Lebanon has known permanent and successive human occupations since the Lower Palaeolithic, which contributed largely to its rich archaeological and cultural heritage. Numerous archaeological excavations have unearthed remains spanning most prehistorical and historical periods. The Chalcolithic (ca. mid-5th to mid-4th millennium BCE in the Levant), the focus period of this paper, represents a critical transitional phase in prehistoric societal evolution, though absolute chronological data from this period in Lebanon remains limited. A few sites from this period have been studied in Lebanon, with very few 14C dates produced. The RML79 site lies on the northern slope of the Ashrafieh hill, to the east of the capital Beirut, and was excavated intermittently between 2008 and 2012. The preliminary phasing of the site is based on the retrieved ceramics, which indicate that the site was occupied as early as the Chalcolithic period, giving for the first time new insights into a human occupation from this period in the eastern outskirts of the capital. Radiocarbon dates of four charcoal samples collected from the Chalcolithic phase of RML79 confirmed that the latter occupation occurred during the second half of the fifth millennium, with a possible peak in human activity between 4330 BCE and 4000 BCE.

This paper presents 56 AMS radiocarbon dates from three early medieval sites in Italy: nine from the Roman Villa of Vacone in Vacone (RI), Lazio, 29 from the Roman Villa of Selvicciola in Ischia di Castro (VT), Lazio, and 18 from the necropolis of Povegliano Veronese (VR), Veneto. These results more than double the number of previously published radiocarbon dates from early medieval Italy and are therefore a substantial contribution to the absolute chronology of early medieval cemeteries of Italy. These dates have implications for the relative dating of grave goods, grave reuse, and explaining the presence of graves with multiple individuals.

Bayesian modeling applied to accelerator mass spectrometry radiocarbon (AMS 14C) dates on samples associated with burials and seasonal campsites of various cultures suggests a revised chronology for the Sal steppes and northern fringes of the Kuma-Manych Depression in the Lower Don region in the south of the Russian Plain. The new chronological framework makes it possible to eliminate existing time gaps and refine or extend chronological periods. It also shows short overlapping periods with co-existence of regional groups. The time range covers several millennia, from the fifth millennium BC to the middle of the second millennium AD. The new radiocarbon chronology reveals significant regional differences. These results are very important because the Lower Don region stands out from other regions due to its geographical location, and because its populations had a large impact on the cultural development in eastern Europe and beyond throughout millennia.

Oil contamination in estuarine and coastal ecosystems presents major challenges for environmental monitoring due to the complex mixture of organic matter from biogenic and petrogenic sources. This review synthesizes recent advances and limitations in the combined use of carbon isotopes δ13C and Δ14C to trace petroleum contamination in marine sediments. Sixteen empirical studies were analyzed to evaluate the effectiveness of this dual-isotope approach in identifying fossil carbon, estimating its degradation state, and assessing its environmental persistence. While δ13C provides insights into organic matter sources and transformation, Δ14C offers a sensitive tracer for detecting fossil carbon inputs, even in low concentrations or mixed matrices. The review highlights how their integration strengthens source attribution and enhances the resolution of hydrocarbon monitoring in dynamic coastal settings. An exploratory typology based on Δ14C and Fm is proposed to semi-quantitatively classify contamination severity and support cross-study comparisons. Despite its potential, the approach faces challenges such as high analytical costs, limited laboratory access, and a lack of methodological standardization. Future efforts should focus on integrating compound-specific isotope analysis, expanding applications in mangrove ecosystems, and refining interpretative models to improve the forensic utility of carbon isotopes in oil spill investigations. This review contributes to the systematization of isotopic methods in environmental forensics and reinforces their role in tracing petroleum-derived carbon in sensitive coastal environments.

The recently excavated double church at the site of al-Jumayil (Bishoprich of Madaba, Jordan), devoid of inscriptions, has been tentatively dated to the late 6th century CE, based on stratigraphic evidence, architectural parallels with securely dated churches, and stylistic analysis of mosaic floors. This study aims to advance understanding of the complex’s chronological development through a multidisciplinary approach. The primary methodology involves radiocarbon dating organic inclusions found in the construction mortars used for joint filling and wall coating, alongside an investigation into the mortars’ production technology. The results are integrated with data from previous archaeological excavations and relevant historical sources to refine the site’s chronological framework and address existing gaps in the architectural sequence. The results showed the use of three recipes with varying percentages of organic and inorganic inclusions to produce lime-based white plaster and dark gray mortar coatings and fillings. The results indicate that the complex was constructed in the late 6th to the first half of the 7th centuries CE and underwent stages of ecclesiastical use, destruction, and post-ecclesiastical use before its collapse and abandonment. The results are in good agreement with the regional widespread church construction during the late Byzantine period, a period of regional economic prosperity.

