云南纳帕海17Ka的植硅体记录以及环境意义

Phytolith and Its Paleoenvironmental Signifi cance During the Last 17 Ka in the NaPa Lake,Northwestern Yunnan,China

地处中国滇西北横断山脉中段的纳帕海受印度季风和高原季风的共同影响,气候复杂多变,利于研究南亚季风和东亚季风的耦合关系。本文从植硅体角度对香格里拉纳帕海湖芯钻孔(ZD981)0~6.35m部分进行古气候研究,得到了一系列环境气候信息,结合已有的AMS14C测年数据,重建纳帕海近17Ka的古气候演化过程,并探讨其变化规律以及影响因素。分析结果表明,由于局部环流和地形作用的影响,纳帕海植硅体记录所反映的气候特征与其他地区所重建气候存在明显差异性,17800年以来纳帕海的气候变化主要经过了温凉偏干—温暖—湿热—温—湿热—温凉偏干的6个阶段。该结果丰富了我国西南地区古气候变化、古环境变迁的相关研究。

The Napa lake,located in the middle of the transverse mountain range in northwest Yunnan,is influenced by the Indian Ocean monsoon and plateau monsoon,and its climate is complex and changeable.It is an ideal area to study the coupling of southwest monsoon and East Asian monsoon.In this paper,the palaeoclimate of strata above 6.35 m in Napa lake,Shangri-la,Yunnan province was studied from phytologist perspective,and a series of environmental and climatic information was obtained.Combined with AMS14C dating,the palaeoclimate environmental process in the study area was reconstructed in the last 17 Ka,and its variation law and influencing factors were discussed.The analysis results show that the climate of Napa lake since17800 has experienced slants cold dry-warm-damp and hot-warm-damp and hot-cold from the dry process,because of the influence of the local climate and terrain effect,Shangri-la Napa lake,in the early holocene climate record is a reflection of the implanted silicon body and other parts of the different indexes by reconstruction exist obvious differences in climate.