哈尼泥炭地15 cal.ka B.P来的古环境恢复与重建  

The Environmental Reconstruction of Hani Peatland since 15 cal.ka B.P

作　　者：阳金秀 李楠楠 介冬梅 陈雪松 胡楚天 陈玉洁 

机构地区：[1]东北师范大学地理科学学院,吉林长春130024 [2]国家环境保护湿地生态与植被恢复重点实验室,吉林长春130024

出　　处：《山地学报》2014年第5期541-549,共9页Mountain Research

基　　金：国家自然科学基金资助项目(30870238;40971116);环保行业公益项目(201109067);高校基本业务费资助前瞻性项目(10JCXK010);2012年度国家大学生创新性实验计划基金资助项目(201210200089)~~

摘　　要：以泥炭粒度作为古气候代用指标,结合孢粉信息,重建了15 cal.ka B.P以来哈尼地区的古气候,完善了本区晚更新世以来的古环境演化过程。通过哈尼泥炭沉积物的粒度组成、粒度参数和粒度分布频率曲线等粒度特征,发现哈尼泥炭剖面的粒度组成以粉砂和砂为主,沉积物平均粒径由上至下逐渐变细,泥炭灰分粒度频率分布以对称分布为主。通过与典型风成沉积、湖泊沉积和河流沉积的粒度频率分布曲线比较认为,本区泥炭灰分粒度组成主要受流水动力影响,其水流搬运强度介于湖相和河流相沉积之间,故泥炭灰分的粒度信息可以用于指示夏季风强弱变化规律,反演古气候变化。泥炭粒度分布数学分形结果发现分维值与泥炭灰分颗粒的分选系数呈正相关,说明泥炭灰分的分维值也可有效反映沉积物颗粒级配和粗细及古气候演化。结合泥炭粒度分析结果和孢粉谱,揭示了15 cal.ka B.P年来古气候的"冷干-温湿-冷湿-暖干"的变化过程,并识别出新仙女木事件(Younger Dryas)以及9.2 ka和8.2 ka气候转冷事件。Based on the grain-size of peat as the climate index,combining Pollen information,the paleo-climate at Hani area during the 15 cal.ka B.P is reconstructed and environment evolution is improved since late Pleistocene.The distribution of sediments grain-size,the parameters of sediments grain-size and the characteristics of grain-size frequency curves are analyzed,The results show that ash of Hani peat is dominated by silt and sand and the grainsize of sediments is tapering from top to bottom,the grain-size distribution is symmetrical distribution.Based on the analysis of the characteristics of grain-size frequency curves of typical Wind sediment,lake sediment and fluvial sediment grain size,this paper argues that peat deposits in this area between lake sediment and fluvial sediment and peat ash particle size was mainly affected by water power,So the peat ash can be used to indicate the summer monsoon and can be used for rebuilding the evolution of paleo-climate.The results of the grain-size fractal dimensions show that they are positive correlation between fractal dimensions and sorting coefficient of sediment and the fractal dimensions can also effectively reflect the grain distribution and paleo-climate evolution.Combining the grain size and Pollen information,reveals that paleoclimate were cold-dry,humidity-cold,cold-wet,warm-dry from 15 cal.ka B.P,and recognizes Younger Dryas,9.2 ka and 8.2 ka drought events.

关 键 词：泥炭 粒度 分维值 孢粉 古环境 

分 类 号：X144[环境科学与工程—环境科学]