The Holocene clastic and organic sediments from the La Falda section (northern Puna, Argentina), covering the late Northgrippian to early Meghalayan periods, were analyzed. These sediments contain abundant plant macrofossils and microfossils, including leaves and stems attributed to Cyperaceae and Poaceae, as well as pollen. Charcoal is also present in significant amounts. The analysis of these remains provides insights into past environmental and climatic conditions. Our results suggest that palaeoenvironmental and palaeoclimatic changes during this period were relatively minor, with a clear trend of geomorphological stability. Geochronological data, based on 15 radiocarbon dates, confirm through a depth-age model that no major erosion or accumulation events occurred between 4750 and 3450 cal BP.

The Fuji River flows approximately 128 km from north to south near the center of the Japanese archipelago, with its mouth located near the collision boundary between the Eurasian Plate and the Philippine Sea Plate. To investigate the Holocene activity of an onshore subduction thrust at the northern end of the Nankai Trough, we measured radiocarbon ages of terrestrial plants and marine shells in sediments collected from across the Fuji River. Ten sediment cores, Ng-1 to 4, Km-1 to 5, and Nz-1, were obtained from an uplifted terrace to a subsidence lowland along the border of Suruga Bay. Based on analyses of lithology, molluscan assemblages, and radiocarbon dating, the cores were classified into six sedimentary facies. In ascending order, they are river channel, floodplain, estuary, estuary front, inner bay, and lagoon. These paleoenvironmental changes are primarily associated with sea-level fluctuations and tectonic movements during the post-deglacial period. The terrestrial accumulation curve aligns with the horizons of Kawago-daira pumice and Kikai-Akahoya volcanic ash. Reservoir ages of six pairs from the estuary to inner bay facies of the Ng1 core ranged from 150 ± 70 to 470 ± 60, during the period from 7900 to 6800 cal BP, and their average was calculated to be 310 ± 120 years. The chronological changes in the reservoir effect can be correlated with Holocene sediments from the coastal area of Southwest Japan under the influence of the Kuroshio warm current.

This research presents AMS radiocarbon dating results obtained from recently excavated burials and dwellings at three sites—Xiaxinguang, Wulasitai, and Daxigougoukou—located in the Wulasitai Valley of the Middle Tian Shan Mountains and attributed to the Chawuhu culture. The Bayesian modeling of these data yields a high-resolution chronological framework for Early Iron Age activity in the valley. The results identify a tripartite sequence comprising an Early Stage (cal 900–750 BC), a Middle Stage (cal 750–400 BC), and a Late Stage (cal 400–100 BC), with potential continuity into the turn of the Common Era. The δ13C and δ15N values suggest C3 plant–based diets with moderate animal protein intake, though some individuals show nearly pure plant consumption. Furthermore, through the integration of radi ocarbon data and contextual analysis, the research underscores that the Early Stage of the Chawuhu culture was contemporaneous with the Early Iron Age occupations of eastern Kazakhstan and the Altai region. Particular attention is drawn to the significance of residential graves at Xiaxinguang and Daxigougoukou, where child burials were intentionally integrated into domestic architecture, reflecting complex social and ritual practices. Additionally, radiocarbon evidence indicates that the transition from single to multiple interments occurred between the Early and Middle Stages. These discoveries offer important insights into settlement organization, mortuary practices, and cultural dynamics in the region during the Early Iron Age.

The chronology of Late Glacial and Early Holocene dune formation and wildfire activity at the Łaskarzew site, eastern Poland, was reconstructed using a combination of accelerator mass spectrometry (AMS) radiocarbon dating (14C) and optically stimulated luminescence (OSL) dating. The stratigraphic profile records 13 aeolian-soil cycles, characterized by alternating phases of aeolian deposition, soil formation, and wildfire episodes, reflecting the interplay between short-term climatic oscillations and aeolian processes. Radiocarbon dates were obtained from 26 charcoal samples embedded within palaeosols and charcoal horizons and calibrated using the IntCal20 curve, while OSL dating of quartz grains provided additional chronological control for aeolian sediments. The integration of these two dating methods established a robust timeline of environmental changes. The aeolian activity began during the Oldest Dryas and intensified during the Allerød interstadial, with four distinct wildfire events associated with rapid vegetation recovery and fire-prone landscapes. The Younger Dryas was marked by widespread aeolian deposition under arid climatic conditions, with no organic layers preserved. In the Holocene, nine independent wildfire episodes spanning approximately 4500 years were identified, linked to warm climatic conditions and the dominance of pine forests. Aeolian activity persisted into the Middle Holocene, accumulating nearly three meters of sediment before stabilizing around 7 ka BP due to increased vegetation cover. This study underscores the effectiveness of integrating radiocarbon and luminescence dating to resolve Late Quaternary chronologies, providing insights into fire-vegetation dynamics and aeolian processes within the European Sand Belt.

