A Nonlinear Phenomenon of Chemical Dynamics in Geology: The Case of Skarns
In our poster, we wish to draw the attention of the chemists to certain transformations met in geology. They are observed in the rocks called skarns: these are the result of the transformation of various rocks, particularly limestones, by the operation of aqueous fluids in strong disequilibrium with them. These waters percolate through the mass of the rock that they progressively transform. They may originate from a granitic mass under crystallization and/or they may be waters moved by convection at the vicinity of a hot granitic intrusion. These phenomena occur at depths of 4–5 km or more, at temperatures of the magnitude 400–600°C and pressures of the magnitude 1–2 kb. The transformations may affect several m3 of rocks. Such rocks may be observed today (their formation having ended several millions years ago) thanks to orogenic movements and erosion.