The Neolithic of the northeastern Iranian Plateau is defined basically by the materials recovered from the twin mounds of Sang-e Chakhmaq, the West Mound and the East Mound. The radiocarbon dates from these mounds span almost two thousand years, from around 7000 BCE to the last centuries of the sixth millennium BCE, with a chronological hiatus between ca. 6700–6200 BCE. Recent excavations at a proto-ceramic Neolithic site, Rouyan, in the vicinity of Sang-e Chakhmaq, provided occupational evidence, augmented by a series of Radiocarbon dates, which fill in the long-standing temporal hiatus of the Neolithic of the region. Both 14C dates and archaeological evidence from this excavation suggests that Rouyan was founded simultaneously with the West Mound of Sang-e Chakhmaq, but its occupation continued without discontinuity into the fifth millennium BCE. The excavation also yielded a small ceramic assemblage from the earliest deposits of the site, indicating the site’s first settlers were familiar with this technology as early as ca. 7000 BCE.

The chronology of the Bronze Age in the Carpathian basin is largely based on relative chronologies, i.e. stylistic analysis of ceramic (and other) materials. While the number of radiocarbon dates is generally increasing, certain important sites are still poorly dated. One of the largest necropolises from this period, i.e. Mokrin necropolis, which traditionally belongs to Maros culture, is dated only with 6 radiocarbon dates. Here we synthesize the previous 6 radiocarbon dates with 13 new radiocarbon dates, with two goals in mind: 1) to explore the absolute chronology of the site, specifically to determine its chronological limits; and 2) to test hypotheses about the spatio-temporal organization of the site. Our data show that the chronological limits of the necropolis were most probably between 2073 and 1822 BC. Concerning traditional relative chronologies, none of the previous hypotheses about the internal chronological development of the necropolis is supported by data. Our results suggest that all parts of the necropolis were used relatively simultaneously.

The dietary habits of Neanderthals are considered an issue of great interest in the literature and have opened an important number of fruitful debates. Indeed, understanding diets can provide important information regarding issues of palaeoenvironmental reconstructions and subsistence strategies. In this respect, dental remains can play a vital role in the conducted efforts to reconstruct the palaeoecological niches securely and accurately since dental microwear analyses have precisely detected dietary patterns of the populations in the past. In this context, the Iberian Peninsula forms an interesting model for examining Neanderthal populations, their subsistence strategies, and adaptive skills. This study aims the examination of already published data in order to provide a holistic approach regarding the dietary habits of H. neanderthalensis populations in the Iberian Peninsula, along with the importance of the utilization of dental microwear analysis in the archaeological record.

We investigated radiocarbon dates of human bone samples from several medieval sites in Trondheim, central Norway. Stable isotope data was used to estimate marine correction for the radiocarbon dates, which is necessary to correct the radiocarbon ages and establish age models for the archaeological layers. We observed that a marine correction without ΔR does not lead to a well-defined model for all sites. Allowing a variable ΔR improves the model, which indicates that food sources and trade routes have changed over time, influencing the mobility of food resources as well as of people. However, this does not work for all sites, indicating that variation of reservoir ages could also be the result of individual preferences for the food and that fish with different ΔR, and thus different geographical origin, was consumed during the same periods. Many radiocarbon and stable isotope (δ13C, δ15N) measurements have been carried out for the project. We calculated %marine consumption from the isotope values and found that it varies greatly, between 7% and 51%, and apparently independent of period, social status, churchyard location or other factors. Based on these data, we determined average reservoir ages for the marine food consumed in Trondheim during different phases, varying between ΔR = –150 and 280 years.

Marine aerosols can enter the terrestrial environment via sea spray which is known to affect the stable isotope fingerprint of coastal samples (plants, animals/humans), including δ13C. However, the impact of sea spray on 14C dating of terrestrial organisms at coastal sites has not been investigated so far. Besides a direct effect, sea spray is accompanied by physiological effects, e.g., due to salinity. In an artificial sea spray experiment in the greenhouse, the effect of sea spray on 14C in plant tissue was investigated. Beach grass was sprayed with mineral salt solutions containing only traces of NaCl or with brackish water from the Schlei inlet or the Baltic Sea. These plants should give a 14C signal close to the modern atmospheric 14CO2 composition. However, three treatment groups showed variable radiocarbon concentrations. Plants sprayed with water from the Schlei inlet, Baltic Sea water, or with a mineral salt solution with very high HCO3– concentration are depleted in 14C content relative to contemporary atmospheric composition. While δ13C reflects physiological effects in the plants, caused either by salinity (NaCl) or HCO3– stress, resulting in decreased discrimination against 13C, the uptake of high amounts of 14C (ca. 53–67%) from DIC (dissolved inorganic carbon) partly masks the underlying physiological reactions, as is visible in the radiocarbon signature of the plant tissues. This preliminary study indicates that sea spray effects on plant tissue could potentially influence faunal tissue 14C composition at coastal sites. Further research is required to better understand the observed reservoir effect.

