MAGNITUDE AND GEOGRAPHIC-VARIATION OF THE RADIOCARBON CONTENT IN ANTARCTIC MARINE LIFE - IMPLICATIONS FOR RESERVOIR CORRECTIONS IN RADIOCARBON DATING

Radiocarbon age estimates on marine-derived materials from the Antarctic appear old in comparison with the terrestrial radiocarbon timescale as a result of significantly depleted C-14 concentrations in Antarctic seas. We review measurements of C-14 concentrations in modern Antarctic marine life from South Georgia, the Shetland Islands and Antarctic Peninsula and suggest correction factors required to relate radiocarbon measurements on fossil marine materials from these areas to the conventional radiocarbon timescale. For dates based on shells, seaweeds, sealbones and penguin bones the minimum correction factor for South Georgia is ca. 750 years and for the South Shetland Islands and Antarctic Peninsula it may be up to 1250-1300 years. For whalebones, a minimum correction of 1000 years may apply over a wide geographic area. For comparison, we also review radiocarbon measurements on marine species and seawater from other sectors of the Antarctic. In high latitudes. correction factors of ca. 1400 years are generally applicable to shell, seal and penguin samples.