Chapter Two - The Alps: Present Day Structure

Abstract

Publisher Summary This chapter discusses the present day structure of the Alps. The nappe pile of the Alps consists of three stacked groups of units. From the base to the top, these groups are (1) of European origin, (2) of oceanic origin, and (3) of Apulia-African origin. The Central Alps are the orographic, western continuation of the Eastern Alps from the Grisons as far west as Lake Geneva. Successive metamorphic events can be distinguished in the Alps and correspond, respectively, to ocean–continent subduction and to the formation of a collisional prism. The arc-shaped Western Alps can be followed from the Dent Blanche–Cervin massif as far south as the Maritime and Ligurian Alps on the Mediterranean coast. The paleogeographical and structural characteristics of the Western Alps differ from those of the Central Alps. Industry seismic profiles and deep-scientific seismic profiles acquired by the ECORS–CROP, NFP, and TRANSALP programs provided new insights into the shallow and deep structure of the Western, Central, and Eastern Alps especially when complemented with surface structural geology studies, seismic refraction, seismic tomography, and gravity surveys.