太行山中南段测鱼地区中新生代构造变形及构造应力场

Mesozoic-Cenozoic Structural Deformation and Tectonic Stress Fields in the Ceyu Area of the Middle-Southern Taihang Mountains

太行山中南段测鱼地区中新生代构造变形强烈,构造形迹以断裂构造为主。以测鱼地区广泛发育的共轭剪节理和断层为研究对象,在详细的野外构造观测和解析基础上,应用共轭剪节理统计和断层滑动矢量数据分析,对研究区中新生代构造应力场进行了反演。构造解析表明,测鱼地区中新生代经历了3期构造应力场的演化,分别是中晚侏罗世NW-SE向挤压、早白垩世NW-SE向伸展和古新世-始新世NE-SW向挤压。根据区域构造演化特征,推测中晚侏罗世NW-SE向挤压应力场可能与古太平洋板块由NW向亚洲大陆东部俯冲消减有关;早白垩世NW-SE向伸展应力场与东亚活动陆缘的弧后伸展有关,形成于华北克拉通破坏阶段;古新世-始新世NE-SW向挤压应力场可能与太平洋板块的俯冲方向由NNW向往NWW向逆时针偏转有关。测鱼地区的上述3期构造应力场记录了太行山中南段中新生代构造演化和动力学背景信息。

The Ceyu area in the middle-southern Taihang Mountains in the Mesozoic-Cenozoic experienced intense structural deformation,with the main structural features being faults.In this paper,we present new structural data related to the conjugate shear joints and faults in the Ceyu area to define the tectonic stress fields in the Mesozoic-Cenozoic.This research conducted an analysis of the conjugate shear joint and fault slip vector data,based on detailed field structural observations.Structural analysis shows that the Mesozoic-Cenozoic tectonic stress fields in the Ceyu area had undergone three stages of evolution:the late Jurassic NW-SE compression,the early Cretaceous NW-SE extension,and the Paleocene-Eocene NE-SW compression.According to the characteristics of regional tectonic evolution,it is speculated that the NW-SE compression stress field might be related to the NWward subduction of the Paleo-Pacific Plate by the late Jurassic to the eastern margin of the Asian continent;the NW-SE extension stress field was related to the early Cretaceous arc-back extension of the East Asian active continental margin,which occurred during the destruction stage of the North China Craton;and the NE-SW compression stress field was related to the retrograde rotation of the subduction direction of the Paleo-Pacific Plate from NNW to NWW during the Paleocene-Eocene.The three stages of tectonic stress fields in the Ceyu area recorded information about Mesozoic-Cenozoic tectonic evolution and dynamic background in the middle-southern sections of the Taihang Mountains.