The Final Neolithic and the Bronze Age (3000–800 BC) are periods of great transformations in the communities inhabiting the area of modern-day Belgium, as testified by archaeological evidence showing an increasing complexity in social structure, technological transformations, and large-scale contacts. By combining 599 available radiocarbon dates with 88 new 14C dates from 23 from funerary sites, this paper uses kernel density estimates to model the temporality in the use of inhumation vs. cremation burials, cremation deposits in barrows vs. flat graves, and cremation grave types. Additionally, by including 78 dates from settlements, changes in population dynamics were reconstructed. The results suggest a phase of demographic contraction around ca. 2200–1800 BC highlighted by a lack of dates from both settlements and funerary contexts, followed by an increase in the Middle Bronze Age, with the coexistence of cremation deposits in barrows and, in a lower number, in flat graves. At the end of the 14th–13th century BC, an episode of cultural change with the almost generalized use of flat graves over barrows is observed. Regional differentiations in the funerary practices and the simultaneous use of different grave types characterize the Late Bronze Age.

Short-duration archeological sites situated entirely within plateaus in the radiocarbon calibration curve pose unique challenges for our understanding of past processes at regional and global scales. This paper aims to overcome these limitations by leveraging the specific characteristics of two depositional contexts, the Early Neolithic Swifterbant Culture sites S3 and S4, located in the Dutch wetlands. These sites are of exceptional significance as they provide the earliest conclusive evidence of crop cultivation and animal husbandry outside the expansion of Linearbandkeramik (LBK) farmers in north-western Europe. Here, we present a customized approach that combines radiocarbon dating and Bayesian modeling, predicated on vertical sequences of short-lived plant remains. Our innovative approach enables us to determine, at a fine scale, the temporal position and duration of the prominent archeological contexts at S3 and S4, and explore the chronological relationship between the two sites. Through our analysis, we propose a new chronology for the onset of Neolithization in the Dutch wetlands.

Radiocarbon (14C) dating of the total organic carbon (TOC) content of lacustrine sediments is always affected by a 14C reservoir effect and the 14C dates are often systematically older than the true ages. However, there are few studies of the temporal changes of the 14C reservoir effect, with reference to the specific influencing factors. We collected TOC samples from the Holocene sediments of Lake Kanas, in the southern Altai Mountains, for AMS 14C dating and compared the results with AMS 14C ages based on terrestrial plant macrofossils from the same depths. The results show that the reservoir ages progressively increased from ∼0 to ∼2800 yr between ∼9700 cal BP and ∼530 cal BP. As the lake catchment was glaciated prior to the Holocene, and Holocene soils and peats are the main sources of the TOC in the lake sediments, we argue that soil erosion is the major factor contributing to the progressive increase in the reservoir age. Based on previously reported evidence for increasing moisture in central Asia and glacier advances in the mid-to-late Holocene, we suggest that the intensified soil erosion on the hillslopes was caused by increased precipitation during the mid-to-late Holocene and by anthropogenic forest clearance after 1500 cal BP.

We have radiocarbon-dated the main settlement of Skarkos (Skarkos II) on the Cycladic island of Ios, using a set of animal bone samples. The site of Skarkos stands on a hill in a coastal plain, mid-way down the western side of Ios island and about 1 km from the island’s harbour. It is the first time this important settlement with a wealth of finds and an extraordinary building system with two-storey houses is dated in absolute terms complementing the chronology of the Cycladic EBA II period. The radiocarbon determinations show that the major phase of the settlement came to an end between circa 2550 and circa 2500 BC. The dates also confirm the archaeological evidence that the main occupation period is dated archaeologically to the EC II period (Keros-Syros culture). Furthermore, in order to embed the new Skarkos dates within the overall Cycladic chronology and define better the end of the EC II phase, we treated the Skarkos dates together with published dates from other Cycladic sites using Bayesian analysis considering two different models.

