Deep-sea Pollen Record during 3.0-2.0 Ma B.P. from ODP Site 1143 and Its Response to Global Climate Changes  

作　　者：袁金红[1] 罗运利[1] 徐兆良[1] 孙湘君[1,2] 

机构地区：[1]中国科学院植物研究所系统与进化植物学重点实验室 [2]同济大学海洋地质教育部重点实验室,上海200092

出　　处：《Marine Science Bulletin》2006年第1期1-10,共10页海洋通报（英文版）

基　　金：the National Natural Science Foundation of China projects （40371116） ; the National Major Basic Research Program of China （G200078502）.

摘　　要：In order to study vegetation evolution and environmental changes around 2.5 Ma B.P., a total of 146 pollen samples with an average time resolution of 7 000 years were analyzed in the deep-sea record at the depth of 135 - 95 m （in composition depth） from ODP Site 1143 （9° 22＇ N, 113° 17＇ E） in the southern South China Sea. The results show that the pollen influx has a distinct change. During 2.6 - 2.0 Ma B.P., the average value of pollen influx increased evidently compared with that of 3.0 - 2.6 Ma B.P. It shows that the sea level of SCS dropped dramatically around 2.6 Ma B.P., corresponding to the formation of the Northern Hemisphere ice-sheets and the enhancement of the East Asian Monsoon. The pollen influx variations reflect the glacial-interglacial cycles corresponding with the deep-sea oxygen isotope curve and indicate that the sea level of SCS rose and dropped many times after 2.6 Ma B.P. The spectrum analysis results of pollen influx show that there are cycles at 0.1Ma （eccentricity） and 46.9 ka （obliquity） during 3.0 - 2.0 Ma B.P.为了探索和揭示2.5MaBP前后东亚季风演变历史及植被演替对气候演化的响应,对南海南部大洋钻探ODP1143站(9°22'N、113°17'E)深海柱状样的上部135～95m(3.0～2.0MaBP)共146个孢粉样品进行了分析研究,时间分辨率为7ka/样,孢粉谱显示沉积率变化显著,以2.6MaBP为界可明显分为两个阶段,与前一阶段3.0～2.6MaBP相比,2.6～2.0MaBP时段各类型花粉及孢子沉积率均有显著提高。该结果表明2.6MaBP南海海平面有显著下降,可与北半球冰盖形成、东亚季风增强相对应。2.6MaBP以后,各类型孢粉沉积率高低变化揭示南海海平面有多次上升和下降,代表了多次冰期-间冰期旋回。该结果与深海氧同位素分期相对应。频谱分析表明3.0～2.0MaBP存在0.1Ma(偏心率)和46.9ka(斜率)的周期。

关 键 词：pollen influx 3.0 - 2.0 Ma B.P. ODP Site 1143 the South China Sea 

分 类 号：P467[天文地球—大气科学及气象学]