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Titolo:
THE FALLOUT ISOTOPE BI-207 IN A DELAWARE SALT-MARSH - A COMPARISON WITH PB-210 AND CS-137 AS A GEOCHRONOLOGICAL TOOL
Autore:
KIM G; HUSSAIN N; CHURCH TM; CAREY WL;
Indirizzi:
UNIV DELAWARE,COLL MARINE STUDIES NEWARK DE 19716 UNIV DELAWARE,COLL MARINE STUDIES LEWES DE 19958
Titolo Testata:
Science of the total environment
fascicolo: 1, volume: 196, anno: 1997,
pagine: 31 - 41
SICI:
0048-9697(1997)196:1<31:TFIBIA>2.0.ZU;2-P
Fonte:
ISI
Lingua:
ENG
Soggetto:
SEDIMENTATION-RATES; RIVER ESTUARY; LAKE-SEDIMENTS; ACCUMULATION; DEPOSITION; MICHIGAN; METALS; CORES; INPUT;
Keywords:
BI-207; PB-210; CS-137; SALT MARSH; DELAWARE; SEDIMENTATION RATE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
41
Recensione:
Indirizzi per estratti:
Citazione:
G. Kim et al., "THE FALLOUT ISOTOPE BI-207 IN A DELAWARE SALT-MARSH - A COMPARISON WITH PB-210 AND CS-137 AS A GEOCHRONOLOGICAL TOOL", Science of the total environment, 196(1), 1997, pp. 31-41

Abstract

We report the presence of the fallout isotope Bi-207 (half-life = 38 years) in salt marsh sediments collected from Wolf Glade Salt Marsh, Lewes, Delaware and evaluate its usefulness as a transient tracer for geochronology. The commonly used geochronological tracers of salt marshes, Pb-210 and Cs-137, were also measured to corroborate the results. The average sedimentation rate based on a constant excess Pb-210 flux model in three cores (2 plus 1 duplicate) is estimated to be 3.2 +/- 0.1 mm/year. Based on Cs-137 and Bi-207 data and an assumption that thefallout activities of these nuclides peaked during 1963, average rates are 3.5 +/- 0.7 and 3.7 +/- 0.2 mm/year, respectively. The scatter on the down-core Pb-210 activity is relatively large which may be ascribed to variations in the atmospheric deposition rate of Pb-210, core compaction, or sedimentation. The Cs-137 is present in sediments older than 50 years and suggests that these sedimentation rates may be compromised by the post-depositional mobility of Cs-137 in salt marsh environments. The presence of Bi-207 is detected at similar depths in all three cores which is consistent with a pulsed input of this nuclide into the environment from nuclear detonations and a post-depositional immobility. A higher degree of reliability in sedimentation rate estimates may thus be obtained using Bi-207. Based on the measured flux of Bi-207 into salt marsh and an assumed inventory ratio of Bi-207/Cs-137, the total production of Bi-207 from nuclear weapon testings is estimated to be on the order of 10(15) Bq. (C) 1997 Elsevier Science B.V.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/11/20 alle ore 19:08:58