摘要
以华北原地台为例，太古宙陆壳可能是由分散的陆核在涡旋构造机制的驱动下聚集而成的。早元古代伊始，板块构造机制控制了地壳演化的进程，出现不同性质的活动带同刚性地块并存的构造格局。巨厚的火山－沉积建造，以其成岩环境和构造样式的多样性，宣告了一个新的地壳演化阶段的开始，明显具有太古宙克拉通基底的华北原地台、塔里木原地台和扬子原地台在它们的接触部位发育有早元古代增生带，说明至少在太古宙末它们是互相分离的。而华夏古陆则是从早元古代以来逐渐向扬了原地台靠拢的，现代华北地台北缘，早元古代建造近南北向的早期构造方位表明，它在早元古代及其以前，可能同西伯利亚板块的基底是相连的。
ith North China Protoplatform as an example, the Archaean continental crust might bemade from the dispersed nuclei in operation of whirl tectonics 2. 5Ga ago.From the beginning of the early Proterozoic the crust evolutional process was controlled bythe plate tectonics. There emerged the tectonic regime of coexistence of mobile belts ofdifferent natures and rigid blocks. The diversity of tectonic setting and structural pattempronounced a beginning of new epoch of curstal evolution.The North China Protoplatform, the Tarim Protoplatform and the Yangtze Protoplatformare considered to have separated from each other at least during the end of Archaean because ofthe early Proterozoic accretion zones developed between them. Whereas the Cathaysia hadgradually clcosed with the Yangtze Protoplatform since the early Proterozoic time.The nearly N/S priniary structural orientation of the early Proterozoic formation in thenorthern margin of the modern North China platform indicates that the North ChinaProtoplatform had been connected with Siberian craton, during and before early Proterozoictimes.
出处
《地球学报》
EI
CAS
CSCD
1994年第Z2期73-87,共15页
Acta Geoscientica Sinica
关键词
前寒武纪
地壳演化
中国
early Precambrian crust evolution China
