MIS3以来神农架泥炭沉积发育与古气候演变

The low-latitude processes for the concept of the Asian monsoon-driven research associated with the monsoon hydrological cycle and dry and wet climatic changes of history, and typical of the Asian monsoon region in Shennongjia Dajiuhu lake basin in recent 60 ka.B.P. peat deposits can be recovered since monsoon rainfall history to reveal the low latitude of East Asian monsoon-driven there are important scientific significance. The results of this project will improve the understanding of asian monsoon history and paleoclimate change. Based on the study of Dajiuhu lake basins topography and geomorphology, and the analysis of more than 20 shallow drillings, the development history of the peat deposits and their spatial distribution will be investigated. Cellulosic determination of peat ages by high-accuracy AMS14C will provide an independent time scale for Dajiuhu lake reaching 60kaB.P. This will be done by carrying out an analysis of cellulosic δ 13C in growth periods and a comparative analysis of their ratios for today's vegetation in relation to precipitation and temperature. The proposed project will analyse the α-cellulosic δ 13C of the Organic remains of Carex argyi of grain to assess the paleoclimate changes by the high-resolution data available for the study area. The results will provide useful insights of high-resolution atmospheric humidity and precipitation process into the space and time pattern of the East Asia monsoon and are expected to improve the understanding of global climate changes.

亚洲季风的低纬驱动概念迫切要求研究与季风相关的水文循环和干湿变化历史，而位于典型亚洲季风区的神农架大九湖盆地近60 ka.B.P.以来的泥炭沉积物可以恢复季风降水历史，对揭示亚州季风的低纬驱动有重要的科学意义。本研究在神农架大九湖盆地地形、地貌调查和20余个浅钻孔取芯的基础上，恢复埋藏泥炭的发育历史，揭示盆地内部泥炭沉积的分布规律及相变模式；通过泥炭纤维素的高精度AMS14C年代的测定，取得独立时间标尺，建立大九湖泥炭沉积60ka B.P.以来的年代时间框架；进行现代植被不同类型和生长期纤维素δ13C的分析，明确现代植被纤维素δ13C与大气湿度和降水的关系；提取泥炭沉积中红穗苔草残体并测定其α-纤维素的δ13C，恢复研究区MIS3以来高分辨率的大气湿度和降水变化过程，为东亚季风完整的时空格局及全球气候模型的构建提供更广泛的数据来源。

亚洲季风的低纬驱动概念迫切要求研究与季风相关的水文循环和干湿变化历史，而位于典型亚洲季风区的神农架大九湖盆地近 60 ka以来的泥炭沉积物可以恢复季风降水历史和冷暖变化过程，对揭示亚州季风的低纬驱动有重要的科学意义。本研究在神农架大九湖盆地地形、地貌调查和 20 余个浅钻孔取芯的基础上，恢复埋藏泥炭的发育历史，揭示了盆地内部泥炭沉积的分布规律及相变模式；通过泥炭纤维素的高精度 AMS14C 年代的测定，取得独立时间标尺，建立了大九湖泥炭沉积 60ka以来的年代时间框架；对研究区现代植被不同类型和生长期纤维素δ13C 和δ18O的分析表明：现代植被纤维素δ13C 与大气湿度和降水的关系明显，δ18O可以明确指示大气温度的变化。提取泥炭沉积中红穗苔草残体并测定其α纤维素的δ13C和δ18O。基于对现代过程的研究结果，恢复了研究区 MIS3 以来高分辨率的降水历史和冷暖变化，为东亚季风完整的时空格局及全球气候模型的构建提供更广泛的数据来源。