This article discusses the magnitude and rate of change of radiocarbon reservoir ages from the surface ocean in the South Pacific during the Holocene. 14C reservoir ages are calculated from paired U/Th and 14C measurements. Seventeen pairs of coral dates were determined from samples collected on Rendova and Tetepare Islands, in the Solomon Islands, and from Espiritu Santo Island, Vanuatu. The samples are all Holocene in age, with 230Th ages ranging from about 400 to 9400 BP. Samples were collected as drill cores or surface outcrops. About half of the surface samples appear to have incorporated modern carbon through postdepositional recrystallization. Two of the core samples were also affected by carbon exchange. The Holocene 14C reservoir ages observed in this data set show stable values for the last 3000 yr, and substantial variability from 5000–6000 BP (~100 to ~950 14C yr). Persistent low values (<200 14C yr) were observed for samples from 7000–8000 BP. We attribute these variations to temporal changes in lateral advection and vertical mixing, and possibly to local environmental conditions related to the interplay between sea-level rise and episodic uplift, characteristic of all the coral localities.

The Saquarema archaeological site, on the Atlantic coast of the Rio de Janeiro State, is one of many shellmounds built on the Brazilian coast by hunter-gatherer populations during the Holocene. We used archaeological material from this site with the aim of evaluating the marine reservoir effect (MRE) in the region. Radiocarbon ages of 45 marine and 6 terrestrial samples from this shellmound provided data for assessing the MRE and the influences of freshwater and seasonal coastal marine upwelling in this specific locality. Samples of charcoal, fish otoliths, and mollusk shells were analyzed and the 14C dates were modeled in the OxCal platform to determine the marine reservoir correction. The result obtained is R = 265 ± 70 14C yr and the offset ΔR was found to be –140 ± 66 14C yr. To support the accuracy of this value for correcting conventional 14C marine ages, taxonomic analyses of the samples were performed.

Radiocarbon analyses of 14 modern, pre-bomb marine organisms collected between AD 1836 and 1946 along the eastern Adriatic coast were performed. The 14C ages of five algal and nine mollusk samples were measured by accelerator mass spectrometry (AMS). Marine 14C reservoir ages (R) and regional offsets (ΔR) were calculated and compared. The marine reservoir ages of shells and algae significantly differ, even though both inhabit the hard substrate from the intertidal zone to shallow sea. Coralline algae had a considerably lower reservoir age (355 ± 34 14C yr) and ΔR value (–9 ± 34 14C yr) than mollusks (R 513 ± 53 14C yr; ΔR 154 ± 52 14C yr), though the variability of R was high in both groups. Although the microlocations of pre-bomb samples were not known and the studied mollusk species are able to inhabit marine or estuarine environments, it can be assumed that they were not significantly influenced by a freshwater admixture, due to their δ13C values being mostly in the marine range. However, as the entire eastern Adriatic is formed in carbonates, mollusk shells could be influenced by limestone-depleted 14C. In examining new data together with previously published data, the marine reservoir effect (MRE) for the Adriatic area is estimated to be 424 ± 57 14C yr (ΔR is 77 ± 57 14C yr). Without mussel shells, the estimated MRE is 378 ± 44 14C yr (ΔR is 28 ± 45 14C yr). The presented values are comparable to the MREs and mean ΔRs obtained for the Mediterranean by other authors.

The aim of this article is to discuss radiocarbon dating offsets due to freshwater and marine reservoir effects (FRE and MRE, respectively) in the southeastern Baltic. Thirty-six 14C dates from Lithuanian coastal and inland Subneolithic, Neolithic, and Bronze Age sites as well as two Mesolithic-Neolithic cemeteries are presented here. Accelerator mass spectrometry (AMS) dates, sometimes paired or tripled, have been obtained on samples of various origin, foodcrusts, or visible charred deposits adhering to the surfaces of ceramic vessel walls were also dated and investigated for stable isotope signals. The results argue for a significant freshwater component in the food processed in ceramic vessels during the Subneolithic and Neolithic. Paired dating of ungulate and human bones at the Spiginas and Donkalnis cemeteries (6300–1900 cal BC) does not suggest an FRE, although stable isotope data on human bone collagen strongly suggest a large input of freshwater food in the diet. An FRE in the order of 320–510 yr was estimated for the Šventoji paleolagoon around 3000 cal BC. At the same time, the FRE of the Curonian Lagoon could be larger as implied by large apparent 14C ages of modern pike-perch (981 ± 30 BP) and bream (738 ± 30 BP) bones as well as “foodcrust” offsets (650–530 yr) at Nida (3500–2500 cal BC). An MRE of 190 ± 43 yr was estimated for the southeastern coast of the Littorina Sea according to offsets between dates of seal bones and terrestrial samples at Nida and Šventoji. Any FRE at Lake Kretuonas remains uncertain due to the limited work to date.

