Nile Waters, Saharan Sands by Martin Williams

Author:Martin Williams
Language: eng
Format: epub
Publisher: Springer International Publishing, Cham

The obvious question to ask was whence came the silt. The limestone hills were often pretty bare and barren, with a few shrubs and bushes providing a meagre feed for the flocks of hardy goats (Fig. 12.6). However, in sheltered patches in the landscape there were deep and often extensive deposits of yellow-brown or red-brown silt. This material was in fact wind-blown desert dust and had been deposited across the landscape during windier, dustier times some twenty thousand years ago. In places the desert dust or loess was sufficiently thick to allow caves to be fashioned in it to be used as dwellings. We slept one night in one such cave dwelling. A decade later, during a visit to the great Loess Plateau of central China , I was to see similar cave dwellings carved in the very thick loess deposits there, which attained a remarkable thickness of 200–300 m in many places, and reflected well over a million years of desert dust deposition.

Fig. 12.6Goats grazing on barren limestone hills, Tunisia

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