Fig. 1: εHf compared with age.
From: Contemporaneous mobile- and stagnant-lid tectonics on the Hadean Earth
a, Detrital zircons from JH2. Data from refs. 11,24,46,47. b, Detrital zircons from BGSB13. Starting in the Hadean, zircons from both regions fall on coherent trends corresponding to the reworking of Hadean protocrust with 176Lu/177Hf = 0.01–0.02. In BGSB, unradiogenic εHf values persisted until about 3.8 Ga, indicating intra-crust reworking. Vertical trends and near-chondritic εHf values (CHUR) after 3.8 Ga show input of juvenile material (grey band), consistent with the onset of subduction. The zircon εHf trajectories from the JH are similar, but with two periods of juvenile input indicating subduction at about 4.0 Ga and 3.6 Ga.