The 14C marine reservoir age in the North Atlantic and Norwegian Sea has varied through the late glacial period. Here I present a curve, called Norcoast25, for the calibration of late glacial and Early Holocene marine 14C ages from the Norwegian coast. I also present a table of ΔR values that could be used for the calibration of 14C ages with Marine20. The results are based on paired 14C dates of terrestrial plant fragments and articulated marine shells found in shallow marine deposits on the outer coast of Western Norway. The shells calcified in marine water and the 14C reservoir ages represent the surface water off the Norwegian coast. The ΔR value relative to Marine20 decreases from + 300 14C yr at 14.4 cal ka BP to − 100 14C yr at 14.2 cal ka BP and is constant throughout the Allerød. At the transition to the Younger Dryas (YD) the ΔR value increases, and reaches a maximum in the middle YD of + 80 14C yr. At the YD/Early Holocene boundary, the ΔR value drops 200 14C yr. These late glacial ΔR values from Norway’s west coast are 150–300 14C yr lower than has been reconstructed from 14C-dated sediment cores from the open ocean. The Norcoast25 calibration curve can be uploaded to the OxCal calibration program. A link to the file (Norcoast25.14c) is provided at the end of the paper.

River deltas play a crucial role in the global carbon cycle, acting both as significant carbon sinks and as sources of CO₂ to the atmosphere. The Rhône River delta is a key site for studying these processes due to its high sedimentation rates and its unique radiocarbon signatures influenced by anthropogenic activities. This study compiles over 10 years of research to assess the sources and fate of organic matter (OM) in the Rhône River delta, using stable (δ13C) and radiogenic (Δ14C) carbon isotopes. New data from the MissRhoDia II campaign (2018) are compared with previous datasets (CarboRhone 2012; DICASE 2014) to analyze the interactions between terrestrial, riverine, and marine OM sources. The study examines sedimentary processes along a transect from the river mouth to the continental shelf, considering both sediment burial and porewater analyses. Results indicate that OM mineralized in proximal sediments is primarily of terrestrial origin, freshly supplied by the river, and potentially influenced by nuclear-related activity. In contrast, on the continental shelf, remineralization occurs at a slower rate due to the limited availability of organic substrate and isotopic signatures reveal a predominantly marine origin with a minimal anthropogenic influence. In the Rhône pro-delta sediments, the burial of radiocarbon-free organic carbon (aOC) underscores the role of sediment transport in long-term carbon storage, with contributions from both petrogenic and aged terrestrial organic carbon sources. The mineralization of young, labile carbon and the burial of more refractory carbon create significant differences between the 14C signatures measured in porewaters and sediments, highlighting the need to analyze both compartments. This study improves our understanding of carbon dynamics in the Rhône delta and provides valuable perspectives to better understand coastal carbon budgets, carbon sources, as well as the anthropogenic influence on marine ecosystems.

The southwestern Atlantic margin plays a crucial role in understanding ocean circulation, with the Brazil Current (BC) driving surface flow and various water masses (TW, SACW, AAIW, UCDW, NADW, LCDW) influencing different depths. The Santos Basin, a marginal basin formed following the breakup of Gondwana, remains understudied with respect to late Quaternary sedimentary processes, and the recent literature offers conflicting interpretations of sediment sources and depositional processes. Additionally, radiocarbon data for this region are scarce, and calibration uncertainties and regional reservoir effects have limited previous studies. This study compiles a comprehensive radiocarbon dataset (264 datings from 70 sediment cores) for the upper to middle slope of the Santos Basin (120–2000 mbsl), combining published and unpublished data (69 new ages). Previously published ages were recalibrated using Marine20 and SHCal20 curves, applying a regional ΔR correction. The dataset, showing minimal age inversions, provides a robust foundation for future research on late Quaternary sedimentary and paleoenvironmental dynamics in the southwestern Atlantic.

