太白山佛爷池湖泊沉积理化分析反映的8000aBP以来环境变化

An 8 000 Years Environmental Change Record of Lacustrine Deposits of Foyechi Lake at Taibai Mountains

封闭湖泊沉积物比较完整地记录了环境演化信息,是研究古环境变化的理想材料。通过对太白山佛爷池湖心剖面沉积物样品粒度参数、总有机碳、有机碳同位素、(TiO2/K2O)、碳酸盐含量等气候环境代用指标的分析,结合剖面的岩性特征与14C测年,指出本区气候环境经历了四个变化阶段:(1)8200aBP～5900aBP的温暖潮湿阶段,出现较为适宜的气候;(2)5900aBP～4400aBP气候变得恶劣,较为冷干;(3)4400aBP～2700aBP气候恢复为温湿类型;(4)2700aBP以后气候再一次急剧变冷干,大至到900aBP逐渐变得温湿,与太白山地区现代气候类型相符。

<Abstrcat>Foyechi Lake locates at Taibai Mountains(33°41′～34°10′N,107°19′～107°58′E),with altitude of 3 410 m above sea level.The lake is glacial erosion formation.Based on field observation and sampling of the lacustrine deposits and the analysis of grain size,TOC,δ^(13)C,TiO2/K2O,carbonate,and ^(14)C datings of the deposits,the local climate have been undergoing four periods change:(1)the climate was warm and humid in 8 200～5 900 aBP;(2)the climate changed rigour cold and dry in 5 900～4 400 aBP;(3)the climate was warm and humid again in 4 400～2 700 aBP;(4)the climate became cold and dry again since 2 700 aBP.