Mushroom, Table and Pedestal Rocks

Wind is a relentless sculptor in deserts, but it does not work alone. The same gusts that carry sand and dust also carve the rock they strike, and the same abrasive action that wears down surfaces can leave behind strange, isolated remnants. These are the mushroom, table and pedestal rocks — landforms that look almost artificial, yet are purely the work of wind.

The process begins with deflation and abrasion. Deflation is the lifting and removal of loose particles by the wind; abrasion is the grinding and polishing of rock surfaces by those very particles as they are carried along. In deserts, many rock outcrops are easily worn down by this combined attack. The softer, weaker parts of the rock are eroded quickly, while harder, more resistant portions survive. What remains is a polished remnant shaped like a mushroom — a slender stalk below and a broad, rounded, pear-shaped cap above. The cap is the resistant rock that withstood abrasion; the stalk is what was left after the surrounding softer material was worn away.

Sometimes the top surface is not rounded but broad and flat, like a table top. In other cases, the remnant stands tall and narrow, like a pedestal. These are variations of the same basic form, differing only in the shape of the surviving cap and the proportions of the stalk. All of them are erosional features — they are what is left behind after wind has removed the rest.