metamorfmetamorphic

Metamorfmetamorphic is a term used in some geological discussions to describe a form of metamorphism in which a rock experiences more than one metamorphic transformation, effectively metamorphism that undergoes subsequent metamorphic change. The word blends metamorphosis with metamorphic, highlighting a multi-phase or recursive history rather than a single event. It is not a formal, widely adopted category in standard petrology; instead it serves as a descriptive label for rocks with complex, polyphase metamorphic histories.

In practice, rocks labeled as metamorfmetamorphic are interpreted as having undergone sequential metamorphic events. An initial metamorphic phase may alter mineralogy and texture, followed by later conditions that overprint parts or all of the rock, producing new mineral assemblages or textures. Features typical of this scenario include preserved relics of earlier metamorphism, reaction rims around minerals, and textural overprinting where younger minerals crystallize across existing grain boundaries. The concept emphasizes the importance of time-dependent changes in pressure, temperature, and fluid chemistry, which together drive multiple metamorphic pulses.

Metamorfmetamorphic interpretations rely on integrating petrographic observations with geochronology and phase diagrams to reconstruct polyphase P–T–t paths. While it is not a standard classification, the idea helps describe rocks that cannot be explained by a single metamorphic event alone and highlights the complexity of petrogenetic histories in many tectonically active regions.

See also: polyphase metamorphism, overprinting metamorphism, retrograde metamorphism, metamorphic petrology.