A review of current research reveals multiple lines of evidence suggesting that no single freshwater reservoir offset (FRO) correction can be applied to accelerator mass spectrometer (AMS) ages obtained on carbonized food residue from cooking vessels. Systematically evaluating the regional presence, magnitude, and effects of a freshwater reservoir effect (FRE) is a demonstrably difficult analytic problem given the variation of ancient carbon reservoirs in both space and time within water bodies, and which should be performed in advance of AMS assays. In coastal and estuarine contexts, a priori partitioning FRE from known marine reservoir effects (MRE) is also necessary to eliminate potential mixed effects. Likewise, any FRE varies based on the proportional mix of resources producing the residues and the ancient carbon uptake of those products. Processing techniques are a significant component of assessing potential FRE, and each pot/cooking vessel is therefore an independent context requiring analytic evaluation. In northeastern North America, there is little ethnohistoric/ethnographic evidence for fish boiling/stewing in ceramic cooking vessels; rather, fish were more often dried, smoked, or cooked for immediate consumption on open fires. Assays of fatty acids extracted from prehistoric vessel fabrics even on known fishing sites reveals no evidence for fish in the food mix. These observations suggest that the likelihoods of FRE in carbonized food residue in northeastern North America is therefore low, and that assays potentially suffering from FRO are minimal. In turn, this suggests that AMS ages from carbonized food residues are reliable unless analytically demonstrated otherwise for specific cases, and should take primacy over ages on other associated materials that have historically been employed for critical threshold chronological events.

An overview of current knowledge on the human paleodiet of the southern Russian Far East is presented. The earliest data are available for the Neolithic complexes of Primorye Province, dated to ~7000–5800 BP. For 10 humans from the coastal site of Boisman 2, a heavy reliance on marine fish and mammals (~70–80% of the total diet) has been established; this is similar to the Jomon and Chulmun complexes of Hokkaido Island and Korea. For two individuals from the inland site of Chertovy Vorota, a mixture of terrestrial and riverine (including anadromous species such as salmon, ~25% of the total diet) food resources is evident. In the Amur River basin, the diet of the Paleometal (i.e. Bronze/Early Iron Ages) population (dated to ~2500–1800 BP) was probably based on a mixture of C4 plants (millet, ~50–60% of the total diet), C3 plants, and terrestrial animals, while in the Middle Ages (~1500–300 BP) the contribution of C4 food was lower at ~20–25%. On Sakhalin Island, the maritime-oriented economy existed for a long time, at least since the Late Neolithic/Paleometal Age (dated to ~2500–1800 BP) and until the ethnographic time period (from the 17th–18th centuries AD onwards). Up to ~80–90% of the diet consisted of marine mammals and fish, and this is in accord with dietary patterns of the Epi-Jomon and Okhotsk cultural complexes on Hokkaido Island. Information on the paleodiet of the coastal populations of the Japan and Okhotsk Seas should be taken into account when calibration of 14C dates run on human bones from these regions is undertaken, because the predominant consumption of marine food caused a distortion of the true 14C age.

A program of paired dating of human and faunal remains on a sample of 11 prehistoric (Mesolithic/Neolithic to Early Bronze Age) graves in the Upper Lena basin, southeast Siberia, was initiated to investigate the freshwater reservoir effect (FRE). The results show the presence of a substantial but highly variable offset, ranging from 255 to 1010 14C yr. In contrast to previous studies centered on Lake Baikal and the Angara River, human stable nitrogen isotope values show little or no correlation with the radiocarbon offset, despite the clear trophic differences seen in δ15N between terrestrial and aquatic sources of protein in the region's isotope ecology. However, stable carbon isotope measurements show a moderate negative correlation of some predictive value (r = −0.70, p = 0.016, df = 10). Two different regression equations have been calculated, the first using human δ13C values for the entire data set (r2 = 0.49) and the second, using both δ13C and δ15N values, limited to the Early Bronze Age of the southern Upper Lena (r2 = 0.84, p = 0.030, df = 5). The source of the old carbon in the Upper Lena River system is not clear. While the river flows over carbonate bedrock and is moderately alkaline, we suggest that old terrestrial carbon entering the riverine foodweb through bank erosion and other processes is a more likely candidate for the majority of the 14C offset.

