Generation of Earth’s Early Continents From a Relatively Cool Archean Mantle

Several lines of evidence suggest that the Archean (4.0–2.5 Ga) mantle was hotter than today’s potential temperature(TP ) of 1350 ýC. However, the magnitude of such di erence is poorly constrained, with TP estimation spanningfrom 1500 ýC to 1600 ýC during the Meso-Archean (3.2-2.8 Ga). Such di erences have major implications for theinterpreted mechanisms of continental crust generation on the early Earth, as their e cacy is highly sensitive to theTP . Here, we integrate petrological modeling with thermo-mechanical simulations to understand the dynamics ofcrust formation during Archean. Our results predict that partial melting of primitive oceanic crust produces felsicmelts with geochemical signatures matching those observed in Archean cratons from a mantle TP as low as 1450ýC thanks to lithospheric-scale Rayleigh–Taylor-type instabilities. These simulations also infer the occurrence ofintraplate deformation events that allow an e cient transport of crustal material into the mantle, hydrating it.