中文摘要：

陆架海域因接纳了大量河流入海沉积物而成为研究全新世气候变化的理想区域.海南岛东南部陆架海域晚全新世以来的平均沉积速率由1315BC～518A.D.期间的0.52mm/a逐渐增加至1450A.D.以来的1.00mm/a;沉积物高岭石含量及＜2μm的粒度组分在1315BC～518A.D.期间没有明显变化,自518A.D.以来表现出一定程度的增加,自1450A.D.以来则表现出明显的增加,而MgO/A12 O3则表现出相反的变化趋势,表明自1450A.D.以来,来源于珠江源区的细颗粒沉积物对海南岛东南部陆架海域的贡献逐渐增大,而有机碳含量及C/N的增加则揭示了近百年来人类活动的影响增大;晚全新世以来海南岛东南部陆架沉积特征和沉积速率的变化是不同演化阶段物质来源来量不同所致.沉积物微量元素Sr含量及Sr/Ba比值、底栖有孔虫的垂向分布揭示了该海域主要受近岸混合水团的控制,并且自518A.D.以来,近岸混合水团的影响逐渐增强;浮游有孔虫含量可能指示了海南岛东南部海域在晚全新世以来上升流发育强度呈周期性变化,即1000BC～500A.D.期间上升流强度总体降低,在500 ～1300A.D.期间又逐渐加强,而在1300A.D.以来的上升流强度又逐渐减弱.晚全新世以来海南岛东南部陆架海域海洋环境的变化受东亚季风驱动.

英文摘要：

Continental shelves receive a large amount of terrestrial materials discharged from rivers and therefore become a suitable research area for Holocene climate changes. A sediment core with a length of 222cm named C706 was collected at the continental shelf off the southeastern Hainan Island, where the water depth is 137m. The core sediment sample was cut with 10cm interval and 2cm thickness in laboratory. Sediment grain size, clay minerals, total organic carbon and nitrogen contents, geochemical elements were analyzed, and also benthonic and planktonic foraminifera was identified; furthermore, AMS 14C dating was conducted at three layers using foraminifera samples. The mean sedimentation rate on the continental shelf off the southeastern Hainan Island increased from 0.52mm/a between 1315BC and 518A.D. to 1.00mm/a since 1450A.D. The contents of kaolinite and the constituents of 〈21xm in sediment did not vary much during 1315BC-518A.D. ; they increased slightly since 518A.D. and remarkably since 1450A.D., while the variation of MgO/A1203 showed opposite patterns, indicating that the contribution of fine sediment discharged from the Pearl River increased since 1450A.D. The increase in organic carbon content and C/N ratio revealed an enhanced influence of human activities over the recent hundred years. The variations in sedimentary structures and sedimentation rates in the study area during the Late Holocene resulted from different sediment inputs at different stages. The vertical distribution of the trace metal content of Sr, the Sr/Ba ratio and the benthonic foraminifera suggested that the continental shelf off the southeastern Hainan Island was controlled by coastal mixed water mass in the Late Holocene, with its influence being increasing since 518A.D. The distribution of planktonic foraminifera revealed the periodical variation of upwelling intensity in the region： the upwelling intensity decreased from 1000BC to 500A.D., increased from 500A. D. to 1300A. D., and decreased again after 1300A.D. The variations