Landscape dynamics revealed by luminescence signals of feldspars from fluvial terraces - GéoHydrosystèmes COntinentaux - EA6293 Accéder directement au contenu
Article Dans Une Revue Scientific Reports Année : 2019

Landscape dynamics revealed by luminescence signals of feldspars from fluvial terraces

Résumé

Luminescence signals of quartz and feldspar minerals are widely used to determine the burial age of Quaternary sediments. Although luminescence signals bleach rapidly with sunlight exposure, incomplete bleaching may affect luminescence ages, in particular in fluvial settings where an unbleached remnant signal is commonly encountered in modern alluvium. Here, we use feldspar single-grain post-infrared IR stimulation (pIRIR) dating to show that recent (<11 ka) fluvial terraces of the Rangitikei River (New Zealand) were formed in a context of non-linear incision rate. We relate this pattern to the rapid reinstatement of steady-state incision following the formation of a major, climate-driven, aggradation terrace, causing a phase of accelerated incision. In addition, we show systematic variations in the proportion of unbleached grains in the fluvial sediments over time, mirroring incision rate at the time of deposition. Deposits formed during rapid incision contain fewer bleached grains, which we attribute to large input of unbleached material and limited bleaching opportunities during fluvial transport. This finding demonstrates that the luminescence signals recorded in fluvial terraces not only yield age information, but also inform us on past fluvial transport and ultimately, landscape dynamics.

Domaines

Géomorphologie
Fichier principal
Vignette du fichier
bonnet-SciRep-2019.pdf (1.8 Mo) Télécharger le fichier
Origine : Publication financée par une institution
Loading...

Dates et versions

insu-02157686 , version 1 (17-06-2019)

Identifiants

Citer

Stéphane Bonnet, Tony Reimann, Jakob Wallinga, Dimitri Lague, Philippe Davy, et al.. Landscape dynamics revealed by luminescence signals of feldspars from fluvial terraces. Scientific Reports, 2019, 9 (1), pp.8569. ⟨10.1038/s41598-019-44533-4⟩. ⟨insu-02157686⟩
367 Consultations
102 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More