HP-LT Variscan metamorphism in the Cubito-Moura schists (Ossa-Morena Zone, southern Iberia)

Multi-equilibrium thermobarometry shows that low-grade metapelites (Cubito-Moura schists) from the Ossa-Morena Zone underwent HP-LT metamorphism from 340-370 degrees C at 1.0-0.9 GPa to 400-450 degrees C at 0.8-0.7 GPa. These HP-LT equilibriums were reached by parageneses including white K mica, chlorite and chloritoid, which define the earliest schistosity (SI) in these rocks. The main foliation in the schists is a crenulation cleavage (S-2), which developed during decompression from 0.8-0.7 to 0.4-0.3 GPa at increasing temperatures from 400-450 degrees C to 440-465 degrees C. Fe3+ in chlorite decreased greatly during prograde metamorphism from molar fractions of 0.4 determined in syn-S-1 chlorites down to 0.1 in syn-S-2 chlorites. These new data add to previous findings of eclogites in the Moura schists indicating that a pile of allochtonous