全新世前撒哈拉环境的变迁

CHANGES IN THE SAHARIAN ENVIRONMENT BEFORE THE HOLOCENE EPOCH

本文根据近年对航天飞机雷达图象和陆地卫星图象的分析、深海岩芯分析、古沙丘和内陆湖泊沉积物的放射性同位素断代、古气候构模以及古生物、古人类研究和考古等方面的成果,论述了距今3600万年到1万年期间撒哈拉及其附近地区环境的一系列重大变化。早第三纪非洲北部气候湿热,在渐新世形成横贯非洲北部的大河。晚第三纪干燥度递增,从中新世开始形成沙漠。更新世干旱期间,沙漠向南扩张;湿润期间则转变为热带稀树草原,适于古人类生息和繁衍,并出现发达的旧石器文化。

This article has expounded the great changes of environment about Sahara and nearty regions from 36 million years to 10 thousand years ago according to the results of the image analysis of the Shuttle Imaging Radar and Landsat,the abyssal core analysis, the radioisotope dating of ancient dunes and inland lake sediments, the pattern of the ancient weather fabric, researches on the ancient organisms and the ancient human beings and other archaeological studies.The weather was wet and hot in the Eogenc Period. The trans-African drainage system came into being in the Oligocenc Epoch.The degree of aridity was increasing in the Nogence Period.The desert came into being in the Miocene Epoch.It extended to the south at the dry period and changed into savanna at the wet period in the pleistocene Epoch.Such natural condition was suitable for the ancient human beings to live and multiply. It was at this period that the advanced Palaeolithic culture appeared.