quantitative determinations from a few profiles,
Gamma-ray
spectra of equal amounts of soil from different depths were
compared directly to arrive at
(1)
a qualitative evaluation
of the vertical distribution of the radionuclides and
(2)
a
semiquantitative estimate of relative amounts of radionuclides
at different depths.
Gamma-ray spectra were made with a system
which included a 3-inch by 3-inch solid,thallium-~activated,
sodium iodide crystal and a 256-channel analyzer.
In addition,
selected samples were taken for analyses of the pure beta:
emitter,
sr?
0
.
RESULTS AND DISCUSSION
Vertical distribution in relation to soil type is made by
comparing young and old soils.
young soil,
Examples are Kabelle Sand,
a
(Fig. 2) and Gogan Gravelly Sandy Loam (Fig. 3) and
Lomuilal Sand (Fig. 4), old soils.
Their characteristics are
given in Tables I and III.
The young soil has little organic material except that in
an algal surface crust about l cm thick.
Hermit crabs, Coeno-
bita perlatus, at the base of a few shrubs, the borrowing ghost
crab,
Ocypode ceratopthalmia,
present.
and ants are the main animals
Litter accumulation is found only at the bases of
the scattered shrubs and is a minor part of this soil system.