Combined uranium-series and electron spin resonance dating from the Pliocene fossil sites of Aves and Milo’s palaeocaves, Bolt’s Farm, Cradle of Humankind, South Africa

A groundbreaking study utilizing combined uranium-series and electron spin resonance (US-ESR) dating techniques has established the age of fossil sites at Bolt’s Farm, Cradle of Humankind, South Africa, providing critical insights into the Pliocene timeline. The research reveals that Aves Cave dates to between ~3.15 and 2.61 million years ago (Ma), while Milo’s Cave is dated to ~3.1–2.7 Ma, aligning with biochronological estimates based on fossilized species like Stage I Metridiochoerus andrewsi. Preliminary palaeomagnetic analysis further refines the age of Milo’s Cave to between ~3.03 and 3.11 Ma, reinforcing the absence of definitive deposits older than 3.2 Ma at Bolt’s Farm. The study demonstrates that US-ESR dating can reliably date fossil sites in this region beyond 3 million years, though bulk sample analysis is recommended for optimal accuracy.

Yu, W., Herries, A. I. R., Edwards, T., Armstrong, B., & Joannes-Boyau, R. (2024). Combined uranium-series and electron spin resonance dating from the Pliocene fossil sites of Aves and Milo’s palaeocaves, Bolt’s Farm, Cradle of Humankind, South Africa. PeerJ, 12, e17478. Portico. https://doi.org/10.7717/peerj.17478