Concentration and stable carbon isotopic composition of organic carbon of DSDP Hole 28-266

The 7% carbon-13 depletion in cold water phytoplankton provides a striking signal that is traceable in deep-sea cores taken in high latitude regions of the Southern hemisphere. This signal may be weakened by noise due to (1) terrestrially derived debris in areas close to the continents; (2) changing current patterns resulting in varying settling trajectories; (3) erosion and redeposition and (4) maturation-diagenetic effects. Data for two cores taken southwest of Australia are evaluated with respect to these interferences.