PROWENIENCJA MATERIAŁU OKRUCHOWEGO PIASKOWCÓW KARBOŃSKICH Z WARYSCYJSKICH BASENÓW PRZEDPOLA W POŁUDNIOWO-ZACHODNIEJ POLSCE I NA MORAWACH

Abstract

PROVENANCE OF CARBONIFEROUS SANDSTONES FROM THE VARISCAN FORELAND BASINS IN SOUTHWESTERN POLAND AND MORAVIA

Abstract. The study contains the results of petrographic and geochemical research of ca. three hundred samples of Upper Visean-Lower Namurian sandstones from thirteen boreholes situated in the Wielkopolska area and from outcrops in Moravo-Silesian Zone. These sandstones, belonging to the flysch succession in the eastern part of the Variscan fold-and-thrust belt, were sourced from the Variscan collisional orogen, i.e. from the Fore-Sudetic Block and the Sudetes. The source areas mainly comprised plutonic/gneissic roots of the magmatic ares together with their schistose envelopes and volcanic covers. Variscan fold-and-thrust belt and ophiolitic complexes, representing oceanic lithosphere of marginal basin, were of minor importance. The sedimentary record reflects rapid exhumation in the source area consisting in erosional removing of the volcanic covers and unroofmg of deep basement. The major change of detrital modes of sandstones in Wielkopolska foreland basin took place during GoBeta zone. The analytical data may indicate the presence of continental magmatic ares in the Sudetes and Fore-Sudetic Block. It is not clear whether, in part, arc characteristics of detritus are related to Early Carboniferous geotectonic setting in this part of the orogen, or whether they reflect an erosion of any older arcs.