Physical explanation of the formation and evolution of inversion zones andmarginal troughs

Inversion zones are elongate structures, some tens of kilometers wide and u p to hundreds of kilometers long, that have deformed in response to compres sion and produced topography. Inversion zones in the Alpine foreland are ma inly associated with Mesozoic grabens and troughs, and although very import ant in the geologic picture, the conditions of their formation and evolutio n and their regional geologic significance are not entirely understood. The internal structure of inversion zones is variable and depends on details i n the pre-inversion setting, the inversion-inducing stress held, and the se dimentary fill. However, on a larger scale, most inversion zones share cert ain principal observational features, which sample the physical structure a nd the theologic properties of the lithosphere and thereby provide an oppor tunity to test hypotheses of lithospheric rheology and dynamics. The quanti tative model presented in this paper explains how inversion zones and the a ssociated marginal troughs are related to Lithospheric zones of differentia l shortening and regional isostatic compensation of the induced topography.