冲绳海槽中部沉积物物质来源和沉积环境分析

发布时间：2019-04-01 14:01

【摘要】：本文基于AMS~(14)C高精度测年,通过对柱状沉积物HOBAB2-S2的粒度、微量元素和稀土元素的分析,对冲绳海槽中部区5 300a以来的物质来源和沉积环境进行了研究。通过对该孔的稀土元素与微量元素的研究发现研究区沉积物质具有陆源属性,并且通过不同物源区沉积物的稀土元素散点图表明5 300a以来沉积物主要来自于台湾。文中将粒度特征作为研究区域沉积环境,尤其是水动力(黑潮)强弱的指示参数,根据粒度变化曲线,可将沉积过程分为4个阶段:第一阶段(5.30~3.81ka BP),粒径由粗变细,黑潮强度逐渐减小;第二阶段(3.81~2.70ka BP),粒径波动较大,无明显增大或减小趋势,表明沉积环境处于相对波动状态,水动力强弱不稳定;第三阶段(2.70~0.97ka BP),粒径变化较小,表明沉积环境处于相对稳定状态,研究区的水动力条件较稳定;第四阶段(从0.97ka BP至今),粒径逐渐变粗,水动力条件增强。
[Abstract]:Based on the high precision dating of AMS~ (14) C, the material sources and sedimentary environment of the central Okinawa trough since 5 300 years have been studied by means of the analysis of the grain size, trace elements and rare earth elements of HOBAB2-S2 in columnar sediments. Through the study of the rare earth elements and trace elements in this hole, it is found that the sedimentary materials in the study area have the land source attribute, and the REE dispersion map of the sediments from different provenance areas shows that the sediments have mainly come from Taiwan since 5 300 years. According to the grain size variation curve, the sedimentary process can be divided into four stages: the first stage (5.30~3.81ka BP), which is regarded as the indicator parameter of the sedimentary environment, especially the hydrodynamic (Kuroshio) intensity. The strength of Kuroshio decreases gradually as the particle size changes from coarse to fine. In the second stage, the particle size of 3.81~2.70ka BP), fluctuates greatly, and there is no obvious trend of increase or decrease, indicating that the sedimentary environment is in the state of relative fluctuation, and the hydrodynamic force is unstable. The third stage (2.70~0.97ka BP), particle size change is relatively small, indicating that the sedimentary environment is relatively stable, the hydrodynamic conditions in the study area are relatively stable; in the fourth stage (from 0.97ka BP to date), the particle size gradually thickens, and the hydrodynamic condition increases.
【作者单位】：中国科学院海洋研究所海洋地质与环境重点实验室;青岛海洋科学与技术国家实验室海洋矿产资源评价与探测技术功能实验室;中国科学院大学;
【基金】：国家重点基础研究发展计划(973计划)项目(2013CB429700) 中国科学院战略性先导科技专项(XDA11030302) 国家自然科学基金项目(41325021) 泰山学者工程专项(ts201511061) 青岛海洋科学与技术国家实验室‘鳌山人才’计划项目(2015ASTP-0S17) 青岛海洋科学与技术国家实验室鳌山科技创新计划项目(2015ASKJ03)
【分类号】：P736.21

【相似文献】