Late Holocene marine radiocarbon reservoir correction for the south and east coast of South Africa

The marine reservoir effect is the difference in radiocarbon (14C) between the atmosphere and the marine surface ocean. In order to overcome the dating errors induced, it is necessary to correct ma r in e radiocarbon ages for this effect. ΔR is the difference between the marine 14C age and the marine calibration curve based on an ocean-atmosphere box diffusion model which accounts for the time delay in diffusion of carbon into the ocean from the atmosphere and biosphere. This global assessment however requires computation of a regional ΔR value for calibration to cater for studies based on a local scale. In this paper the marine reservoir effect is assessed for the south and east coast of South Africa using radiocarbon dating on pre-1950 marine shells of known age. The resultant ΔR values enable a more complete understanding of the marine reservoir effect along the south and east coastal zone of South Africa. Radiocarbon age determinations were conducted on 15 shell samples of known age and the results used to calculate regional marine reservoir correction values for the region. The east coast has a weighted mean ΔR of 121 ± 16 14C years, while the south coast has a weighted mean ΔR of 187 ± 18 14C years.