镇巴—阳日断裂东段的构造特征及其演化

Tectonic Characteristics and Their Evolution in the Eastern Part with the Zhenba-Yangri Fault

镇巴—阳日断裂带为南大巴山前陆褶皱冲断带南缘的边界断层,对其构造属性和演化历史等长期存在不同的认识。通过构造剖面测制并结合区域地质调查资料,对镇巴—阳日断裂带东段进行了系统研究,研究表明断裂带总体表现为逆冲断层,分别在印支期、早燕山期、晚燕山期、喜马拉雅期均有不同形式的构造活动。笔者系统总结该断裂带在不同活动时代的构造活动特点,并提出喜马拉雅期镇巴—阳日断裂带东段构造演化的新认识,为南大巴山及整个扬子板块内部处于造山后的大规模、多期次的陆内调整构造背景提供佐证。

The Zhenba-Yangriwan fault is the boundary of the foreland thrust fold in the southern Dabashan thrust nappe,and there has been controversy for the structural properties and the evolution. By surveying the constructed section and researching the regional geological data,this paper argues that the faults are thrust faults,and has been active in Indosinian,Early Yangshanian,Late Yanshanian and Early Himalayan. By summing the fault of tectonic activity characteristics of different periods,the authors suggest some new understanding that can be used as evidences of the large-scale and multistage tectonic movement after the orogeny in the southern Dabashan and even the Yangtze plate.