Taramite-bearing metabasites from Rakovec (Gemeric Unit, the Western Carpathians)

The Rakovec Group, which forms a narrow belt along the northern and eastern boundaries of the Early Paleozoic of the Gemeric Unit, is represented mostly by greenschist-facies metabasites and phyllites. The metabasites usually contain albite, epidote, chlorite and actinolite. However some metamorphosed basaltic rocks near Rakovec, located in the western part of this Group, contain Al-rich Na-Ca and Ca amphiboles instead of actinolite. Compositionally, these amphiboles correspond to taramite and sodian ferropargasite and reveal textural equilibrium with albite, epidote, chlorite, Cagamet and biotite. The presence of taramite and sodian ferropargasite in metabasites are a result of relatively higher metamorphic pressures and temperatures than in other parts of the Gemeric Unit, but the influence of the whole-rock composition in favoring the appearance of greenish-blue amphiboles is also possible. Mineral zoning indicates a decrease of pressure and temperature during metamorphism. Regarding the metamorphic conditions of the Early Paleozoic sequences of the Gemeric Unit, the northern part, as represented by the Rakovec Group, underwent metamorphism in the high-pressure part of the greenschist facies.