Large-Scale Geometry of Migmatites — Implications for the Seismic Properties of Continental Crust

摘要: A quantitative analysis of migmatitic textures is used to describe the complex large-scale geometry a Variscan migmatite terrain (Argentera massif, western Alps). Small-scale textural variations in migmatites, which can be observed hand-sample and outcrop scale, closely resemble overall structural style kilometer-scale distribution texturally distinct migmatites within Argentera basement. Three-dimensional contouring properties this area suggests strong influence migmatization processes on resulting seismic image continental crust. three-dimensional model has been derived from geologically reasonable extrapolation field data shows that regional mainly results formation “textural gradients”. Such gradients destroy pre-existing fabrics, lithological boundaries layers various acoustic impedances. Apart typical occurrence granitic intrusions domain, basement gneisses believed largely responsible for transparency mid- upper crustal parts internal European Variscides.