tectonomagmatic

Tectonomagmatic refers to the intertwined relationship between tectonics and magmatism. It encompasses how plate tectonic processes influence the generation, ascent, storage, and emplacement of magma, and how magmatic activity in turn affects crustal evolution. The term is used to describe magmatic systems that are strongly controlled by the geometry and dynamics of plate boundaries, including subduction zones, mid-ocean ridges, continental rifts, and collisional belts.

In subduction zones, dehydration of the subducting slab releases volatiles into the overlying mantle wedge, promoting flux melting and producing arc magmas that range from basalt to andesite and dacite. In divergent settings, extension causes decompression melting of the mantle, yielding basaltic magmas that may evolve to more silicic compositions through crustal differentiation. In back-arc basins, rollback of the slab and mantle flow create complex melting regimes resulting in magmas from basalt to andesite. Delamination or slab break-off in collisional settings can generate intraplate-like magmatism within continental crust.

Tectonomagmatic processes explain the spatial distribution of igneous rocks, the maturation of continental crust, and the formation of ore deposits linked to magmatic differentiation. Geochemical and isotopic data, together with geophysical imaging and geochronology, are used to infer the tectonic controls on magmatism and to reconstruct subduction geometry, slab dynamics, and mantle processes.