The Manych Depression is a relatively narrow elongated depression of tectonic origin, connecting the Caspian and Azov-Black Sea basins. The Caspian Sea repeatedly discharged its waters through this depression into the Black Sea and further into the Mediterranean Sea during the Quaternary period. The last discharge occurred in MIS 2 when the Khvalynian transgression waters exceeded the drainage divide between those two basins. The geochronology of the last flow of Caspian waters into the Black Sea was established recently based on 14C dating of Khvalynian shells, carried out mainly by liquid scintillation counting, and the end of this event was dated to 12.5–12.8 ka cal BP. Recently obtained OSL dates for one of the most complete sections of the Khvalynian deposits of the Manych Depression indicate an older time for the end of the flow. This study aimed to clarify the timing of the Khvalynian transgression discharge by examining two sections containing the Khvalynian mollusk fauna in layers that, according to their stratigraphic and geomorphological position, belong to the final phase of the flow of the Caspian waters. Four 14C AMS dates were obtained from single shells of Didacna ebersini and Hypanis plicata, which agree with the OSL dating results. The results indicate that the last overflow of Caspian waters through the Manych Depression had ceased at around 14.5 ka cal BP.

Plague and famine are two of the worst killers in human history. Both struck the Czech lands in the Middle Ages not long after each other (the famine of 1318 CE and the plague of 1348–1350 CE). The aim of our study was to try to relate the mass graves found in the vicinity of the Chapel of All Saints with an ossuary in the Kutná Hora–Sedlec site to these two specific events. For this purpose, we used stratigraphic and archaeological data, radiocarbon dating, and Bayesian modeling of 172 calibrated AMS ages obtained from teeth and bones of 86 individuals buried in the mass graves. Based on the stratigraphic and archaeological data, five mass graves were interpreted as famine graves and eight mass graves were interpreted as plague graves. Using these data and the calibration of the radiocarbon results of the tooth-bone pairs of each individual, we constructed the Bayesian model to interpret the remaining mass graves for which no contextual information was available (eight mass graves). In terms of Bayesian model results, the model fits stratigraphic data in 23 out of 34 cases and in all seven cases based on calibration data. To validate the model results on archaeologically and stratigraphically uninterpreted data, ancient DNA analysis is required to identify Yersinia pestis.

An international consortium of radiocarbon laboratories has established the origin of the Church of St. Margaret of Antioch in Kopčany (Slovakia), because its age was not well known from previous investigations. In total, 13 samples of charcoal, wood, mortar, and plaster were analyzed. The 14C results obtained from the different laboratories, as well as between the different sample types, were in good agreement. Resulting the final 14C calibrated age of the Church, based on dating a single piece of a wooden levelling rod is 774–884 AD (95.4% confidence level), which is in very good agreement with Bayesian modeling result based on dating of wood, charcoal and mortar samples (788–884 AD, 95.4% confidence level). The probability distribution from OxCal calibration shows that 79% of the probability distribution lies in the period before 863 AD, implying that the Church could have been constructed before the arrival of Constantine (St. Cyril) and St. Methodius to Great Moravia. If we take as the terminus post quem the documented date of consecration of the church in Nitrava (828 AD), the Bayesian modeling suggests the age of the Church in the range of 837–884 AD (95.4% confidence level). Although the 14C results have very good precision, the specific plateau shape of the calibration curve in this period caused a wide range of the calibrated age. The Church represents, together with the St. George’s Rotunda in Nitrianska Blatnica, probably the oldest standing purpose-built Christian church in the eastern part of Central Europe.

