EGU22-12285
https://doi.org/10.5194/egusphere-egu22-12285
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

New luminescence chronological tools for dating and tracing sediment movement

Ed Rhodes1,2, Andrew Ivester1,3, James Dolan4, Judith Gauriau4, Russ Van Dissen5, and Tim Little6
Ed Rhodes et al.
  • 1University of Sheffield, Department of Geography, Department of Geography, Sheffield, United Kingdom of Great Britain – England, Scotland, Wales (ed.rhodes@sheffield.ac.uk)
  • 2Earth, Planetary, and Space Science, University of California Los Angeles, Los Angeles, CA, USA
  • 3University of West Georgia, Department of Geosciences, Carrollton, GA, USA
  • 4University of Southern California, Department of Earth Sciences, Los Angeles, CA, USA
  • 5GNS Science, Lower Hutt, New Zealand
  • 6Victoria University of Wellington, School of Geography, Environment and Earth Sciences, Wellington, New Zealand

As part of a large research project reconstructing fault slip rates, palaeoseismiology and landscape evolution in New Zealand, we have developed a range of new chronological tools with applications to sediment. These closely related methods are based on Infra-Red Stimulated Luminescence (IRSL) signals of alkali feldspar, and allow us to determine aspects of transport and burial at the scale of individual grains over time periods ranging from 1 to 300,000 years. In particular, we have introduced and tested a method referred to as 3ET-IRSL (Three Elevated Temperature IRSL), and we are also applying a MET-IRSL (Multiple Elevated Temperature IRSL) approach comprising measurement sequences that include five IRSL measurements at different temperatures. These techniques can be used in different ways to filter complex single grain IRSL apparent age distributions that arise from processes including short duration reworking associated with incomplete trapped charge removal during transport. These methods were primarily designed to improve chronological control for sediment dating in contexts where conventional approaches encounter significant challenges owing to the geomorphic setting including high volume, rapid deposition. However, these approaches can provide significant insight into the dynamics of sediment transport routes and rates at the individual grain scale. We will demonstrate the performance of these methods at key test sites, and assess the implications of our findings in New Zealand (NZ), coupling observations of relict fluvial terrace formation with landscape response to the Mw 7.8 Kaikoura earthquake of 2016. At one of our NZ sites, fluvial system response to this event is the opposite of that expected from the literature in terms of sediment deposition and erosion; the degree to which this represents a transient response is assessed. We highlight the amazing potential of these new tools for improving our understanding of source-to-sink sediment transport dynamics.

How to cite: Rhodes, E., Ivester, A., Dolan, J., Gauriau, J., Van Dissen, R., and Little, T.: New luminescence chronological tools for dating and tracing sediment movement, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12285, https://doi.org/10.5194/egusphere-egu22-12285, 2022.