Plume-induced subduction and continents formation on the Archean Earth and Venus

We recently observed plume-induced subduction (PIS) in laboratory experiments where a brittle viscous-elasto-plastic lithosphere was self-consistently developing on top of a convecting mantle. Necessary conditions for PIS depend of the mechanical properties and thermal structure of the lithosphere and mantle, the buoyancy of the lithosphere and the buoyancy and size of mantle plumes. Scaling show that PIS could currently occur on Venus and observations suggest that it may indeed be the case at two coronae, Artemis and Quetzalpetlatl. Our scalings further suggest that the hot lithosphere of Venus could be an analogue for early Earth. Inspection of the geological record on Earth suggests that such a strong association between plumes and subduction in presence of water may have been instrumental in the nucleation and growth of cratons. The big peak in continental crust growth observed at 2.7 Gyr then could have originated from a global plume event due to the sudden destabilization of a denser layer at the bottom of the mantle. The simultaneous nucleation of subduction all over our planet would then greatly contribute to the establishment of continuous plate tectonics. Moreover, a PIS mechanism for continent formation could also have operated on early Venus when it still had water oceans as suggested by recent modeling of the coupled evolution of magma ocean and atmosphere.