Measurements of the radiocarbon (14C) content of subannual wood cellulose samples over the 1963 bomb spike have revealed an apparent delay between the increase in atmospheric radiocarbon content and that of wood cellulose. This delay is apparent in both coniferous and deciduous tree species and is of a magnitude of approximately 4 weeks. The delay in wood cellulose 14C change as measured in a Sitka spruce from Washington state, USA, was previously used to estimate the relative influence of tree physiological effects contra environmental effects. We repeated the measurements with the increased measurement precision of today’s AMS systems and compare the new results to the ones of a Scots pine tree from Trondheim, central Norway and a white oak from Oregon state, USA. The results challenge the assumption that the 14C tree ring records directly show the atmospheric 14C concentration of a homogeneous, zonally well-mixed atmosphere. Instead, the apparent 1963 delay reflects local influences of the ecosystem and tree physiology. The 1963/1964 data allows for exploratory modeling of the effects of biospheric decay CO2 and local environmental influences assuming the absence of stored photosynthates from the previous year. Compared to the 10–30% contribution from biospheric CO2, the effects of delayed incorporation of carbon into the wood cellulose and the effect of stored photosynthate are small in the conifers. Highly detailed 14C records of stem cellulose can, in combination with stable isotope studies, contribute to our understanding of variability of the local carbon cycle, climate, and the environment.

The green tree python is quite a favorite pet for sale on the international market. The species is therefore protected by the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES). Since the illegal poaching of large numbers of specimens in the wild might lead to the detriment of native populations, and wildlife breeding farms were found to be serving as conduits to funnel wild-caught green tree pythons out of Indonesia, a forensic tool to distinguish wild-caught from captive-bred specimens could support the enforcement of CITES protections. To disrupt the illegal trade of green tree pythons, we have developed an effective tool to distinguish the animals supposedly bred in captivity from those caught in the wild, based on the strontium isotope composition in conjunction with trace element data. Like in human hair, 87Sr/86Sr values seem to vary according to the relative contribution of endogenous and exogenous sources. Thus, we infer that if there is enough sustainable strontium available for the analysis, it might be possible to use the 87Sr/86Sr values in parallel with trace elements to distinguish wild-originated specimens from the in captivity-bred ones. Indeed, our pilot study on the shed skins of animals where the geographic origin was either the Czech Republic or Indonesia, confirms that shed skins can be effectively used for further forensic Sr radiogenic isotope analyses.

This study aims to discuss the chronology of the Egyptian 5th dynasty of the Old Kingdom and the tentative date of accession of king Djedkare based on material from his royal necropolis at South Saqqara and non-royal cemetery of Abusir South, Egypt. A series of radiocarbon (14C) dates were established through analysis of archaeological material from several monuments at the necropolis, including the king’s pyramid complex, pyramid complex of his queen, and two elite tombs (Isesiankh and Khuwy). In addition, two samples from non-royal tombs in the Abusir South cemetery, were taken into consideration for further precision during the modeling, associated with king Huni (end 3rd dynasty) and king Niuserre (5th dynasty). The contextualized 14C dates together with re-evaluation of historical evidence on Djedkare’s rule, results in a new model of temporal probability density which can be further refined with any new data from archaeological research. It shows that Djedkare’s reign can be currently modelled between 2503 and 2449 BCE (95.4%), thus slightly older than expected by literature. This presented model provides a more precise chronological frame for the late 5th dynasty period of Egyptian history, which was period of a significant socio-economic transformation.

Radiocarbon (14C) measurements play important roles in dating and tracing applications where the isotopic concentration can differ from 0.1 to 106 pMC (percent modern carbon). A liquid scintillation counter cannot provide enough sensitivity when dealing with low-concentration samples of limited amounts over a reasonable time period. Accelerator mass spectroscopy (AMS) measures low-concentrations well but must first do dilution for high-concentration samples, and suffers from high instrument and maintenance costs. Saturated absorption CAvity Ring-down spectroscopy (SCAR) has now been developed into a practical technique with performances close to AMS but at much lower costs. The dynamic range covers 1–105 pMC, and the measurement uncertainties in the range of 0.4–1 pMC can be achieved within 0.5–2.5 hr of operation time. SCAR measures CO2 gases directly without graphitization in sample preparation. The typical sample consumption is ∼1 mg of carbon mass and the time for sample preparation can be as short as 15 min. Applications of SCAR to Suess-effect evaluation, biogenic-component analysis, ancient- and modern-sample dating, food-fraud detection and medicine-metabolism study have all been demonstrated by employing a close-to-automatic sample preparation system.

