东海内陆架泥质沉积反映的古环境演化  

HIGH-RESOLUTION PALEOENVIRONMENTAL RECORD OF THE MUD SEDIMENTS OF THE EAST CHINA SEA INNER SHELF

作　　者：王可[1] 郑洪波[1] Maarten Prins 郑妍[1] 

机构地区：[1]同济大学海洋地质国家重点实验室,上海200092 [2]Faculty of Earth and Life Sciences, VU University Amsterdam,the Netherlands

出　　处：《海洋地质与第四纪地质》2008年第4期1-10,共10页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目(40676033);国家自然科学基金国际(地区)合作交流项目(40710099);科技部“中荷科技联盟”项目(2004CB720506);上海科委科研计划项目(07DZ14002)

摘　　要：通过对东海内陆架闽浙沿岸泥质沉积体的MD06-3040孔进行粒度及年代测试,重建了东海内陆架1万年以来的古环境。认为研究区的沉积环境曾发生过3次变化:孔深18·6m至底部(10～10.7kaBP)对应近滨环境;15·13～18.6m(7.1～10kaBP)为过渡带环境;0～15.13m(0～7.1kaBP)是海侵结束后高海平面的浅海环境,自10kaBP以来东海沿岸流开始影响本区并不断输送河流来源物质,7kaBP起形成稳定的泥质沉积体。根据该孔沉积物的沉积速率与粒度组分特征,说明不能简单地应用平均粒径指示冬季风强度,在东海地区,不仅冬季风控制着沿岸流强度,夏季风也会影响河流入海物质的搬运沉积作用。Based on a high-resolution grain-size analysis and AMS 14C dating of core MD06-3040, located in the mud area off the Fujian-Zhejiang coast on the inner-shelf of the East China Sea, we attempt to recover the Holocene paleoenvironment evolution of the East China Sea inner-shelf. The core was divided into 3 sections according to its changes in lithology, color and sedimentary structure. The sedimentary environments belong to nearshore, transitional stage and shallow sea, respectively. From 10 kaBP, the studied area was influenced by Zhejiang-Fujian Coastal Current （ZFCC）. River-derived materials were transported southward. Since 7 kaBP, the sedimentary environment was dominated by the ZFCC and mud sedimentation began to form. Linear sedimentation rates of the core show clear steps through time=- 0.4 cm/a since 1.5 Ka, 0.11 cm/a between 1.5 and 4 ka,and 0. 2-0.3 cm/a between 4 and 8 ka. When compared with changes of growth rates of a stalagmite （D4） from Dongge Cave in South China, which is a measure of summer monsoon intensity, they show very strong correlation. This indicates that the supply of sediments to the inner shelf is strongly affected by summer monsoon intensity. The increase of sedimentation rate at 1.5 ka may indicate increasing land use due to human activity. Previous studies claimed that there existed a good correlation between the mean grain-size of fine shelf sediments and the mean annual temperature of China's Mainland. It was also claimed that the mean annual temperature correlated well with winter monsoon intensity, which in turn controlled the strength of the coastal currents which transported the sediments. Therefore, mean grain-size of the fine population was used as a proxy of winter monsoon intensity. However, our results of end-member modeling and standard deviation of grain-size analysis do not seem to support the above-mentioned correlation. The present study suggests that the supply, transportation and deposition of the sediments in the inner shelf are controlled by very complex p

关 键 词：全新世 古环境 粒度 东海 

分 类 号：P736.21[天文地球—海洋地质]