摘要
华北地区在3000～2500aBP的晚全新世初期,曾发生过一次环境变化。其主要表现有:气候变凉、变干;植被衰退;降水减少且时、空分配不均;河流以暴涨暴落的洪水为主,改道频繁;山地强烈切割,形成第一级阶地;平原快速堆积,造陆作用增强;大部分湖沼洼地被埋没;海岸线后退。因而使得动物迁徙或灭绝,人类活动向第一级阶地、泛滥平原及滨海平原延伸。地质历史进入了晚全新世。该变化既具有渐变性质,又具有突变特征。该文分析其变化的原因、机理及中、晚全新世的时代划分。
In the early period of the late Holocene (3 000～2 500aBP) in North China, there was an environment change, which was presented as follows: the weather became cool and dry, vegetation declined, rainfall decreased and was bad-distributed in temporal and spatial, rivers rose and fell sharply with the flood and changed their channels frequently, mountains were segmentalized and spread to the first terrace, constructional plain was formed, much lake depression was buried and coast line receded. It caused the animal migration and human activity spreading to the first terrace, flood plain and coasted plain. The geological period come into the late Holocene. The change not only has the gradual change character, but also has mutation character. This paper analyzes the cause and mechanism of change and how to divide the late Holocene.
出处
《地理与地理信息科学》
CSSCI
CSCD
北大核心
2003年第2期97-101,共5页
Geography and Geo-Information Science
