Isostatic rebound due to tectonic denudation: A viscous flow model of a layered lithosphere

摘要: A four-layer model of the upper 150 km Earth is used to calculate viscous response continental crust and underlying mantle tectonic denudation. The comprises a strong crustal layer, weak lower very lithosphere asthenosphere which in accord with experimental constraints on strength-depth profiles for lithosphere. strength each layer represented by its effective viscosity. Flow driven buoyancy forces, arise from unloading an allochthon along detachment fault series instantaneous displacements (earthquakes or rapid creep events). Numerical solutions, obtained using finite element technique, predict footwall uplift, Moho deflection, surface topography that are consistent observations Basin Range province western United States. calculated curvature uplift also similar observed sensitive geometry fault. Such bending need not be elastically controlled; hence curvatures domes do clearly place limits elastic thickness extending crust. upward deflection viscosity structure enable us bound range various viscosities. By matching province, indicate no low magnitude (≤3–5 km), we estimate crustal, lithospheric viscosities ranges 1021–1023 Pa s, 1019–1021 respectively.