撒哈拉沙漠东北部全新世气候环境与人类活动

现代极端干旱的撒哈拉沙漠东北部,在12000 aB.P.前出现了代表湿润气候记录的湖相沉积;全新世以来,在9900~2400 aB.P.形成了大面积的连续湖泊,并在9800~6450 aB.P.达到鼎盛时期。在6000 aB.P.~3600 aB.P.前,湖泊演化进入波动期,反映了该时期气候环境周期性的变动并具600年的准周期。撒哈拉沙漠东北全新世湿润时期,是该区古人类发展与进步、繁演与分化的时期;也是自然演变史上一个十分重要的时期,其中强烈的风化作用和碎屑物质积累为今日撒哈拉沙漠的形成奠定了物质基础。

HOLOCENE CLIMATIC ENVIRONMENT AND HUMAN ACTIVITIES IN NORTHEASTERN SAHARA DESERT

The data of continued age determination of lake facies sedimentation in Northeastern Sahara Desert showed that there were a lot of large lakes formed in 9 900￣2 400 a.B.P..Moreover,the time of 9 800~6 450 a.B.P.is a period of great prosperity in the processes of lake forming.From 6 000 a B.P.to 3 600 a.B.P.,the evolution of lake arrived at its fluctuating period which responsed the changing climatic environment,and the changing period was about 600 years.The humid period represented by lake facies sedimentation in Holocene in the Northeastern area of Sahara Desert was also the period of developement,progress,evolution and differentiation of ancient human being in this area,as well as the key period in natural evolution history.The heavy erosion function and detrital accumulation in this period had laid a foundation of material source for forming Sahara Desert.