The sedimentology, stratigraphy and paleoenvironmental significance of a late Pleistocene alluvial fill: Central coastal areas of Western Australia

Abstract

A Late Pleistocene alluvial fill — termed the Red Alluvium — occurs in a number of drainage basins in the Geraldton region of the central coastal areas of Western Australia. Measured sections were established and analysed for lithofacies characteristics. 14C dates and the stratigraphic position of the alluvial fill provide an age bracket for the unit of > 40000 yrs.B.P. and < 120000 yrs.B.P. The details of the various lithofacies indicate a paleoenvironmental setting conducive to the development of a braided stream regime, with predominantly bed load channels and a high rate of sediment supply. Channel switching and overbank deposition were an integral part of the channel regime. Soil forming intervals were long enough to produce argillic horizons and carbonate segregations by pedogenetic processes.