Australian marine reservoir effects: A guide to ΔR values

Radiocarbon ages obtained on contemporaneous terrestrial and marine samples are not directly comparable. Samples grown in marine environments exhibit older apparent radiocarbon ages caused by the uptake of carbon which has already undergone radioactive decay through long residence times in the deep ocean. Variation in 14C activity in marine environments, although related to changes in atmospheric activity, depends greatly on local and regional factors, such as hinterland geology, tidal flushing and terrestrial water input. Such factors are highly variable and can introduce uncertainties of up to several hundred years into dates obtained on marine samples in some parts of the world. In this paper, I briefly discuss the principles of marine reservoir correction before presenting a guide to regional and subregional Australian DeltaR values extracted from the Reimer and Reimer (2006) database and Ulm (2002)