ABSTRACT
The same worldwide climatic changes which ended the last ice age in Europe and north Asia and which saw the glaciers retreating and the temperate forests spreading north, had far-reaching effects in Arabia. About 17,000 years ago, the lakes in Yabrin, Layla, Mundafan and the Ramlat al Sabatayn in the south, which had existed since the onset of the great rains 35,000 years ago, dried Pleistocene lakebed at the foot of one of the long transverse uruq in the southwest Rub al Khali. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315063232/5c8746ab-3b9d-40c9-b747-989c457b3797/content/fig00096_B.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/> Part of the evidence for late Pleistocene and recent climatic shifts is to be found in the dunes themselves. In the Dahna west of Khurais, and in the western Rub al Khali at Mundafan and elsewhere, areas of hard silty mud can be seen at different levels on the dunes. These are relic stretches of the old lakebeds. Some – the older, Pleistocene levels – protrude from the base of the dunes; others, dating from the second wet period, occur high up in todays dunes. Carbon 14 dating of the fresh-water molluscs in these muds enable us to date their formation and their ending. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315063232/5c8746ab-3b9d-40c9-b747-989c457b3797/content/fig00097_B.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/>
