The significance of yardangs and ventifacted rock outcrops in the reconstruction of changes in the late Quaternary wind regime in the western desert of Egypt [L'importance des yardangs et des affleurements de roches modelées par le vent dans la reconstitution des changements du régime des vents au Quaternaire supérieur dans le désert libyque, Egypte]

Abstract

The orientation of elongated yardangs in playas, supported by the direction of the abrasion of rock outcrops, suggests that the prevailing surface winds in northern Egypt were westerly during the pre-Holocene phase with its and cold climate, in an area where only the winter winds are westerly at present. In southern Egypt, m Dakhla and Kharga, no similar change in the wind regime has been detected. Here the prevailing winds were northerly even in pre-Holocene times, as they are at present.