Supports· moderateYDIH-E002
North American sedimentary platinum enrichments at eleven sites
- what the source states
- Fire-assay and ICP-MS analyses at 11 sites in six U.S. states reported Pt abundances in the boundary layer averaging 6.0 ppb (range 0.3–65.6) against above/below background averaging 0.3 ppb — roughly 12× — with all sites showing peaks near strata dated to the Younger Dryas onset.
- what we infer
- Real measurements that extend the Greenland observation onto the continent — made by a proponent-affiliated team, sampled around pre-identified horizons, and now formally decoupled (by the authors' own 2026 correction) from the extraterrestrial-source conclusion the paper originally drew.
- limitations
- Single research group with CRG-affiliated authors; no independent-laboratory replication of these specific measurements.
- Sampling targeted the putative boundary; without continuous background sampling the peaks' extraordinariness is unquantified.