The longevity of hillslope soil in SE and NW Australia

Auteur(s) et Affiliation(s)

FIFIELD, L.K.

Dep. of Nuclear Physics, research School of Physics and Engineering, Australian National Univ., Canberra, Australie

WASSON, R.J.

Charles Darwin Univ., Northern Territory, Darwin, Australie

PILLANS, B.

Research School of Earth Sciences, Australian National Univ., Canberra, Australie

STONE, J.O.H.

Quaternary Research Center and Dep. of Geological Sciences, Univ. of Washington, Seattle, Etats-Unis

Description :
The cosmogenic nuclide 10Be that is produced in the atmosphere and falls out in rainfall (‘garden-variety’ 10Be) is used at a site in SE Australia and one in NW Australia to estimate soil formation rates and natural erosion rates. These soil formation rates are then compared with estimates of modern erosion rates based on surveys of sedimentation in farm dams or 137Cs in hillslope soils. In both cases, modern erosion rates are markedly higher than either soil formation rates or natural erosion rates measured here. At the NW Australian site, the 10Be data are complemented by measurements of in situ 36Cl in nearby limestone cuesta surfaces. These show that the hard-rock surfaces are eroding more slowly than the soils, and that relief is therefore increasing in this landscape. Therefore, the ‘garden-variety’ 10Be can be a very useful tracer, but only if its transport both within the solum and saprolite is taken in account.

Type de document :
Article de périodique

Source :
Catena (Giessen), issn : 0341-8162, 2010, vol. 81, n°. 1, p. 32-42, nombre de pages : 11, Références bibliographiques : 48 ref.

Date :
2010

Editeur :
Pays édition : Allemagne, Cremlingen-Destedt, Catena

Langue :
Anglais