ESR-dating of the Arctic sediment core PS1535 dose-response and thermal behaviour of the CO2--signal in foraminifera

Citation
D. Hoffmann et al., ESR-dating of the Arctic sediment core PS1535 dose-response and thermal behaviour of the CO2--signal in foraminifera, QUAT SCI R, 20(5-9), 2001, pp. 1009-1014
Citations number
11
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Earth Sciences
Journal title
QUATERNARY SCIENCE REVIEWS
ISSN journal
0277-3791 → ACNP
Volume
20
Issue
5-9
Year of publication
2001
Pages
1009 - 1014
Database
ISI
SICI code
0277-3791(200103)20:5-9<1009:EOTASC>2.0.ZU;2-J
Abstract
ESR-spectra of foraminifera in arctic sediment cores display the CO2--signa l (g = 2.0006). Research on the thermal behaviour of the CO2--signal shows that both natural and artificial irradiation generates a precursor and a th ermal unstable component of the CO2--signal. The precursor can be transfere d to the stable radical, and unstable radicals can be removed by heating. T he signal-change by heating depends on the irradiation dose. Because of the varying response on thermal treatment, the dose-response curves show syste matic differences depending on the applied procedure (single- or multi-aliq uot method with or without heating). A model for the description of the CO2 --signal-change is presented. The combination of two exponential saturation functions seems to be an adequate analytical description of the dose-respo nse curve of the CO2--signal in foraminifera. Due to the limited thermal st ability this signal can be used for dating foraminifera with ages up to abo ut 190 ka. (C) 2000 Elsevier Science Ltd. All rights reserved.