Low-grade metamorphism / Метаморфизм низких фаций

Metamorphism is broadly a process of solid-state change in the mineralogy, texture and chemistry of rocks in the Earth's crust. It provides a powerful record of change in the Earth's most active settings where metamorphism has proceeded in response to global tectonics. Metamorphic rocks are defined in most petrological texts as having mineralogies and textures that are a consequence of recrystallization under PT regimes different from the diagenetic realm. Metamorphism 'proper' can thus be clearly recognized where rocks have been fully recrystallized and no direct evidence of the protolith remains. It is in such rocks that the principles of equilibrium thermodynamics have allowed, over the past two decades or so, an increasingly quantitative assessment of metamorphic processes <...>