Desert Landforms

Names and descriptions of hot desert landforms created from both wind and water.

Yardang

Yardang

Look like an upturned boat. Formed when vertical layers of resistant and less resistant rock are aligned to the prevailing wind’s direction.

Zeugen

Formed in the same way as yardangs but the rock layers are horizontal. Often have pedestal-like shapes due to abrasion deeping the furrows. They are created by wind erosion.

Deflation hollows

Formed by wind removing fine sediment, lowering the desert floor in the process. This leaves only coarse gravel.

Desert pavements

The desert floor which is covered by coarse rocks that were not eroded away by the wind.

Ventifacts

Faceted cobbles and pebbles that have been abraded and shaped by wind-blown sediment. Formed in the direction of the prevailing wind.

Pedestal rocks

Made of alternating horizontal bands of sedimentary rock. Though to be the final remains of a zeugen and formed primarily through aeolian abrasion - winds carrying sediment cut and polish the exposed rock.

Barchan dunes

The typical cresent shaped dunes, found in isolation in deserts that have a small supply of sand, but a dominant wind direction. Form at right angles to the prevailing wind.

Seif/longitudinal dunes

Elongated + linear sand dunes. Formed from two dominant prevailing wind directions that form dunes that are parallel to the wind direction.

Sand dunes

Wind blows sand into an arrangement of troughs, ripples and crests that are perpendicular to the wind direction. They become a dune when the crest is about 30m high and the slip-faces angle of repose is 34 degrees.

Pediments

They form at the foot of a steep slope or cliff of a mountain range by running water. They are typically composed of alluvium deposits and mark the change between the cliff face and the pediment plain.

Playas

These lakes form in low areas of deserts after intense precipitation. They are shallow, saline and short-lived. When the water evaporates, the dry lake bed is called a salt pan.Al

Inselbergs

Also known as “island mountains”, these are rocks beneath the surface which get eroded by water and wind, leaving a round-topped rock. It then moves to the surface and appears as a huge boulder.

Formation of Uluru

Formed around 550 million years ago when water compressed mud and rock into sandstone and granite. Then, 400 million years ago, the sea retreated, and tectonic shifts altered the landscape. The aeolian erosion then removed the softer rock above the boulder and left the inselbergs behind.

Wadis/Arroyos

Formerly part of a perennial drainage system, now only recieve run-off from storms. The water erodes deep channel systems and these channels can quickly fill after rain and flash floods.

Bajadas

The convergence of several alluvial fans. Common in dry climates and can be sources of groundwater.

Alluvial fans

At the edge of mountain ranges, sediment is washed out and forms this landform. Cones of sediment are deposited by rivers due to a loss of energy and the deposited sediment is sorted in size. These can extend for several kilometers.