Page 157 - Arabian Studies (II)

Fig, 1. The geology of the northern part of the Union of Arab Emirates.

while sand dunes, encroaching from the west, partly covered the fine
deposits. The main infilling of the erosion gullies, however, took
place during a sub-pluvial period, occurring probably in Neolithic
times (Butzer, 1961), when there was a partial return to conditions
when rainfall was more effective. The material that infilled the gullies
was washed off the surface of the outwash fans. This sub-pluvial
period was also probably responsible for the well-defined outwash
fans that occur north of Habhab. The fans show no evidence of
erosion, and slopes of these outwash fans (8—10°) are appreciably