Structure and seismic response of extended continental crust: Stochastic analysis of the Strona-Ceneri and Ivrea zones, Italy

A two-dimensional stochastic seismic model of the crustal cross section exposed in the Strona-Ceneri and Ivrea zones, northern Italy, was derived from geologic maps and petrophysical data with techniques used in microfabric analysis. The model has a layered self-affine structure, which agrees with the intrinsic scale independence of geologic phenomena. Synthetic seismograms from this model replicate many pertinent features observed in deep seismic reflection data and allow insight into crustal structure: (1) reflectivity depends on the lithological populations present and their distribution within a crustal unit; (2) transparent zones within the reflective lower crust can arise from metamorphic reactions; (3) the transition from upper to lower crust may be a change in small-scale seismic fabric rather than a first-order seismic discontinuity.