Detall
Numerical simulation of subcontinental lithosphere dynamics: stability, evolution and formation. SEMINARIS DE LA FACULTAT DE GEOLOGIA I L'INSTITUT DE CIÈNCIES DE LA TERRA 'JAUME ALMERA'
Hongliang Wang (Durham University, Regne Unit)
The strength and buoyancy contrast between cratonic and non-cratonic lithosphere, induced by mantle depletion and dehydration, are considered to be the most important factor of long-term craton stability. Recent laboratory study about mantle rheology, however, argues the effect of water on upper mantle is rather small (Fei, et al 2013). We perform new numerical models and find long-term craton stability could be provided even with lower amounts of strengthening and/or buoyancy. Mantle plumes have been proposed to be play an important role on removal of continental root that observed such as in North China Craton and Kaapvaal craton. Our numerical model with realistic rheology and buoyancy structure shows that the mechanical erosion effects on the chemical root by the plume induced flow is very limited in the long term, unless it changes the rheology and buoyancy of the root. In the end, I would further show some preliminary models about the thickening of cratonic lithosp.
