AN IMPROVED MODEL OF SUBSIDENCE OF HEAVY BODIES IN THE ASTHENOSPHEREB. M. Naimark and A. T. Ismail-zadeh
We assume the mechanism of sedimentary basin evolution based on subsidence of heavy bodies (eclogite lenses) in the asthenosphere formed through filtration of magmatic melt into asthenosphere bulges and its subsequent gabbro-eclogite phase transition. Subsidence of such heavy bodies induces depressions on the earth's surface. We improve the numerical model of this process allowing for density discontinuities in bicubic spline approximation and introducing time-dependent jumps of density. The numerical method is based on bicubic spline approximation of the stream function and on the Runge-Kutta method for the solution of differential equations for the density and viscosity. Two simple illustrative models and a simplified model of the Illinois basin are computed. The subsidence curve derived for the model is in good agreement with that obtained for the Illinois basin.