Radiocarbon dating is essential for establishing robust chronologies in archaeological and paleoenvironmental contexts spanning the last 55,000 years. Pottery, pervasive in the archaeological record, offers a crucial framework for dating human activity during the Holocene. Traditionally, radiocarbon dating of pottery has relied on targeting carbonaceous inclusions such as organic temper or measuring stratigraphically associated materials like bone and charcoal. Inaccuracies can arise, however, if the targeted fraction does not reflect the timing of vessel use or if stratigraphic associations are uncertain. An alternative involves radiocarbon dating of lipid residues, particularly fatty acids absorbed into the ceramic matrix during the processing and storage of plant and animal-derived resources. This approach holds promise for delivering highly accurate measurements directly correlating to vessel use. At the Oxford Radiocarbon Accelerator Unit, efforts have been made to develop this methodology through compound-specific radiocarbon dating of pottery, employing a gas chromatography (GC)-preparative fraction collector (PFC) approach. Here, we describe the protocol and present preliminary findings, including analyses conducted on pottery samples sourced from an archaeological site with an established chronology.

This paper presents new radiocarbon (14C) measurements from annual tree rings of English oak (Quercus robur L.) from Kujawy, Poland, spanning 1042–1062 CE. The results confirm an increase in Δ14C values between 1053 and 1055 CE, within the Oort Minimum of solar activity, consistent with literature values (Brehm et al. 2021a; Eastoe et al. 2019; Terrasi et al. 2020). The data reveal a sustained increase in Δ14C values between 1053 and 1055 CE, rising from −6.9 ± 1.8‰ to −2.6 ± 1.8‰. For the preceding period (1042–1052 CE), the average Δ14C value is −11.0 ± 1.9%, indicating a significant increase of 8.4 ± 2.6‰ toward 1055 CE. The study estimates the 14C production rate during this period and suggests the radiocarbon increase likely began before 1054 CE, indicating it is unlikely to be significantly attributed to the supernova in 1054 CE. The study contributes to refining the understanding of rapid changes in atmospheric radiocarbon and their potential causes.

At ANSTO, we have developed an automated dissolved inorganic carbon (DIC) processing line, known as A-DIC, designed to sequentially process 10 water samples for radiocarbon analysis without any operator intervention. The A-DIC works at ambient pressure using helium (He) gas as a carrier. It includes a water pump capable of drawing adjustable sample volumes between 22-180 mL into a 250 mL reaction vessel. Upon the addition of 5 mL of phosphoric acid to the vessel, the sample is sparged with helium (He) gas at a rate of 45 mL/min for 16 min. The desorbed CO2 from the sample is then carried along with He through a series of traps: water vapor traps at –75 °C, a sulphur (SOx) trap containing silver wires at 650 °C, and two CO2 traps at –196 °C. The A-DIC is automated via a Python script executed on a PC connected via USB. It demonstrates consistent performance and CO2 trapping efficiency across batches of up to 10 samples. For contamination study, the CO2 gas collected is transferred to graphitization units to be converted into graphite for AMS analysis.

Burial mounds, or kurgans, are a widespread archaeological feature in ancient Eurasia. In the South Caucasus, the Kura-Araxes (KA) culture adopted these funerary structures to express horizontal social ideology through collective inhumations. KA communities also constantly re-engaged with the dead through the regular reopening of burials, contributing to a rich organic archive that relates to episodes of funerary manipulation. This article reports on the results of a radiocarbon wiggle-match obtained from a semi-burnt branch of Juniperus sp. associated with Kurgan 8 at Uzun Rama (Ganja, Azerbaijan). This structure yielded evidence of burial activity during the KA I phase (ca. 3500–3000/2900 BCE) and the post-KA, the “Early Kurgan” period (ca. 2500–2000 BCE), and the Late Bronze Age (ca. 1500–1150 BCE). The sample came from a wooden structure constructed and then burnt in the ritual closure of the kurgan by fire, marking the final stage of its KA use. The results of the wiggle-match allowed us to produce a close estimate for the felling of the branch, thus providing a refined Terminus Post Quem (TPQ) for the construction of the wooden structure itself and its use within 3204–3174 BCE. These results shed light on finer temporal resolution of burial history not just pertaining to funerary sequences, but also in terms of social engagement with visible landmarks and long-term cultural or generational memory. The results correlate with broader trends observed in other KA kurgans and settlements excavated along the Kura basin, pointing at large-scale landscape (or even historical) reconfigurations across the Kura-Araxes world.

