On the Use of the Term Laterite

In the first place, perhaps an apology might be thought in order because of the use now of a word which, fortunately, has very seldom appeared In the publications of this Association. Crowther (1±) has recently said of Laterite" that the tyranny of an easy term has already led to hopeless confusion, and that continued use will make confusion worse confounded. And yet "Laterite" is a term which continues to have world wide use, and .there is a real danger that it will be used with continually more divergent, narrower meanings or broader, less definite ones, a danger that it will be applied more and more to indicate rather fine and only difficultly measured chemical differences of certain weathering and weathered materials for which there are no easily applicable field criteria. It is noteworthy that Crowther j (ij.) although a chemist, has said "there can be little doubt that undue concentration on laboratory work tends to lead to the neglect of many soil properties which are important not merely in soil classification but in the practical application of soil science." It is thus important that we who study soils in the field should not use the term unless we specially define what we mean by it. The principal reason for calling attention of this Association to the question of "Laterite" at this time is that Professor Mohr has recently (5) clearly described and strikingly figured the processes of soil profile development under the humid tropical conditions, with soil moisture movement continuously or nearly so downward — conditions which will develop red lixivium soils, and which, if they impress themselves for a long enough period upon suitable parent material, will produce a typical laterite profile. Than if such a profile has been developed, after erosion has accomplished its part, the result will be an iron pan horizon, often slaglikev?), exposed at the surface of the ground. It Is thus apparent that the writer believes that the term laterite should continue to be applied to this material, In the sense in which lt had been for such a long time used in India. If the term be used in any of the other senses which have been proposed from time to time, the special meaning should be clearly stated in each case. It would seem that the best reason for using "laterite" in this definite and practically original sense is that lt is a definite material widely scattered in the tropics, for which a name in noil classification la needed. For this material the only alternative which has been suggested Is "bauxite" but to use that word which is so generally and specifically used for the ores from which aluminum is obtained, would only add to the confusion. Because of the indefinite and often inexact uses of the term "Laterite" it is worthwhile to turn back to the original description of laterite. As the original publication is inaccessible, I quote from Scrivenor (8):