Researchers detected carbon spherules in soil layers from before, during, and after the Younger Dryas, not only at the event's onset.
Notes on verification
Confirmed by peer-reviewed GRL paper (Scott et al. 2010), corroborated by AGU press release, SpaceNews, WashU news, and reinforced by Pinter et al. 2011 review. Multiple independent sources agree carbon spherules span a wide range of ages, undermining the Younger Dryas impact hypothesis. [tier=gold indep_score=0.988 clusters=4 claim_tier=notable]
Sources
- Fungi, Feces Show Comet Didn't Kill Ice Age Mammals? (seed:history_and_archaeology)
- https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010GL043345 (corroboration)
- https://news.agu.org/press-release/fossil-evidence-casts-doubt-on-younger-dryas-impact-theory/ (corroboration)
- https://www.sciencedirect.com/science/article/abs/pii/S0012825211000262 (corroboration)
- https://source.washu.edu/2010/09/impact-hypothesis-loses-its-sparkle/ (corroboration)