Quantifying the marine radiocarbon reservoir effect, offsets (ΔR), and ΔR variability over time is critical to improving dating estimates of marine samples while also providing a proxy of water mass dynamics. In the northeastern Pacific, where no high-resolution time series of ΔR has yet been established, we sampled radiocarbon (14C) from exactly dated growth increments in a multicentennial chronology of the long-lived bivalve, Pacific geoduck (Paneopea generosa) at the Tree Nob site, coastal British Columbia, Canada. Samples were taken at approximately decadal time intervals from 1725 CE to 1920 CE and indicate average ΔR values of 256 ± 22 years (1σ) consistent with existing discrete estimates. Temporal variability in ΔR is small relative to analogous Atlantic records except for an unusually old-water event, 1802–1812. The correlation between ΔR and sea surface temperature (SST) reconstructed from geoduck increment width is weakly significant (r2 = .29, p = .03), indicating warm water is generally old, when the 1802–1812 interval is excluded. This interval contains the oldest (–2.1σ) anomaly, and that is coincident with the coldest (–2.7σ) anomalies of the temperature reconstruction. An additional 32 14C values spanning 1952–1980 were detrended using a northeastern Pacific bomb pulse curve. Significant positive correlations were identified between the detrended 14C data and annual El Niño Southern Oscillation (ENSO) and summer SST such that cooler conditions are associated with older water. Thus, 14C is generally relatively stable with weak, potentially inconsistent associations to climate variables, but capable of infrequent excursions as illustrated by the unusually cold, old-water 1802–1812 interval.

The Minoan eruption of Santorini, Greece, is an important and often-debated chronological marker in contexts of the Eastern Mediterranean region. Among various age estimates of this event, one based on wiggle-matching of radiocarbon (14C) dates from an olive branch found in Santorini by Friedrich et al. (2006) has been widely discussed. Calibrated age estimates based on wiggle-matching of these 14C ages have been changing with improvements in the 14C calibration curve. As also shown earlier, calibration of average 14C age of multiple tree rings dated together should not be done using a single-year calibration curve. Since recent calibration curves include many single-year 14C datasets, a different approach should be considered to calibrate the average 14C age of block of multiple tree rings. Here we have demonstrated the use of multiple moving average (MA) calibration curves for calibrating the sequence of four 14C ages reported for the Santorini olive branch. The resultant calibrated ages for the Minoan Eruption are relatively younger than previous estimates and range from the late-17th century BCE to mid-16th century BCE date.

Archaeologists keep a limited arsenal of methods for dating stone features at alpine sites. Radiocarbon (14C) dating is rarely possible, and it is common that dates do not accurately represent the activity of interest (stone feature construction). In this paper I review a legacy set of 89 14C dates for stone driveline sites built by hunter-gatherers in Colorado’s Southern Rocky Mountains. I amend the sample of dates using chronometric hygiene and focus on dates with direct association to hunting features. I then present a newly calibrated set of 29 lichenometric dates for rock features at these sites and use hygiene protocols to remove inaccurate dates. Size-frequency lichenometry, though poorly known in archaeology, provides a way to date stone features indirectly by measuring the growth of long-lived lichens that colonize rock surfaces after construction events. Bayesian modeling of the combined set of dates suggests that the tradition of alpine game driving spans over 6000 years BP, with abundant use over the last 2000 years. Archaeologists must use multiple methods for dating stone features in alpine environments. This Bayesian analysis is a formal effort to combine lichenometry and 14C dating for archaeological interpretation.

In this study, the temporal accession date of king Pepy II is modeled by using a series of 14C dates based on samples from the burial of Djau at Deir el-Gebrawi in Middle Egypt. Djau was one of Pepy II’s officials—overseer of Upper Egypt and nomarch of the 8th and 12th provinces. Five samples of Djau’s wrapping as well as his wooden coffin were analyzed. ATR-FTIR (Attenuated Total Reflection–Fourier Transform InfraRed spectroscopy) analyses were carried out on textile samples to ensure they were not contaminated by organic chemicals due to the embalming process, prior to being dated using the conventional radiocarbon method at the IFAO Laboratory (Cairo). Based on archaeological evidence, the temporal density associated with Djau’s death is then used as a chronological marker for the death date of king Pepy II. Taking into account the possibility of either biennial, annual or irregular censuses to assess the duration of his reign, the accession date of Pepy II is thus modeled using OxCal software. The results place king Pepy II’s accession date between 2492 to 2256 BCE with 95.4% probability, and between 2422 to 2297 BCE with 68.3%.

