Abstract: According to the deep PT-conditions of the Yanhuai basin,the compressional and shear wave velocities of the representative rocks in this area were measured. Variations of wave velocities induced by phase transition of quartz and hornblende are found at certain depths. It is suggested that in the middle crust the material with both low velocity and high conductivity may not be the quartzite or rich quartz bearing rocks,but may be the rocks with aqueous minerals. The upper part of the upper crust may be composed of rocks of argillaceous limestone or its kinds,while the lower part of the upper crust may be composed of granodiorite or its kinds. In the areas without high conductivity and low velocity layer,the middle crust may be composed of granodiorite and quartzite,and in the areas with high conductivity and low velocity layer,the middle crust may be composed of rocks of hornblendite facies. The lower crust may be composed of hornblende gneiss,andesine-granulite and augite-granulite.

Key words: Wave velocities, High pressure-high temperature test, Crust, Yanqing-Huailai basin

摘要： 依据延怀盆地深部的地温地压条件,用模拟实验方法测定了该区代表性岩石的纵波和横波速度以及石英、角闪石在一定深度相变引起的波速变化,提出在中地壳同时具备低速高导的物质可能不是含石英多的岩石而可能是含水矿物多的岩石;讨论了研究区的地壳组成,认为上地壳的上部可能是由泥质灰岩一类的岩石组成,下部可能是由花岗闪长岩一类的岩石组成,没有低速高导层的地区可能是由花岗闪长岩和石英岩等组成,有低速高导层的地区可能由角闪岩相的岩石组成,下地壳可能由角闪片麻岩、中长麻粒岩、辉石麻粒岩等组成。

关键词: 波速, 高压－高温试验, 地壳, 延庆－怀来盆地