O values in ice and water samples from the Arctic and Antarctic, as well as the δ 13 C values of dissolved inorganic carbon in the water of the polar oceans. In addition, our laboratories offer the possibility [...] input) and changes in the supply of nutrient silicon and its use in polar and subpolar ocean regions (e.g. Southern Ocean, North Pacific) can be reconstructed on geological time scales. For the measurements [...] Clumped isotopes δ 13 C + δ 18 O (biog. carbonate, foraminifers) Option: clumped isotopes Changes in ocean circulation, nutrient content and deep water ventilation (δ 13 C) Hydrographic changes (δ 18 O, Δ47)