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Studies in Tropical Soils II. Some Characteristic Igneous Rock Soil Profiles in British Guiana, South America

Published online by Cambridge University Press:  27 March 2009

F. Hardy
Affiliation:
Imperial College of Tropical Agriculture, Trinidad, British West Indies
R. R. Follett-Smith
Affiliation:
Department of Agriculture, British Guiana

Extract

1. Five typical British Guiana soil profiles, derived under humid tropical conditions from igneous rocks of different silica contents, are described, and the results of their detailed petrographical, chemical and ecological examination are presented and discussed.

2. Each kind of rock has produced a sandy, acidic, nutrient-deficient surface soil, but the katamorphic changes that have occurred during rock alteration, weathering and leaching have been fundamentally different.

3. The basic and intermediate igneous rocks have given rise within the zone of alteration to “primary gibbsitic laterite”, covering the parent rock in a thin crusty layer. Within the zone of secondary changes, the laterite has been resilicated, presumably through the agency of ground water containing soluble silica or alkali silicates (partially in the more basic rock profiles, and completely in the intermediate types), into kaolinitic earths, coloured yellow and red by hydrous iron oxides. Residuary gibbsite and iron oxides have accumulated in the more basic profiles as concretionary gravelly masses.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1931

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References

REFERENCES

(1)Campbell, J. Morrow. Laterite; its origin, structure and minerals. Min. Mag. (1917), 17, 67, 120, 171, 220.Google Scholar
(2)Follett-Smith, R. R. Report of a soil survey of an area of the North-West District of British Guiana. B.G. Dept. Agric., Chem. Bull. (1930), 1, 1.Google Scholar
(3)Hardy, F. (a) Some aspects and methods of soil survey work, J. Agric. Sci. (1929), 19, 734. (b) Tropical soil surveying, Trop. Agric. (1930), 7, 235, 274, 300.CrossRefGoogle Scholar
(4)Hardy, F. Studies in tropical soils. I. Identification and approximate estimation of sesquioxide components by adsorption of alizarin. J. Agric. Sci. (1931), 21, 150.CrossRefGoogle Scholar
(5)Harrison, J. B.Geology of the Goldfields of British Guiana (1908). London, Dulau and Co.Google Scholar
(6)Harrison, J. B. The residual earths of British Guiana commonly termed “laterite”. Geol. Mag. (1910), Dec. 5, 7, 439, 488, 553.Google Scholar
(7)Harrison, J. B. Formation of a laterite from a practically quartz-free diabase. Geol. Mag. (1911), Dec. 5, 8, 120, 355, 477.Google Scholar
(8)Harrison, J. B. Reports and correspondence relative to bauxite in British Guiana, 1910–1917. Combined Court (1919), Georgetown, Demerara.Google Scholar
(9)Martin, F J. and Doyne, H. C. Laterite and lateritic soils in Sierra Leone. J. Agric. Sci. (1927), 17, 530.CrossRefGoogle Scholar
(10)Scrivenor, J. B. Laterite. Malayan Agric. J. (1929), 17, 454.Google Scholar
(11)Scrivenor, J. B. Laterite. Letter to Editor, Geol. Mag. (1930).Google Scholar