Geochemical and Mineralogical Characterisation of Carbonate-Rich Lake Sediments from Lake Kolon, Hungary

The Danube–Tisza Interfluve in central Hungary, a key region for Quaternary paleoenvironmental reconstruction, hosts ephemeral saline lakes that serve as highly sensitive archives of past climate variability but are increasingly threatened by desertification. Carbonate-rich lacustrine deposits within these systems form through a complex interplay of biogenic CO2 uptake and inorganic precipitation driven by evaporation. To refine paleoenvironmental reconstructions from these archives, a lacustrine sediment core was analysed using XRPD for mineralogy and XRF for major and trace element geochemistry. The results reveal four distinct environmental phases: a cold, siliciclastic-dominated Late Glacial period (c. 23,600–13,400 cal BP); an abrupt shift to massive autogenic carbonate production during the warmer Late Glacial Interstadial, which was also marked by intense aeolian activity (Zr enrichment); the development of a Holocene fen (from c. 11,200 cal BP) with fluctuating hydrology; and a recent interval (from c. 800 cal BP) showing extreme enrichment in phosphorus, lead, and sulphur from anthropogenic sources.