Figure 2
Chronostratigraphic model of reference core 1145GC and correlation with cores 1143GC and 1174GC. Core 1145GC has been subdivided into three lithostratigraphic units and interpreted based on a radiocarbon tie point at the base of Unit II and integrated with paleoproductivity proxies and organic matter parameters (Br/Sum8, C/N ratio, δ13C, δ15N) to identify the Holocene sediment interval (Unit I). The typical marine organic matter is composed of plankton and algae and is characterized by C/N values between 4 to 10, δ13Corg between −23 and −16‰ and δ15N as high as 7‰78,79,80. Terrestrial organic matter mainly includes material from vascular land plants showing C/N values above 2079, lighter δ13C values ranging from − 29.3‰ to − 25.5‰81 and δ15N close to atmospheric nitrogen composition (~ 0‰)78. Mollusc shells collected from Unit II in cores 1145GC, 1143GC and 1174GC provided radiocarbon ages > 46,220 cal years BP and cannot be used for correlation. Unit II and Unit III represent the Younger Dryas – post Bolling period and the Bolling interstadial, respectively. IRD = Ice-rafted debris.
