Plate generation in a simple model of lithosphere–mantle flow with dynamic self-lubrication
نویسنده
چکیده
One of the more enigmatic features of the Earth’s style of mantle convection is plate tectonics itself, in particular the existence of strike-slip, or toroidal, motion. Toroidal motion is uncharacteristic of basic thermal convection, but necessarily forms through the interaction of convective flow and nonlinear rheological mechanisms. Recent studies have implied that the empirically determined power-law rheologies of mantle silicates are not sufficient to generate the requisite toroidal motion. A simple source–sink model of mantle or lithospheric flow shows that dynamic self-lubrication, which arises through the coupling of viscous heating and temperature-dependent viscosity, is highly successful at generating strike-slip motion. In particular, as the viscosity of the fluid system becomes more temperature dependent, the toroidal flow field makes an abrupt transition from a state of weak, unplate-like motion to a state with intense and extremely focused structure. In essence, the fluid dynamical model develops strike-slip faults.
منابع مشابه
Generation of plate tectonics from lithosphere–mantle flow and void–volatile self-lubrication
The formation of plate tectonics from mantle convection necessarily requires nonlinear rheological behavior. Recent studies suggest that self-lubricating rheological mechanisms are most capable of generating plate-like motion out of fluid flows. The basic paradigm of self-lubrication is nominally derived from the feedback between viscous heating and Ž temperature-dependent viscosity. Here, we p...
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