末次冰消期以来东海内陆架沉积速率及其气候环境响应

SEDIMENTATION RATE AND TYPICAL CLIMATIC EVENTS RECORDED IN THE INNER SHELF OF THE EAST CHINA SEA SINCE THE LAST DEGLACIATION

对位于东海内陆架浙—闽沿岸泥质带的EC2005孔岩性、粒度以及AMS14C年代进行了分析,着重探讨了研究区自末次冰消期以来的沉积速率变化,划分出4个大的沉积阶段和4次快速沉积事件。千年时间尺度上大的沉积阶段主要受控于物源供应、海平面变化以及可容空间的大小。百年时间尺度上揭示的4次快速沉积事件主要受控于东亚冬季风的增强或是气候的变冷,与中国湖光玛珥湖沉积物Ti含量以及北大西洋浮冰碎屑具有良好对应,与世界范围内存在的新仙女木事件、7300 a BP冷事件、第二新冰期(5500 a BP强降温事件)以及北大西洋1400a BP浮冰事件也均有良好的对应。全新世高海平面以来东海内陆架泥质沉积物百年时间尺度上的沉积速率可以作为东亚冬季风变化的沉积学代用指标。

Based upon analysis of lithology, grain-size, and AMS14C dating for Core EC2005 located in the mud area off the Zhejiang-Fujian coast, the sedimentation rates and typical climatic events recorded in the inner shelf of the East China Sea （ECS） were discussed. Four large sedimentary stages and 4 rapid depositional periods disclosed by Core EC2005 well correspond to the climatic and sea level changes. The large sedimentary stages on millennium scale are mainly dominated by climatic changes, sea level variations, and the formation of mud wedge itself. The four rapid depositional periods on century time scale are controlled mainly by climate cooling or the strengthened East Asian winter monsoon（EAWM）, corresponding to the worldwide Younger Dryas, 7.3 ka cold event, Neoglaciation or 5.5 ka cold event, and 1.4 ka ice rafted debris event, respectively. The sedimentation rate of mud sediment in the inner shelf of the ECS on century time scale since the Holocene sea level highstand can be used as a sedimentology proxy for EAWM evolution.