Fig. 4

Geochemical properties of sediment core PG2203, showing total organic carbon (TOC), nitrogen (N), atomic TOC/N ratios, stable carbon isotope values (δ¹³C), and mercury concentrations (Hg) in parts per million. The red shaded area indicates the industrialization of the Northern Hemisphere, starting in the mid-nineteenth century as determined by ²¹⁰Pb and ¹³⁷Cs dating. Ages are given in common era next to core depths. Dashed lines indicate mean values for the whole sequence