摘要
近十年来许多国家开展了陆壳深部(地震反射、深部钻探、高压捕虏体、下地壳剖面等方面)的研究.其成果表明,不同构造区的地震反射特征存在差异;显生宙地区普遍存在层纹状强反射性下地壳,其成因与造山带演化晚期的伸展作用有关.以上发现导致对大陆莫霍面及中地壳界面的重新评价.显生宙地区的下地壳广泛发生板底垫托作用,它们代表麻粒岩相变质事件,对于造山带向克拉通方向的转化具有重要意义.
Many countries have begun to investigate the deep continental crust since 80' s by means of seismic-reflection,super-deep drilling and survey of the high-pressure xenolith and restoration of the lower crustal section. The results indicate that there is a variety of characteristic seismic reflections among different tectonic regions. The strong reflective laminated lower crust,which results from later extension of orogen, is found common in Phanerozoic areas. This discovery makes necessary the reeval-uation of the continental Mono and mid-crustal disconinuity. Therefore,underplating occurs extensively in the lower crust of Phanerozoic areas, which represents the event of granulite facies metamor-phism,and is therefore very important for transformation of orogen to craton.
出处
《地质科技情报》
CAS
CSCD
北大核心
1991年第1期9-16,共8页
Geological Science and Technology Information
