摘要
华北平原孢粉沉积相研究表明 ,洪积扇和三角洲平原区沉积的花粉较多 ,花粉沉积浓度多在 30 0 0粒 /g以上。冲积平原区沉积下来的花粉较少 ,花粉浓度多在 10 0 0粒 /g以下。冲积物的花粉浓度可以作为划分不同地貌单元的指标。不同的沉积相存在着不同的孢粉组合。主流相一般沉积的花粉粒很少或不含花粉 ,花粉植物类型也较少。漫滩、心滩沉积的花粉较多 ,花粉植物类型也较丰富。边滩沉积的花粉较少 ,花粉浓度也低。自然堤和泛滥相以含有较多的松、卷柏孢子和当地花粉植物为特征。这些特征可以作为识别沉积相的指标。
A number of pollen grains were deposited on alluvial fans and delta plains of North China Plain, and the concentration grains of pollen grains is more than 3000 per gram. Few pollen grains were deposited on fluvial plains, and the concentration of pollen grains is less than 1000 per gram. The concentration of alluvial pollen can be taken as an indicator to distinguish different geomorphological units. There exists obvious difference in pollen assemblages among different sedimentary facies. Usually, in deposits of main current of a river, pollen grains and pollen types are few. The flood plain and central bar have more pollen types, while point bar has fewer pollen grains, and the pollen concentration is lower. The natural levee and overflow facies have more Pinus, Selaginella and local plant pollen grains. All the above features can be taken as the indicators of sedimentary facies.
出处
《古地理学报》
CAS
CSCD
2001年第2期55-63,共9页
Journal of Palaeogeography：Chinese Edition
基金
国家自然科学基金 (4 97710 72
496 710 6 6 )
河北省自然科学基金 (4 93134
499339)联合资助项目
关键词
华北平原
孢粉沉
积相
冲积物
North China Plain,fluvial sediments,pollen, sedimentary facies