This article presents the results of radiocarbon dating and a chronology of the Preobrazhenka 6 site of the Odino culture (Baraba forest steppe, western Siberia). Currently available 14C data for the necropolis do not allow accurate determination of the presence or absence of reservoir effects, and as such, further research is needed. Accelerator mass spectrometry (AMS) 14C dating of paired samples of terrestrial faunal and fish remains from a Neolithic pit suggest the absence of a reservoir effect in fish bone collagen. Middle Bronze Age burials have therefore been estimated to date to the 23rd–20th centuries cal BC. Pits with fish remains are dated earlier than burials, to the 63rd–61st centuries cal BC. Stable isotope measurements of human bone collagen (high δ15N and low δ13C values) indicate diets based on C3 plants and fish. Apparently, the role of animal protein in the diet was not significant. Dental paleopathology analysis has confirmed the important role of wild plants in human diet. Neolithic fish bones are elevated in δ13C [–13.5‰, average mean (n = 4)]. They are significantly different from the associated values of fish from the Late Bronze Age settlement of Chicha 1 [–22.5‰, average mean (n = 10)], which is also located in the Baraba forest steppe. The difference in δ13C values in fish bones may be determined by the origin of the samples, being derived either from lakes or rivers.

Radiocarbon dating and research into offset correction for freshwater reservoir effect were conducted at the pile-dwelling site Serteya II, located in the Dvina-Lovat' basin (northwestern Russia). Cultural layers of this site are situated underwater, hence the unique state of preservation of material culture of the 3rd millennium cal BC. 14C dating of different organic materials [wood, hazelnut (Corylus avellana), and elk bones] from this site allows their ages to be correlated and 14C age offsets caused by freshwater reservoir effects (hardwater effects) in the dating of materials such as organic crust, pottery, bones, and lake sediments to be estimated. Consideration of the late Neolithic subsistence strategy underpinning the archaeological finds from this site and analysis of lipid components in ceramic vessels, as well as the determination of 14C activity of modern aquatic and terrestrial samples, allows us to calculate the local freshwater reservoir effect and 14C age offset for charred food crusts from different ceramic vessels more precisely.

Freshwater reservoir effects (FRE) can cause problems when radiocarbon dating human skeletal material from the Eurasian steppe. This article presents the first results of research into the extent of the FRE in the sites of Borly 4 (Eneolithic) and Shauke 1 and 8b (Early Bronze Age), northeastern Kazakhstan. Accelerator mass spectrometry (AMS) 14C dating and stable isotope (δ13C, δ15N) analysis of associated groups of samples (32 samples, 11 groups in total) demonstrate the following: (a) the diet of the humans and fauna analyzed was based on the C3 foodchain with no evidence of a C4 plant (such as millet) contribution; aquatic resources apparently were a continuous dietary feature for the humans; (b) the first 14C dates obtained for the Upper and Middle Irtysh River region attribute the Eneolithic period of the area to the 34th to 30th centuries BC, and the Early Bronze Age to the 25th to 20th centuries BC, with a ~450-yr hiatus between the two periods; (c) the maximum fish-herbivore freshwater reservoir offset observed equals 301 ± 47 14C yr. As such, 14C dates from aquatic and human samples from the area need to be interpreted with caution as they are likely to be affected by the offset (i.e. appear older). The article also discusses the effect of a sodium hydroxide (NaOH) wash on δ13C, δ15N, C:Natomic levels and collagen yields of the bone samples. Our results indicate a minor but significant effect of NaOH treatment only on C:Natomic ratios of the samples.

Four inhumations from Kivisaare and Riigiküla I settlement and burial sites were dated in the course of a project about hunter-gatherer mortuary practices in Estonia, as they were believed to belong to the Stone Age. However, these burials appear to be Early Bronze Age inhumations instead, and thus are discussed separately in the present article. These burials are the first evidence in Estonia of a long-lasting tradition of inhumations without any visible aboveground structures. As the archaeology of the Early Bronze Age in Estonia is poorly known, these four inhumations contribute immensely to our understanding about this time period. Moreover, stable isotope values show that these people had a more terrestrial subsistence strategy than Stone Age hunter-gatherers. Nevertheless, aquatic resources were probably still significant components of their diet, particularly at Kivisaare, and the radiocarbon dates could therefore be subject to significant freshwater reservoir effects. This creates ambiguity in the chronological relationship of these four individuals to burials in stone-cist graves, which are attributed to the Late Bronze Age and which appear to be associated with fully agricultural communities.

The Seversky Donets River (Northern Donets) basin in eastern Ukraine and the Lower Don River valley in Russia were inhabited by populations that have been considered to be one of the earliest pottery-using cultures in Europe. The early pottery sites are all located on riverbanks and contain middens with many mollusk shells and fish bones. This suggests the intense exploitation of freshwater resources. The accuracy of radiocarbon dates obtained from these locations is of crucial importance for understanding the development of new technologies, diversification of the food consumed and its preparation strategies, as well as the degree of sedentism in this region, associated with the beginnings of pottery-making technology. The chronology of Neolithic sites in this region, however, was developed on the basis of 14C dates commonly obtained through the dating of freshwater mollusk shells, pottery with mollusk shell temper, or organic residue on pottery shards. Such samples are potentially affected by the freshwater reservoir effect, raising concerns about the accuracy of those dates. This paper presents accelerator mass spectrometry (AMS) 14C dates from a small pilot study from sites in eastern Ukraine in order to test for the presence of the reservoir effect in this region. The AMS 14C dates presented in this paper challenge the 14C chronology based on mollusk shell or organic residue, which appears to generate much older dates than those on wood charcoal or terrestrial animal bone.

