Chronological framework
N. Rahimzadeh, S. Tsukamoto, T. Lauer
March 2023
Establishing a precise and reliable chronostratigraphic framework of Neanderthal occupation, their extinction, and replacement by early modern humans is a fundamental research desideratum that can be achieved by applying numerical dating methods. The optically stimulated luminescence (OSL) dating is one of the most intensively and commonly applied numerical dating techniques. OSL dating enables the determination of the time elapsed since the last exposure of sediment to sunlight, i.e. depositional age (Aitken, 1998). Quartz and feldspar are the two most widely used minerals in OSL dating. Although quartz has been found to be a robust and accurate dosimeter, the applicability of quartz OSL is commonly limited to the last 100–150 kyr (Wintle and Murray, 2006). As a result, other luminescence signals from quartz have been explored as an attempt to extend the upper age range of quartz, e.g. thermally transferred OSL (TT-OSL; Wang et al., 2006), violet stimulated luminescence (VSL; Jain, 2009; Rahimzadeh et al., 2021, 2022), isothermal thermoluminescence (ITL; Jain et al., 2005; Rahimzadeh et al., 2023)
In the quest for extending the range of dating beyond this limitation of quartz, feldspar infrared stimulated luminescence (IRSL) has been suggested. However, the use of feldspar as a dosimeter has major drawbacks including signal loss of IRSL during burial, known as anomalous fading (Spooner, 1994), which can lead to age underestimation. This problem can be accounted for by using IR signals less affected by fading, the so-called post-IR IRSL (Thomsen et al., 2008), and pulsed IRSL (Tsukamoto et al., 2017), and post-measurement fading correction models (Huntley and Lamothe, 2001; Kars et al., 2008). Using both quartz and feldspar, we aim to establish a robust luminescence chronology of palaeoenvironmental archives and associated Palaeolithic assemblages in northern Germany.
Where possible, OSL dating will be applied along with other dating techniques such as radiocarbon- or electron spin resonance (ESR) dating, which can be a powerful approach for producing more accurate chronological constraints. Luminescence- and ESR dating will be applied at the Leibniz Institute for Applied Geophysics (LIAG) in Hannover (https://www.leibniz-liag.de/institut/sektionen/s3.html). The laboratory is equipped with both, Risoe- and Lexsyg luminescence readers, and also provides the possibility of using gamma spectrometry to define the quantity of radionuclides (dose rate).
