关键词: 华北克拉通, 镁铁质岩墙群, 构造应力场, 伸展作用, 燕辽-中条拗拉槽系

Abstract: The Mesoproterozoic mafic dyke swarms are extensively distributed in the central North China Craton(NCC), which are not deformed and metamorphic, emplacing the pre-existed fractures, so the dyke swarms become the conspicuous marks to reconstruct the Mesoproterozoic tectonic stress field of the central NCC. The mafic dykes in the northern block are transtensional while the dykes in the central and southern blocks are extensional. The Mesoproterozoic tectonic stress field could be simulated on the analysis of the distribution and mechanical origin of the Mesoproterozoic mafic dyke swarms in the central NCC. The simulation result shows that the mafic dyke swarms were formed in the extensional tectonic setting in the NCC in the Mesoproterozoic time, which are related to the extension of the Mesoproterozoic Yanliao-Zhongtiao aulacogens cross the central NCC.

Key words: North China Craton(NCC), mafic dyke swarms, tectonic stress field, extension setting, Yanliao-Zhongtiao aulacogens