The conquest of the Shang Dynasty at Anyang around 1046 BCE by the Zhou is one of the major events for not only Chinese Bronze Age but also early interaction between the pastoralist groups from the Eurasian Steppes and agriculture ones in the Central Plains of China. It is well-known from historical texts that the pre-Zhou people lived in the ancient Bin region (豳), the exact location of which is unclear, but most likely in the Jing River valley. At some point the leader Gugong Danfu (古公亶父) moved from Bin to the capital Qi (Zhouyuan), which preceded the Zhou invasion of Anyang. We have produced a new high resolution radiocarbon chronology for Zaolinhetan, a small settlement in the pre-Zhou heartland. This shows not only an exceptionally long chronological span for the site, but also a different phasing compared to the traditional pottery typology, which raises new questions regarding the regional variation of pottery typologies. Intriguingly, the analysis also reveals a rapid abandonment of Zaolinhetan around 1100 BCE, at the same time many larger sites, such as Zhouyuan, which later became the capital of the Western Zhou dynasty, were significantly expanding. We argue that the drastic decline of Zaolinhetan as revealed by the substantial number of radiocarbon dates and probably also the movement of pre-Zhou political center from Bin to Qin, was part of bigger picture that involved a range of social and environmental factors.

We present a timeseries of 14CO2 for the period 1910–2021 recorded by annual plants collected in the southwestern United States, centered near Flagstaff, Arizona. This timeseries is dominated by five commonly occurring annual plant species in the region, which is considered broadly representative of the southern Colorado Plateau. Most samples (1910–2015) were previously archived herbarium specimens, with additional samples harvested from field experiments in 2015–2021. We used this novel timeseries to develop a smoothed local record with uncertainties for “bomb spike” 14C dating of recent terrestrial organic matter. Our results highlight the potential importance of local records, as we document a delayed arrival of the 1963–1964 bomb spike peak, lower values in the 1980s, and elevated values in the last decade in comparison to the most current Northern Hemisphere Zone 2 record. It is impossible to retroactively collect atmospheric samples, but archived annual plants serve as faithful scribes: samples from herbaria around the Earth may be an under-utilized resource to improve understanding of the modern carbon cycle.

Fluvial and colluvial deposits of Late Holocene age in South-Central Ontario catchments have provided few 14C dates, most by conventional methods registering century-old ages. Other young deposits, dated by conventional and accelerator mass spectrometry radiocarbon (AMS 14C), have yielded bomb-affected post-1950 ages over variable time limits. Attempts to date the base of Ah and lower-in-section soil horizons, in Early to Late Holocene stream terrace deposits, have yielded atomic bomb effects. Comparing bomb contamination in Late Holocene fluvial deposits, using both conventional and AMS methods, identifies a mix of bomb-affected beds juxtaposed with dated beds, the latter yielding ages with narrow standard deviations. Colluvial deposits overlying key glacial sections in the Rouge Catchment, while rare, yield bracketed AMS ages for an Ahbk horizon that refines weathering times relative to previously obtained conventional 14C dates. Bomb-affected sediment appears variably distributed within floodplain soils and in the ground soil of a colluvial section. Mass wasted deposits, with AMS 14C ages spread over the last few centuries, appear related to Little Ice Age (LIA) changes in climate, corroborated by pollen records. Further, these AMS-14C dated beds calibrate weathering of secondary Fe-Al oxihydroxides over the first half a millennium of weathering time.

Through Bayesian analysis of new radiocarbon dates, this paper demonstrates that the Topará tradition did not emerge until after Paracas monumental sites were ritually closed in the Chincha Valley of the Peruvian south coast. These findings controvert a long-held hypothesis of Topará as a foreign tradition which intruded into the Paracas heartland and initiated the period of transformation known as the Paracas-Nasca transition. We present the first radiocarbon dates from Jahuay, the earliest accepted Topará site. These dates are compared with new analyses of published radiocarbon dates from three other sites associated with this transitional period: a Late Paracas politico-ceremonial site in the Chincha Valley, a Late Paracas settlement in the Palpa Valley in the Río Grande de Nasca Drainage, and an Initial Nasca site in the same valley. This work shows Paracas site closures began earlier than has previously been appreciated and demonstrates that the first appearance of the Topará ceramic style post-dates the onset of Paracas decline in the region’s northern valleys. This analysis represents a successful attempt to develop a radiocarbon-based chronology across a calibration plateau by incorporating stratigraphic data into a Bayesian model.

