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Abstract:
Here, we studied sedimentary evolution of the South Danamandıra Lake (SDL), in the peatland in Çatalca Peninsula, located north of the Sea of Marmara. The peat-bearing sedimentary infill of the SDL, using bathymetric mapping and subsurface imaging by ground penetrating radar (GPR), mineral magnetic, geochemical and radiocarbon dating analyses of sediment cores were analyzed. The mineral magnetic analysis includes magnetic susceptibility (κLF), anhysteretic remanent magnetization (ARM), and isothermal remanent magnetization (IRM) measurements were performed on five sedimentary cores. The lithological sequence in the lake consists of an upper peat unit and a lower sand-silt-clay unit. The SIRM and ARM profiles of the SDL cores clearly define the lithological boundary between the peat and siliciclastic units, with relatively uniform, low values of magnetic parameters in the upper unit, and high and relatively variable values in the lower unit. According to our results, the SDL formed in a shallow depression of a fluvial channel at ca 10.88± 0.61 cal kyr BP. It became a eutrophic lake during the early Holocene warm period, and has gradually developed into a swampy peatland at 8.1 ± 0.06 cal kyr BP. Mineral magnetic properties indicate that the peat unit accumulated under anoxic conditions below a thin oxic surficial layer. The human influence in the area started at 5.4 cal kyr BP, as indicated by an increased erosion with high siliciclastic input and increase in the Taraxacum, Asteraceae, and Poaceae pollen percentages. Archaeological findings corresponding to the human influence in the studied area also support our records.
