SIMON HANMER; Shear zone reactivation at granulite facies: the importance of plutons in the localization of viscous flow. Journal of the Geological Society ; 154 (1): 111–116. doi: https://doi.org/10.1144/gsjgs.154.1.0111
Localization of flow in natural quartzo-feldspathic shear zones at granulite-facies temperatures does not occur purely by dislocation creep and dynamic recrystallization. From a review of some natural shear zones, initial faulting focused along a pre-existing shear zone, and/or the boundary of a volume of relatively strong crust or lithosphere, guides emplacement of hot mantle-derived melts into the base of the crust, leading to extensive melting. When crystallized, the sub-solidus plutons represent a focused zone of thermally softened material, capable of deforming readily and developing the full range of crystal-plastic microstructures and fabrics associated with mylonites, contrasting with the intrusion-free wall rocks.