Continuous vs. discontinuous melt segregation in migmatites: insights from a cellular automaton model

A cellular automaton model is presented that simulates melt extraction from migmatites. The Varying parameters are the relative amount of melt, thresholds for melt connection leading to movement and melt escape, and type of deformation (pure and/or simple shear), It is shown that when the melt percentage is about half that of the melt escape threshold, the competition between production and deformation-assisted extraction results in a discontinuous rate of melt extraction. The process can be compared to stick-slip motion during frictional experiments. At higher melt fraction, it is continuously extracted. Deformation assists significantly in segregating melt, particularly when a pure shear (compaction) component is added to simple shear.