摘要
本文选择在第四纪沉积厚度较大的北京昌平地区行打钻取样,获得连续的沉积样品,通过AMS 14C测年手段建立年代框架,提取钻孔上部2～12.4 m沉积物的孢粉,通过分析孢粉的质量浓度及种属组合变化,进而恢复北京地区的古气候状况.研究表明北京昌平地区30 000 yr BP以来的古气候演变经历了4个阶段：29 090～27 200 yrBP为气候寒冷湿润;27 200～19 100 yr BP,主要发育以蒿、藜为主的中旱生草原,反映了这一时期寒冷干燥的气候特征;19 100 ～ 11 700 yr BP,主要分布以蒿、藜为主的草原植被,但是覆盖度很低,说明气候进一步变冷变干,是北京气候最寒冷干旱的时期;11 700～4460 yrBP,为全新世早中期,植物种类丰富,适宜木本植物生长,植被发育针阔叶混交林,气候较为温暖湿润.
The continuous sediments were collected in Changping district of Beijing, where the quaternary sedimentary is rather thick. A chronostratigraphic framework of the sediments was established by AMS t4C dating, and the concentration and species composition of pollen in the sediments were analyzed. The results showed the climate change in Beijing since 30 000 yr BP was divided into 4 stages： the climate was cold and humid during 29 090 - 27 200 yr BP; in 27 200 - 19 100 yr BP, the climate was cold and dry which dominated by Artermisia- Chenopdiaceae steppe; in 19 100 -11 700 yr BP, the Artermisia-Chenopdiaceae steppe＇s coverage became lower and the climate continued to be colder and drier; the last stage corresponded to early and middle period Holocene during 11 700 - 4 460 yr BP, the climate was warm and humid, there were varieties of plants and mixed coniferous broad leaved forest developed.
作者
李阳
徐岱南
魏明建
Li Yang Xu Dainan Wei Mingjian(Global Environmental Change Laboratory, Capital Normal University, Beijing 100048)
出处
《首都师范大学学报（自然科学版）》
2016年第6期80-84,66,共6页
Journal of Capital Normal University：Natural Science Edition
