In
pedology, leaching is the removal of soluble materials from one zone in soil to another via water movement in the
profile.
It is a mechanism of
soil formation distinct from the soil forming process of
eluviation, which is the loss of mineral and organic
colloid
A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others exte ...
s. Leached and eluviated materials tend to be lost from
topsoil
Topsoil is the upper layer of soil. It has the highest concentration of organic matter and microorganisms and is where most of the Earth's biological soil activity occurs.
Description
Topsoil is composed of mineral particles and organic mat ...
and deposited in
subsoil
Subsoil is the layer of soil under the topsoil on the surface of the ground. Like topsoil, it is composed of a variable mixture of small particles such as sand, silt and clay, but with a much lower percentage of organic matter and humus. The su ...
. A
soil horizon accumulating leached and eluviated materials is referred to as a zone of
illuviation.
Laterite
Laterite is a soil type rich in iron and aluminium and is commonly considered to have formed in hot and wet tropical areas. Nearly all laterites are of rusty-red coloration, because of high iron oxide content. They develop by intensive and prolo ...
soil, which develops in regions with high temperature and heavy rainfall, is an example of this process in action.
See also
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Bioleaching
*
Biomineralisation
*
Dissolved load
*
Leaching (agriculture)
*
Groundwater recharge
*
Soil salinity control
References
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Economic geology
Sedimentology
Soil science