关键词: 变质核杂岩, 拆离断层, 同构造岩体, 伸展构造, 医巫闾山

Abstract:

The Yiwulüshan pluton is an important part of the Yiwulü metamorphic core complex. Due to its deformation and relationship with surrounding tectonic belts, the Yiwulüshan pluton is determined as the syn-extensional granite. The pluton emplaced along or parallel to ductile shear zone as a bedding-sill, which modifies previous view that the pluton caused by magma emplacement under compressed environment. The emplacement time of both the Yiwulüshan pluton and the Jianlazishan pluton is about 160 Ma, which implies intensive crustal extension occurred in the Yiwulüshan and Yanshan region in late Middle Jurassic and the tectonic pattern of the northern part of North China had been transformed in Middle Jurassic period. There were two extensional stages in the area in the Mesozoic. The earlier occured in the Late Jurassic and accompanying with the emplacement of the Yiwulüshan pluton. The later extension occurred in the Early Cretaceous and resulting in the formation of the Waziyü detachment fault.

Key words: metamorphic core complex, detachment fault, syn-tectonics pluton, extensional tectonics, Yiwulüshan