近年来，青藏高原东缘发生了汶川、玉树、芦山、九寨沟等四次7级以上的地震，表明该区具有很高的地震危险性。了解这个地区的地震活动性具有重要的科学和现实意义。传统的探槽方法仅能给出短时间尺度或少数几次的古地震事件；而区域广泛分布的古堰塞湖湖相沉积和新的沉积学手段，为开展长时间尺度且连续的古地震研究提供了机遇。本研究拟以岷江上游沙湾湖相沉积剖面为研究对象，开展野外软沉积物变形的精细观察和室内沉积学研究，查明软沉积物变形指示的地震事件；同时采用高分辨率地球化学和地球物理微观环境指标，获得剖面连续的元素和物性变化信息，确定未导致软沉积物变形的地震事件；厘定沙湾长序列剖面记录的古地震事件的次数。结合碳十四和光释光测年，探讨沙湾晚第四纪古地震事件的年代、期次和区域的地震活动性，为该区防震减灾提供基础数据。

In recent years, four earthquakes with M ≥7 occurred in the eastern margin of Tibetan Plateau, such as Wenchuan, Yushu, Lushan and Jiuzhaigou, indicates that the area has a very high level of seismic risk. Understanding the seismicity is of great scientific and realistic significance in this area. However, the traditional trench for paleoearthquake research can only give short-time scales or a few times of paleoearthquake events. The widespread dammed lacustrine sediments and new sedimentology methods provide opportunities for long-term and continuous paleoearthquake research. In this study, we will carry out detailed field observation of the soft-sediment deformation and sedimentology research on Shawan lacustrine sediments which located in the upper reaches of the Min River, to ascertain the paleoearthquake events. The high-resolution geochemical and geophysical sedimentation indexes will be used to obtain the continuous elemental and physical information of Shawan section, to ascertain the paleoearthquake events that did not induce soft-sediment deformation. The ultimate goal is to determine the number of paleoearthquake events recorded in Shawan long continuous sequence. Meanwhile, the 14C and OSL chronology of lacustrine sediments will be used to determine palaeoearthquake time and frequency during the late Quaternary. The main purpose of this study is to understand the regional seismicity, and provide basic data for seismic risk assessments in this area.