The role of mobile belts for the longevity of deep cratonic lithosphere: The crumple zone model

Many Archean cratons are surrounded by Proterozoic mobile belts that have e xperienced episodes of tectonic re-activation over their lifetimes. This su ggests that mobile belt lithosphere may be associated with long lived, inhe rited weakness. It is proposed that the proximity of this weakness can incr ease the longevity of deep Archean lithosphere by buffering Archean cratons from mantle derived stresses. The physical plausibility of this idea is ex plored through numerical simulations of mantle convection that include cont inents and allow for material rheologies that model the combined brittle an d ductile behavior of the lithosphere. Within the simulations, the longevit y of deep cratonic lithosphere does increase if it is buffered by mobile be lts that can fail at relatively low stress levels.