通过对CSH1岩心131个沉积物样品中的稀土元素进行分析,恢复了冲绳海槽北部88ka以来碎屑物质来源及古环境的演化历史。结果显示,88ka以来稀土元素含量发生了剧烈的波动,范围为111~171.3μg/g(均值为130.9μg/g),高值出现在MIS2期,低值主要出现在MIS1期。在MIS4期存在显著的Ce负异常,这与底层水体通风减弱相关。物源分析表明,8ka以来冲绳海槽北部沉积物存在火山碎屑的贡献,MIS2—MIS5a期以陆源碎屑为主。在MIS2期与MIS4期及末次冰消期早期和晚期沉积物来源存在显著的差异。海平面与东亚夏季风是控制冲绳海槽北部陆源碎屑物质累积的主要因子。
The history of terrigenous detritus accumulation and paleoenvironment since the last 88 ka was reconstructed using the results of rare earth elements(REEs)from 131 samples from the Northern Okinawa Trough.The results show that the contents of∑REEs vary between 111~171.3μg/g with an average value of 130.9μg/g.The apex of∑REEs occurs in MIS 2,while the low values exist in Holocene.Negative Cerium anomaly exists in MIS 4,which is mainly controlled by the ventilation of deep water.Provenance analysis suggests that the sediment components are dominated by terrigenous detritus during MIS 2and MIS 5a,while the contribution of volcanic detritus significantly increases over the last 8ka.There exists provenance difference between MIS 2-MIS4,and the early and late last deglacial periods.Both sea level and East Asian Summer Monsoon are the main controlling factors for terrigenous detritus accumulation in the northern Okinawa Trough.