Human and animal bone collagen from different Steppe Bronze Age cultures, including the Yamnaya, East Manych Catacomb, and Lola cultures, show large variations in δ13C and δ15N values. More positive values of δ13C and δ15N are caused by change in diet and/or a more arid climate. Human bones show reservoir effects caused by aquatic diet components. These effects can be quantified by paired dating of human bone and associated terrestrial samples. Previous research showed reservoir corrections for several cultures of the Eurasian steppes Bronze Age, leading to a revision of the local chronologies. Additional investigations showed that some paired dates do not reveal reservoir effects. Recently, our database was extended significantly with new 13C, l5N, and 14C analyses of the Lola, Krivaya, and Babino cultures. The size of the reservoir offset for the studied cultures is discussed.

An overview will be presented of stable isotope data (δ13C and δ15N) available from animal and human bones from Roman to post-Medieval Belgian sites. The data will be used to assess trends in the human diet and evaluate the possible impact of reservoir effects originating from the consumption of fish derived from marine or freshwater environments. Historical and archaeozoological data demonstrate drastic changes in fish consumption throughout the last 2 millennia and thus suggest that fluctuations through time of the impact of the reservoir effects can be expected. However, the present stable isotope data set does not support this suggestion.

Dietary offsets in radiocarbon dates are becoming increasingly interesting to researchers, not only because of their impact on the reliability of chronologies but also because of the possibilities for extracting further dietary information from the 14C data itself. This is the case with the cemeteries of the Cis-Baikal region being studied as part of the international Baikal-Hokkaido Archaeology Project set up to examine hunter-gatherer cultural dynamics in eastern Asia. Fortunately, to control for a freshwater reservoir offset, we were able to obtain a number of paired terrestrial herbivore and human material for 14C dating. This article tests the correspondence between stable isotope evidence and the offsets seen in 14C values and the implications for the analysis of the 14C measurements as “chronometric dates.” This is an unusually well-documented example of freshwater reservoir offsets, providing an ideal case study to test different approaches to analyzing such offset information. Here, a purely Bayesian approach is compared with the more frequently applied linear regression analysis.

Archaeologists interested in radiocarbon dating shell midden sites express concern regarding the accuracy of shell dates and how such determinations should be interpreted. This article discusses the problem of dating shells from sites in the southeastern United States. New results are presented comparing shell, bone, and soil-charcoal age determinations from the Crystal River site, located along the west-central Gulf Coast of Florida. Crystal River is a large multimound site whose occupants engaged in long-distance exchange throughout eastern North America during the Woodland period (∼1000 BC to AD 1050). In the summer of 2012, test units were excavated in several contexts at the site, including both mounds and occupation areas. Samples were collected for 14C dating, which were then processed at the University of Georgia Center for Applied Isotope Studies. This article focuses on samples from the stratified shell midden, from which it was hoped to construct a local correction for marine shell that could be used to date other contexts. The soil-charcoal and bone collagen from these samples have very similar ages (bone samples ranging from about 100 cal BC to cal AD 530 and soil-charcoal from cal AD 345 to 560); however, the shell samples collected from the same stratigraphic units are significantly older than the terrestrial dates (ranging from 1300 to 390 cal BC). The difference in calibrated ages between organic materials and the shells ranges between 560 to 1140 yr. This phenomenon cannot be explained solely by the marine reservoir effect. It appears that all the shell samples formed in mixed marine (∼50–60%) contexts, as indicated by the stable isotope ratios and the amount of atmospheric carbon remaining in the samples. The age of the shell samples cannot be used to date archaeological events as they are influenced not only by the marine reservoir effect, but also the local hardwater effect, which makes them significantly older.

Previous stable isotope studies of modern and archaeological faunal samples from sites around Lake Mývatn, within the Mývatnssveit region of northeast Iceland, revealed that an overlap existed between the δ15N ranges of terrestrial herbivores and freshwater fish, while freshwater biota displayed δ13C values that were comparable with marine resources. Therefore, within this specific ecosystem, the separation of terrestrial herbivores, freshwater fish, and marine fish as components of human diet is complicated when only δ13C and δ15N are measured. δ34S measurements carried out within a previous study on animal bones from Skútustaoir, an early Viking age settlement on the south side of Lake Mývatn, showed that a clear offset existed between animals deriving their dietary resources from terrestrial, freshwater, and marine reservoirs. The present study focuses on δ13C, δ15N, and δ34S analyses and radiocarbon dating of human bone collagen from remains excavated from a churchyard at Hofstaoir, 5 km west of Lake Mývatn. The results demonstrate that a wide range of δ34S values exist within individuals, a pattern that must be the result of consumption of varying proportions of terrestrial-, freshwater-, and marine-based resources. For that proportion of the population with 14C ages that apparently predate the well-established first human settlement of Iceland (landnám) circa AD 871 ± 2, this has enabled us to explain the reason for these anomalously old ages in terms of marine and/or freshwater 14C reservoir effects.

