aa,
Daas
At present the activity in the lower levels differs
Theresulting gamma activi-
little from that of the upper.
ties forthe deep fishes are therefore, very simliev ¢
those for plani:ton of the upper laycrs.
%~ should be noted
that the foregoing study was made within the influence of
the Bikini Eddy System and may be representative of that eroa
only.
265
RADIOACTIVITY EACKGROUND OF THE CCEAN PLOOK
A series of 16 samples cf the ocean Floor were tekken
a
around Bikini Atoll. These were obtained with a coving
and & bottom dredges.
3
wet
They consisteé of small bits «f ccral,
baselt, mongenese nolules, coarse ccral sand and fhre
gioblgerina core (fossils of
minete organisms
of ths order
§?
Portions of such material were velshel, dried
,
Foraminifera).
et 130° GC. in elurcinum planchets, and counted for gauma radioactivity.
Several of the cores were lost dus te the inability
or the core barrel to peuetrate, anz the core-cetcier to pe-
was also countec and was found
than th:¢ water.
to be considerably mere eative
The top laver of each core, end portions of
the dredge samples were assayed.
Yhe results are skown in
igure 2. in which the activity of the gamma radiation
er
"3
*
od
- —~
s
devire
greu of ccean flcor surface is viotted at locations semplec.-
In general, the most radioactive samples consisted of globS cue
Zire ooze (Fig. Z.core Ca2, C(t, Ce104).
~
Manganese nodules
QB,