Undermines· strongYDIH-E004
Hall's Cave: osmium isotopes point to volcanism, not a cosmic source
- what the source states
- Highly-siderophile-element abundances and 187Os/188Os ratios in Hall's Cave (Texas) sediments spanning the Younger Dryas showed that the reported geochemical anomalies there are most consistent with distant volcanic gas emissions, not with an extraterrestrial impactor.
- what we infer
- The one time source-discriminating isotope geochemistry has been applied to a claimed YD platinum-group anomaly, it returned a terrestrial answer. This does not make every anomaly volcanic; it demonstrates that "platinum peak = impact" is not a valid inference rule — which is the diagnosticity claim's core problem.
- limitations
- One site; explicitly does not resolve the origin of the Greenland anomaly or other localities.