The Lowering Of The Desert Floor As Wind Eroded Sediments

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.

The lowering of the desert floor as wind eroded sediments. When the wind blows across loose sediment it removes small particles like clay silt and sand leaving the courser heavier sediment behind. This process of removing lighter sediment is called deflation. 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.

A wind s bed load consists of the heavier grains usually sand that hop and skip along the ground by saltation. 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. As a grain strikes another grain or surface it erodes that surface. 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.

The ground actually gets lower over time and those heavier sediments become quite firm in the ground. 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. Loess is a very fine grained wind borne deposit that can be important to soil formation. In arid regions small particles are selectively picked up and transported.

Deflation is the lowering of the land surface due to removal of fine grained particles by the wind. Now a german geologist has analyzed lakebed sediments to shed. Winds in the desert are often extreme and unrestricted by trees and vegetation. 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.

Sand dunes are common wind deposits that come in different shapes depending on winds and sand availability. Wind can carry small particles such as sand silt and clay. A marvel of nature the lakes of ounianga in the sahara desert have lasted thousands of years and withstood dramatic climate change. 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.