Blueschists
Blueschists are metamorphic rocks that form under high-pressure, low-temperature conditions, typically in subduction zone environments. They are named for their characteristic blue minerals, most notably the blue amphibole glaucophane, which gives the rock its distinctive color.
The mineral assemblage of blueschists commonly includes glaucophane and lawsonite, together with epidote, chlorite, and phengite.
Formation and conditions: Blueschist facies represent high-pressure, relatively cool metamorphism associated with subducting oceanic crust. P–T
Occurrence and significance: Blueschists occur in many subduction-related terranes around the world. Classic exposures include the
Relation to other metamorphic facies: Blueschist metamorphism lies within a continuum of subduction-zone metamorphism. If rocks