Researchers obtained 71 radiocarbon dates throughout the Page-Ladson sediment sequence, and the artifact deposit was covered by four meters of sediment and a shell layer dated to 14,400 years ago.
Notes on verification
Confirmed directly by the peer-reviewed Science Advances paper (Halligan et al. 2016) and corroborated by multiple independent secondary sources including university press releases and PubMed. [tier=gold indep_score=1.0 clusters=3 claim_tier=notable]
Sources
- Discovery Points to Earlier Arrival of First Americans (seed:history_and_archaeology)
- https://www.science.org/doi/10.1126/sciadv.1600375 (corroboration)
- https://pubmed.ncbi.nlm.nih.gov/27386553/ (corroboration)
- https://news.umich.edu/new-evidence-that-humans-settled-in-southeastern-us-far-earlier-than-previously-believed/ (corroboration)