The metamorphic rocks in the Arquia valley were affected by prograde metamorphism, which was followed by a retrograde event after reaching maximum temperature and pressure conditions.
The relationships among the various types of rocks that form the Arquia Group are consistent with prograde metamorphism.
The prograde metamorphism was followed by a retrograde metamorphic event that affected the mineral associations formed at the metamorphic peak.
Accordingly, during the prograde metamorphism that affected the Arquia Group, the rocks with mineral assemblages formed under greenschist facies conditions reached temperatures of 433[degrees]C and pressures of 11.
1] show a prograde metamorphism event with a continuous increase in temperature and pressure.