<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><p>Due to the construction of a new North-South subway in Cologne, Roman time harbour sediments were exposed and were sampled for luminescence dating. A very good independent age control was given by the precise knowledge of the chronology of Roman activity and by radiocarbon ages of charcoal samples. Hence, different methodological approaches within luminescence dating were applied for Holocene heterogeneously bleached fluvial samples and were compared to the known ages. For one sample, optically stimulated luminescence (OSL) dating was applied to coarse-grained quartz using a single aliquot regenerative-dose (SAR) protocol. After De-measurements, different statistical approaches were tested (i.e. arithmetic mean, median, minimum age model, finite mixture model, leading edge method and the Fuchs and Lang approach). It is demonstrated that the Fuchs and Lang approach along with the leading edge method yielded the best matching OSL ages with respect to the known ages.</p><p>For the other sample which showed feldspar contamination within the quartz signal, the post-IR blue stimulated luminescence (double SAR protocol) was measured in three different ways to calculate the Devalue: with continuous wave (CW) stimulation with an IR-bleach at 50°C and at 225°C for 100 s prior to the OSL, and pulsed OSL (POSL). It was demonstrated that the IR-stimulation at 225°C has very good potential to remove the feldspar signal contribution as well as pulsed OSL, but the former might deplete parts of the quartz OSL signal.</p></abstract>

Due to the construction of a new North-South subway in Cologne, Roman time harbour sediments were exposed and were sampled for luminescence dating. A very good independent age control was given by the precise knowledge of the chronology of Roman activity and by radiocarbon ages of charcoal samples. Hence, different methodological approaches within luminescence dating were applied for Holocene heterogeneously bleached fluvial samples and were compared to the known ages. For one sample, optically stimulated luminescence (OSL) dating was applied to coarse-grained quartz using a single aliquot regenerative-dose (SAR) protocol. After De-measurements, different statistical approaches were tested (i.e. arithmetic mean, median, minimum age model, finite mixture model, leading edge method and the Fuchs and Lang approach). It is demonstrated that the Fuchs and Lang approach along with the leading edge method yielded the best matching OSL ages with respect to the known ages.For the other sample which showed feldspar contamination within the quartz signal, the post-IR blue stimulated luminescence (double SAR protocol) was measured in three different ways to calculate the Devalue: with continuous wave (CW) stimulation with an IR-bleach at 50°C and at 225°C for 100 s prior to the OSL, and pulsed OSL (POSL). It was demonstrated that the IR-stimulation at 225°C has very good potential to remove the feldspar signal contribution as well as pulsed OSL, but the former might deplete parts of the quartz OSL signal.

Geoarchaeological studies on Roman time harbour sediments in Cologne — comparison of different OSL dating techniques

Leibniz Institute for Applied Geophysics, Section 3: Geochronology and Isotope Hydrology, Stilleweg 2, 30655, Hannover, Germany

Geowissenschaftliche Dienstleistungen, Wasser Boden Landschaft, Zülpicher Str. 7, 50674, Köln, Germany

Geological Department, TU Bergakademie Freiberg, Gustav-Zeuner-Strasse 12, 09599, Freiberg, Germany

Römisch-Germanisches Museum / Archäologische Bodendenkmalpflege der Stadt Köln, 50667, Köln, Germany

Geochronometria

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Due to the construction of a new North-South subway in Cologne, Roman time harbour sediments were exposed and were sampled for luminescence dating. A very good...

Geoarchaeological studies on Roman time harbour sediments in Cologne — comparison of different OSL dating techniques

Publié en ligne: 22 sept. 2011

Pages: 341 - 349

DOI: https://doi.org/10.2478/s13386-011-0020-y

Mots clés
OSL, feldspar impurities, statistical models, Romans, Geoarchaeology

© 2011 Silesian University of Technology, Gliwice, Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Geoarchaeological studies on Roman time harbour sediments in Cologne — comparison of different OSL dating techniques

Publié en ligne: 22 sept. 2011

Pages: 341 - 349

DOI: https://doi.org/10.2478/s13386-011-0020-y

Mots clésOSL, feldspar impurities, statistical models, Romans, Geoarchaeology

© 2011 Silesian University of Technology, Gliwice, Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Mots clés
OSL, feldspar impurities, statistical models, Romans, Geoarchaeology