Back to today’s briefing

Story perspectives

Ancient Proto-Earth Material Discovered in Earth's Mantle

11/26/2025

27 4 Full Breakdown

Summary

Story summary

Researchers argue that parts of proto-Earth remain in Earth's mantle, indicating ancient material can persist deep inside the planet.
They measured potassium isotopes in ancient rocks and volcanic samples, finding a unique potassium-40 deficit that suggests origins in isolated regions formed before the Moon-forming impact.
These regions avoided significant mixing and may feed mantle plumes that bring ancient material to the surface.

1 of 1

Story summary

Researchers argue that parts of proto-Earth remain in Earth's mantle, indicating ancient material can persist deep inside the planet.
They measured potassium isotopes in ancient rocks and volcanic samples, finding a unique potassium-40 deficit that suggests origins in isolated regions formed before the Moon-forming impact.
These regions avoided significant mixing and may feed mantle plumes that bring ancient material to the surface.