Petrologic composition model of the upper crust in Bohai Bay basin, China, based on Lamé impedances
Zhang Xi1, Louisa L. H. Tsang2, Wang Yanghua2, and Zhao Bing1
1. State Key Laboratory of Lithospheric Evolution, CAS, Beijing 100029, China.
2. Centre for Reservoir Geophysics, Department of Earth Science and Engineering, Imperial College London, SW7 2BP, UK.
Abstract：
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 non-uniqueness can be largely reduced using Lamé 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 Lamé impedance related to the topmost 10 km of the Bohai Bay crust.
张晰,Louisa L. H. Tsang,王仰华等. 中国渤海湾盆地上地壳岩石成分模型[J]. 应用地球物理, 2009, 6(4): 327-336.
ZHANG Xi,Louisa L. H. Tsang,WANG Yang-Hua et al. Petrologic composition model of the upper crust in Bohai Bay basin, China, based on Lamé impedances[J]. APPLIED GEOPHYSICS, 2009, 6(4): 327-336.
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2009, Vol. 6 
