Pervasive melt migration in continental crust: a micro-scale process with large-scale implications
Melt migration is the key process transferring mass, heat and volatiles from the Earth’s depth towards the surface, and therefore shaping the chemical and thermal structure of the lithosphere. Common understanding of crustal melt migration is biased towards mechanisms that can be easily identified as they preserve macroscopic segregations of melt in outcrops, such as in dykes or leucosome-bearing migmatites. In contrast, recent observations show that micro-scale pervasive flow of melt along grain boundaries can affect significant portions of hot continental crust. The project aims to define criteria for clear identification of this cryptic melt flow and determine conditions necessary for its development and persistence. We will evaluate the effects of this flow on the chemical composition, rheology and deformation of the rock and, on a larger scale, on dynamics of the hot continental crust.