ESR dating of aeolian sediments from Pleistocence desert environments
Zusammenfassung der Projektergebnisse
Despite various methodological difficulties which arose in the course of the research project and despite considerable staff-related problems, available results for samples from Belgium, southeastern Australia and South Africa rendered valuable contributions for assessing the overall potential of ESR dating of single quartz grains. Concerning ESR dates from loess samples collected in Belgium (diploma thesis of M. Kirch), the ESR signal of Ti-H centre was found closest to the expected ages. The Ti-H requires the shortest exposure to bleaching processes. In this case, the samples loess stratigraphy is predominantly made out of reworked loess sediments. This could explain why the Ti-Li, the Ti-all and the Al centres rendered highly overestimated ages. However, independent age control for Belgian samples is missing. ESR ages obtained for coastal barrier dunes of the Coorong (Australia) were derived from the bleachable component of the Al centre and are in fair to good agreement with the expected age ranges. For two tested South Australian samples, the Ti-Li centre gives higher values for the regenerative approach after bleaching compared to regeneration after thermal annealing. Apparent sensitivity changes need to be further investigated. The regenerated spectra of the Ti centre showed slower signal built up for Ti-Li than for Ti-H. In contrast to the South Australian samples, the Ti-Li centre of the South African samples produces no systematic overestimation relative to the equivalent dose found by OSL dating. For the regeneration after thermal annealing method, the composite signal of Ti-Li and Ti-H is consistent with the OSL data for 3 out of 5 samples. However, when artificial bleaching is used as the method of resetting the signal prior to regeneration, the De of the Al centre shows good agreement with the OSL doses. Therefore, at this point of the study, the Al centre seems to be most suitable for the ESR dating of aeolianites, even though a signal residual for the Al centre has to be calculated and substracted from the dating signal. From a geomorphological perspective, ESR dating of Australian aeolian sediments could be a vital tool for dating Early and Middle Pleistocene sediments. As Australia has been tectonically relative stable throughout the Pleistocene, numerous archives for the future testing and application of ESR dating is available. However, in order to establish ESR dating in Quaternary Science as a reliable dating tool, not only a higher density of data is necessary but also an improvement of the ESR equipment. Finally, scattering effects were found to be still very high and, up to this point in time, it has remained unclear which centre delivers the most reliable ESR signal for age estimation. At this stage, ESR dating of quartz grains still cannot be considered as independent dating method. Moreover, ESR dating of sediments is particularly time consuming compared to the more commercialized OSL dating technique.
Projektbezogene Publikationen (Auswahl)
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(2006). On the use of Ti centres for estimating burial ages of Pleistocene sedimentary quartz: Multiple-grain data from Australia. Quaternary Geochronology 1: 151-158
Beerten, K., Lomax, J., Clémer, K., Stesmans, A., Radtke, U.
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13th Sep 2007. “ESR dating of sedimentary quartz regeneration of Ti-related centres after thermal resetting”. Sheffield Luminescence and ESR Dating Conference, 12th-14th September 2007
K. Beerten, S. Rittner, U. Radtke
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13th Sep 2007. “The potential use of the Ti-centre in ESR dating of aeolian quartz”. Sheffield Luminescence and ESR Dating Conference, 12th-14th September 2007
S. Rittner, K. Beerten, U. Radtke
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28th Jul – 03th Aug 2007. “The potential use of Ti-related centres in ESR-dating – an intercomparison of ESR with OSL data from two Pleistocene dunes in SE Australia”. INQUA meeting, Cairns, Australia
S. Rittner, K. Beerten, J. Lomax, U. Radtke
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30th Nov – 02nd Dec 2007. “Potentieller Nutzen von ESR-Signalen von Ti-Zentren – ein Vergleich von ESR mit OSL Altersdaten für zwei Pleitozäne Dünen in SE Australien”. LED: Central Europe Luminescence and ESR Meeting, Wien/Vienna, Austria
S. Rittner, K. Beerten, J. Lomax, U. Radtke
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(2008). Dose recovery tests using Ti-related ESR signals in quartz: First results. Quaternary Geochronology 3: 143-149
Beerten, K., Rittner, S., Lomax, J., Radtke, U.
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18th-22nd Sep 2008. “Applying ESR dating on aeolianites: an inter-regional comparison”. 12th International Conference on Luminescence and ESR Dating, September 18-22, 2008, Beijing (China)
S. Rittner, M.D. Bateman, A. Carr, U. Radtke, A. Vött
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18th-22nd Sep 2008. “ESR dating of beach ridges from the Coorong Coastal Plain in Southeastern Australia”. 12th International Conference on Luminescence and ESR Dating, September 18-22, 2008, Beijing (China)
S. Rittner, U. Radtke, A. Vött
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19 May 2008. “Potential and limitations of Electron Spin Resonance dating of Pleistocene Aeolian sediments”. Scientific Colloquium, University of New South Wales
S. Rittner, A. Vött, U. Radtke
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(2009). Neue Methoden für alten Sand – Einsatz der Lumineszenz- und Elektronenspinresonanz-Datierung zur Rekonstruktion der Landschaftsgeschichte in Trockengebieten. Nova Acta Leopoldina NF 108/373: 243-259
Radtke, U., Hilgers, A., Hülle, D., Lomax, J., Rittner, S.
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23rd Sep 2009. “Die Elektronenspinresonanz-Datierung (ESR) an pleistozänen äolischen Sedimenten”. 57. Deutscher Geographentag, 19th-26th September 2009, Wien, Fachsitzung 63: “Zeit als Dimension des Wandels – eine Säule geographischer Forschung”
S. Rittner, U. Radtke, A. Vött
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16th Mar 2010. “The Electron Spin Resonance (ESR) dating method on Pleistocene sedimentary quartz”. Geological Society of Australia Meeting, Australia National University
S. Rittner
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26th Oct 2010. “To see the past in a grain of sand”. University of New South Wales (UNSW) and Australian Defence Force Academy (ADFA) Research Day, University of New South Wales (UNSW) and Australian Defence Force Academy (ADFA)
S. Rittner
