Metamorphic conditions of the metabasites in the Roc de Frausa massif (Eastern Pyrenees)

An approach to the metamorphic conditions based in mineral paragenesis of metabasites from different areas of Roc de Frausa Massif has been made. Regional peak metamorphism is showed by the metamorphic paragenesis in granulites conditions from Les Hies sector (Clpx + PI + Amph + llm); P-T conditions during Hercynian metamorphism are 750 ± 20 °C and 4.5 ± 0.5 Kb (18 -20 km) witch a geotermal gradient account betwen 39 - 42°C / km. A subsecuent retrograde metamorphism appear in low grade conditions 3.5 ± 0.5 Kb and 480 * 20C (14-16 km ) wich a geotermal gradient betwen 31 -34 °C / km. This retrograde metamorphismis showed in the Montalba sector by Gr - Amph - PI- llm paragenesis; their metamorphic conditions are 510 i 20 °C and 4 Kb ( 16 Km ) witch a geotermal gradient betwen 30 ± 2°C / k