Several lines of evidence suggest that the Archean (4.0–2.5 Ga) mantle was hotter than today's potential temperature (T_P) of 1350 °C. However, the magnitude of such difference is poorly constrained, with T_P estimation spanning from 1500 to 1600 °C during the Meso‐Archean (3.2–2.8 Ga). Such differences have major implications for the interpreted mechanisms of continental crust generation on the early Earth, as their efficacy is highly sensitive to the T_P. Here we integrate petrological modeling with thermomechanical simulations to understand the dynamics of crust formation during Archean. Our results predict that partial melting of primitive oceanic crust produces felsic melts with geochemical signatures matching those observed in Archean cratons from a mantle T_P as low as 1450 °C thanks to lithospheric‐scale RayleighTaylor‐type instabilities. These simulations also infer the occurrence of intraplate deformation events that allow an efficient transport of crustal material into the mantle, hydrating it.