尚义-赤城断裂最新活动迹象及构造含义

尚义-赤城断裂是燕山构造带内一条重要的地质构造分界线,形成于太古代末至早元古代,控制着区内的构造演化、岩浆活动、地震分布及矿床形成。本文在卫星影像解译基础上,通过地形地貌分析、地质地貌调查对尚义-赤城断裂的最新活动迹象进行观测和研究,结合小震分布和张北震区地层结构特征归纳断裂活动现象的本质。研究表明：尚义-赤城断裂具有复杂的多期活动特征,最新活动表现为高角度逆冲/正断-左旋走滑运动特征；主体段落最新活动时代主要为中更新世,多个地段晚更新世仍有活动迹象,是张北地区活动性最强的断裂。结合前人相关研究成果,发现该断裂与张北6.2级地震的关系更为密切,可能是该地震的发震构造。

The latest signs and tectonic implicationsof the Shangyi-Chicheng fault

The Shangyi-Chicheng fault is an important tectonic boundary in the Yanshan tectonic belt. It formed in the late Archean to early Proterozoic, and controlled the tectonic evolution, magmatic activity, earthquake distribution and deposit formation in the area. On the basis of satellite image interpretation, this paper observes and studies the latest activities of the Shangyi-Chicheng fault through geological and geomorphological investigation. The results show that the Shangyi- Chicheng fault has a large scale, and the latest activities are characterized by high angle thrust (positive fault) and left-slip movement; The latest age of the main section is the Middle Pleistocene, and there are still signs of activity in the late Pleistocene, which is the most active fault in the Zhangbei region. Combined with previous research results, it is found that the relationship between the fault and the Zhangbei 6.2 earthquake is more closely related, which may be the seismotectonics of the earthquake.