Isostatic compensation and continental lithospheric thickness

Abstract

Lateral density inhomogeneities are a general feature of the continental crust and upper mantle. This suggests the generalization of the interpretation of isostatic response functions by introducing internal loads into the conventional model of an elastic plate flexed under a topographic load. With this modification, analyses of continental response functions favour lithospheric thicknesses larger than the average thickness of the crust. These values also conform with independent estimates of the long-term thickness of the continental lithosphere and are therefore more satisfactory than recent estimates of only a few kilometres based on a pure flexure model.