Clastic spring sediments: a tool for palaeoflood reconstruction?

Auteur(s) et Affiliation(s)

GALE, S.J.

School of Geography, Earth Science and Environment, Univ. of the South Pacific, Suva, Fidji

PENNY, D.A.

School of Geosciences, Univ., Sydney, Australie

Description :
Clastic spring sediments at Mount McKinlay Spring in the Gammon Ranges of northeast South Australia were dated by 14C analysis. Five samples of pollen grains taken from sediments interpreted on geomorphic grounds as post-dating European contact (AD 1843) all yielded dates of AD 1955-1958. These are likely to be the product of sedimentation in March 1956 following the greatest single day's rainfall in the instrumental record. This event, with a return period of around 100 years, may have caused the undercutting of the banks of the creek downstream of the springs, the collapse of mature River Red Gums growing adjacent to the channel and the accumulation of a jam of logs across the creek. The spring deposits appear to represent solely the product of high-magnitude, long return period floods. A series of older spring sediments at the site dating from the first millennium BC to the mid-18th century may therefore provide an opportunity to establish event magnitude and frequency, to determine return periods, and to assess the role of climatic change and human environmental impact on flood frequency.

Type de document :
Article de périodique

Source :
Zeitschrift für Geomorphologie, issn : 0372-8854, 2012, vol. 56, n°. 3, p. 387-400, nombre de pages : 14, Références bibliographiques : 2 p.

Date :
2012

Editeur :
Pays édition : Allemagne, Stuttgart, Gebruder Borntraeger

Langue :
Anglais