combination of both the regular (displacement-based) and the hypersingular (traction-based) Boundary Integral Equation Method (BIEM). First, the accuracy and convergence characteristics of this hybrid BIEM are studied. Then, a series of problems involving four different configurations of a reference geological deposit with both interface and internal cracks are solved, for a loading that is due to a seismically-induced pressure wave propagating upwards from the underlying rigid half-plane. The purpose of the numerical study is to investigate the influence of various key parameters of the problem, such as frequency and incidence angle of the incoming wave, size of the surface relief, location and size of the buried cracks, interaction effects between cracks and finally the presence of layers, on both the scattered displacement field and the stress concentration field.     

Storm deposits and storm-generated coarse carbonate breccias on a pelagic outer shelf (South-East Basin, France)

Uppermost Jurassic limestones of the South‐East Basin (France) are organized into four facies associations that were deposited in four distinct zones: (1) peritidal lagoonal limestones; (2) bioclastic and reefal limestones; (3) pelagic lime mudstones; (4) lime mudstones/calcarenites/coarse breccias. Calcarenite deposits of zone 4 exhibit sedimentary structures that are diagnostic of deposition under wave‐induced combined flow. In subzone 4a, both vertical and lateral transitions from lime mudstone/calcarenite to breccia indicate in situ brecciation under wave‐cyclic loading. Breccias were produced by heterogeneous liquefaction of material previously deposited on the sea floor. Deposits in subzone 4a record relatively long periods (>400 kyr) of sedimentation below wave base, alternating with periods of deposition under wave‐induced currents and periods of in situ deformation. In this zone, storm waves were attenuated by wave–sediment interaction, and wave energy was absorbed by the deformation of soft sediment. With reference to present‐day wave attenuation, water depths in this zone ranged between 50 and 80 m. Landwards of the attenuation zone, in zone 3, storm waves were reduced to fair‐weather wave heights. Storm wave base was not horizontal and became shallower landwards. As a consequence, water depth and wave energy were not linearly related. On a small area of the seaward edge of subzone 4a, cobbles were removed by traction currents and redeposited in subzone 4b. There, they formed a 100‐m‐thick wedge, which prograded over 3 km and was built up by the stacking of 5‐ to 20‐m‐thick cross‐stratified sets of coarse breccia. This wedge records the transport and redeposition of cobbles by a high‐velocity unidirectional component of a combined flow. The increase in flow velocity in a restricted area is proposed to result from flow concentration in a channel‐like structure of the downwelling in the gulf formed by the basin. In more distal subzone 4c, the hydrodynamic effect of wave‐induced currents was quasi‐permanent, and brecciation by wave–sediment interaction occurred only episodically. This indicates that, seawards of the attenuation zone, hydrodynamic storm wave base was deeper than mechanical storm wave base. Uppermost Jurassic carbonates were deposited and soft‐sediment deformed on a hurricane‐dominated ramp of very gentle slope and characterized by a zone of storm wave degeneration, located seawards of a zone of sedimentation below wave base.     

SOURCE RADIATION AND RESPONSES OF WAVE PROPAGATION

Recordings of seismic waves propagating from earthquake source to a station at the earth's surface are a system response function.The convolution operator in time domain can be simplified as a multiplication operator in frequency domain.We discuss in frequency domain the separation of source,path and site effects for global scaling of earthquake source radiation.Also discussed are source scaling model,faulting mechanism,and the H/V inversion problems with crustal and near surface structures.Gross features of apparent source spectra appear to be not much region-dependent although there may be difference between tectonic styles within a region of tectonic mixture for which we need further study as data accumulate.Vertical spectra may be a better approach to approximate source radiation,as it has less crustal amplification effects than horizontal spectra.The H/V ratio is evidently a comprehensive indicator of amplification effects from near surface to deep structure.This gives it potential as an inversion tool to deduce site crustal structure.