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

摘要： 在高温高压条件下对华北北部太古宙变质岩做了波速(V_P)测定,经拟合公式处理后划分出代表岩石酸性程度的波速级数,结合地质、地震测深资料,认为这种变质岩现时期的上地壳组成为"克拉通岩石组合",其成分为TTG变质岩+孔兹岩系+花岗岩+少量基性变质岩和含石榴石基性岩;下地壳由三部分物质组成:"克拉通岩石组合"物质,太古代后幔源基性和超基性物质,地幔岩浆侵入时"克拉通岩石组合"围岩部分熔融留下的残余基性物质,后两种物质的生成使原"克拉通岩石组合"地壳基性化;中地壳为"克拉通岩石组合"物质+幔源基性物质。

关键词: 华北, 变质岩, 波速, 地壳分层