摘要
我国太古宇陆壳主要见于华北克拉通区内，由高级变质的麻粒岩相带、角闪宕相区和低、中级变质的绿岩－花岗岩区组成。按地质时序可划分为始、古、中、新太古４个阶段。麻粒岩相带的组成主要由英云闪长质片麻岩为主和少量表壳岩或主要由表壳岩含一些花岗质岩石。绿岩－花岗岩区时代主要属新太古代，绿岩属基性火山－沉积建造，基性岩的原岩物质来自相对亏损的上地幔，形成于大陆边缘的裂谷环境。太古宙末，板块体制已经形成，麻粒岩相带是板块体制的俯冲碰撞机制的产物。对克拉通古陆块能长期成为大陆的解释，应认为是下地壳的挤压环境，促使陆壳以板底垫托叠置、垂直增生所致。
Archean continental crust in China mainly occurs with in the North China or Sino-Korean cra-ton.It consists of the high grade metamorphic granulite facies belts,areas of various amphibolites fa-cies and intermediate lower grade greenstone-granite terrains and the metamorphic assemblages maybe divided into 4 episodes of evolution:Eoarchcan,Paleoarchcan,Mesoarchean and Neoarchean,Granulite facies belt comprises mainly tonalitic granite gneisses with a small amount of supracrustalrocks or chiefly supracrustal rocks with some granites.The greenstone granite terrains are mostly ofNeorchean in ages,the greenstones are of mafic-volcanic sedimentary associations.The source of themafic volcanics in this association may derive from re latively depleted upper mantle in rifting environ-ment of continental margin.At the end of Archean the plate tectonic regime in general began to dis-play after the Late Archean cratonization of the continental crust of the most part of the North ChianCraton.Since then,the North China Craton becomes one of the typical cratons of the world.All ofthose rock assemblages mentioned are the products of the subduction and collision processes of collagein the model of the plate tectonics.The situation of the old continental blocks or cratons maintained to-pographically in their high position,surely,may be caused by the vertical enthickening with horizonalsheeted piles in the lower crust in compressional underplating model.
