Extended age model of sediment core GeoB18530-1 by correlation of Ca/Sr record to NGRIP chronology

The previously published 14C-AMS based chronology of GeoB18530-1 by Max et al. (2022; doi:10.1594/PANGAEA.943562), covering the upper 0 - 7.16 m core section down to Heinrich Event layer H2, was revised and extended to the full core length of 10.64 m, including now also Heinrich Event layers H3 to H6. The age model was first extended back to 34.6 ka using two older 14C AMS dates by Lars Max (doi:10.1594/PANGAEA.943562). This radiocarbon chronology now covers H1 – H3 within inferred age brackets of 15.3 to 17.3 ka (H1), 23.3 to 25.3 ka (H2) and 27.7 to 32.0 ka (H3) respectively. The ages of the older Heinrich Event layers H4 – H6 were obtained by correlating the Ca/Sr and δ18O records to the NGRIP chronology, obtaining age brackets of 37.5 to 39.9 ka (H4), 44.9 to 48.6 ka (H5) and 55.7 to 58.9 ka (H6). Between these age tie points, we linearly interpolated sediment ages in 1 cm depth increments and assigned Heinrich Event numbers (H1 to H6) and (Heinrich-related) interlayer numbers (I1 to I6) to the respective stratigraphic units.