extensively altered strata near the atoll margin. Aragonite dissolution
and calcite cements (radiaxial and cloudy prismatic) are abundant in
fore-reef, reef, and some back-reef strata. Petrographic and

geochemical data indicate aragonite dissolution and calcite cementation

in seawater at burial depths of 100 to 300 m. Dolomite occurstin slope
and deeply buried reefal carbonates. Most dolomitization occurred at
burial depths of more than 1000 m in cool marine waters circulating
through the atoll. lagoonal strata are not significantly altered by
marine diagenesis and still contain abundant primary aragonite and

magnesium calcite.

Major Descriptors:

*MARSHALL ISLANDS -- REEFS;

*REEFS -- DEPOSITION

Descriptors: ALGAE; CALCITE; CARBONATE ROCKS; CORALS; DISSOLUTION; FOSSILS;
GEOCHEMISTRY; MIOCENE EPOCH; STRATIGRAPHY
Broader Terms: ALKALINE EARTH METAL COMPOUNDS; CALCIUM CARBONATES; CALCIUM
COMPOUNDS; CARBON COMPOUNDS; CARBONATE MINERALS; CARBONATES; CENOZOIC
ERA; CHEMISTRY; CNIDARIA; GEOLOGIC AGES; GEOLOGIC STRUCTURES; GEOLOGY;
ISLANDS; MICRONESIA; MINERALS; OCEANIA; OXYGEN COMPOUNDS; PLANTS; ROCKS
; SEDIMENTARY ROCKS; TERTIARY PERIOD
Subject Categories: 020200*
-- Petroleum -- Reserves, Geology, &

Exploration

10/5/375

(Item 75 from file:

02364806

EDB-89-110778

Author(s):

Shingleton,

Title:

103)

Summary of the Bikini Atoll ionizing-radiation survey
K.L.;

Cate,

J.L.;

Trent,

M.G.;

Robison,

Griffith, R.V.;
Anderson, K.J. (eds.)
Title: Hazards Control Department annual technology review,

Corporate Source:

Lawrence Livermore National Lab.,

Publication Date:

Jul 1988

Report Number(s):

Order Number:

p 1-13

CA

W.L.;

1987

(USA)

UCRL-50007-87

DE89002470

Note: Portions of this document are illegible in microfiche products
Document Type: Analytic of a Report
Language: English
Journal Announcement: ERA8900

Availability: NTIS, PC AQ7/MF AOl;
Subfile:

ERA

Exchange);

(Energy

INS

Country of Origin:

Research

1.

Abstracts); ETD

(US Atomindex input).

United States

JMT

(Energy Technology Data

(DOE contractor)

Country of Publication: United States

Abstract:

This survey was designed to measure the beta dose rate from /sup

137/Cs and /sup 90/Sr//sup 90/Y relative to previously measured gamma

dose rates on Bikini and Eneu Islands. The authors exposed modified
Panasonic-802 thermoluminescent dosimeters (TLDs) in over 100 sites for

Six months to accomplish this task. The sites were selected to be
either in areas of known high gamma dose rates, in areas where the

Marshallese would likely spend most of their time upon resettlement, or
in areas where experimental environmental changes has been made.
Therefore, the beta and gamma does rates do not represent island
averages. The mean beta dose rate on Enue ranged from 23 mrem/yr at 1
cm to 6 mrem/yr at 100 cm, as compared with a mean deep dose rate of
17.5 mrem/yr. The mean beta dose rate around houses and in general area

on Bikini ranged from 425 mrem/yr at 1 cm to 178 mrem/yr at 100 cm,

compared with a deep dose rate of about 154 mrem/yr. Because monitoring &
sites were specifically placed in the most-contaminated areas of Bikini @
and Eneu, the unshielded beta dose rates reported provide an upper
limit of radiation dose;actual doses received by the Bikinians would be™
reduced significantly by clothing, footwear, and ground cover such as
crushed coral,

which reduces the beta dose rate by

80-90%.

The amount

of time spent in houses and in the minimally contaminated areas around
houses and the lagoon would further reduce the beta dose rates reported

here.

17 referenced,

12 figures,

1 table.

Major Descriptors: *BIKINI -- RADIATION MONITORING; *CESIUM 137
DOSIMETRY; *STRONTIUM 90 -- BETA DOSIMETRY
Descriptors: PROGRESS REPORT; SURFACE CONTAMINATION

-- BETA

Select target paragraph3