A terminal Pleistocene open site on the Hawkesbury River,: Pitt Town, New South Wales

Abstract

Salvage excavations of 25 m 2 on a levee adjacent to the Hawkesbury River near Pitt Town, New South Wales, identified a 1.5 m deep sand body containing three discrete artefact assemblages, collectively designated as site PT12. Six optically stimulated luminescence (OSL) ages provide a chronology for the sand body, which began forming >50 ka. Peak artefact numbers for the two lowest assemblages were centred on ca 15 ka and ca 11 ka, and had Capertian (pre-Bondaian) characteristics. These included amorphous pebble tools and manuports of locally-derived river cobbles, which were probably exposed through entrenchment of the river during lower sea-levels. Comparisons with the KII rockshelter, approximately 20 km upstream, show a similar assemblage dated to ca 13 ka. The uppermost assemblage at PT12 was dominated by backed artefacts and composed primarily of silcrete. Reliable OSL ages indicate this assemblage may have been deposited in the early Holocene, with a proliferation of backed blades occurring ca 5 ka, although typological comparisons with other local assemblages suggest an age of <4.5 ka is more likely. Along with other studies, the site indicates the systematic exploitation of resources along the Hawkesbury River from ca 15 ka before an apparent abandonment of the region in the early/mid-Holocene. Late Holocene artefact numbers suggest a subdued reoccupation of the area following this hiatus.