Mushroom Rock Plain

Mushroom Rock Plain is an original illustration set in Western Desert, Egypt. It lies in the subtropics, where the climate is hot desert — evaporation far outruns rainfall.

A wide resistant cap sits balanced on a narrow pedestal, undercut most severely in the lowest metre above the ground. Horizontal abrasion grooves ring the pedestal. Dark gravel pavement covers the plain, with small stones scattered across it.

Why is the rock undercut only near the ground?

Wind carries sand, but only close to the ground — above roughly a metre the load drops off sharply. So the sandblasting concentrates at ankle height and eats the base out from under the block, leaving the top almost untouched. The horizontal grooves record the same thing. It is a shape that can only be made by wind-driven sand, never by water or frost.

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