【摘要】 岩石的地震波性质是解释地震观测资料的基础。本文首先以中国大陆超深钻主孔的榴辉岩为例,将榴辉岩在高温高压(最大为500MPa和700℃)下观测矿物组成、晶格优选定向(LPO)、温度和压力对其地震波性质的影响。然后对岩石地震波性质数据库进行统计分析,指出长英质岩石的波速与石英或长石的含量没有相关性;从酸性岩、基性岩到超基性岩,随着SiO2含量的降低和铁镁矿物含量的增高,岩石波速逐渐增高,云母和角闪石的LPO是陆壳地震波各项异性的主要来源;波速与孔隙率的负相关受流体与压力的影响。更多还原

【Abstract】 Seismic properties of rocks are fundamental for interpreting seismic observations. As a case study, an eclogite from the main hole of the Chinese Continental Scientific Drilling Project was collected to present an integrated study on seismic properties and microstructure of rocks. P-wave velocities of the eclogite were measured at pressures up to 500 MPa and temperatures up to 700 °C. The experimental results are compared with the calculated seismic velocities and anisotropy to investigate the effects of modal composition, lattice-preferred orientations (LPO) of minerals, pressure and temperature on seismic properties of eclogites. The statistical analysis on the Database of Rock Seismic Properties indicates that for felsic rocks there is no correlation between velocities and contents of quartz or feldspar. In general, seismic velocities of rocks increase with the decreasing SiO2 content and increasing volume fraction of mafic minerals. The seismic anisotropy of continental crust is mainly controlled by the LPO of mica and hornblende. Pore fluids and pressure will affect the negative correlation between porosity and seismic velocities of rocks.更多还原