Heavy minerals as detritus provenance indicators for the Jurassic pre-Callovian palaeokarst infill from the Czatkowice Quarry (Kraków–Wieluń Upland, Poland)

Abstract

Heavy mineral assemblages from the infill of Jurassic pre-Callovian palaeokarst in the Czatkowice Quarry, in the Krakow–Wielun Upland, are zircon dominated. They contain also garnet, tourmaline, rutile and scarce grains of kyanite, staurolite and single chromian spinel. The textural features of the heavy minerals suggest that certain types of source rocks supplied the clastic material infilling in the karst studied. Most of the heavy minerals were derived from sedimentary or metasedimentary rocks as suggested by the high degree of roundness of the grains and also by high ZTR (zircon–tourmaline–rutile) index values. Rounded minerals may derive from Carboniferous, Permian and Triassic clastic rocks occurring in the area surrounding the Czatkowice Quarry. The chemical compositions of rounded detrital garnet and tourmaline grains suggest metamorphic and igneous rocks as initial sources, perhaps located in the Bohemian Massif. However, a hypothetical landmass located south of the Krakow–Wielun Upland might have been an additional source area. The euhedral zircon and garnet grains were transported directly from crystalline rocks, which may have been Carboniferous-Permian volcanic rocks and crystalline basement elevations of Brunovistulicum exposed during Jurassic pre-Callovian sedimentation in the Czatkowice area.