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本文通过研究华北克拉通中部中元古代基性岩墙群的单体形态和分布规律,分析岩墙群形成的力学机制,认为这些基性岩墙群主要是基性岩浆侵位于先存的张性或张剪性破裂中而成。晋北地区和五台—太行山地区的岩墙群主要为张剪性的,吕梁山地区和中条山地区的主要为张性。根据岩墙群的分布规律、侵位方向和力学机制及其与燕辽-中条拗拉槽系之间的关系,认为华北克拉通中部中元古代的区域构造应力场是张性和张剪性构造环境,其主压应力来自燕辽-中条拗拉槽系的扩张。未变形未变质的前寒武纪岩墙群的存在表明前寒武纪华北克拉通已经具有了刚性板块的性质。
In this paper, by studying the monomer morphology and distribution of Mesoproterozoic mafic dikes in the central part of North China Craton, the mechanics mechanism of the formation of dyke swarms is analyzed. It is considered that these basic dyke swarms are mainly mafic magma intruded into preexisting sheets Sexual or Zhang shear rupture in. The dikes in the Northern Shanxi Province and the Wutai-Taihang Mountains are mostly shear-thin, while the Luliang Mountain and Zhongtiaoshan areas are mainly Zhang Xing. According to the distribution law, emplacement direction and mechanical mechanism of the dyke swarms and their relationship with the Yanliao-Zhongkuo Aulaca system, it is considered that the regional tectonic stress fields in the middle Paleoproterozoic of the North China Craton are tensility and Zhang She In the tectonic setting, the principal compressive stress comes from the expansion of Yanliao-Zhongdu aulaca system. The presence of undeformed Precambrian dyke swarms indicates that the Precambrian North China craton has the property of a rigid plate.