The last formation: dating recrystallisation events of evaporites using lyoluminescence

Sufficient knowledge of the timing and dynamic of Quaternary (last 2.58 million years) climate phases through palaeoenvironmental studies is indispensable for accurate risk assessment and decision-making towards climate resilience of our modern societies.

Geochronological frameworks are the backbones of such studies, and new and innovative chronological tools can further boost their impact and value towards a better adaption to climate change.

Our project, Lyoluminescence, is about innovation in geochronology designed to contribute to the mission goals of Horizon Europe: “Adaption to Climate Change”.

Lyoluminescence is the emission of light while dissolving a previously irradiated solid (such as sodium chloride) into a liquid solvent (water) due to the production of free radicals in the solution. The amount of light increases proportionally with the radiation dose absorbed by the material after crystallisation.

Therefore, the process is a suitable candidate to be exploited as a dating method.

The signal resetting through dissolution and recrystallisation renders lyoluminescence a potentially dating tool for the last 10 thousand to 5 million years.

The aim of this project is the breakthrough development of lyoluminescence as a dating tool on salts (sodium chloride and potassium chloride) for application in geography & Earth sciences.

We hypothesise that lyoluminescence naturally occurring in salt minerals such as halite and sylvite will allow dating the last recrystallisation event beyond the age limits of conventional luminescence-dating methods and that these features can be exploited for routine use in Quaternary geochronology.

Our project will (1) design, develop and test a new portable lyoluminescence reader, (2) apply the newly developed device to natural salt sites to develop dating protocols and analysis routines, and (3), if successful, map out a commercialisation plan. The project will be hosted at the Ruprecht-Karl University of Heidelberg, Germany.