In autumn of 2016, the National 1MV Accelerator Mass Spectrometry (AMS) Laboratory at The Scientific and Technological Research Council of Türkiye (TÜBİTAK), Marmara Research Center (MRC), Türkiye (Turkey), started to offer radiocarbon (14C) analysis service internationally. In this article, the process from sample acceptance to reporting and the primary procedures implemented and applied for 14C analysis at the TÜBİTAK AMS Radiocarbon Dating Laboratory are described. The service provided by the laboratory includes sample evaluation for 14C analysis, sample preparation, graphite production, AMS measurement, data supervision, calendar date calculations, and consultancy. For commercial testing and analysis, a one-page official report which shows the 14C age and uncertainty is provided for each sample. In addition to a dedicated wet chemistry laboratory to process samples before measurement with AMS, there are two systems for the conversion of CO2 to elemental carbon process; an automated graphitization system (AGE III) and a manual graphitization system based on a glass high vacuum line. A 1MV UAMS NEC Pelletron system installed in the laboratory is used for natural level 14C samples needed to be analyzed for archeological, geological, geographical, and environmental and forensic science applications. In addition to commercial 14C testing and analysis activities, national and international research projects can be developed or contributed to within the scope of project management or partnership.

Late Quaternary fluvial channel deposits are notoriously difficult to date. In the midwestern United States, shells of aquatic mollusks can be found within many fluvial channel sediments and therefore can be radiocarbon (14C) dated to determine the age of the deposits. However, carbonate platform rocks are abundant in this region, potentially causing freshwater 14C reservoir effects (FRE) in mollusk shells. We 14C dated 11 aquatic gastropod and bivalve shell samples from specimens collected live from a stream in southwestern Ohio during three different years to assess the modern 14C reservoir effect. Modern samples yielded an average 14C FREmodern of 518 ± 65 14C yrs for 2020 (n=5), 640 ± 34 14C yrs for 2021 (n=2), and 707 ± 76 14C yrs for 2022 (n=4). We also 14C dated matched pairs of organic wood or charcoal and aquatic mollusk shells from late Pleistocene and Holocene deposits in the Four Mile Creek floodplain to determine the FREfossil. These samples, free of any potential influence from nuclear bomb testing, yielded an overall weighted mean FREfossil of 1029 ± 345 14C yrs. We then assess the advantages and limitations of both the FREmodern and FREfossil methods for determining freshwater reservoir effects. Finally, we apply the FREfossil correction to a series of shell ages from fluvial terrace deposits as a case study. The results indicate that although there is a 14C FRE in streams from the midwestern United States, aquatic shells can provide robust age control on fluvial channel deposits. More research is needed to understand the spatial and temporal variability of FREs, as well as any species effects, among various watersheds across the midwestern United States.

The Swan Point site in interior Alaska contains a significant multi-component archaeological record dating back to 14,200 cal BP. The site’s radiocarbon (14C) chronology has been presented in scattered publications that mostly focus on specific archaeological periods in Alaska, in particular its terminal Pleistocene components associated with the East Beringian tradition. This paper synthesizes the site’s 14C data and provides sequential Bayesian models for its cultural zones and subzones. The 14C and archaeological record at Swan Point attests that the location was persistently used over the last 14,000 years, even though major changes are evident within regional vegetation and local faunal communities, reflecting long-term trends culminating in Dene-Athabascan history.

Politiko-Troullia has generated the largest radiocarbon (14C) dataset from a Prehistoric Bronze Age settlement on Cyprus. We present Bayesian modeling of 25 calibrated AMS ages, which contributes to an emerging multi-site 14C chronology for Cyprus covering most of the Prehistoric Bronze Age. Our analysis places the six stratified phases of occupation at Troullia between about 2050 and 1850 cal BCE, in contrast to a longer estimated occupation inferred from pottery analysis. We provide a rare 14C determination for the transition from Prehistoric Bronze Age 1 to 2 just after 2000 cal BCE, associated with a major architectural dislocation at Politiko-Troullia in response to local landscape erosion, possibly due to increased regional precipitation. We present a regional 14C model for Prehistoric Bronze Age Cyprus combining the chronology for Politiko-Troullia with modeled 14C ages from Sotira Kaminoudhia and Marki Alonia, which is bolstered by individual ages from five other settlements on Cyprus. Through the Prehistoric Bronze Age, agrarian villages on Cyprus developed the foundations for the emergence of urbanized settlement and society during the ensuing Protohistoric Bronze Age. Politiko-Troullia, in conjunction with other key settlements on Cyprus, provides a significant independent contribution to increasingly robust Bronze Age 14C chronologies in the Eastern Mediterranean.

