豫西焦作北山地区构造特征及其演化过程分析

太行山南缘的构造特征、区域演化史及应力场一直是众多学者所研究的热点。豫西焦作北山地区位于太行山背斜的东南方向,太行山山前大断裂由此穿过,造成该地区构造特征的复杂性。在对豫西地区的区域地质背景分析的基础上,通过大量野外构造现象调查,分析了豫西焦作北山地区构造的几何学特征;在此基础上,探讨了研究区的构造演化史及其动力学机制。研究结果表明:豫西焦作北山地区构造现象比较复杂,区域构造以断裂构造和宽缓波状褶曲为主,伴随发育许多拖曳褶皱、推覆构造、次级小断层等构造现象。显著的地貌标志、构造标志和地层缺失等地质现象都印证了凤凰岭断层的存在;研究区构造演化主要受燕山期的太行山背斜和凤凰岭大断层的控制。该研究完善了太行山南部山前断裂发育特征及其演化的基础地质资料,并对豫西地区构造控矿规律有重要的实践意义。

Analysis on structural characteristics and evolution process on the Northern Jiaozuo of the western Hennan

The structural characteristics, regional evolution and strain field of southern margin of Taihangshan uplift have been the research focus in the recent years. The Northern Jiaozuo of the western Henan is located in the southeast of Taihangshan anticline, and traversed by the Taihang fault, which causes the complexity of the regional structure characteristics. In this paper, based on the regional geological background, filed investigation of geological structures, the structure geometry, tectonic evolution and dynamic mechanism of the study area have been revealed. It shows that the geological structures of the northern Jiaozuo are very complex. The regional structure is dominated by fracture structures and rolling wave folds, accompanied with towed folds, nappe structures and secondary faults. The existence of Fenghuangling Fault is verified by significant geomorphic markers, structural signs and the lack of formations; the tectonic evolution was mainly controlled by the Taihang anticline and Fenghuangling Fault. This research has improved the basic geological data about the development and evolution of piedmont fault zone of the Thanghang Mountain. Also, it has important practical significance of ore-controlling regularity of the western Henan.