Late quaternary alluvial history of Nowlands Creek, Hunter Valley, NSW

Abstract

SUMMARY The valley‐fill sequence of Nowlands Creek, a 5.5 km2 basin in the Central Lowlands of the Hunter Valley, is characterised by three inset river terraces whose sediments contain either Aboriginal or European artefacts. The highest and oldest terrace is characterised by a well‐developed yellow duplex soil with Aboriginal artefacts in the A horizon. Deposition of the bulk of the terrace sediments occurred before 11 400 yrs BP when Nowlands Creek was a low‐sinuosity, high‐energy, gravel‐bed stream. Texture contrast of the terrace soil is due partly to the superpositioning of Holocene sandy colluvium over Pleistocene fluviatile clay. The middle terrace is characterised by a deep minimal prairie soil containing Aboriginal artefacts. Deposition of the middle‐terrace sediments occurred mainly after 11 400 yrs BP when Nowlands Creek was a small‐capacity, mud‐bed channel with chains of ponds and well‐vegetated banks. The lowest terrace occupies a discontinuous trench incised into the middle terrace and was ...