Fig. 6

Samples of some typical metabasalts of the Bôrka Nappe (localities Hačava, Brdárka, Kobeliarovo, Honce—Figs. 1 and 2, Table 1): a HP/LT metamorphosed basalt with relic ophitic texture composed of Na-amphibole, epidote, chlorite and leucoxenized ilmenite. Deep blue coloured glaucophane originated at the expense of older Ti–rich high-temperature Ca-amphibole. Relic fan-forming texture in former plagioclase laths indicate their transformation into prehnite preceding replacement by epidote, sample VHA-3; b basalt with original ophitic texture transformed into blueschist composed of glaucophane, albite, garnet, chlorite, clinozoisite and leucoxenized ilmenite, sample VHA-7; c basalt with original hyaloporphyric texture metamorphosed to blueschist composed of violet glaucophane, yellow epidote and fine-grained Fe–Ti oxide pigment, sample VHA-57; d basalt with ophitic texture experiencing metamorphic transformation and deformation in the prehnite–pumpellyite facies before alteration in blueschist facies conditions. Magmatic clinopyroxene (beige grains) partly replaced by metamorphic Na–Ca pyroxene is still preserved. Glaucophane, white mica, chlorite and leucoxenized ilmenite are also present, sample VVS-16; e basalt with ophitic texture previously metamorphosed to blueschist and then retrogressed in the greenschist facies conditions. Na-actinolite with sporadic relic of Na–Ca amphibole, albite, epidote, chlorite and leucoxenized ilmenite are main constituents of the rock together with magnetite octaedres. Glaucophane is present only as rare inclusions enclosed in epidote, sample VVS-41; f basalt with well-preserved relic ophitic texture transformed into blueschist. Na–Ca pyroxene replacing original magmatic clinopyroxene is mostly decomposed to brown pigment, pale-violet glaucophane and green chlorite. Some epidote and albite is also present. Shapes of some chlorite pseudomorphs indicate that also olivine crystals could have been present originally, sample VVS-173. Blueschist-facies radiolarites from the locality SW of Honce village, sample HNC: g metaradiolarite with dispersed Fe–Mn oxide ore pigment; h oval-shaped phantoms of radiolarians in the metaradiolarite; i spessartine garnets in the metaradiolarite; i–l BSE images of the HP/LT metaradiolarite with typical minerals: Aeg aegirine (for chemical analyses see Online resource 3), Sps spessartine garnets (for chemical analyses see Online resource 4), Qz quartz, Chl chlorite, Cal calcite, Mrbk magnesio-riebeckite, Tr tremolite (for chemical analyses see Online resource 2)