Evidence of transient topographic disequilibrium in a landward passive margin river system : knickpoints and paleo-landscapes of the New River basin, southern Appalachians

Auteur(s) et Affiliation(s)



Description :
The AA. use focused topographic analysis of the upper New River basin to delineate a perched, low-relief paleo-landscape that is experiencing transgressive dissection due to incision by the New River and its tributaries. Accelerated incision has decoupled hillslopes from the drainage network, generating knickpoints which represent the boundary between remnants of the paleo-landscape and actively adjusting topography downstream. In the absence of tectonic forcing, the AA. favor a climatically-forced drop in external base level as driver of the incision pattern they observe. Plio-Pleistocene glacial damming and diversion of the Teays River to form the modern Ohio River lowered regional base level for the study area, potentially forcing the paleo-landscape developed during the Teays era to adjust to the modern drainage pattern. The upper New River may therefore represent the potential for glacially-driven drainage rearrangement to drive transient topographic evolution hundreds of kilometers away from the ice margin, long after the disappearance of ice sheets.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2013, vol. 38, n°. 14, p. 1685-1699, nombre de pages : 15, Références bibliographiques : 2 p.

Date :
2013

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