In this article, we present the first results from radiocarbon dating of the Kirakle-Tobe settlement located in the central part of the Volga River Delta, southern Russia. Archaeological artifacts and 14C measurements on charcoal indicate three stages of settlement development on the Kirakle-Tobe knoll. The oldest 14C age corresponds to the Late Sarmatian period—early 4th century CE. The abundance of archaeological artifacts associated with the 6th–8th centuries CE indicates a long period of occupation. The youngest 14C age presumably corresponds to the Khazarian period (9th century CE). These results suggest dynamic human activity in the central part of the Volga River Delta during the Great Migration Period. These initial results can be used to verify the impact of fluctuations in the Caspian Sea level on the Volga River Delta during the Great Migration Period.

Despite the continuous reporting of radiometric chronology of lithic assemblages in the Korean peninsula, systematic evaluation of reliable radiocarbon (14C) dates and discussion on the lithic technological variability have not been adequately presented. This paper attempts to address the issue reviewing the available data on the Early Upper Paleolithic (EUP) of Korea, with a focus on 14C chronology and lithic technology. Also, these recent advances in Paleolithic studies in Korea provide interesting aspects of the transition to Upper Paleolithic (UP) technology in East Asia. The transition to the UP is characterized by two key developments: the emergence of blade technology and tanged points, and the use of quality raw material that had been previously disregarded. Reliable 14C dates published recently indicate that this transition began around 43,000–40,000 cal BP. We propose that the emergence of the UP tradition on the Korean peninsula can be explained by focusing on the mobility, regional exchange networks and population dynamics of hunter-gatherers rather than the continuing resort to the simple unidirectional dispersal.

In recent decades, numerous excavations have been conducted at prehistoric sites in northwestern Iran, and the results of these studies have contributed to the development of a chronological framework for the region. The early Chalcolithic period in this area is referred to as the Dalma or Hasanlu X period. Various theories have been proposed regarding the chronological span of this culture, yet challenges and debates about its dating remain. The Belachak 3 site is one of the settlements attributed to this period, excavated by the first author of this article. The excavation results indicate that the site was temporarily occupied. The pottery recovered from this site closely resembles the ceramics found at well-known Dalma sites such as Dalma Tepe and Nad Ali Beig. This article aims first to explore the relative and absolute chronology of the Belachak 3 site. Subsequently, it evaluates the dating of this culture based on the absolute chronology of this and other Chalcolithic sites in western and northwestern Iran. For dating Belachak 3, five animal bones were sent to the Poznań Radiocarbon Laboratory. The results indicate that the site was occupied around 5000–4700 BCE. Additionally, based on the pottery findings and absolute dating, it can be suggested that the Dalma culture likely emerged in the late 6th millennium BCE and became widespread across large areas of western and northwestern Iran from around 5000 BCE onward.

Five unknown Holocene flank eruptions from the Masaya caldera are reported here. These eruptions comprise basaltic lava flows emplaced in Masaya’s northern rift zone along the Cofradía fault zone, east of Managua City. The lava flows were defined as Mosintepe, Portillo, Gorgonia, Campuzano, and Martha units. Paleosol samples were collected below each lava flow, and radiocarbon AMS analyses were performed, yielding ages of 2250 ± 30, 1610 ± 30, 1600 ± 30, 1140 ± 30, and 790 ± 30 yrs BP, respectively. Calibrated age intervals are 285–229 cal BC for Mosintepe, 496–534 cal AD for Portillo, 496–535 cal AD for Gorgonia, 914–976 cal AD for Campuzano, and 1226–1268 cal AD for Martha; all stratigraphically consistent. These eruptions emitted magma bulk volumes between 0.02 and 0.51 km3, reaching up to 8 km from their eruptive vent and 13 km from Masaya’s polygenetic system summit crater. Their mineral paragenesis, and major and trace element geochemical fingerprint reveals a common volcanic provenance from the Masaya caldera due to lateral magma draining. This study demonstrates that basaltic lava flow flank eruptions are common in the Masaya caldera along its northern volcanic rift zone. Therefore, this information should be considered in future hazard and risk assessments.

Accelerator mass spectrometry (AMS) is a worldwide recognized method for radiocarbon (14C) dating. The advantageous aspects of this method include the variety of materials and the small sample size (1 mg of carbon) that can be measured. However, these pose several challenges in the laboratory, such as developing appropriate chemical pretreatment methods. In the summer of 2022, the Radiocarbon and Mass Spectrometry Laboratory in Gliwice, Poland, launched the MICADAS accelerator spectrometer. The report on background and reference materials measurement results for the period from September 2022 to July 2024 is presented in this publication. Quality assurance and quality control processes are extremely important to guarantee the high quality of the results obtained in the laboratory. Hence, our Radiocarbon and Mass Spectrometry Laboratory in Gliwice took part in the Glasgow International Radiocarbon Inter-Comparison (GIRI) program. The radiocarbon ages for wood, bone, humic acid, and barley mash samples were determined and compared with reported values. The resulting data confirmed that our Laboratory is capable of dating samples across a spectrum of materials and ages ranging from contemporary to the limits of the radiocarbon method, achieving precision on par with that of other laboratories.

