plinthite


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plinthite

[′plin‚thīt]
(geology)
In a soil, a material consisting of a mixture of clay and quartz with other diluents, that is rich in sesquioxides, poor in humus, and highly weathered.
References in periodicals archive ?
The more specific terms proposed by the soil science community have not replaced traditional names: a Scopus search on 10 July 2015 returned 3200 occurrences for laterite, 844 for ironstone, 76 for plinthite and only 9 for 'petroplinthite.
Plinthite occurs in the deeper part of Ultisols profiles (Kc, Tim2, Pga, Pk, Cp).
A significant portion (approximately 40 percent) of the southeast Coastal Plain in Georgia has plinthic soils characterized by very sandy A horizons underlain by restricting plinthite and Hawthorn Formation materials beginning at depths of 0.
Plinthite layers are cemented by a special type of clay common to the tropics.
Soils subject to wetting-drying cycles contain concentrations of iron and aluminium oxides known as plinthite (see also vol.
Plinthite changes irreversibly to an ironstone hardpan or to irregular aggregates on exposure to repeated wetting and drying, especially if it is exposed also to heat from the sun.
A second field experiment was set up during the second week of October 1999 at Ukulinga Farm, near Pietermaritzburg in KwaZulu-Natal on a shallow, poorly drained soil underlain by soft plinthite (Table 1), classified as Westleigh form, Helena family (Soil Classification Working Group 1991), Typic Plinthaquept (Soil Survey Staff 1998), and Hydrosol (Isbell 1996).
This study showed that in areas of the southeastern Coastal Plain with plinthite and clayey subsoils, where shallow lateral water movement is the dominant loss pathway, agrichemicals applied in the spring move laterally downslope during the rainy wet months and may take several seasons before completely leaving the upslope area and moving through the riparian forest.
3+]] iron) is clearer in the wetter parts of the savannah biome than anywhere else in the tropics; the ferrous iron appears in the forms of concretions, ferruginous crusts, hardened layers (hardpans), nodules of plinthite, etc.
The soils were mostly from the Bassendean Association and all consisted of litter on an organic sandy topsoil overlying either deep grey or yellow sands, or in two cases a grey clay loam E horizon (duplex soils) over plinthite (McArthur 1991) with an Australian Soil Classification (Isbell 1996) of Podosols.
The soil was Tifton loamy sand (fine-loamy, siliceous, thermic, Plinthic Kandiudult) underlain with plinthite and Miocene age materials of very low permeability.