Late Carboniferous woody debris, secondarily embedded in Quaternary deposits in the Sudety Mts., SW Poland

Abstract

Several dozen samples of silicified wood were discovered during a renewed geological mapping survey in the Sudetes Mountains (NE Bohemian Massif, SW Poland). The material originates from the Metuje River valley, near Kudowa-Zdrój (Kudowa-Słone locality), where woody debris is embedded in the unconsolidated gravelly Quaternary alluvial deposits that form a river terrace. The silicified wood occurs as clasts in a gravelly lithofacies. To determine the taxonomic affinity, taphonomic history, and provenance of the material, the specimens were analysed macroscopically and using petrographic microscopy, cathodoluminescence imaging and scanning electron microscopy. The wood is assigned to Cordaixylon, a cordaitalean genus, characteristic of Late Palaeozoic forest ecosystems. Despite its occurrence as barkless and branchless fragments in unconsolidated, Quaternary sediments, the secondary xylem anatomy is exceptionally well-preserved. This combination of anatomical fidelity and physical abrasion indicates that the material is allochthonous and records a multi-stage depositional history. Sedimentological and palaeobotanical evidence demonstrates that the wood was derived from Carboniferous strata and had experienced at least two phases of fluvial redeposition: first within Carboniferous arkosic channel deposits, and later within Late Quaternary river-terrace sediments. Palaeoflow indicators and clast petrography from the Kudowa-Słone exposure show persistent southward transport of gravel and woody debris, with the principal source area located to the north. These data support a provenance from the Late Carboniferous Jivka Member of the Odolov Formation, in the eastern (Czech) part of the Intra-Sudetic Basin, where cordaitalean wood is abundant and exposed in Carboniferous strata, incised by the Metuje and Dřevič rivers.