The mesoproterozoic mafic dyke swarms are extensively distributed in the central north china craton , 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 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。
Throughout researching it has been found that three main types of copper deposits , which mafic - ultramafic rock , marine volcanic rock and porphyry , with middle proterozoic , paleozoic and mesozoic in gansu , china . the cu - bearing formation , deep major faults and late structural - magmatic zones formed in specific geotectonic setting are main ore - controlling and metallogenic factors for copper , gold and polymetallic minerals in this area , and their convergent positions are effective ones formed ore bodies in space 通过研究认为：镁铁质-超镁铁质岩型、海相火山岩型及斑岩型三种铜矿类型，是甘肃的主要铜成矿类型，其主成矿阶段为中元古代、古生代以及中生代；特定大地构造背景下形成的含矿建造、区域性深大断裂以及后期斜向构造-岩浆活动带，是该区铜、金及多金属成矿的主要控矿因素，三者在空间上的复合是矿床体形成的有利部位。
