Seminar ANNE GUYEZ, GET TOULOUSE (IRD). FELDSPAR LUMINESCENCE IN FLUVIAL SEDIMENTS: AN INDICATOR OF EROSION RATES?

FELDSPAR LUMINESCENCE IN FLUVIAL SEDIMENTS: AN INDICATOR OF EROSION RATES?
The presentation will focus on the many applications and developments of luminescence for dating fluvial terraces and studying geomorphological processes. Luminescence is a tool for dating Quaternary sediments. This method assumes that the grains measured were sufficiently exposed to light before they were buried. In fact, in a fluvial context, it has been found that the signal is rarely completely reset, and that this can pose problems for dating. I will briefly explain how I used the measurement of the luminescence signal of single-grain feldspars to date terraces where the grains had not been properly exposed to light. Then, I will show how to take advantage of the 'bad' resetting of the signal to study transport and erosion processes, in particular by showing the link with cosmogenic 10Be concentration in several New Zealand catchments.