摘要
本文在总结渭河谷地 2 0多个孢粉剖面的基础上 ,依据古地磁资料确定其时代 ,并在空间和时间上进行孢粉组合对比 ,从而建立了 1 0个区域孢粉组合带。由此提出 3.5 Ma BP以来孢粉植物群的演化经历了 5个阶段 :由阔叶林—针叶林—森林草原与草原—森林草原与荒漠草原—草原—森林草原与草原。这 5个阶段标志着地表环境系统发生巨大变革 ,变革时间为 2 .5 Ma BP,2 .0 Ma BP,1 .4/ 1 .6 Ma BP和0 .8Ma BP。
Weihe valley is one of the areas where the study on late Cenozoic palynology began very early,involving more than twenty sections. By comparing the temporal and spatial distribution of the sporollon assemblages coupled with paleo geomagnetism dating,we have ten areal zones. Since 3 5MaBP,the palynoflora were found to have evolved go through five stages,i.e.broad leaf trees stage,conifer trees stage,woody grassland and grassland stage,woody grassland and desert grassland stage,grassland stage,and lastly woody grassland and grassland. These stages mark the megaevolution of the surface's environments beginning respectively from 2 5MaBP,2 0MaBP,1 4/1 6MaBP,and 0 8MaBP.
出处
《地质力学学报》
CSCD
2000年第4期11-18,共8页
Journal of Geomechanics
基金
原地质矿产部重点项目! (95 0 113)
中国科学院湖泊沉积与环境研究开放实验室资助
关键词
渭河谷地
晚新生代
地表环境巨变
孢粉植物群
Weihe valley
late Cenozoic
surface's environment megaevolution
palynoflora
