摘要
本文对在舟山群岛附近海域钻取的第四纪钻孔进行了粒度测试和分析。结果显示,沉积物平均粒径介于2.18~7.76Φ,分选较差—差,偏度介于-1.75~2.76之间,表现为平坦、正态分布。这些粒径变化特征揭示了沉积动力环境的变化,粗粒沉积物对应了高水动能环境,细粒沉积物对应了低水动能环境。用粒度参数散点图对沉积环境判别表明粗粒沉积物与现代东海陆架沙脊、扬子浅滩、潮流沙脊间洼地和河道沉积等类型相近,可能指示快速海进过程中的高能沉积环境,如河道等,亦或是陆相侵蚀环境;细粒沉积物与现代泥质区沉积类似。沉积物粒度在垂向上的准旋回性变化可能指示了气候冷暖交替背景下沉积动力发生了显著变化。
A research on the sediments of DZ-1 borehole drilled from East China Sea near Zhoushan Islands was conducted for sediment grain-size analysis.The results indicate that the average grain size ranges 2.18-7.76Φ,poorly sorted,mesokurtic,with skewness ranging-1.75-2.76.The coarse-fine changes of grain size can be correlated with sedimentary dynamics,which fine sediments indicate a relatively low dynamics,and coarse sediments indicate a high dynamics.The relationship among the sediment grain-size parameters of coarse sediments suggests the characters are close to continental sandy ridge of East China Sea,Yangtze Shoal,low-standings of tidal flats,and river in channels,indicating a high dynamics possible during a rapid transgression or erosional facies due to regression;and the one of fine sediments is similar to the modern sediments in muddy zone in East China Sea.The vertically quasi-cyclic changes of the sediment grain-size will be a potential indictor for cold-warm climate-related sediment dynamics.
作者
陈燕萍
李琰
CHEN Yan-ping;LI Yan(Key laboratory of Engineering Oceanography,Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China;School of Ocean Sciences,China University of Geosciences (Beijing),Beijing 100083,China;Leibniz Institute for Applied Geophysics (LIAG),Hanover 30655,Germany)
出处
《海洋学研究》
CSCD
北大核心
2018年第4期53-59,共7页
Journal of Marine Sciences
基金
国家自然科学基金青年科学基金项目资助(41602349).
关键词
粒度分析
粒度参数
沉积环境
东海
grain-size analysis
grain-size parameters
sedimentary environment
East China Sea