末次冰期以来印度季风降雨在安达曼海中的沉积记录

The Indian Monsoon rainfall is an important part of the Asian climate system, which plays an important role in the sediment erosion, transportation and deposition processes. Abundant terrigenous sediments corroded and carried by the monsoon rainfall provide ideal advantage for rebuilding the high resolution paleoenvironment and paleoclimate evolutional history in the Indian Ocean. The stratigraphic sequence since the last glaciation is rebuilt through the integrated analysis of the sediment cores. The paleotemperature evolvement can obtained by Mg/Ca ratio calculated from the Plankton foraminifer G. ruber, the salinity information could also be got from the temperature result combined with the δ18O data measured from the Plankton foraminifer G. ruber since the last glacial. Further more, based on the high resolution chronology and the paleotemperature and paleosalinity results recorded in the sediment cores from different latitudes, the evolvement history of monsoon rainfall in the Andaman Sea could be revealed, and the regional characteristic of the Indian Monsoon and the response to the global climate change could also be discussed deeply in this research.

印度季风降雨是亚洲气候系统中的一个重要组成部分，对其控制区物质侵蚀、输运、沉积过程具有决定性作用。东北印度洋的安达曼海，沉积了季风降雨控制下的大量陆源侵蚀物质，相对较高的沉积速率为重建晚第四纪高分辨率的古环境和古气候演变历史提供了有利条件。为此，本项目拟通过综合分析安达曼海典型柱状沉积物组成，重建末次冰期以来高精度年代地层框架。利用浮游有孔虫单种G. ruber的Mg/Ca比值测试结果恢复海水古温度变化，并结合其δ18O结果计算得到海水盐度信息，进一步恢复海水古盐度变化。在精确年代框架的基础上，综合分析不同纬度柱状沉积物记录的古温度、古盐度恢复结果，揭示末次冰期以来印度季风在安达曼海的沉积记录，重建安达曼海季风降雨的演化历史。基于这些研究进一步探讨印度季风降雨的区域性特征及其对全球气候变化的响应。