龙门山地区关口断裂形成与演化分析

根据大量野外露头剖面资料与钻井数据，系统分析了关口断裂形成过程与演化特征。认为关口断裂在印支早、中期为张性大力构造背景下形成的同沉积正断层，在晚三叠世卡尼克期为生长性正断层；印支晚期构造事件中该断裂改变为逆冲断层。关口断裂活动性较强，其中在燕山晚期活动性最强。关口断裂在喜马拉雅期有多期次的、长时期的强烈活动；并且目前仍是一条活动性的断层。

Formation and Evolution of the Guankou Fault in the Longmen Mountains

This paper deals with formation and evolution of the Guankou fault in the Longmen Mountains based on field observation and drilling-logging data. The study indicates that the Guankou fault was a contemporaneous normal fault during the early and middle Indo-Chinese epoch, a growth normal fault during the Late Triassic Carnian stage and transferred to a thrust fault due to the tectonic event in the Late Indo-Chinese epoch. The activity of the Guankou fault was relatively weak in the south part of Anxian during the Early Yanshan epoch. However, it was markedly active in the late Early Cretaceous. The Guankou fault has undergone multiphase strong activity during the Himalayan epoch, and it is still active at present.