| Popis: |
The extreme desert of south-western Egypt and north-western Sudan has revealed traces of numerous small, shallow, rain-fed lakes, relict from earlier periods of less arid climate. In 1976, sites of such lakes at the oases of Selima, Laqiya Arba'in and Merga were studied. Samples of lacustrine deposits yielded sufficient carbonate material for radiocarbon dating, and values obtained indicate that the lakes dried up some 6000 years ago, occasioning the withdrawal of the Neolithic inhabitants. Sediment cores taken at Merga for pollen and radiocarbon analysis suggest a later hyperarid phase ending about 600 years ago. |