The application of a tube combustion system (pyrolyzer) for the batch combustion of low carbon content environmental matrices, such as soil and sediment, for determining 14C specific activity is examined. The samples were combusted at 600°C, and the CO2 species produced were trapped in 3N NaOH, precipitated as BaCO3 by adding BaCl2, and subjected to acid-hydrolysis to transfer the CO2 species to the absorber-scintillator mixture for liquid scintillation counting (LSC). The method was validated by analyzing the samples by accelerator mass spectrometry (AMS) method. The minimum detectable activity (MDA) for the method, at 2σ confidence level, was 10 Bq kg–1C (4 pMC) for a counting time of 500 min and 7 Bq kg–1C (3 pMC) for 1000 min. The capability of the method to quantify a small excess of 14C specific activity (a few Bq kg–1C or pMC) in the environment of a nuclear facility, when compared to the ambient natural background level, was demonstrated by analyzing a total of 23 soil and 7 sediment samples from the vicinity of a pressurized heavy water reactor (PHWR) nuclear power plant (NPP) at Kaiga, India. The maximum excess 14C specific activity values recorded for soil and sediment matrices were 37 ± 7 Bq kg–1C and 11 ± 7 Bq kg–1C, respectively, confirming minimal radioecological impact of the operation of the NPP on the environment. The 14C specific activity ratio for the recently fallen leaf litter and the soil underneath at most of the sampling points in the vicinity of the NPP had a mean value of 1.03 with an associated standard deviation of 0.07. Statistical tests confirm that the mean values of the data set of 14C specific activity of leaf litter and underlying soil are not significantly different.

A limitation in fine-tuned tree-ring radiocarbon (14C) data is normally associated with overall data uncertainty. Tree-ring 14C data variance as a result of sample heterogeneity can be reduced by adopting best practices at the time of sample collection and subsequent preparation and analysis. Variance-reduction of 14C data was achieved by meticulous sample handling during increment core or cross-sectional cuttings, in-laboratory wood reductions, and cellulose fiber homogenization of whole rings. To demonstrate the performance of those procedures to final 14C results, we took advantage of the replicated data from assigned calendar years of two Pantropical post-1950 AD tree-ring 14C reconstructions. Two Cedrela fissilis Vell. trees spaced 22.5 km apart, and two trees of this species together with one Peltogyne paniculata Benth tree spaced 0.2 to 5 km apart were sampled in a tropical dry and moist forest, respectively. Replicate 14C data were then obtained from grouped tree-ring samples from each site. A total of 88% of the replicated 14C results fell into a remarkably consistent precision/accuracy range of 0.3% or less, even though multiple tree species were used as pairs/sets. This finding illustrates how adopting a few simple strategies, in tandem with already established chemical extraction procedures and high-precision 14C analysis, can improve 14C data results of tropical trees.

The cycling of carbon in riverine systems is a critical component of global carbon cycle research. However, the sources and performances of riverine carbon in the Qinling Mountains, a pivotal hydrological nexus in China, remain poorly understood. This study investigates the seasonal variations of dissolved organic carbon (DOC) concentration in the Tianyu River within the Qinling Mountains. By utilizing a combination of carbon isotopic signatures (Δ14C-δ13C) and the stepped-combustion method, we examined the sources of DOC and the contribution ratio of each end-member. Our findings reveal that: (1) the concentrations and dual carbon isotope ratios of DOC in the Tianyu River are influenced by regional climatic factors, exhibiting distinct seasonal patterns; (2) the 14C age of DOC in the Tianyu River is comparatively older than the global average for rivers but younger than that of China’s three major rivers (the Yellow, Yangtze, and Pearl Rivers); and (3) the DOC mainly comes from exogenous sources, with a proportion of about 85.8%–88.4%. Vegetation and riverine sediments are identified as primary contributors. These findings suggest that exemplary ecological preservation exists within the Qinling region while operating within an efficient carbon cycling system. This investigation provides initial insights into how regional climatic conditions influence riverine carbon cycles and enhances our understanding of biogeochemical processes related to carbon.