Theory question 204
Wind and Desert LandformsWith the aid of suitable diagrams describe the appearance and process of formation of any two of the following landforms (a) Rock pedestal (b) Depression (c) Barchan (d) Inselberg
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Rock pedestal: mushroom-shaped rock, wide top on a narrow base; formed in deserts by wind-borne sand abrading the lower part most (sand rarely lifted above 1-2 m), helped by softer lower layers.
Depression (desert): hollow scooped out by wind deflation, e.g. Qattara depression; wind removes loose sand down to the water table, where oases may form.
Barchan: crescent-shaped sand dune with horns pointing downwind, gentle windward slope and steep leeward slip face; formed where wind blows from one direction over a limited sand supply around an obstacle; moves forward slowly.
Inselberg: isolated steep-sided rocky hill rising abruptly from a plain, often granite (e.g. Idanre, Zuma Rock); formed when the surrounding land is worn down by weathering and erosion while the resistant rock remains.
Each with a labelled diagram.
Choose two and include a labelled diagram for each.