The Lowering Of The Desert Floor As Wind Eroded Sediments

Deflation is the lowering of the land surface due to removal of fine grained particles by the wind.

The lowering of the desert floor as wind eroded sediments.

Sand dunes are common wind deposits that come in different shapes depending on winds and sand availability. Once these eroded materials are settled and piled up in a new location it is referred to as deposition. Water is also able to erode land by the effects of currents and ocean waves. The ground actually gets lower over time and those heavier sediments become quite firm in the ground.

The lowering of the desert floor when wind removes the smallest sand particles abrasion the wearing away of an object caused by the direct contact between moving particles. Loess is a very fine grained wind borne deposit that can be important to soil formation. A fan shaped deposit of sediment formed when a stream s slope is abruptly reduced alluvial fan a flat area on the floor of an undrained desert basin playa that fills and becomes heavy rain. Wind can carry small particles such as sand silt and clay.

Deflation concentrates the coarser grained particles at the surface eventually resulting in a surface composed only of the coarser grained fragments that cannot be transported by the wind. In arid regions small particles are selectively picked up and transported. A wind s bed load consists of the heavier grains usually sand that hop and skip along the ground by saltation. When the wind blows across loose sediment it removes small particles like clay silt and sand leaving the courser heavier sediment behind.

As they are removed the ground surface gets lower and rockier causing deflation. Wind erosion abrades surfaces and makes desert pavement ventifacts and desert varnish. Winds in the desert are often extreme and unrestricted by trees and vegetation. What is left is desert pavement a surface covered by gravel sized particles that are not easily moved by wind particles moved by wind do the work of abrasion.

Now a german geologist has analyzed lakebed sediments to shed. This process of removing lighter sediment is called deflation. Wind can be an effective erosion and transportation agent if it is strong and blows across fine grained sediment such as sand silt and clay. Typically made out of sedimentary rocks usually sandstone laid down in horizontal layers this layering generally makes the zeugen flat topped and stepped in profile because most abrasion is concentrated within a metre or so of the desert floor zeugen often have a slightly narrower more eroded lower portion.