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 ?
Laterite is a residual product of rock decay that is red in color and has high content in the oxides of iron and hydroxide of aluminum.
Generally, laterites show very high resistivity, even upto several hundred ohm-m.
Transformation matrix component analysis performed on sediment samples laterite shows the value of mobility following elements: Ni (0.769), Fe (0.843), Co (0.841) and Cr (1.0).
The first domain, Zone A, is described as laterite in geological logging with 20% 30%.
The ever upward trend in the cost of basic conventional materials like cement and sand has geared concentration of research efforts towards either purely partial or total replacement of ordinary Portland cement (OPC) in concrete on one hand, or the replacement of sand with laterite on the other.
Presenters at technical conferences over the past few years have highlighted laterite ore processing challenges, which include high energy requirements involving both heat and pressure, high consumption of expensive reagents and sulphuric acid, and environmental risks, to name just a few.
Workability of the laterized concrete decreases as the percentage of VA and laterite (lat) increases.
Building on its reputation with the open-pit software packages Three-D, Four-X and Opti-Cut, Whittle Consulting has now developed a procedure that it believes will be equally significant to the mining of bulk commodities, such as iron ore, coal or laterite nickel.
For ENK, its principal property is the Acoje nickel laterite project in Luzon covering about 3,765 hectares.
Sherritt International reported on January 22, that the Ambatovy laterite nickel-cobalt project in Madagascar had reached commercial production.
17 September 2012 - Philippines-based diversified group DMCI Holdings Inc (PSE:DMC) said today that together with investor D&A Income Ltd it had secured a stake of 87.7% in British nickel laterite developer ENK Plc (LON:ENK; ASX:ENK) under their joint takeover bid.
London-based Toledo Mining develops nickel laterite deposits in the Philippines and has strategic interests in four big nickel deposits on the island of Palawan.