Remnant peat deposit provides clues to the inundated cultural landscapes of Kepa Kurl, southwestern Australia

Abstract

In early 2021 several tree stumps embedded in a remnant peat deposit were found in the intertidal zone of Wharton Beach, southwestern Australia by Esperance Tjaltjraak Rangers. Attempts were made to identify the tree using both dendrochronological and anthracological methods but were limited by the lack of reference information from tree species in the southwestern Australia. Radiocarbon dates from one stump indicates the tree lived for approximately 200 years, growing into the peaty sediments sometime before ca. 7340 cal yrs BP and died directly or indirectly as a result of marine transgression. The peat deposit is dated to 7608–7429 cal yrs BP but its exposed seaward edge was unconformably underlain by younger sand, dated by OSL to around 3550 years, which may have intruded as a result of a storm event. An OSL age of 12,600 years was obtained from the base of a laminated dune sequence behind the exposed peat deposit, and is significant given a similar age for a previously documented infant burial site in the area. Together these records provide a rare insight into the former wetland landscape and a cultural and scientific link to the drowned coastal plain. A need for more integrative research along this cultural corridor is clear but this preliminary study has demonstrated the value of combining Cultural Knowledge Systems and Western Science, for Tjaltjraak Healthy Country Program and analogous Aboriginal ‘caring for country’ programmes throughout Australia.