Preliminary report on REE content in metamorphic black schists from the Precambrian Hecla Hoek Succession, West Spitsbergen

Abstract

We studied Proterozoic metamorphic rocks of the Hecla Hoek Succession that were collected from the area between Torllbreen and Hornsund, Spitsbergen. We analyzed schists of the Vimsodden Subgroup which occurs between Werenskioldbreen and Vimsodden. Analyzed rocks include quartz-mica black schists, carbonate-quartz-mica black schists and light quartz-sericite schists. Black schists life fineblastic assemblages of quartz, muscovite, paragonite, chlorite, chloritoide, with a metaanthracite-semigraphite pigment. As accessory minerals pyrite, zircon, and tourmaline were found. The schists probably represent bituminous clay shales metamorphosed in two stages: in albite-epidote-amphibolite facies, then in greenschist facies. The REE concentration is generally higher in the black schists than in other schists of the Vimsodden Subgroup. HREE abundances in black quartz-mica schists are similar to those in light quartz-sericite schists.