Petrologic composition model of the upper crust in Bohai Bay basin,China,based on Lamé impedances  

中国渤海湾盆地上地壳岩石成分模型(英文)

作　　者：张唽 Loui sa L.H.Tsang 王仰华 赵兵[1] 

机构地区：[1]中科院地质与地球物理研究所岩石圈演化国家重点实验室,中国北京100029 [2]Centre for Reservoir Geophysics,Department of Earth Science and Engineering,Imperial CollegeLondon

出　　处：《Applied Geophysics》2009年第4期327-336,393,394,共12页应用地球物理（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant 20930140);the Chinese Academy of Sciences and the sponsors of the Centre for Reservoir Geophysics of the Imperial College

摘　　要：Seismic attributes, such as P- and S-wave velocity, Poisson＇s ratio, and acoustic impedances, all generally can be used for distinguishing different rock types. The nonuniqueness can be largely reduced using Lame impedances instead of acoustic impedances as additional constraints. We have followed this method to constitute a petrologic composition model of the upper crust in the Bohai Bay basin, China. We briefly review the seismic parameters used for discrimination of rock types and focus our attention on the sensitivity of different combinations of parameters to determine the composition of materials. Corrections for pressure and temperature are performed in order to compare elastic wave velocities and densities measured at room temperature and surface pressure in laboratory with those for representative rock parameters. In a second step, we find the rock classes in the tested area by contrasting known data to laboratory measurements on a variety of rock samples extracted in the area. The basic field data are P-wave velocity values collected along a seismic profile conducted in the Bozhong Depression. The different rock types belonging to a particular rock class are finally constrained by the seismic velocities, Poisson＇s ratio, density, acoustic impedance, and Lame imoedance related to the topmost 10 km of the Bohai Bav crust.许多地震属性,比如地震的纵横波速度,泊松比,声波阻抗,都能用来区分不同的岩石类型,利用拉梅阻抗作为进一步的约束来代替声波阻抗能更好的降低结果的非唯一性。我们用这种方法构建了渤海湾地区一条剖面的岩石成分模型。我们简要介绍了区分岩石类型的地震参数,重点在于不同的参数组合对于分辨岩石类型的敏感性。为了与室温常压条件下测得的有代表性的岩石的地震波速度和密度进行对比,我们首先需要做温度和压力的校正。接着,我们需要用已知资料和实验测得的各种岩石样品做对比,来确定研究区的岩石类型。我们收集了渤中凹陷一条剖面的纵波速度资料。该剖面10km深范围内的属于同种岩石类型的不同岩石最终通过地震波速度、泊松比、密度、声波阻抗、以及拉梅阻抗综合约束。

关 键 词：seismic velocity Poisson＇s ratio acoustic and Lam6 impedances Bohai Bay 

分 类 号：P315.31[天文地球—地震学]