Riņņukalns is the only known prehistoric shell midden in the eastern Baltic, and is one of the few middens in northern Europe consisting mainly of freshwater mussel shells. Situated on the Salaca River at the outlet of Lake Burtnieks, in northeastern Latvia, the site was originally excavated in the 1870s, and reinvestigated several times over the following decades. A new excavation in 2011 showed that part of the midden remained intact. The new exposure, dated to the later 4th millennium cal BC, yielded rich fishbone and mollusk shell assemblages, herbivore, human and bird bones, and a wide range of artifacts typical of a subsistence economy based on fishing, hunting, and gathering. Human remains from burials excavated in the 1870s were also located in archives. The co-occurrence at Riņņukalns of human remains with a broad range of terrestrial and aquatic food remains provides an ideal setting to study freshwater reservoir effects and other isotopic signals of diet and mobility. The extent of 14C depletion in local freshwater resources is an essential parameter for such studies; on the basis of 14C ages of modern and paleoenvironmental samples, we estimate that the applicable reservoir age in Lake Burtnieks is in the order of 800–900 14C yr.

The Chauvet-Pont d'Arc Cave is one of the most important sites for the study of the earliest manifestations and development of prehistoric art at the beginning of the Upper Paleolithic. Different dating techniques have been performed thus far (AMS 14C, U/Th TIMS, 36Cl dating) to model the chronological framework of this decorated cave. The cave yielded several large charcoal fragments, which enabled the opportunity for obtaining multiple dates; thus, a First Radiocarbon Intercomparison Program (FIP) was initiated in 2004 using three charcoal pieces. The FIP demonstrated that those cross-dated samples belonged to a time period associated with the first human occupation. One of the statistical interests of an intercomparison program is to reduce the uncertainty on the sample age; thus, to further assess the accuracy of the chronological framework, the Second Intercomparison Program (SIP) involving 10 international 14C laboratories was carried out on two pieces of charcoal found inside two hearth structures of the Galerie des Mégacéros. Each laboratory used its own pretreatment and AMS facilities. In total, 21 and 22 measurements were performed, respectively, which yielded consistent results averaging ∼32 ka BP. Two strategies have currently been developed to identify statistical outliers and to deal with them; both lead to quasi-identical calibrated combined densities. Finally, the new results were compared with those of the FIP, leading to the important conclusion that five different samples from at least three different hearth structures give really tightened temporal densities, associated with one short human occupation in the Galerie des Mégacéros.

The chronological framework of European protohistory is mostly a relative chronology based on typology and stratigraphic data. Synchronization of different time periods suffers from a lack of absolute dates; therefore, disagreements between different chronological schemes are difficult to reconcile. An alternative approach was applied in this study to build a more precise and accurate absolute chronology. To the best of our knowledge, we have collected all the published 14C dates for the archaeological sites in the region from the Ebro River (Spain) to the Middle Danube Valley (Austria) for the period 1800–750 BC. The available archaeological information associated with the 14C dates was organized in a database that totaled more than 1600 14C dates. In order to build an accurate and precise chronology, quality selection rules have been applied to the 14C dates based on both archaeological context and analytical quality. Using the OxCal software and Bayesian analysis, several 14C time sequences were created following the archaeological data and different possible scenarios were tested in northern Italy and southern France.

Bayesian analysis is now routinely applied for the construction of site-specific stratigraphic chronological models. Other approaches have analyzed the chronology of phases of archaeological activity across regions. The available radiocarbon results—the nature of the samples and their associations—provide the basis for what chronological questions it is possible to address for any site or region. In dealing with regional analyses, due consideration must be made of data selection. While data selection might be a relatively self-evident consideration in the analysis of a site chronology, working with data from a larger region poses a number of specific data selection issues. Robust association between dated samples and a particular type of diagnostic material culture or site may provide one means of producing regional chronologies. However, if the activity under investigation includes a number of different cultural traits, which are related but with each having a slightly different chronological currency, defining the temporal end of data selection becomes more problematic. This article presents one approach, using a case study from the British Mesolithic-Neolithic transition, with 880 simulation OxCal models used to investigate the effect of variously defining the end of a regional archaeological phase. The results emphasize that for a regional case study, sensitivity analysis may provide a useful tool to ensure representative models; the study also highlights the importance of comparing multiple model posteriors.

The calibration procedure, and especially the nonlinear shape of the calibration curve, makes analyzing a possible dating result a far from straightforward process. This is especially so if the goal is to distinguish between two relatively close events. Proposed herein is a calculator, or alternatively a graph, which enables reading of the difference between two radiocarbon ages corresponding to their expected calendar ages. The result may surprise the less experienced 14C users. Such a calculation also indicates the time periods with high or low potential for application of the wiggle-matching method.

The Mesolithic-Neolithic transition in the wetland margins of the southern North Sea basin occurred well over a millennium after the transition in neighboring loess regions. This article investigates the possible role of hydrological dynamics in the presence of the last hunter-gatherer-fishermen in these wetland regions. A Bayesian modeling approach is used to integrate stratigraphic information and radiocarbon dates both from accurately datable archaeological remains and key horizons in peat sequences in the Scheldt floodplain of northwestern Belgium. This study tests whether the Swifterbant occupation of the study area was contemporaneous with hiatuses in peat growth caused by organic clastic sedimentation due to increased tidal influences and local groundwater rise. The results suggest that the appearance of this culture followed shortly after the emergence of a brackish tidal mudflat landscape replacing a freshwater marsh.

Sum probability and Bayesian modeling of a substantial series of radiocarbon dates from a former extensive lake area in NW Belgium, known as the Moervaart area, allow important hydrological changes to be synchronized with Greenland Interstadial lb (or Intra-Allerød Cold Period). It is postulated that the disappearance of nearly all open water systems (Moervaart lake, anastomosing gullies, and dune-slacks) in response to this short but abrupt cooling event was responsible for a nearly total retreat of hunter-gatherers already some centuries before the start of Greenland Stadial 1 (Younger Dryas).