摘要
拉张型过渡壳是地壳的主要类型之一,是地壳演化的重要阶段。裂谷(作用)只是拉张型过渡壳的一种形式,或只在拉张型过渡壳形成的某一阶段起过作用。内蒙古狼山群、渣尔泰群和白云鄂博群的沉积建造、火山—深成岩建造的研究表明,在早元古代末固结的华北原地台北缘,从中元古代早期开始解体,发展成拉张型过渡壳。经长城纪末期的白云鄂博运动(约14亿年)和蓟县纪晚期的什那干造陆抬升(11亿年左右),地壳成熟度不断提高,形成连续稳定的克拉通,成为华北地台基底固结最晚的地区。
Tensile type gradual crust is a major kind of crust marking an important evolution stage.Rift-valley is only one of the types of tensile gradual crust.Rifting may played a role only in certain forming stage of the tensile type gradual crust. The study of the sedimentary formation and volcanoplutonic fo- rmation of the Langshan Group,Chaertai Group and Baiyunebo Gro- up of Neimongo;reveals that the northern margin of the North Ch- ina proto-plate consolidatel in the end of Early-proterozoic st- arts to dismember in the early Mid-proterozoic developing into ten- sile type crust.The Baiyunebo Movement of terminal Changcheng Period(about 1400Ma)and the Shinagan uplifting of the late Jixian Period(about 1100Ma)increased the crustal maturity forming a co- ntinuous stable craton.This is the last consolidated part of the base for the North China Plate.
