Heavy minerals of the aeolian sediments in the East Slovak Basin (Western Carpathians) – Implications for their origin, transport process and sedimentary history

Abstract

Aeolian sediments usually indicate glacial or periglacial arid-climate conditions, and knowledge of their sedimentary character and mineral composition can reveal the locality’s palaeo-environment and palaeo-geographic history. Reconstruction is provided by heavy-mineral surface micro-textural and geochemical analysis, and this detected the source area, source rocks and transport conditions for the Würmian wind-blown sands which form several dune types in the East Slovak Basin. The heavy-mineral morphology, surface micro-textures and low mineral maturity of the aeolian sediments preserve traces of past sub-aquatic environments and local aeolian transport. The heavy-mineral geochemistry suggests initial detrital derivation from local sources. This was formed by re-worked and re-mobilised Magura Nappe flysch sandstones in the Western Carpathians, with likely contribution of the Pieniny Klippen Belt flysch sediments indicated in sporadic pyrope-rich garnet. The associated detrital pyroxene and amphibole geochemistry denotes primary andesite source rocks which dominate lithology in the surrounding Neogene volcanic mountain chains. These are the Slanské vrchy, Vihorlatské vrchy and Zemplínske vrchy Mountains. The further occurrence of detrital hydrogrossular indicates derivation from contact-metamorphic zones associated with the volcanic rocks. Although different garnet types in the distinct dune profile zones may have resulted from heavy mineral re-sorting during active dune movement, they suggest sources changed by local wind directions. Orientation of basic linear features of the dunes derived from the digital terrain model indicates (paleo)wind generally from the north.