Laterite

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laterite

[′lad·ə‚rīt]
(geology)
Weathered material composed principally of the oxides of iron, aluminum, titanium, and manganese; laterite ranges from soft, earthy, porous soil to hard, dense rock.

Laterite

 

red ferruginous or ferruginous-aluminiferous eluvial formations typical of humid tropical and subtropical regions. The term “laterite” was first proposed by the English geologist F. Buchanan in 1807 to designate the red ferruginous rocks of the weathering mantle, used in India and other countries to make bricks used in construction. Later the term came to be used for a group of red rocks that differed in composition and origin. In soil science “laterite” is often used to denote ferruginous soil horizons of infiltrative origin. Climate is the chief factor in tropical weathering. Laterite forms only in tropical and subtropical regions with more than 1,300–2,000 mm of average annual precipitation and mean annual temperatures of 20°-30° C. The laterites overlie aluminosilicate rocks of various composition and form through laterization, during which up to 90 percent of the SiO2 and bases (of their total content in the parent rock) are removed.

In the tropical zone of the globe laterites cover vast plateaus and hilly areas. Their thickness ranges from a few meters to 50 m. Their age varies from Jurassic to Recent.

In the USSR residual and redeposited laterites of Mesozoic and Cenozoic age are found in the Ukraine, Kazakhstan, Siberia, the Urals, and in Middle Asia. Abroad the development of laterite of Recent (Anthropogene) age has been proved in the Democratic Republic of Vietnam and on Pacific islands (Hawaii, Samoa, Tahiti).

Various minerals are associated with laterites, including aluminum, iron, manganese, nickel, and other ores (Cuba, New Caledonia) and very large bauxite deposits (Guinea, Ghana). In India laterite is used to make bricks used in construction.

REFERENCES

Laterity: Sb. st. Moscow, 1964.
Glinka, K. D. Pochvovedenie, 6th ed. Moscow, 1935.
Fridland, V. M. Pochvy i kory vyvetrivaniia vlazhnykh tropikov. Moscow, 1964.
Bushinskii, G. I. Geologiia boksitov. Moscow, 1971.
Fox, C. S. Bauxite and Aluminous Laterite. London, 1932.

N. A. LISITSYNA and V. P. PETROV

References in periodicals archive ?
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Kew GA, Gilkes RJ (2006) Classification, strength and water retention of lateritic regolith.
An ideal sketch of litholog with resistivity in the Deccan trap lateritic terrain is as follows: (Not to scale).
The mine is based on two large, weathered lateritic nickel deposits located approximately 3 km apart.
Aluminum oxyhydroxides, mainly gibbsite and boehmite, are common in many Western Australian lateritic soils.
performing earthworks, including, but not limited to, site facilities, the construction of a vehicle wheel wash area, the construction of a perimeter construction fence, the cleaning of the project pitch and the clearing of right-of-ways, earthworks of building platforms and footpaths, embankments made of sand insensitive to water and lateritic materials, the construction of construction tracks, the rehabilitation of tracks and platforms.
(NAC) - the country's largest producer of lateritic nickel ore and one of the largest in the world, the support his company got from the community around its mining operation in Manicani, a small island off Eastern Samar, is more than enough to prove its existence.
It is the Philippines' largest producer of lateritic nickel ore and one of the largest in the world.
Both the Lateritic and Oolitic units show an overprinting secondary ferruginisation, often seen as resistant vertical and horizontal bands which have exploited bedding and fracture surfaces, and as concentric zonations within the units and typically between ferruginous fractures.
In Cuba, Sherritt International through a vertically integrated nickel and cobalt mining, processing and refining joint venture owns the Moa Cuba mining and processing facility to produce lateritic nickel and cobalt ore, which is processed on site.