MODELING OF DYNAMIC UPLIFT, DENUDATION RATES, AND THERMOMECHANICAL CONSEQUENCES OF EROSION IN ISOSTATICALLY COMPENSATED MOUNTAIN BELTS

In this paper we present a simple one-dimensional model to examine the interplay between dynamic uplift and denudation in response to simult aneous surface erosion and lithospheric deformation under the assumpti on that the surface elevation of a mountain belt is isostatically comp ensated and the lithosphere undergoes vertically homogeneous deformati on. We also discuss the dynamics of isostatically compensated mountain belts in relation to surface erosion, based on a 'Brace-Goetze' litho spheric model consisting of a quartz-dominated crust and an olivine-do minated upper mantle. The mechanical strength of such a lithosphere is governed by a combination of brittle failure and power law or Dorn la w creep. Assuming a simple linear dependence of erosion rate on elevat ion, we find that contrary to previous suggestions, the effect of high denudation rates on the mechanical strength of the lithosphere does n ot involve significant weakening of the lithosphere.