Weathering-limited hillslope evolution in carbonate landscapes

Abstract : Understanding topographic evolution requires integrating elementary processes acting at the hillslope scale into the long-wavelength framework of landscape dynamics. Recent progress has been made in the quantification of denudation of eroding landscapes and its links with topography. Despite these advances, data is still sparse in car-bonate terrain, which covers a significant part of the Earth's surface. In this study, we measured both long-term denudation rates using in situ-produced 36 Cl concentrations in bedrock and regolith clasts and surface convexity at 12 sites along ridges of the Luberon carbonate range in Provence, Southeastern France. Starting from ∼30 mm/ka for the lowering of the summit plateau surface, denudation linearly increases with increasing hilltop convexity up to ∼70 mm/ka, as predicted by diffusive mass transport theory. Beyond this point denuda-tion rates appear to be insensitive to the increase in hilltop convexity. We interpret this constant denudation as indicating a transition from a regime where hillslope evolution is primarily controlled by diffusive downslope regolith transport, toward a situation in which denuda-tion is limited by the rate at which physical and chemical weathering processes can produce clasts and lower the hilltop. Such an abrupt transition into a weathering-limited dynamics may prevent hillslope 1 denudation from balancing the rate of base level fall imposed by the river network and could potentially explain the development of high local relief in many Mediterranean carbonate landscapes.
Type de document :
Article dans une revue
Earth and Planetary Science Letters, Elsevier, 2016, 446, pp.10 - 20. 〈10.1016/j.epsl.2016.04.017〉
Liste complète des métadonnées

Littérature citée [48 références]  Voir  Masquer  Télécharger

https://hal-amu.archives-ouvertes.fr/hal-01790041
Contributeur : Vincent Godard <>
Soumis le : vendredi 11 mai 2018 - 16:12:46
Dernière modification le : mercredi 19 septembre 2018 - 01:34:57
Document(s) archivé(s) le : mardi 25 septembre 2018 - 16:16:52

Fichier

article_formated_final.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

Citation

Vincent Godard, Vincent Ollivier, Olivier Bellier, Cécile Miramont, Esmaeil Shabanian, et al.. Weathering-limited hillslope evolution in carbonate landscapes. Earth and Planetary Science Letters, Elsevier, 2016, 446, pp.10 - 20. 〈10.1016/j.epsl.2016.04.017〉. 〈hal-01790041〉

Partager

Métriques

Consultations de la notice

100

Téléchargements de fichiers

29