Overview
- Lead authors Todd Surovell and Claudio Latorre published the reassessment in Science on March 19.
- The team sampled sediments at nine spots along Chinchihuapi Creek and applied radiocarbon and optically stimulated luminescence dating within a stratigraphic framework.
- The study dates a volcanic ash layer to roughly 11,000 years and places cultural materials above it, implying a younger occupation.
- The authors argue wood dated to about 14,500 years was redeposited by creek processes and is not in-situ evidence of early humans at the site.
- Original excavator Tom Dillehay and other experts, including Michael Waters, dispute the conclusions, challenging the sampling strategy, the ash layer’s extent, and the handling of previously dated artifacts, while urging independent reanalysis of the site.