as sedimentation one designates a depositing/a setting from particles from liquids or gases off under the influence of the force of gravity and other forces, like for example the centrifugal energy in a centrifuge (here not more near describes). Zuunterst a layer of suspended matters forms, then one calls this sediment also sediment or DEK-did.
Sediments can be divided into three main groups: the klastischen sediments (by water or wind transported and so mechanically formed particles, e.g. Sand), chemical sediments (by chemical processes from aqueousSolutions separated, e.g. Carbonates) and biogenous sediments (deposits of organisms or from organism remainders, e.g. Corral reefs), whereby the biogenous sediments are classified also as sub-group of the chemical sediments.
The deposited particles laminate themselves after their density and have therefore alsoa different sedimentation speed (dropping speed). „The closest “particles settle first, lie thus zuunterst, which can be also used for it the different materials of a mixture to separate (see a decanting).
Sediments become, in case of of running waters, mainly by the erosionthe cross section registered. A further effect is the sediment entry. Here sediments (and other solids) from the catchment area are registered.
In the mill laboratory a sedimentation test is accomplished, with that the volume of the sediment flour water of a suspension as measure for the source abilitythe protein materials in the flour applies. In the Bodenkunde sedimentation attempts serve the determination of the particle size distribution of a soil.
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as a special case is to be noted that itbeside „the normal described above “also to a so-called inverse grading to come can, which shows up for example with eruptiven pumice stones. There pumice a up-foamed, glassy rock is, possesses larger pumice lapilli a smaller density than smaller Lapilli, which itselfdeposit therefore first.
The suspended matters are advanced in case of a natural sedimentation by erosion processes and here above all through usually fluviatilen transport, which for its part usually a decomposition of the output rock preceded. Depending upon distanceto the demolition place and usually increasingly the flow rate smaller thereby, the particle size distribution of the particles carried in the water exhibits clear differences. Here that applies the grain size of the particles with the distance and a dropping flow rate decreases, there the largest and/or. heaviestParticle (Geschiebe) sedimentieren first and the current often no more in a the position is not to be whirled up these by the waters reason.
Particularly in standing waters these suspended matters train those by gravitative deposit sediment layers (Warven), partially for age determination (Stratigrafie) to be used. This is above all because of which is present here contrary to running waters no more current and can therefore also very small particles settle. Additionally sedimentation often shows a different sample depending upon climatic systemin the yearly variation, since for example in the winter with one frozen over waters the finer particles set off. Thus, similarly with trees, rougher and finer layers per year, which are called Warven , develop for the Jahresringen. These often close organisms or their tracesalso, which can develop in the course of the Fossilisation to fossils. Also the developing conditions (Paläoklima) individual sighting often documented in these, why sediments represent important climatic archives. Particularly navy, flat navy and seeische deposits have in this connection onehigh force of expression, why they represent also the principal purpose of climatological research drillings.
In the course of sedimentation zuunterst lying layers experience a ever higher pressure, which in connection with dia. towards tables processes to the formation of sedimentary rocks can lead. A special case places herethe snow , which can be laminated likewise and be consolidated under pressure influence to ice. If this effect continues over several years, then this can lead to the training of a glacier.