关键词: 大青山, 早前寒武纪, 高级变质杂岩, 顺层伸展变形

Abstract: Located in the northern margin of North China craton, Daqingshan-Wulashan district is one of well-developed high-grade metamorphic regions in China. The high-grade metamorphic complexes, extending from east to west, experienced multiple phases of deformation and metamorphism. The horizontal bedding extensional deformation occuring in granulite facies rocks can be taken as the oldest plastic flow deformation in high grade metamorphic complex. Due to the deformation, accompanied by metamorphism in granulite facies and anatexis, such structural features were formed as bedding slid ductile belts, dome, intra-bedding diapiric folds and L-tectonite. The deformation is also responsible for horizontal structural contact between khondalite suite and granulites, the stack stratigraphic frameworks of lens slices among different stratigraphic units in khondalite suite, as well as different types of anatectic gneisses. The confirmation of horizontal bedding extensional deformation has an important theoretical significance on studying the crustal evolution of Early Precambrian high-grade metamorphic region and the high-grade metamorphic stratigraphic frameworks.

Key words: Daqingshan, Early Precambrian, high-grade metamorphic complex, bedding extensional deformation