The continental crust on Earth cannot be extracted directly from the mantle, and the primary crust extracted
directly from an early magma ocean is not preserved on Earth. We review geophysical and geochemical aspects
of global crust–mantle material exchange processes and examine the processes which, on one side, form and
transform the continental crust and, on the other side, chemicallymodify themantle residue fromwhich the continental
crust has been extracted. Major mechanisms that provide crust–mantle material exchange are oceanic
and continental subduction, lithosphere delamination, and mafic magmatism. While both subduction and delamination
recycle crustal material into the mantle, mafic magmatism transports mantle material upward and
participates in growth of newoceanic and continental crusts and significant structural and chemicalmodification
of the latter. We discuss the role of basalt/gabbro–eclogite phase transition in crustal evolution and the links
between lithosphere recycling, mafic magmatism, and crustal underplating. We advocate that plate tectonics
processes, togetherwith basalt/gabbro–eclogite transition, limit crustal thickness worldwide by providing effective
mechanisms of crustal (lithosphere) recycling.
The processes of crust–mantle interaction have created very dissimilar crustal styles in Europe, as seen by its seismic
structure, crustal thickness, and average seismic velocities in the basement. Our special focus is on processes
responsible for the formation of the thin crust of central and western Europe, which was largely formed during
the Variscan (430–280 Ma) orogeny but has the present structure of an “extended” crust, similar to that of the
Basin and Range province in western USA. Major geophysical characteristics of the Variscan lithosphere are discussed
within the frame of possible sequences of crust–mantle material exchange mechanisms during and after
main orogenic events in the European Variscides.