ESR and luminescence thermochronometry of the Rhône valley, Switzerland
Détails
ID Serval
serval:BIB_3DDA48E7BC0C
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
ESR and luminescence thermochronometry of the Rhône valley, Switzerland
Périodique
Quaternary Geochronology
ISSN
1871-1014
Statut éditorial
Publié
Date de publication
02/2024
Peer-reviewed
Oui
Volume
80
Pages
101496
Langue
anglais
Résumé
The impact of Quaternary glaciations on rates of erosion remains disputed. This is mainly due to a lack of geochronological data that cover the timespan of 103−106 years. To fill this temporal gap, we develop electron spin resonance (ESR) thermochronometry using both the Al- and Ti-centres in quartz. The combination of ESR thermochronometry with numerical modelling allows rock cooling histories to be determined, enabling changes in erosion rates to be related to glacial advance. In this study, we conducted a series of laboratory experiments using samples from the upper Rhône valley (Switzerland) that is thought to have substantially deepened around 1 Ma ago. Ten quartz samples, from a transect collected near Sion, were used to (i) optimize the measurement protocol (i.e., preheat conditions), (ii) constrain ESR signal growth and thermal stability of the Al- and Ti-centres to estimate trap kinetic parameters; and (iii) invert the ESR data to constrain rock cooling histories. A preheat plateau experiment showed that 170 °C is the appropriate preheat temperature whilst sensitivity changes are not significant. For most samples the Ti-centre has higher thermal stability than the Al-centre, although the thermal stability of the different samples investigated is highly variable. Preliminary inversion results yield consistent cooling histories of around 30−60 °C/Myr during the Late Quaternary period, except for two valley bottom samples that suggest more rapid rock cooling.
Mots-clé
ESR thermochronometry, Western European Alps, Thermal stability, Rock cooling
Web of science
Financement(s)
Conseil Européen de la Recherche (ERC) / 851614
Création de la notice
11/05/2024 12:27
Dernière modification de la notice
12/07/2024 6:03