Estimating the local paleo-fluid flow velocity: New textural method and application to metasomatism. Earth and Planetary Science Letters, Elsevier, 2009, 280 (1-4) Finally, a two-stage tectono-hydrodynamic model is proposed for the metsomatism. The first stage is genetically linked to the sill injection, and the second is characterized by a wider event with hydrothermal flow passing along the leucogranite sills.