Geodynamic and geomorphic evolution of the Permo-Triassic appalachian mountains

The basic topography of a steady state, accretionary mountain range is a function of the critical taper of the accretionary wedge, which in turn depends upon the convergence flux at the toe, internal rock strength, basal slope, and erosion rate off the top. It is possible to obtain a first-order estimate of this topography for ancient mountain ranges by constraining these parameters using sediment thicknesses in adjacent, flexurally-produced sedimentary basins. Here we apply the technique to the Early Permian central Appalachians, by first obtaining the steady-state mass of the wedge from a flexural loading model of Beaumont and others. Then, the equations of a critically tapered wedge are solved using a Monte Carlo method of parameter selection. Those solutions that match the observed mass of the wedge suggest that the Early Permian Appalachians possessed a central Andean topography with average relief of from 3.5-4.5 km and width of 250-300 km.