RECREATE · Reducing empiricism in luminescence models to measure rates of Earth surface processes

Reducing empiricism in luminescence models to measure rates of Earth surface processes

The interdisciplinary project “Reducing Empiricism in luminesCence models to measuRE rATes of Earth surface processes” (RECREATE) combined solid state physics and geosciences to enhance our understanding of the physical processes governing luminescence thermochronometry. Luminescence thermochronometry is used to constrain rock cooling and exhumation rates. Feldspar luminescence signals function as low-temperature thermochronometers. With a closure temperature <100 °C, they can constrain rock cooling histories over timescales from 0.1-0.4 Myr, dependent on cooling, dose and fading rate. Luminescence thermochronometry relies upon numerical models that describe the build-up of luminescence due to ionising radiation and its decay due to thermal and athermal depletion. Several numerical models with different underlying physics exist, and it is challenging to evaluate their performance against geological data. Although the model parameters describe physical constants related to defects or the crystal lattice, we observe that the parameter values are strongly dependent on the model chosen to estimate them, potentially leading to an erroneous understanding of past landscape evolution. Whilst a combination of different luminescence signals, models and model parameters may adequately describe the laboratory kinetic data, each combination can yield divergent results over geological time scales. Consequently, the purpose of this project was to eliminate this subjectivity, and thus to reduce the uncertainty and empiricism in the feldspar luminescence thermochronometry to derive rates of Earth surface processes.

Data: CORDIS, © European Union