From rift to drift: Mantle melting during continental breakup

摘要: [1] Volcanic rifted margins show a temporal evolution in igneous crustal thickness and thus provide additional insights into mantle dynamics compared to the steady state situation at mid-ocean ridges. Although details between different provinces vary, volcanic generally short-lived pulse of extreme magmatism that quickly abates ridge. The generation thick crust requires either melting hot material higher degrees than observed ridges or larger amounts would be case for plate-driven upwelling. To assess under what conditions buoyantly driven upwelling small-scale convection rifting plate boundaries is important, fluid dynamical model with non-Newtonian viscosity includes feedback from on physical properties developed. generate high magmatic production density structure also leads excessive fluctuations productivity sustained continues long after breakup. A increase due dehydration caused by effectively suppresses buoyant above depth dry solidus, thereby restricting shallow flow While this stabilizes time dependence forces values consistent ridge accretion, it does so expense eliminating breakup instability. Models assume an abrupt change prerift lithospheric suffer same deficits. However, including sublithospheric layer can predict refraction seismic data southeast Greenland margin.