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.

There are now 101 radiocarbon dates from the long Paleolithic and post-Paleolithic culture-stratigraphic sequence in El Mirón Cave, Cantabrian Spain. Here we report on two dates on bone from two different humans whose remains were found in disturbed surface sediments in the cave vestibule rear and that confirm the existence of burials in addition to previously reported residential occupations in the vestibule front pertaining to the Chalcolithic and early Bronze Age periods (ca. 5500–3500 cal BP). In another attempt to resolve problems of stratigraphic incoherence of dates from the early Magdalenian periods in the vestibule rear, six new assays on faunal remains from Levels 119, 117, 114, 108, and 106 were run at Queen’s University in Belfast. There continue to be date inversions in the Lower Magdalenian range of levels that may be explained by a combination of intensive anthropic and rodent activity, major rock fall, slope wash and gravity-caused object movements, as well as possible problems in following some thin levels during excavations over a large area and across many years of work in the cave vestibule interior, particularly in the absence of any layers that are culturally sterile or even poor. Nonetheless, the coherent age of the Initial Magdalenian is fully confirmed by a new date from Level 21 in the vestibule front at ca. 22,000–20,500 cal BP), as is the general age range of the Lower Magdalenian (ca. 20,500–18,000 cal BP).

Khirbet Al-Sheikh Humaid is found 615 m above sea level in the central highlands of Palestine, northwest of the city of Nablus. During rescue excavations carried out at the site, part of a male human skull with a tooth attached was discovered. Accelerator mass spectrometry radiocarbon (AMS 14C) dating and stable isotope analysis were performed on the tooth at the Hertelendi Laboratory in Debrecen, Hungary. Dating revealed the individual had lived in the time frame 900–1030 AD, which is within the Abbasid period (750–1258 AD). Dietary analysis gave information on the daily life of the inhabitants of the settlement, showing local agriculture provided a diet of legumes and vegetables.

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.

This paper uses a “dates as data” approach to understand how grave good use and cemetery space changed across the early medieval period in England. A series of composite kernel density estimations were created, based on a dataset of nearly 1100 graves with associated radiocarbon dates, from between the fourth and ninth centuries AD. This modeling revealed a previously unrecognized peak in grave furnishing around 600 AD, which coincides with a peak in isolated burials, and a low point for unfurnished graves and for small cemeteries. It argues that this peak is unrecognized as previous models of chronological change have focused only on graves containing chronologically distinctive artifacts and highlights the importance of radiocarbon dating as a way of avoiding this limitation.

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.

Skin-based samples (leather, skin, and parchment) in archaeological, historic and museum settings are among the most challenging materials to radiocarbon (14C) date in terms of removing exogenous carbon sources—comparable to bone collagen in many respects but with much less empirical study to guide pretreatment approaches. In the case of leather, the 14C content of materials used in manufacturing the leather can vary greatly. The presence of leather manufacturing chemicals before pretreatment and their absence afterward is difficult to demonstrate, and the accuracy of dates depends upon isolating the original animal proteins and removing exogenous carbon. Parchments differ in production technique from leather but include similar unknowns. It is not clear that lessons learned in the treatment of one are always salient for treating the other. We measured the 14C content of variously pretreated leather, parchment, skin samples, and extracts, producing apparent ages that varied by hundreds or occasionally thousands of years depending upon sample pretreatment. Fourier Transform Infrared Spectroscopy (FTIR) and C:N ratios provided insight into the chemical composition of carbon reservoirs contributing to age differences. The results of these analyses demonstrated that XAD column chromatography resulted in the most accurate 14C dates for leather and samples of unknown tannage, and FTIR allowed for the detection of contamination that might have otherwise been overlooked.

