Overview
- The study, published in Nature Geosciences, identifies a reproducible potassium-40 anomaly using thermal-ionization mass spectrometry.
- An average deficit of about 65 parts per million in K-40 separates these samples from other terrestrial rocks and all known meteorite types.
- The signal appears in some of Earth’s oldest rocks from Isua in Greenland and Nuvvuagittuq in Canada, as well as in hotspot basalts from Hawaii and La Réunion.
- Researchers interpret the pattern as evidence that deep-mantle domains retain Proto-Earth material that was not homogenized by the Giant Impact.
- The isotopic fingerprint’s mismatch with meteorite catalogs indicates the current meteorite inventory is incomplete and that plume volcanism can deliver such primordial material to the surface.