近百万年来亚洲风尘在西菲律宾海的沉积物粒度记录  

Grain-size records of Asian eolian input to the West Philippine Sea over the last one million years

作　　者：于兆杰 万世明[1] 孙晗杰[1] 黄杰[1] 徐兆凯[1] 李安春[1] 李铁刚[1] 

机构地区：[1]中国科学院海洋研究所海洋地质与环境重点实验室,青岛266071 [2]中国科学院研究生院,北京100049

出　　处：《地球环境学报》2012年第2期792-800,共9页Journal of Earth Environment

基　　金：国家自然科学基金(41076003;41230959);中科院知识创新工程方向项目(KZCX2-YW-229)

摘　　要：海洋沉积物中的风尘组分被认为可以用来建立陆地黄土和深海氧同位素记录之间的直接联系。前人研究表明中国内陆黄土可以通过东亚冬季风搬运而输送到西菲律宾海。本文运用粒级一标准偏差方法，对西菲律宾海国际海洋过去气候变化（IMAGES）MD06-3050岩芯400个样品的陆源沉积物粒度组成进行了分析．讨论了过去一百万年以来东亚冬季风和亚洲内陆干旱程度的长期演化。通过对三个敏感粒度组分2．4～4．6μm，14～22μm和36～50μm百分含量、堆积速率的分析，讨论了不同粒级沉积物的物质来源，并选用14—22μm陆源组分堆积速率作为东亚冬季风强度变化的指标。我们的结果结合以前的黄土和深海风尘记录表明了0．6Ma以来亚洲内陆干旱度和冬季风强度相对1．0～0．6Ma整体增强的趋势。The eolian component in ocean sediments has been recognized as providing a direct link between the continental loess and marine δ18O climate records. Previous studies have suggested that the East Asian winter monsoon circulation could have carried eolian dust from central Asia to the West Philippine Sea. Grain-size distribution of terrigenous materials of 400 samples from the International Marine Past Global Change （IMAGES） core MD06-3050 in the basin were analyzed using grain-size class vs. standard deviation method in order to obtain the long-term evolution of the East Asian winter monsoon over the last one million years. Three grain-size populations with high variability through time were defined as 2.4 - 4. 6 μm, 14 - 22 μm and 36 - 50 μm. The mass accumulation rate of 14- 22μm terrigenous materials was used as a proxy of the East Asian winter monsoon intensity and Asian inland aridity. Our proxy combined with previous eolian records both on land and in the deep-sea suggests a strengthened Asian aridity and East Asian winter monsoon since 0.6 Ma than 1.0 - 0. 6 Ma.

关 键 词：风尘 东亚季风 粒度 冰期-间冰期 西菲律宾海 国际海洋过去气候变化(IMAGES) 

分 类 号：P736.21[天文地球—海洋地质]