The development of a chenier sequence on the Victoria Delta, Joseph Bonaparte Gulf, northern Australia

Abstract

A chenier sequence on the Victoria Delta, northwestern Australia, has been dated. Five chenier ridges formed rapidly over a 1000 yr period from 2020 yrs B.P. ∗ to 1210 yrs B.P. ∗. These were associated with the progradation of a fine sandy shoreline during periods of reduced mud input to the southeastern part of the Joseph Bonaparte Gulf. The cheniers formed during an arid phase in the late Holocene and the reduced mud input to the shelf is believed to have been directly related to the associated reduction in fluvial discharge. Shell from a more recent ridge, which formed within the last 1000 yrs, gave dates of between 4050 yrs B.P. ∗ and 5970 yrs B.P. ∗. The progressive winnowing of fines from the inner shelf muddy-sand zone during the periods of low mud input may have resulted in the release, during the last of these periods, of this older shell material. The possibility that the cheniers formed as the result of delta channel switching by the Ord River has not been entirely ruled out.