A quantitative approach to understanding dated dune stratigraphies

Auteur(s) et Affiliation(s)



Description :
In drylands, information on past forcing conditions is progressively modified, degraded and removed from the available stratigraphic record by a series of filters involving changes in the primary forcing factors themselves, geomorphological processes and the sampling/dating procedures. Here, the AA. describe a quantitative model that includes these effects, and use the model to examine the nature of preserved dryland sedimentary records and their relationships to primary forcing conditions : thicker preserved sedimentary records reflect periods of more intense aeolian activity; localized switching between erosion and deposition results in discontinuous and highly variable stratigraphic sequences; a preservation bias towards younger deposits is observed, potentially leading to a continuum of accumulation that decays approximately in proportion to age. Time periods not represented by deposition can in some cases be interpreted as periods of higher precipitation and/or lower wind energy. A new data treatment method (termed Accumulation Rate Variability) provides an efficient proxy for accumulation rates, and therefore the intensity of aeolian activity, with significant improvements over existing date–frequency methods.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2014, vol. 39, n°. 5, p. 614-631, nombre de pages : 18, Références bibliographiques : 1 p.

Date :
2014

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