In freshwater samples, benzalkonium chloride (BAC) effectively prevents radiocarbon (14C) of dissolved inorganic carbon (DIC) from changing owing to its bactericidal effects. The addition of BAC is a promising alternative method to mercury, which is currently the standard method of sterilization. Therefore, it is important to investigate its basic potential in advance for radiocarbon observations in seawater if mercury is prohibited. Since the BAC efficiency decreases in seawater, our investigation focused on salinity, which is the distinguishing characteristic of seawater. The disinfectant effects of BAC in the low- and high-salinity (4.4 and 26.5) seawater samples at a constant BAC concentration and the varying BAC concentrations at a constant salinity (20.8) were examined. With BAC treatment, the higher-salinity samples exhibited larger changes in DIC 14C concentration and δ13C value, indicators of microbial activity, than the lower-salinity samples. At higher BAC concentrations (0.1% or 1%), DIC isotope values changed negligibly over time, whereas at the lower concentration (0.01%) they changed significantly over time. These findings suggest that salt diminishes the efficiency of BAC, potentially by degrading it, thereby reducing its bactericidal activity and allowing microorganism populations to recover, thus altering 14C concentration. Further, they indicate that increasing the BAC dosage may overcome its diminished efficacy in seawater samples.

Radiocarbon dates have become a cornerstone in archaeological reconstructions of past population dynamics. The increasing reliance on large-scale radiocarbon databases, usually aggregated from diverse sources, however, raises persistent concerns about sampling bias, especially heterogeneous sampling intensity across sites. In this paper, we introduce a rescaling method that adjusts the frequency of dates in radiocarbon datasets in proportion to dwelling counts at the settlement level, using weighting and bootstrap resampling. Through a series of simulations, we show that this approach consistently yields probability distributions that more closely reflect hypothetical population trends, particularly in contexts with high inter-settlement variability in sampling intensity. We apply our method to archaeological data from two areas in Korea, the Yeongsan and Geum River Basins, during the Proto–Three Kingdoms (1C BC–AD 3C) and Three Kingdoms Periods (AD 4–7C). Results demonstrate that rescaled datasets offer significantly different interpretations of population organization and reconfiguration than those derived from original data. This study highlights the importance of addressing sampling heterogeneity in local-scale demographic research and suggests that rescaling is a valuable complement to existing bias-correction strategies in archaeological studies of demography.

A truncated conical-shaped building constructed using the cyclopean technique, called Talayot 1 or East Talayot, is conserved in the Talayotic settlement of Sant Agustí Vell. The monument has an internal chamber with two polylithic columns and a pilaster that helps holding up a roof made of large stone slabs, below which three well-conserved wooden beams can be seen, as well as the remains of two other beams, only one end of each is conserved. The study of a sample of each of these beams extracted from the outer rings of the trunks enable us to determine that all the beams come from the Olea europea L. (olive tree) species. The radiocarbon dating of the samples suggest that the trees from which the trunks come were felled between 1259–1123 cal BC. It was the first time that construction elements of a Menorcan talayot could be dated.

The discovery of radiocarbon (14C) peaks in AD 774–775 and AD 993–994 sparked the search for other anomalous events, leading to the identification of one around 660 BC. However, the ∼660 BC event appears to show a more prolonged increase, raising the question whether the event is qualitatively different. To investigate this, we measured high-latitude tree rings from Finnish Lapland, expected to be highly sensitive to energetic particle events. We measured the 14C content of full rings, as well as their separated earlywood and latewood components. We found that the 14C concentrations start rising already in the latewood of 665 BC and reach almost its full intensity by 664 BC. This rapid increase is similar to that at another high-latitude site (Yamal, Russia) but contrasts with that of low-latitude sites, which show a later peak. The earlier increase of the 14C at high-latitude tree rings compared to lower latitudes is consistent with similar observations for the AD 774 and AD 993 Miyake events. Based on carbon-cycle box modeling, the structure of the subsequent amplitude increase can be explained by either single or double initial 14C pulses. The fast increase coupled with a slower subsequent peak structure suggests similar mechanisms behind the high-latitude observations, i.e., tropospheric 14C production and/or a fast component of polar air flow across the tropopause combined with the full stratospheric-tropospheric CO2 exchange. Our results strongly emphasize the need for dynamic carbon cycle models to understand the observed differences between high- and lower-latitude data.