Aeolian sediment

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As aeolian sediment (named after Aeolus , the Greek god of the wind) is called the wind transported and deposited by him sediments . Because air as a transport medium has a very low density and viscosity compared to the flow of water , aeolian sediments are very fine-grained with a maximum grain size in the middle sand range (0.20–0.63 mm).

Transport mechanisms

There are three types of transport to be distinguished: Transport in suspension (“floating”) as well as by saltation (“jumping”) and reptation (“creeping”). Grains that are held in suspension by a turbulent flow are referred to as suspended cargo . Sediments that roll or slide on the ground (reptation) or jump over it (salting) are referred to as soil load . The three transport mechanisms (suspension, saltation, reptation) are similar to those in water. The Hjulström diagram shows when a grain of sediment starts to move and is then sedimented again .

The different types of wind transport can be clearly distinguished in reality. Suspended matter is transported in dust storms that reach miles into the air and can cover great distances. Saltation (and reptation) can cause sandstorms, which are characterized by grains of sand jumping up to two meters above the ground.

Geographical distribution

The main distribution area of ​​the Aeolian sediments are the subtropical dry belts of the earth. The reason for this are the prevailing climatic conditions, which cause a combination of high wind speeds and drought . The lack of erosion-inhibiting vegetation also facilitates the aeolian transport of these sediments. If aeolian sediments accumulate, special geomorphological forms such as B. dunes .


An important and widespread aeolian sediment is loess , a deposit from the Quaternary cold ages . It mainly consists of silt , is widespread in the temperate climate zone and often forms very fertile soils .

The Mediterranean Terra rossa is also partly Aeolian and, according to recent analyzes, contains red mineral dust from the Sahara and the Sahel zone .

Sandstones that were formed as aeolian sediments are usually very well sorted , which means that the grains are all similar in size. Under these conditions, the remaining cavity between the grains is particularly large, so that water, but also crude oil or natural gas, can be stored in the cavities . One example is the Schneverdinger sandstone from Unterperm , which is an important natural gas storage rock in northern Germany.

Non-siliciclastic dunes, which are formed from limestone particles near the beach in tropical seas, are rare.


  • Frank Ahnert: Introduction to Geomorphology . 2nd Edition. Eugen Ulmer Verlag, Stuttgart 1999, 440 pp.
  • Wolf von Engelhardt : The formation of sediments and sedimentary rocks . Schweizerbart'sche Verlagsbuchhandlung, Stuttgart 1973, 378 pp.
  • Multimedia Hochschulservice Berlin GmbH (2005): CD-ROM: The Earth - The Dynamic Planet . 2nd Edition.

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