Life beyond the lakes: An analysis and implications of a Pleistocene combustion feature on the Pike River in South Australia

The Pike River is an anabranch and palaeochannel of the Murray River located in South Australia's Riverland region, in the southwestern part of the Murray-Darling Basin. The floodplain contains abundant and varied archaeological evidence of Aboriginal life, including extensive deposits of shell midden exposed along the high cliff-line bounding the southeastern margin of the floodplain. The oldest of these deposits has been securely dated, so far, to ∼29 ka cal BP. This article presents the results of chronological, micromorphological and sedimentary analyses of a combustion feature also located on this cliff-line. Based on our analysis and interpretation of the feature's stratigraphic context, in combination with ¹⁴C and OSL dating, we argue that the feature is ∼43 ka old. Whilst the combustion feature contains no associated cultural material (e.g. stone artefacts or faunal remains) we argue that a cultural origin is, nonetheless, supported given the feature's geometry, sedimentary structures, geochemistry and magnetic response. As such, we argue that the feature provides a rare glimpse into the earliest peopling of the Murray River corridor. Further, the feature is amongst some of the earliest pieces of evidence for human pyrotechnology in the Australasian region and only one of a few examples from an open-air site that is microstratigraphically (micromorphologically) contextualised. The preservation of combustion features of this antiquity in open-context sites is extremely rare, both in this region and globally.