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

摘要： 华北克拉通中部广泛发育中元古代镁铁质岩墙群。这些岩墙群未变形和未变质，侵位于先存破裂中，成为恢复华北克拉通中部中元古代构造应力场的显著标志。克拉通北部地块的镁铁质岩墙群为张剪性，而中部和南部地块为张性。根据华北克拉通中部中元古代镁铁质岩墙群的分布和成因机制分析，来恢复模拟中元古代的构造应力场。数值模拟结果表明镁铁质岩墙群在中元古代形成于伸展的大地构造背景，与横穿华北克拉通中部的燕辽-中条拗拉槽系的伸展作用有一定的联系。

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