-li-
Ielead
|
~
Pigure 4& shows the dec] ine
for island soil as well as the
only two observations for beech
send eat Belle.
The slope for
4
.
island 801] of -1.06 (Table 1)
eerrespamed Civeciy with tnat
of survey meter readings.
Prom an initial level on
the first day of 1? alillicuries
per kilogram, the island soil
declined fairly regularly for a
period of two years.
The dip
at 130-200 days is reflected in
the decline curves for land
hermit crab but is not apparent
in the data for green leaves of
Plants on Belle.
=
soreWeren war ve tawe
Pig. 4
Figure 5 shows the decay of
samples of island soil from Belle
(plate 7542) and from Edna (plate 9170),
and of intertidal beach sand from Henry
(plate 9711A).
A slope of -1.2 is in-
Cluded for comparison.
The Belle island soil decay curve
=
is for plate number 7542 which served as ?'
the basis for computation of the decay
correction factors for converting values
back to date of collection.
The same
factors were used for all types of
material except rats collected postNectar at Eniwetok Atoll.
The dashed,
is not 4
curve
the
of
early portion
straight iine because it was originally
extrapolated on semi-log paper.
‘
i.
.
We
For comparison, Figure 6 shows the
decay of the sample of lagoon bottom sand
dredged November 7, 1952 off Tilda \northwest of Vera). This decay was used for
:\
*
1952(Donaldson 1953:25), and for 20-1000
y!
curve of Pigure 2 is striking.
}'
It was
practically uninfluenced by residues from
The more pronounced
previous detonations.
flexures in the curve for Belle island sotl,
as well as its generally more gredual slope
are the result of the influence of the Mike
test residues superimposed upon the Nectar
test effect.
“ree set eorey
3?
wo weer
days its similarity to the theoretical
.
~>
~~--ad
Dey! Me ey 4 200
Pig. 5
calculation of decay correction factors for
the collections following the Mike test in
\
L.
\
\
a
Pig. 6