Mineralogical characteristics of the Bochnia tuff from the Chodenice Beds (Carpathian Foredeep, S Poland)

The tuff from the Chodenice Beds, sampled in a natural outcrop in Chodenice, wassubjected to mineralogical and geochemical analyses. Main components of the rock proved to be glassshards, quartz and feldspar crystals, as well as mixed-layered Ca-Na-smectite, formed by alteration ofvolcanic glass. The distinguished heavy fraction consists of ilmenite (predominating component), zircon,secondary iron oxides and scarce crystals (or crushed fragments) of apatite, tourmaline, rutile, monazite,garnet and staurolite. SEM/EDS analyses revealed crypto-inclusions of a metallic, Ni-Fe-rich phase, presumablyof cosmic origin.