Order number 940330-160606-96
-001-001
page 18
set 11 with 111 of 111 items
western Pacific Ocean, with the Te and Tf zqgnes of the
previously established Tertiary Far East Letter
Zonation. Correlation using these two benthic groups is
critical because calcareous nannofossils and planktic
foraminifers are absent in the lower Miocene strata.
Biostratigraphic data from these boreholes delineate a
thick (greater than 700 feet) sequence of upper
Oligocene and lower Miocene strata corresponding to
lower and upper Te zone. These strata document a major
period of carbonate accumulation at Enewetak during the
Late Oligocene and early Miocene
ago).
KEYWORDS
(26 to 18 million years
ENIWETOK/geologic formations ;GEOLOGIC
FORMATIONS/paleontology ;STRATIGRAPHY; FORAMINIFERA;
BOREHOLES;MARSHALL ISLANDS; THICKNESS ; CARBONATES ; ENIWETOK;
TERTIARY PERIOD; CORRELATIONS; EXPLORATION; AGE ESTIMATION;
PALEONTOLOGY; NUCLEAR EXPLOSIONS
EDB
Item
25
ANALYTIC TITLE ENGLISH Comparative study of plutonium and americium
bioaccumulation from two marine sediments contaminated
ANALYTIC AUTHOR/AFFIL
in the natural environment
Hamilton,
T.F.;
(Australia).
LaRosa,
J.;
Smith,
PAGE
RANGE
DATE
[Melbourne Univ.,
Fowler,
Holm,
E.
Energy
[International
(Monaco).
Lab.
Atomic
LIMITATION CODE
ABSTRACT
S.W.;
of Marine
Radioactivity]; Aarkrog, A.; Dahlgaard,
National Lab., Roskilde (Denmark) J
(YYMMDD)
Parkville
of Inorganic Chemistry];
Agency, Monaco-Ville
PUB.
J.D.
Dept.
H.
[Risoe
211-223
910000
UNL
Plutonium and americium sediment-animal transfer was
studied under controlled laboratory conditions by
exposure of the benthic polychaete Nereis diversicolor
(O. F. Mueller)
to marine sediments contaminated by a
nuclear bomb accident
(near Thule,
Greenland)
and
nuclear weapons testing (Enewetak Atoll). In both
sediment regimes, the bioavailability of plutonium and
{sup 241}Am was low,
with specific activity in the
tissues <1% (dry wt) than in the sediments. Over the
first three months, a slight preference in transfer of
plutonium over
{sup 241}Am occurred and
{sup 241}Am
uptake from the Thule sediment was enhancedwcompared to
that from lagoon sediments of Enewetak Atoll.
Autoradiography studies indicated the presence of hot
particles of plutonium in the sediments. The results
highlight the importance of purging animals of their gut
contents in order to obtain accurate estimates of
transuranic transfer from ingested sediments into
9003452