南海南部50万年以来碳酸钙和有机碳记录及其揭示的东亚夏季风演化  

500000-Year Records of Carbonate and Organic Carbon from the Southern South China Sea and Implication for East Asian Summer Monsoon Evolution

作　　者：梅西[1,2,3] 张训华[3] 郑洪波[4] 刘锐[3] 黄恩清[5] 

机构地区：[1]中国科学院海洋研究所,山东青岛266071 [2]中国科学院研究生院,北京100049 [3]国土资源部海洋油气资源与环境地质重点实验室,山东青岛266071 [4]南京大学地球科学系表生地球化学研究所,江苏南京210093 [5]同济大学海洋地质国家重点实验室,上海200092

出　　处：《地球科学（中国地质大学学报）》2010年第1期22-30,共9页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金(No.40676033);国家重点基础发展计划(No.2007CB815906);创新研究群体科学基金(No.40621063)

摘　　要：为了解南海南部第四纪冰期旋回中表层生产力的变化与东亚夏季风的演化关系,通过对南海南部MD05-2897孔晚第四纪500ka以来碳酸钙和有机碳含量及堆积速率高分辨率的研究发现,碳酸钙含量及堆积速率表现出明显的冰期-间冰期旋回变化,而有机碳的含量及堆积速率则主要呈现频率更高的周期性变化.碳酸钙和有机碳含量及堆积速率都在间冰期时增加,冰期时降低,反映了间冰期时夏季风的增强导致上升流的加强和营养物质的增加,促使表层生产力提高.碳酸钙和有机碳含量及堆积速率具有100ka偏心率周期、40ka斜率周期、20ka岁差和10ka半岁差周期等最为丰富的频谱,显示出低纬海区对轨道周期响应的特色.碳酸钙和有机碳的堆积速率与北半球低纬夏季日射量吻合较好,说明岁差相关的北半球低纬夏季太阳辐射量的变化可能是东亚夏季风强度变化的主要控制因素,而与全球冰量相关的气候变化可能是次要因素.In order to understand the relation between surface productivity changes and the evolution of the East Asian summer monsoon during the Quaternary glacial cycles in southern South China Sea, high resolution study on content and accumulation rate of calcium carbonate and organic carbon of Core MD05-2897 were done to draw the conclusions as follows： the content and accumulation rate of calcium carbonate showed significant glacial-interglacial cycle change while organic carbon mainly showed a higher frequency of the periodic changes. Both of the content and the accumulation rate of calcium carbonate and organic carbon increased in the interglacial periods and decreased in the glacial periods, which reflects the enhancement of the summer monsoon in the interglacial periods caused the strengthening of the upwelling currents and the increase of nutrients, the surface productivity increased consequently. The most abundant spectrum periods of 100 ka eccentricity, 40 ka obliquity, 20 ka precession and 10 ka semi-precession indicate the characteristics of the low latitude sea areas responding to the orbital 13eriods. The accumulation rate of calcium carbonate and organic carbon were in good agreement with summer insolation of tow latitude in the Northern Hemisphere related to precession which may be the main controlling factor of East Asia summer monsoon changes, and elimate changes related to the global ice volume is possibly the secondary controlling factor

关 键 词：南海南部 晚第四纪 东亚夏季风 轨道驱动 有机碳 碳酸钙 海洋学. 

分 类 号：P736[天文地球—海洋地质]