Multi-proxy paleoenvironmental reconstruction of Lake Burdur (southwest Türkiye) Sediments: Tracing middle−late Holocene climate variability and anthropogenic impact

Sediment core BRDR-2 obtained from Lake Burdur in south-western Türkiye provides a high-resolution record of environmental change during the middle−late Holocene, including μ-XRF geochemistry, MSCL (multi-sensor core logger), TOC–TIC analysis (total organic carbon-total inorganic carbon) and grain size analysis. The lowest interval (4590–4160 yr BP) is characterised by low concentrations of detrital elements, a coarse mean grain size and an elevated Ca/Ti ratio, indicating reduced runoff and an increased supply of carbonate derived from marl under dry conditions. Increased concentrations of μ − XRF Si, K, Ti, Fe, Rb, Zr, Sr and TOC between 4160 and 2850 yr BP reflect effective moisture. A subsequent decline in detrital influx (2850–1700 yr BP), together with rising Ca/Ti and TIC, indicates hydrological stability or moderate aridity. A major environmental transition occurred between 1700 and 1200 yr BP, characterised by maximum TOC (4.4%) and a pronounced Mn/Fe peak, indicating enhanced productivity and redox stratification. This interval corresponds chronologically to the Beyşehir Occupation Phase (BOP), characterized by intensified agricultural activity and extensive landscape clearance. After 1200 yr BP, detrital input becomes more variable. A renewed increase in terrestrial input and depositional energy is observed between 60 and 30 cm. This phase, which corresponds to approximately 1123 to 550 yr BP, indicates an increase in both terrestrial input and organic matter. This may reflect earlier changes in regional shifts in catchment dynamics that occurred during this period. In the last ∼500 yr BP, there has been a sharp rise in grain size (sand content), Ca/Ti and salinity proxies, reflecting accelerated marl erosion, evaporation and the impact of modern land use.