Single grain K-feldspar MET-IRSL sediment transport determination: Bleaching patterns and rates

Abstract

This paper describes ways that Infra-Red Stimulated Luminescence (IRSL) signals from K-feldspar grains can be used to determine patterns and rates of sediment transport. In particular, it focusses on the potential provided by single grains to reveal their individual exposure and burial histories by the application of multiple elevated temperature (MET) IRSL measurements. We examine similarities and differences in bleaching behaviour with different light sources and introduce the concept of an equilibrium bleach. We present data on the variability of bleaching parameters for grains from single sediment samples, and discuss different analysis approaches to best determine individual grain histories. We describe a single grain “bleach recovery” experiment, and the application of a combined growth-bleach protocol designed to allow optimal data collection of both aspects of grain behaviour. We discuss the development of a burial-bleach model using numerical simulations based on direct observations of sample characteristics.