Age determination of sediment core PG2208

To gain a composite core record for core PG2208 (Figure 1) we used XRF data, i.e., Sr, to correlate overlapping parts of retrieved sections resulting in 367 cm in total. For dating we scanned the sediment core for macro fossils and retrieved bulk sediment samples at depths without any reliable macro remains. A prior attempt to date samples at the Poznan radiocarbon laboratory resulted in a large deviation between humic acid fraction (soluble in NaOH) and the humin fraction (residual, i.e., alkali-insoluble fraction). Therefore, we kept only the Poznan date of the single macro fossil (terrestrial wood remain) that was present and analyzed with standard (reliable) dating routines. For creating a reliable model, we dated another set of bulk sediment samples at MICADAS radiocarbon laboratory at AWI using an acid treatment method outlined in Vyse et al. (2020). To estimate a reservoir (old carbon) effect we dated an undisturbed surface sample PG2119 that was 1.6 km SW of PG2208.