Madzin, J. & Plašienka, D., 2025: Heavy mineral analysis of the Upper Cretaceous to Lower Eocene synorogenic formations of the Pieniny Klippen Belt (Šariš Unit, eastern Slovakia): new data from the Jar-2 borehole (Jarmuta-Proč Fm.) and outcrops (Malinowa Fm.) [Analýza ťažkých minerálov vrchnokriedových až spodnoeocénnych synorogenetických sedimentov pieninského bradlového pásma (šarišská jednotka, východné Slovensko): nové údaje z vrtu Jar-2 (jarmutsko-pročské s.) a odkryvov (malinowské s.)]. Mineralia Slovaca, 57, 2, 111 – 144.
DOI: https://doi.org/10.56623/ms.2025.57.2.2
Abstract: The study presents new results of heavy mineral analyses including detrital garnet, tourmaline and Cr-rich spinel chemical compositions from the synorogenic Maastrichtian-Ypresian Jarmuta-Proč Fm. of the Šariš Unit of the Pieniny Klippen Belt, penetrated by the structural borehole Jar-2 in eastern Slovakia. For comparison, outcropped fine-grained sandstones of the hemipelagic Turonian-Campanian Malinowa Fm. of the Šariš Unit were analysed. The heavy mineral assemblages of both formations are dominated by garnet with variable amounts of apatite, rutile, tourmaline, zircon and subordinate Cr-rich spinel. Almandine-rich garnets with variable grossular, pyrope, and spessartine proportions prevail in both formations. Unusual complex-zoned X-vacant magnesio-foititic to foititic and schorlitic-dravitic tourmaline grains with fine intergrowth with quartz and abundant inclusions were revealed. Cr-rich spinels show chemistry typical for supra-subduction zone peridotites. The chemistry of the Cr-rich spinels and complex-zoned tourmalines supports their common provenance in the Meliata ophiolite-bearing complexes of the internal Western Carpathian zones. Decreasing-upward Cr-rich spinel contents in the Upper Cretaceous to Lower Eocene flysch deposits of the PKB is evident. A multiple recycling model in which flysch formations of the Klape Unit, situated in a false accretionary wedge position, formed the “proximal” source of the ophiolitic debris recycled to the younger clastic formations of the foreland basins is advocated.
Key words: Western Carpathians, Pieniny Klippen Belt, synorogenic deposits, garnet, tourmaline, Cr-rich spinel, geochemistry, provenance