The Genesis and Morphology of Hawaiian Ferruginous Laterite Crusts 1 
G. Donald Sherman 2 
Massive ferruginous soil horizons have 
been discovered in the profiles of certain 
Hawaiian soils which have morphological 
characteristics similar to the ferruginous lat- 
erite crusts found in other tropical areas. 
Likewise, the nature of the soil weathering 
responsible for these ferruginous horizons 
bears a great resemblance to that described 
for other ferruginous horizons. However, the 
ferruginous soil horizons found in the Ha- 
waiian Islands do not have the hardness 
which is described for ferruginous crusts in 
India or Indo-China. In spite of the lack of 
this degree of hardness the author feels that 
the Hawaiian soils which have a hard fer- 
ruginous surface or near-surface horizon are 
the equivalent of the ferruginous laterite 
crust of other tropical regions. It is the pur- 
pose of this article to describe the genetic and 
morphological characteristics of the Hawaiian 
laterite crusts and to show their similarity to 
other described laterite crusts. 
The original description of a laterite was 
made by Buchanan (1807), who defined it 
as a ferruginous indurate clay which is brick- 
like in nature. Pendleton (1946), a firm 
follower of Buchanan, has defined a laterite 
as follows: "Illuvial horizon largely iron ox- 
ides, slaglike, cellular or pisolitic structure, 
and of such a degree of hardness that it may 
be quarried out and used for building con- 
struction.” Many of the temples in tropical 
Asia are built of these laterite materials. Du 
Published with the approval of the Director of 
the University of Hawaii Agricultural Experiment 
Station, Honolulu, T. H., as Technical Paper No. 
196. Manuscript received March 16, 1950. 
2 Chairman, Department of Soils and Agricul- 
tural Chemistry, University of Hawaii Agricultural 
Experiment Station. 
Preez (1949) has modified Pendleton’s def- 
inition in that he describes a laterite to be a 
vesicular, concretionary, cellular, vermicular, 
slaglike pisolitic or concrete-like mass con- 
sisting chiefly of ferric oxides with or without 
mechanically entangled quartz and minor 
quantities of alumina and manganese; it is 
of varying hardness but it is usually easily 
shattered when struck a sharp blow with a 
hammer. Du Preez’s definition differs from 
Pendleton’s in that it does not require a de- 
gree of hardness to meet the requirements of 
a material suitable for building construction. 
Botelho da Costa and Lobo Azevedo ( 1949) 
have objected to a definition of a laterite 
which requires the presence of a concretionary 
ferruginous layer. In general, Du Preez’s def- 
inition has considerable acceptance. 
Sherman ( 1949) has pointed out that the 
laterite crust will be the end product of trop- 
ical soil weathering under an alternating wet 
and dry season. He has suggested that under 
continuous moist soil conditions the ultimate 
end product of soil weathering in the tropics 
will probably be a soil rich in alumina. The 
ferruginous layer which occurs at or near the 
surface is called a laterite crust in that it is 
usually a hard sterile soil area. The ferru- 
ginous layer may be found below the surface 
which may have resulted from erosion or by 
formation over the water table in coarse- 
textured soils. The ferruginous layer which 
develops in the fine-textured soils materials 
forms below the surface and is later exposed 
by erosion as sterile hard surface soil. 
HAWAIIAN LATERITE CRUSTS 
Hawaiian soils having hard sterile surfaces 
have been described by Sherman et aL 
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