Excitation of thermoconvective waves in the continental lithosphere |
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| Authors: | Boris I Birger |
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| Institution: | The Earth's Physics Institute of Russian Academy of Sciences, 10 Bolshaya Gruzinskaya, Moscow;123810, Russia. E-mail: |
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| Abstract: | For flows associated with small strains, the rheology of rocks is described by the linear integral (having a memory) law, which reduces to the Andrade law in the case of constant stress. A continental lithosphere with such a rheology is overstable. Thermoconvective waves that propagate through the lithosphere with minimal attenuation have a period of about 200 Myr and a wavelength of the order of 400 km. An initial temperature point-concentrated perturbation in the lithosphere excites amplitude-modulated thermoconvective waves (wave packets). When the initial perturbation occurs in a finite area, thermoconvective waves propagate outwards from this area, and thermoconvective oscillations (standing waves) are established inside the area. Thermoconvective waves induce oscillations of the Earth' surface, accompanied by sedimentation and erosion, and can be considered as a mechanism for the distribution of sediments on continental cratons. |
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| Keywords: | mantle convection mantle rheology sedimentary basins |
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