Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)
Malacostratigraphy of the lower Váh River floodplain at Trakovice (SW Slovakia)
Abstract
The sedimentary sequence forming the wide Váh River floodplain between Trakovice and Leopoldov (Northern part of the Slovak Danube Lowland) includes a peculiar complex of pale grayish yellow sandy loam strata that are very high in CaCO3 (25-40 %), but nearly humus- deficient. Their molluscan fauna consists of various terrestrial assemblages, particularly of light woodlands (Cochlodina laminata, Monachoides incarnatus), damp riverine forests (Perforatella bidentata, Clausilia pumila) and xerothermic grasslands (Granaria frumentum, Chondrula tridens, Pupilla muscorum, Vallonia costata, V. pulchella), which corresponds to a patchwork of open and woodland habitats, forming a parkland under climatic conditions corresponding to those at present. Consequently, the yellow layers may be attributed to the Middle Holocene. They are underlain by sterile fluvial sands and gravels and capped by a well developed topsoil of phaeosol type. Similar yellow sediments that cover the valley gravels of the Danube floodplain are older since they include typical open-country malacocoenoses of the Late glacial. From the ecological point of view, the yellow loams of Trakovice represent a peculiar ecosystem characterized by highly calcareous raw soils but also a rather rich biota that strongly differs from all present-day biocoenoses in mid-European floodplains.
