南海东北部MD05-2905站36ka BP以来的陆源碎屑沉积特征与东亚季风的演化  

Sedimentary Characteristic of Terrigenous Clast of Site MD05-2905 in the Northeastern Part of South China Sea after 36ka and Evolution of East Asian Monsoon

作　　者：杨文光[1] 郑洪波[1] 王可[1] 谢昕[1] 陈国成[1] 梅西[1] 

机构地区：[1]同济大学海洋地质国家重点实验室,上海200092

出　　处：《地球科学进展》2007年第10期1012-1018,共7页Advances in Earth Science

基　　金：国家自然科学基金项目"50万年以来高分辨率地磁场长期变化研究"(编号:40676033);国家自然科学基金国际(地区)合作交流项目"晚第四纪印度洋与南中国海古海洋学对比研究"(编号:40710099);科技部"中荷科技联盟"项目"末次冰期以来中国环境(气候)条件的多样性"(编号:2004CB720506);国家高技术研究发展计划项目"大洋钻探技术预研究"(编号:2004AA615030)联合资助

摘　　要：在AMS14C精确定年的基础上,去除有机质、生物碳酸盐和生物硅之后,对南海北部MD05-2905站进行了陆源碎屑的粒度分析。结果显示,15.5~63.5μm粗粒级成分的含量变化特征可用来指示东亚冬季风的变化,2~9μm细粒级成分含量变化可用于指示东亚夏季风的变化。末次冰期以冬季风为主,全新世以夏季风为主,36 ka BP以来东亚夏季风有逐渐增强的总体趋势,但也发生多次突变现象,在全新世早期（8 500~11 200 ka BP）达到36 ka BP以来的最大值,可能是在岁差周期的控制下,与较强的太阳辐射有关。Sediments with high sedimentation rate at Site MD05-2905 in the northern part of the South China Sea provide unique materials for a high-resolution study on paleoenvironment.Based on precision dating of AMS14C,grain size analysis of terrigenous clast at Site MD05-2905 is studied after removing organic matter,biological carbonate and biogenic opal.The results show that 15.5~63.5μm,coarse grain size ingredients,may indicate the East Asian winter monsoon changes.And that 2 ~ 9μm,fine grain size ingredients,may be used as a proxy of evolution of the East Asian summer monsoon.The results of grain size analysis,which suggest the East Asian monsoon intensity,revealed that a winter monsoon dominated glacial regime and a summer monsoon dominated Holocene regime,and that the summer monsoon increased gradually,experienced several abrupt change events and reached to the culmination in the early Holocene（8 500~11 200 ka BP） after 36 ka.This,with control by precession periodicity,may be related with the amount of solar radiation at the highest stage which needs further study.

关 键 词：陆源碎屑 粒度 东亚季风 全新世 南海 MD05-2905 

分 类 号：P736.213[天文地球—海洋地质] P722.7[天文地球—海洋科学]