Ten medieval permanent teeth were subjected to incremental dentine sectioning and stable isotope analysis to investigate dietary changes in high resolution. In addition to this, eight increments were also selected for radiocarbon measurements to examine possible intra-individual age differences. Results reveal the cessation of weaning, various dietary profiles, and in some cases significantly different 14C ages obtained from a single tooth. This case study illustrates how 14C measurements can function as a proxy alongside the commonly used carbon and nitrogen stable isotope values to interpret the diet of past individuals.

From material culture evidence dating as early as 7500 cal BC, it has been established that populations from the interfluvic coast in northern Chile adapted to a maritime economic livelihood. During the 2nd millennium BC, local populations began to experience major social changes arising mainly from an increase in contacts with agropastoral populations from the highlands of the Andes. New radiocarbon data and stable isotope (δ15Ncol, δ13Ccol, and δ13Cap) analyses of human bone remains from interfluvic coastal individuals were obtained. The data showed that these individuals, at the time of contact with highland populations, maintained a mode of subsistence relying principally on marine protein. This suggests that, although instances of social change may have arisen, the livelihoods linked to the consumption of marine resources would have remained constant, demonstrating a high degree of resistance in changing local lifestyles.

Stable isotope ratios of carbon, nitrogen, and sulfur in human bone collagen are used routinely to aid in the reconstruction of ancient diets. Isotopic analysis of human remains from sites in the Iron Gates section of the Lower Danube Valley has led to conflicting interpretations of Mesolithic diets in this key region of southeast Europe. One view (Bonsall et al. 1997, 2004) is that diets were based mainly on riverine resources throughout the Mesolithic. A competing hypothesis (Nehlich et al. 2010) argues that Mesolithic diets were more varied with at least one Early Mesolithic site showing an emphasis on terrestrial resources, and riverine resources only becoming dominant in the Later Mesolithic. The present article revisits this issue, discussing the stable isotope data in relation to archaeozoological and radiocarbon evidence.

Here, we reply to the attempt by Bonsall et al. (2015) to re-assess our results from the sulfur isotopic study of bone collagen from Mesolithic and Neolithic sites along the Danube in the Iron Gates Gorges area (Nehlich et al. 2010). Although we are highly interested to see our data re-assessed, we found certain misinterpretations, mistaken assumptions, and factual errors regarding our results. Therefore, we want to respond and re-assess our previous data, too. We establish for a few individuals a quantitative dietary reconstruction to demonstrate the reliability of our earlier interpretations.

Foodcrusts, the charred surface deposits on pottery vessel surfaces, provide a rich source of data regarding container function. This article reviews recent applications focusing on the detection of aquatic resources (marine and freshwater) in pottery vessels using a range of analytical approaches including bulk isotope measurements of carbon and nitrogen, lipid biomarker analysis, and compound-specific carbon isotope determinations. Such data can help to evaluate the presence of reservoir effects when undertaking radiocarbon dating of foodcrust samples. In particular, molecular and isotopic analysis can aid in the selection of suitable candidates for 14C where it can be demonstrated that aquatic resources are unlikely to contribute to the residue. Prospects for compound-specific 14C analysis of lipids in foodcrusts and ceramic-absorbed residues are also discussed.

The Jomon culture is an ancient Japanese society that existed during approximately 14,000 to 400 BC and which is characterized by Jomon (cord pattern) pottery. To investigate the paleodiet of the people of northeastern Tohoku in Japan during the Final Jomon period (about 1000–400 BC), we studied three sites in Aomori Prefecture, the center of the Kamegaoka culture. The Fubinashi site is on the coast and was supported by a rich fishing culture. Imazu was a coastal salt-making site. Sugisawa is a mountainous inland site on the banks of a river. We determined the 14C ages of the interior and exterior surfaces of carbonized material on potsherds and compared the data with pottery typology and age to study the marine reservoir effect. We also analyzed the bulk carbon and nitrogen stable isotopes and C:N ratios to determine the presence of aquatic foodstuffs. The organic residues from pottery typology corresponding to the described analyses provided a general perspective of differences in the ancient diets at each site. When we recovered sufficient lipids, we analyzed compound-specific stable isotopes of fatty acids to obtain a multilateral view of those diets. Our findings indicate that the diets of inhabitants of both Fubinashi and Imazu consisted primarily of marine products and some terrestrial foodstuffs, whereas people from Sugisawa processed mainly C3 plants and some terrestrial animals and aquatic commodities.