Butte detachment : how pre-rift geological structure and drainage integration drive escarpment evolution at rifted continental margins

Auteur(s) et Affiliation(s)

GUNNELL, Y.

Dep. of Geography, Univ. Paris Diderot, CNRS UMR 8591, Paris, France

HARBOR, D.J.

Dep. of Geology, Washington and Lee Univ., Lexington, Etats-Unis

Description :
Space-for-time substitution along 3 passive margin escarpments (Blue Ridge, Western Ghats, Eastern Ghats) reveals the significance of escarpment jumps and the detachment of topographic outliers, here generically termed ‘buttes’, as key processes of escarpment evolution. The examples show that these continental escarpments are strongly patterned after pre-rift structural and lithological heterogeneities. As seaward sloping drainages cut into the rift margin, they extend their drainage heads in a non-uniform and unsteady fashion. As a result escarpments can form, be destroyed, reform, and leave topographic vestiges (buttes) of the retreating escarpment. Given the pre-rift geological heterogeneities, there are no a priori reasons why escarpment landscape change should be uniform, steady or self-similar.

Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2010, vol. 35, n°. 12, p. 1373-1385, nombre de pages : 13, Références bibliographiques : 52 ref.

Date :
2010

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley

Langue :
Anglais