Sequential thermal analysis allows for deconvoluting the refractory nature and complexity of carbon mixtures embedded in mineral matrices for subsequent offline stable carbon and radiocarbon (14C) isotope analyses. Originally developed to separate Holocene from more ancient sedimentary organic matter to improve dating of marine sediments, the Ramped Pyrolysis and Oxidation (RPO) apparatus, or informally, the “dirt burner” is now used to address pressing questions in the broad field of biogeochemistry. The growing interest in the community now necessitates improved handling and procedures for routine analyses of difficult sample types. Here we report on advances in CO2 purification during sample processing, modifications to the instrumentation at the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility, and introduce sodium bicarbonate procedural standards with differing natural abundance 14C signatures for blank assessment. Measurements from different environmental samples are used to compare the procedure to the different generations of sequential thermal analyses. With this study, we aim to improve the standardization of the procedures and prepare this instrumentation for innovations in online stable carbon isotopes and direct AMS-interface measurements in the future.

We present two new millennium-long tree-ring oxygen isotope chronologies for central and northern Japan, based on 9693 annually resolved measurements of tree-ring oxygen isotopes from 39 unearthed samples consisting mainly of Japanese cedar (Cryptomeria japonica). These chronologies were developed through cross-dating of tree-ring widths and δ18O data from multiple samples covering the periods 2349–1009 BCE (1341 yr) and 1412–466 BCE (947 yr) for central and northern Japan, respectively. In combination with our published chronology for central Japan, the tree-ring δ18O dataset currently available covers the past 4354 yr (2349 BCE to 2005 CE), which represents the longest annually resolved tree-ring δ18O dataset for Asia. Furthermore, the high-resolution temporal record of 14C contents independently developed by Sakurai et al. (2020) was reproduced by our 14C measurements of earlywood and latewood in annual rings for the period 667–660 BCE.

The paper presents the results of radiocarbon (14C) concentration measurements in tree rings in the vicinity of Kursk NPP (Russia) with four operating RBMK reactors. The sampling was carried out from the site with the highest expected accumulation of radiocarbon in vegetation. The site was determined with long-term meteorological data. The measurements of 14C concentration carried out with accelerator-mass spectrometer in Budker Institute of Nuclear Physics, Novosibirsk, Russia. The obtained results demonstrated the influence of exploitation of Kursk NPP to the concentration of 14C in tree rings. Based on the equilibrium between the 14C ratio in the tree rings and the surrounding air, retrospective estimates of the radiocarbon discharge and effective doses were made. Effective doses were calculated with two approaches: IAEA methodology and less conservative approach, considering the real food consumption in the Kursk region. The values of calculated doses by the second method (0.08–2.58 μSv) are more than 2 times less than IAEA approach (0.17–5.30 μSv). The highest difference between measured and background 14C in tree ring is 41.7 ± 5.8 pMC in 2014 during the restoration of graphite stack. The main contribution to 14С exposure in the considering period is caused by background – from 70 to 99%.

Reliable radiocarbon (14C) ages of foraminifera are a prerequisite to generate robust high-resolution age-depth models or to obtain precise understanding of past carbon cycle dynamics. With the advance of small-scale 14C measurements, instrumental precision and levels of contamination (extraneous carbon introduced during sample pretreatment or analysis) became increasingly important to consider. To reduce the effect of carbon contamination, an attempt can be made to remove it by leaching the surface with weak acids. Alternatively, mathematical corrections (e.g., subtraction) based on processing blanks can be applied. We report on 14C analyses of monospecific foraminifera samples compared between different blank corrections (correction against 14C-free CO2, IAEA-C1 and foraminifera) and sample treatments (i) to examine whether chemical pretreatment and mathematical blank subtraction are comparable, and (ii) to determine limitations hindering reliable 14C dating with ever smaller sample sizes. The data show that chemical pretreatment of foraminifera corrected against IAEA-C1 does remove surface contamination and that the same effect can be achieved for untreated samples that were mathematically corrected for blank values determined from sample size-matched 14C-free foraminifera. Leaching only has a beneficial effect on 14C data for older samples, where the isotopic difference between untreated and chemically pretreated samples exceeds the analytical precision.