韩城断裂北东段晚更新世以来最新活动研究

Study on the Latest Activity of the Northeast Section of Hancheng Fault since the Late Pleistocene

摘要:

韩城断裂是汾渭断陷带临汾盆地WS边界的一条控制性断裂，据最新的野外调查研究结果将该断裂分为3段，其中NE段活动性最强，形成的构造地貌也最为显著。本文在野外地质地貌调查的基础上，在NE段选取4个地点进行了探槽开挖和年代样品测试，并对揭示的古地震事件进行了分析探讨，综合各个探槽及典型地质剖面古地震事件分析结果认为，韩城断裂NE段最新的活动时代为距今6～8ka。

Abstract:

The Hancheng fault is a fault controlling the southwest boundary of the Fenwei rift zone. According to the latest field research,the fracture is divided into three sections,of which the northeast section shows the strongest activity,and tectonic landforms are also the most significant. Based on geological and geomorphological field survey,we select four sites to do trench excavation in the northeast section and analyze and discuss paleoearthquake events revealed. The result of a comprehensive analysis of trenches and typical geological profiles shows that the fault's latest activity era dates back between 6~8ka.