Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)
Ti-rich pargasite from spessartite at Slabce village, Křivoklát-region
AbstractAbundant dykes penetrate the NW-sector of Proterozoic and Early Paleozoic volcanosedimentary complexes in the Berounka-river Basin west of Prague. Among aplites, granite-, syenite-, granodiorite- and diorite-porphyries, minettes, kersantites, vogesites, camptonites, and diabases especially spessartites play here an important role. While their geological setting, general mineralogy and chemistry is comparatively well known, detailed studies of their individual minerals have been so far missing. New EMPA study of amphiboles and pyroxenes from a representative 1 km long spessartite dyke on the left bank of the Berounka-river revealed a Ti-content in the hornblende close to 5 wt. % with a core maximum in euhedral prismatic crystals. Co-existing diopside is rather poor in titanium.