3.50Ma BP以来河北衡水地区古植被与环境演化  

Palaeovegetation and Environmental Evolution in Hengshui District of Hebei Province since 3.50 Ma BP

作　　者：范淑贤[1] 刘海坤[1] 徐建明[1] 郑宏瑞[1] 赵华[1] 毕志伟[1] 杨振京[1] 林防[1] 张静[1] 

机构地区：[1]中国地质科学院水文地质环境地质研究所,河北石家庄050061

出　　处：《现代地质》2009年第1期75-81,共7页Geoscience

基　　金：中国地质调查局地质调查项目(200312300002)

摘　　要：依据河北衡水南张庄600m深HS1钻孔中529块岩心样品的孢粉分析，结合古地磁、光释光测试建立的年代地层格架，初步建立了河北平原中部衡水地区3．50Ma BP以来孢粉组合的更迭序列。在3．50～2．58Ma BP期间，研究区沉积环境稳定，主要是极浅水泛滥平原与浅湖相沉积，孢粉不丰富，孢粉组合结构简单，反映降水、气温等变化幅度小，气候由温暖湿润逐渐过渡到冷干；2．58～0．78Ma BP期间，植被出现频繁波动，我国东部古季风气候格局已经基本形成，表现出气候频繁变化的不稳定性，具有早期温和偏干、中期温暖湿润、晚期温凉偏干的气候演化特征；780～15ka BP期间，孢粉带组成成分较为丰富且复杂，在不同时期乔木植物与草本-灌木植物互为消长、相互更迭，反映气候变化幅度大、频率高的特点；15ka BP至今，气候总体表现为干，其波动频率较快，植被属森林和草原兼而有之的类型。Based on the analysis of the spore-pollens in 529 core samples from 600 m deep borehole HS1 drilled in Nanzhangzhuang Village of Hengshui District, Hebei Province and in combination with the chronostratigraphic framework recovered by the palaeomagnetie and optical luminescent dating, the spore-pollen assemblage sequences in Hengshui District of Central Hebei Plain since 3.50 Ma BP have been established. During the period of 3.50 -2.58 Ma BP, the sedimentary environment was stable, mainly with extremely-shallow water flood plain and shallow-lake deposit. The spore and pollen were not abundant and their assemblage structures were simple, indicating that there was not much change in precipitation and temperature, and that the climate was warm and humid by the gradual transition to the cold and dry. During the period of 2.58 - 0. 78 Ma BP, the vegetation changed frequently and the ancient monsoon climate prevailed, representing the frequent change of climate, which was characteristic of being mild and slightly-dry in early stage, warm and humid in the middle stage and cool and slightly-dry in the late stage. During the period of 780 - 15 ka BP, the composition of spore- pollen assemblage was rich and complicated, but it changed greatly within the period, indicating the dramatic magnitude and high frequency of climate change. Since 15 ka BP, the dry climate has occurred in general with quicker change frequency, the vegetation pattern has presented as the forestry-prairie transition.

关 键 词：孢粉组合 古植被 古气候 环境演变 河北衡水 

分 类 号：P532[天文地球—古生物学与地层学]