Nature, Published online: 11 November 2026; doi:10.1038/s41586-026-11280-2

Analysis of a 3.95-Gyr-old trondhjemitic gneiss from eastern Hebei, China, reveals a composition suggesting a low-temperature altered basaltic source, that originated from a mantle depleted in the Hadean, was most likely transported to mantle depths through a transient subduction event and partially melted to produce the trondhjemite.