Lateglacial environmental changes recorded in calcareous gyttja deposits at Gulickshof, southern Netherlands

Environmental changes were reconstructed from Lateglacial calcareous gyttja deposits at Gulickshof, southern Netherlands. Analyses of pollen, fresh-water mollusca, stable isotopes and gee-chemistry were performed and the combined evidence was put into a chronostratigraphic framework based on regional biostratigraphy and accelerator mass spectrometry radiocarbon dating. The pollen diagram showed vegetation development from the Bolling interstadial into the Late Dryas stadial within 2.9 m of lacustrine deposits. Early in the Allerod, around 11900 BP, the composition of aquatic taxa and stable isotopes of calcium carbonate changed significantly. It appears that the final melting of relic ground-ice and subsequent re-establishment of the hydrological cell early in the Allerod were responsible for these changes. Later in the Allerod, around 11250 BP, the disappearance of molluscs, changes in vegetation and isotope composition all point to colder climate conditions attributable to the Gerzensee oscillation. The combination of different lines of evidence in these types of deposits proves to be an excellent tool for unravelling climate and environmental signals.