Changed by subduction, this rock was once sea-floor basalt. It was metamorphosed at high pressures and low temperatures, transforming into a blueschist.
The minerals in this metamorphic rock record the following temperature (T) and pressure (P) conditions within the Earth:
T= 350 - 400°C, P= 7,000 - 10,000 atm.
The minerals in this metamorphic rock record the following temperature (T) and pressure (P) conditions within the Earth:
T = 400-450°C, P = 7,000-10,000 atm.
