冲绳海槽近3.5万a来陆源物质沉积通量及其对气候变化的响应  

Terrestrial flux in sediments from the Okinawa Trough and its response to climate changes over the past 35000 a

作　　者：孟宪伟[1] 杜德文[1] 刘焱光[1] 韩贻兵[1] 

机构地区：[1]国家海洋局第一海洋研究所,山东青岛266061

出　　处：《海洋学报》2007年第5期74-80,共7页

基　　金：国家自然科学基金资助项目(4027602440606016);国家自然科学重点基金项目(40431002)

摘　　要：以冲绳海槽DGKS9603孔沉积物为研究对象,利用元素地球化学成分数据因子分析方法把混合源沉积物分离成陆源、火山源和生物源.结合沉积物干样密度和沉积速率对冲绳海槽近3.5万a以来沉积物中陆源物质沉积通量进行了估计,进而揭示陆源物质供应对气候变化的响应规律.研究表明,冲绳海槽的陆源物质主要来源于长江输运的我国大陆物质.在冰期—间冰期时间尺度上,海平面涨落导致的长江与海槽之间距离的伸缩是制约陆源物质通量变化的主要因素;在盛冰期和气候变冷事件(Heinrich事件)期间,东亚冬季风的增强使更多的粉砂级物质进入冲绳海槽,导致陆源物质通量增加.冲绳海槽沉积物记录的Heinrich事件与增强的东亚冬季风密切相关.A terrestrial flux in sediments is potential not only to reflect the paleoceanographic evolution of sedimentary basin,but also to reveal the paleoclimatic changes in source regions.The sediments of Core DGKS9603 from the Okinawa Trough were quantitatively partitioned into terrestrial,volcanic and biogenitic source end members,using Q-mode factor analysis for geochemical compositional data.Combined with the density of dried sediments and sedimentation rate,the terrestrial flux in the sediments from the Okinawa Trough since the last 35 000 a has been estimated to reveal the response of terrestrial supply to climate changes.It is demonstrated that the terrestrial supply to the Okinawa Trough has mainly derived from China＇s Mainland terrestrial mass via the Changjiang River.On the glacial—interglacial scale,terrestrial supply to the Okinawa Trough was mainly controlled by sea-level changes via changing the relative distance between the Changjiang River mouth and the Okinawa Trough.During the Last Glacial maximum and cooling events（Heinrich events）,the East Asian winter monsoon would have intensified and thus provided much eolain dust to the Okinawa Trough.The Heinrich events recorded in the Okinawa Trough would be related to the intensifitation of the East Asian winter monsoon.

关 键 词：陆源物质通量 元素地球化学成分数据因子分析 东亚冬季风 

分 类 号：P618.7[天文地球—矿床学] P594[天文地球—地质学]