A Guide to Aeolian Landforms: Formation, Types, and Impact

Table of Contents

Aeolian landforms – Landforms formed by fast blowing winds

The wind, which is more effective in arid than in humid regions, is capable of shaping landforms through either erosional or depositional activities. Since there is little vegetation in studd bind the loose surface materials, the effects of wind erosion are almost unrestrained.

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Landforms of Wind Erosion in Deserts

1. Erosional Landforms

Rock pedestals or mushroom rocks:

The sandblasting effect of winds against any projecting rock masses wears back the softer layer so that an irregular edge is formed on the alternate bands of hard and soft rocks, Grooves and hollows are cut in the rock surfaces, carving them into fantastic and grotesque looking pillan called rock pedestals. This process of undercutting produces rocks of mushroom shape called mushroom rocks or gour in the Sahara.

Zeugen

These are tabular masses which have a layer of soft rocks lying beneath a surface layer more resistant rocks. The sculpting effects of wind abrasion wear them into a weird-looking ‘ridge and furrow’ landscape. Mechanical weathering initiates their formation by opening up joints of the surface rocks. Wind abrasion further ‘eats’ into the underlying softer layer so that deep furrows are developed.

The hard rocks then stand above the furrows as ridges or zeugen and many even overhang Su tabular blocks of zeugen may stand 10 to 100 feet above the sunken furrows.

Yardangs

Quite similar to the ‘ridge and furrow’ landscape of zeugen are the steep-sided yardangs. Instead of lying in horizontal strata upon one another, the hard and soft rocks of yardangs are vertical bands and are aligned in the direction of the prevailing winds.

Mesas and Buttes

It is a flat, table-like land mass with a very resistant horizontal top layer, and very steep sides. The hard stratum on the surface resists denudation by both wind and water, and thus protects the underlying layers of rocks from being eroded away. Mesas may be formed in canyon regions e.g. Arizona, or on fault blocks e.g. the Table Mountain of Cape Town, South Africa.

Inselberg

This is a German word meaning ‘island-mountain’. They are isolated residual hills rising abruptly from the level ground. They are characterised by their very steep slopes and rather rounded tops.

2. Depositional Landforms

Barchans

Barchans are crescent or moon shaped dunes which occur individually or in groups They are live dunes which advance steadily before winds that come from a particular prevailing direction. They are most prevalent in the deserts of Turkestan and in the Sahara. Barchans are initiated probably by a chance accumulation of sand at an obstacle, such as a patch of grass or a heap of rocks. They occur transversely to the wind, so that their horns thin out and become lower in the direction of the wind due to the reduced frictional retardation of the winds around the edges. The windward side is convex and gently-sloping while the leeward side, being sheltered, is concave and steep.