2022 Volume 130 Issue 1 Pages 1-19
The Shiraho-Saonetabaru Cave Site is located at ca. 800 m inland from the Shiraho Coast, southeast of Ishigaki Island, Ishigaki City, Okinawa Prefecture. The silty to clayey cave sediments in this cave site contain at least 19 individuals of human bones of the Late Palaeolithic Period. Distributions of these human bones suggest that the Late Palaeolithic people may have used the cave as a gravesite. Meanwhile, the concentrations of human bones, animal bones, stones, charcoal particles, and marine molluscan shells vary depending on the stratum and location, suggesting that the placement and the sedimentary process is not simple. In this study, we statistically evaluate the distribution of human bones, animal bones, stones, charcoal particles, and marine molluscan shells based on their three-dimensional positional coordinates measured during excavation. In addition, we examined the iron and manganese oxides staining on the surface of human bones and the distribution of each identified individual part of human bone. Iron and manganese oxides staining is likely to have been formed near the surface of the cave floor. The fact that the distribution of iron and manganese stains on human bones varies depending on human bones clusters suggests that the placement, movement, and burial processes of human bones differed in each cluster. These distributions of the human bone cluster and staining states were consistent with the distribution of the identified individuals. It is suggested that examining these staining conditions in association with the distribution of human bones at cave sites will enable us to reconstruct the taphonomic process and evaluate the possibility of relocating human remains.