Radiocarbon dates on charred plant remains are often used to define the chronology of archives such as lake cores and fluvial sequences. However, charcoal is often older than its depositional context because old-wood can be burnt and a range of transport and storage stages exist between the woodland and stream or lake bed (“inherited age”). In 1978, Blong and Gillespie dated four size fractions of charcoal found floating or saltating in the Macdonald River, Australia. They found larger fragments gave younger age estimates, raising the possibility that taphonomic modifications could help identify the youngest fragments. In 1978 each date required 1000s charcoal fragments. This study returns to a sample from the Macdonald River to date individual charcoal fragments and finds the inherited age may be more than 1700 years (mode 250 years) older than the collection date. Taphonomic factors, e.g., size, shape or fungal infestation cannot identify the youngest fragments. Only two fragments on short-lived materials correctly estimated the date of collection. In SE Australia, this study suggests that wood charcoal will overestimate the age of deposition, taphonomic modifications cannot be used to identify which are youngest, and multiple short-lived materials are required to accurately estimate the deposition age.

We present case studies on three objects of high importance for cultural heritage in southern Poland, dated in years 2018–2022 at the Gliwice 14C and Mass Spectrometry Laboratory with radiocarbon (14C) and dendrochronology methods. The first was a richly ornamented wooden cane, discovered during excavations on the market in Bytom city. The cane can be associated with medieval court proceedings. The archaeological context indicates the 13th century AD, and the 14C result corresponds perfectly with this time, confirming that it is the oldest object of this type in Poland. The second was a 4-m-tall oak column from St. Leonard Church in Lipnica Murowana, a UNESCO heritage site. The local story said it was previously devoted to Światowid, a pagan deity. Our analysis excluded the pre-Christian age, as the tree was felled no earlier than the late 15th century, which is in agreement with historical records. The third was a wooden Saint Lawrence Church in Bobrowniki. The presbytery was covered with up to five layers of polychromic paintings, some of high artistic value. We dated three samples from the original wooden board, and by wiggle-matching, the calibrated age interval was narrowed to 1731–1754 cal AD.

Accelerator mass spectrometry (AMS) radiocarbon (14C) dating is central to the development of robust chronologies in archaeological and paleoenvironmental contexts spanning the last 50,000 years. For dates to be accurate, samples must be free of exogenous carbon contamination. At the Oxford Radiocarbon Accelerator Unit (ORAU), considerable advancements in the dating of bone collagen have been made through the development of a high performance liquid chromatography (HPLC) method for the dating of the amino acid hydroxyproline, which can mitigate the effects of carbon contamination. However, recent changes in ligand manufacturing methods for the mixed-mode column used in the ORAU protocol (Primesep A, SIELC Technologies; IL, USA) have resulted in unacceptably high analytical backgrounds. Prior to the manufacturing change, backgrounds of > 50k BP were achievable. Since the manufacturing change, a mean background of 32.5k BP has been measured. Due to column bleed, the Primesep A is therefore no longer suitable for 14C measurement of hydroxyproline from older material. Here, we present background data and the chromatography conditions used to isolate hydroxyproline using an alternative column, a preparative-scale Newcrom AH, which shows promising potential as an alternative for the routine isolation and AMS dating of hydroxyproline—especially approaching the age and mass limits of the method.

The Early Iron Age hillfort in Chotyniec (SE Poland) is the westernmost permanent settlement of the Scythian cultural circle. Recognizing the construction of the fortified settlement’s ramparts and their chronology was considered one of the priorities of the systematic research conducted since 2016. Based on 18 radiocarbon dated samples from different parts of the rampart, a chronological model of its functioning was made. It indicates that the construction of this monumental fortifications protecting the settlement in Chotyniec should be dated to between 651–595 or 531–409 BC. This dating synchronizes well with the chronology of the most important ritual and ceremonial object within the Chotyniec settlement—the so-called zolnik and other Scythian settlements from the East European forest-steppe zone.

