Composite travel x of seismic waves and general velocity models of the Voronezh Shield crust and upper mantle

Abstract

Summary. Extensive explosion seismology investigations using industrial quarry blasts have been undertaken across the Voronezh Shield. Various phases of P- and S-waves, including crustal refractions (Pg and Sa, upper mantle refractions (P, and S,), intercrustal Conrad reflections (Pc and Sc), Moho reflections (PM and SM) and reflections from boundaries within the upper mantle (PM1 and SM1, PM2 and SM2) have all been recognized. Independent and compatible velocity models V, (z) and V, (z) of the lithosphere have been derived from the composite travel-time curves and have been used to determine the variation of Poisson's ratio (6) and the seismic parameter (@) with depth. These quantities significantly advance the knowledge of the layered structure and composition of the lithosphere in the Voronezh Shield region. The models for this area are compared with those for the Canadian Shield.