Developing an internally consistent methodology for K-feldspar MAAD TL thermochronology

Abstract

Luminescence thermochronology and thermometry can quantify recent changes in rock exhumation rates and rock surface temperatures, but these methods require accurate determination of several kinetic parameters. For K-feldspar thermoluminescence (TL) glow curves, which comprise overlapping signals of different thermal stability, it is challenging to develop measurements that capture these parameter values. Here, we present multiple-aliquot additive-dose (MAAD) TL dose–response and fading measurements from bedrock-extracted K-feldspars. These measurements are compared with Monte Carlo simulations to identify best-fit values for recombination center density (ρ) and activation energy (ΔE). This is done for each dataset separately, and then by combining dose–response and fading misfits to yield more precise ρ and ΔE values consistent with both experiments. Finally, these values are used to estimate the characteristic dose (D0) of samples. This approach produces kinetic parameter values consistent with comparable studies and results in expected fractional saturation differences between samples.