A Freshwater Diet-Derived ¹⁴C Reservoir Effect at the Stone Age Sites in the Iron Gates Gorge

Abstract

ABSTRACT. Human bones from single inhumation burials and artifacts made from terrestrial mammal (ungulate) bone found in direct association with the skeletons were obtained from the Stone Age site of Schela Cladovei situated just below the Iron Gates Gorge of the River Danube. The results of stable isotope analyses of the human bone collagen are consistent with a heavy dependence on aquatic protein while radiocarbon dating of the samples reveals an offset of 300-500 years between the two sample types, indicating a freshwater reservoir effect in the human bone samples. Since protein consumption is by far the major source of nitrogen in the human diet we have assumed a linear relationship between δ 15 N and the level of aquatic protein in each individual's diet and derived a calibration for 14 C age offset versus δ 15 N which has been applied to a series of results from the site at Lepenski Vir within the gorge. The corrected 14 C ages (7310-6720 BP) are now consistent with the previous 14 C age measurements made on charcoal from related contexts (7360-6560 BP). In addition, the data indicate a change from a primarily aquatic to a mixed terrestrial/aquatic diet around 7100 BP and this may be argued as supporting a shift from Mesolithic to Neolithic. This study also has wider implications for the accurate dating of human bone samples when the possibility exists of an aquatic component in the dietary protein and strongly implies that δ 15 N analysis should be undertaken routinely when dating human bones.

A lack of freshwater reservoir effects in human radiocarbon dates in the Eneolithic to Iron Age in the Minusinsk Basin

“…The majority of FRE research has focussed on Europe (Cook et al 2001(Cook et al , 2002Fischer and Heinemeier 2003;Olsen et al 2010;Keaveney and Reimer 2012;Lougheed et al 2013;Fernandes et al 2014;Meadows et al 2016) and North America (Ingram and Southon 1996;Goodfriend and Flessa 1997;Culleton 2006), and only recently has the importance of freshwater reservoir effects been highlighted for Russia and the Eurasian steppe zone, including the upper Lena River and Lake Baikal region (Nomokonova et al 2013;Schulting et al 2014Schulting et al , 2015, Caspian steppes and lower Don River (Shishlina et al 2007(Shishlina et al , 2009(Shishlina et al , 2012(Shishlina et al , 2014Motuzaite-Matuzeviciute et al 2015), middle and lower reaches of the Dnieper River (Lillie et al 2009), NorthEastern Kazakhstan (Svyatko et al 2015), Sertejka River in Smolensk Oblast (Kulkova et al 2015) and Kubenskoye Lake in Vologda Oblast (Wood et al 2013). The main finding from this research is that freshwater reservoir effects are extremely variable geographically (spanning from zero to several thousand years), and that when dealing with archaeological human remains Beach population thought to be affected by a FRE must be examined individually^ (Wood et al 2013, p. 163).…”

The Catacomb Cultures of the North-West Caspian Steppe: 14C Chronology, Reservoir Effect, and Paleodiet

“…aquatic to total protein). Based on these numbers, we estimate the 14 C reservoir effect as 400 ± 100 14 C yr (Cook et al 2001). …”

“…Such terrestrial samples are needed to properly identify reservoir effects and their correction (see e.g. Arneborg et al 1999;Cook et al 2001). …”

The freshwater reservoir effect in radiocarbon dating

“…However, it took several decades before the FRE was measured and discussed in archaeologically relevant sample types, such as human bones [9][10][11][12][13][14] or food crusts on pottery [15][16][17][18]. In these cases, the consumption or preparation of large amounts of freshwater fish lead to spurious apparent ages of the bones and pottery.…”