Supports· strongYDIH-E024
Hiawatha dated: 58 million years — excluded as a YDIH candidate
- what the source states
- 40Ar/39Ar dating of impact-heated sand and U-Pb dating of zircon in impact-melt pebbles, sampled from glaciofluvial sediment draining the crater, converged on an impact age of 57.99 ± 0.54 million years (Late Paleocene).
- what we infer
- Clean, dual-method, direct dating that removes the only proposed crater from the case — supporting the no-crater claim and, in the process, demonstrating what decisive evidence in this field actually looks like. Retractions cut both ways and so do datings: proponents dropped Hiawatha; the hypothesis's airburst wing never needed it.
- limitations
- Dates the one candidate structure; cannot exclude undiscovered structures, though none with credible ~12.8-ka dating has been proposed.