Acta Musei Moraviae

Chlorites as metamorphic indicators of carbonate and pelitic rocks of the Bôrka nappe at the locality Slavoška (Slovak Republic)

Based on chemical composition of chlorites in marble and in phyllite from the locality Slavoška within the Bôrka Nappe, the tem pe rature conditions of regional metamorphism were established. The identified mineral assemblage of marble consists of calcite, muscovite, Fe-chlorites, albite and fluorapatite. The mineral assemblage of phyllite con sists of quartz, muscovite, Mg-chlorites, albite and fluorapatite. Fe-chlorites (chamosite) in marble reflect metamorphic temperature in the range T1 = 344–392 °C; T2 = 333–381 ± 15 °C and Mg-chlorites (clinochlore) in phyllite formed at T1 = 318–349 °C; T2 = 311–343 ± 10 °C. Mg-Fe chlorites formed by recrystal lization of the original volcanic-sedimentary protolith, while the probable source for the formation of chlo rites was admixture of basic pyroclastic material. Marbles and phyllites were metamorphosed under greenschist facies conditions during the Alpine metamorphic event within the lithostratigraphic sequence of the Dúbrava Formation of the Bôrka Nappe in the Western Carpathians.