长白山天池火山是我国最具喷发危险的火山，晚更新世以来经历了数次大规模爆炸式火山喷发，火山灰分布面积广泛，受到了世界范围内的广泛关注。然而，关于长白山天池爆炸式喷发序列以及火山灰年代学应用方面仍都存在较大争议。本项目拟选用日本海中部IODP346-1425钻孔为研究对象，通过显微火山灰年代学研究方法，分离钻孔样品中显微火山灰层，再利用EPMA和LA-ICP-MS等手段分析各火山灰层地球化学组成，进而判定各火山灰层来源；利用14C和40Ar/39Ar获得的绝对年龄控制点，以及显微火山灰层绝对年龄，建立该钻孔的年代学标尺；与长白山天池近源爆炸式喷发产物对比，建立晚更新世以来长白山天池爆炸式火山喷发序列；对比和关联日本海其他钻孔、日本岛内等沉积物火山灰记录，为区域古气候、古环境研究提供等时参考。这将为长白山天池火山喷发灾害及火山成因等研究提供重要科学依据，也为区域气候演变研究提供重要对比标志。

Changbaishan Tianchi volcano is the most dangerous volcano in China, and it experienced several explosive eruptions since the Late Pleistocene. These eruptions dispersed widely distributed tephras around the volcano, and lot of attentions were paid on this volcano. However, there are still debates on the eruptive sequence of the Changbaishan Tianchi volcano, and tephrochronological applications. In this project, we will apply tephrochronological method to separate cryptotephra layers throughout the IODP346-1425 core, and EPMA and LA-ICP-MS will be used to characterized the source volcanoes of these cryptotephra layers. Combining ages determined by 14C and 40Ar/39Ar methods, with the known ages of cryptotephra layers whose source volcanoes have been identified to construct age model of the core. By correlating these distal tephra and cryptotephra in Japan Sea with the proximal tephra from Changbaishan Tianchi volcano, we construct the ~110 ka eruptive sequence of Changbaishan Tianchi volcano. In addition, regional marker layers will be established by correlating tephras recorded in the sedimentary archives from Japan Island to Japan Sea. This project will provide a valuable basis for the studies of volcanic hazards and petrogenesis of Changbaishan Tianchi volcano, and the widely distributed tephras will provide important time-equivalent marker bed for regional climatic change.