What to make of the ‘Murchison Cement’?A re-examination of a megafaunal fossil site in the Mid West, Western Australia

Abstract The ‘Murchison Cement’ is a term that has been informally used since the 1960s to describe numerous stratigraphic units in the middle catchment of the Murchison and Greenough Rivers, in Mid West Western Australia. The significance of these deposits relates to their embedded artefact and megafaunal assemblages, uncovered by investigations from the Franco-Australian Quaternary Project (FAQP) during the 1970s. Researchers still debate the contemporaneity of the archaeological and megafaunal material within these deposits because of the complex nature of the depositional environment. This paper questions the practicality of the term Murchison Cement and reports on a new megafaunal fossil and possible artefact find at Ballinu (Ballinyoo) Spring. Preliminary sedimentological and micromorphological analyses show similarities in the sediment directly associated with the fossil and some of the artefacts archived from the FAQP. Initial luminescence analyses of silicified sediments associated with the fossil indicate a depositional age of ~56 kya, with evidence of reworking at approximately 14 kya. Whilst late Pleistocene human occupation in the region is indicated, the contemporaneity with megafaunal fossils remains uncertain.