关键词: 华北, 变质岩, 波速, 地壳分层

Abstract: Compressive wave velocities of metamorphic rocks from the Archaean group in the north part of North China have been measured under high pressure and high temperature By the fitting method,these rocks are divided into velocity grades representing acidity and basicity of them With combination of these results with the geological and seismic sounding data we propose the model of the crust The constitution of upper crust in the current period is "craton rock suite" which consists of TTG metamorphic rocks+khondalite series+granit+minor metabasic rocks and garnet basic rocks The lower crust has three parts of materials "craton rock suite" composition; basic and ultrabasic materials from mantle in post Archaeozoic era; residual basic materials through partial melting of country rock "craton suite" while mantle magma intruded Development of both the latter basified the lower crust with primary "craton rock suite" composition The constitution of the middle crust is "craton rock suite" materials and basic materials of mantle source

Key words: North China, Metamorphic rock, Wave velocity, Crustal layering