Dietary Habits and Freshwater Reservoir Effects in Bones from a Neolithic NE German Cemetery

Abstract

Within a project on Stone Age sites of NE Germany, 26 burials from the Ostorf cemetery and some further Neolithic sites have been analyzed by more than 40 accelerator mass spectrometry (AMS) dates. We here present the results of stable isotope and radiocarbon measurements together with reference 14C dates on grave goods from terrestrial animals such as tooth pendants found in 10 of the graves. Age differences between human individuals and their associated grave goods are used to calculate 14C reservoir effects. The resulting substantial reservoir effects have revealed misleadingly high 14C ages of their remains, which originally indicated a surprisingly early occurrence of graves and long-term use of this Neolithic burial site. We demonstrate that in order to 14C date the human bones from Ostorf cemetery, it is of utmost importance to distinguish between terrestrial- and freshwater-influenced diet. The latter may result in significantly higher than marine reservoir ages with apparent 14C ages up to ~800 yr too old. The carbon and nitrogen isotopic composition may provide a basis for or an indicator of necessary corrections of dates on humans where no datable grave goods of terrestrial origin such as tooth pendants or tusks are available. Based on the associated age control animals, there is no evidence that the dated earliest burials occurred any earlier than 3300 BC, in contrast to the original first impression of the grave site (~3800 BC).