We present atmospheric radiocarbon concentrations in CO2 integrated samples taken between January 2019 and December 2021 in the Mexico City Metropolitan Area (MCMA) and explain the variations in terms of changes in emission sources associated with the COVID-19 lockdown restrictions imposed from March 2020. Δ14C values for samples collected during 2019 range between –44.15‰ and –13.17‰, with lower values during months with higher fossil fuels consumption and air stagnation, whereas higher values were found for periods with high number of fires around MCMA or wet months with higher contribution of heterotrophic respiration. For samples collected during 2020, Δ14C values range between –17.7‰ and 2.25‰, with an increasing trend immediately after the initial lockdown and higher values obtained for samples collected during lockdown phases 2 and 3 and the period of extremely high epidemic risk. This agrees with the 38% and 52% decrease in gasoline and diesel sales. Once essential activities gradually opened from July 2020, Δ14C follow a decreasing trend as vehicle traffic started to increase again. Δ14C values for samples collected during 2021 range from –32.89‰ to –10.27‰, with the higher value obtained during a period of extremely high epidemic risk with a 30% reduction in gasoline and diesel consumption. Despite the complexity of emission sources in MCMA, from Δ14C variations it was possible to identify changes in fossil CO2 emissions resulting from the significant reduction in vehicle traffic due to the COVID-19 lockdown and the restrictions imposed to control transmission of the disease.

In-situ cosmogenic 10Be (and 26Al) concentrations in alluvial sediments provide a spatially averaged signal of the erosion rate of the catchment area. Catchmentwide erosion rates reflect the production rate of the entire basin, and their calculation requires knowledge of the complete production rate model. Available calculators determine production rates on a pixel-based approach and achieve computational efficiency by relying on a scaling method that ignores geomagnetic field strength variations. Here we introduce a new python-based tool that determines erosion rates based on the hypsometry of the catchment. The method relies on the fact that production rates are much more sensitive to changes in elevation than latitude. Our tool has two main advantages: (1) computation time is short (<30 seconds) and independent of the scaling method; there is no need to neglect magnetic field variations, and (2) because production rate scaling is performed by a widely used online calculator, the results are fully comparable to exposure ages or point-based erosion rates determined with the same calculator; future updates to production rate scaling are immediately effective for catchmentwide erosion rate calculation. We demonstrate in two case studies that (1) for similar scaling methods, our calculator reproduces pixel-based results within a few percent, and (2) erosion rates determined with different scaling methods may differ by >20%, differences can vary systematically with erosion rate, and using a time-constant scaling method may result in a bias in the interpretation of catchmentwide erosion rates.

Microbial processing of soil organic matter is a significant driver of C cycling, yet we lack an understanding of what shapes the turnover of this large terrestrial pool. In part, this is due to limited options for accurately identifying the source of C assimilated by microbial communities. Laboratory incubations are the most common method for this; however, they can introduce artifacts due to sample disruption and processing and can take months to produce sufficient CO2 for analysis. We present a biomass extraction method which allows for the direct 14C analysis of microbial biomolecules and compare the results to laboratory incubations. In the upper 50 cm soil depths, the Δ14C from incubations was indistinguishable from that of extracted microbial biomass. Below 50 cm, the Δ14C of the biomass was more depleted than that of the incubations, either due to the stimulation of labile C decomposition in the incubations, the inclusion of biomolecules from non-living cells in the biomass extractions, or differences in C used for assimilation versus respiration. Our results suggest that measurement of Δ14C of microbial biomass extracts can be a useful alternative to soil incubations.

The rich architectural heritage of Cyprus from the period of Byzantine and Latin rule includes 10 churches inscribed in the UNESCO World Heritage list. Most of these monuments preserve wooden elements: whether structural, decorative or furnishings. Many preserve wall paintings that are considered among the best examples of Byzantine and Medieval art in the Eastern Mediterranean. The dating of these paintings as well as the church buildings themselves, has been based mainly on style, with occasional dedicatory inscriptions and related historical interpretation. We report early results from a project investigating the wooden cultural heritage of Cyprus and in particular the combined use of dendrochronology with radiocarbon via tree-ring sequenced 14C wiggle-matching to help place initial tree-ring sequences. This includes a floating 264-year Pinus brutia chronology from several monuments, which, with a ca. 5-year gap, suggests prospects for >700-years of P. brutia chronology for Cyprus, and, with one gap of several decades to fill, ca. 1100 years of Pinus nigra chronology for Cyprus. Several currently floating elements from the multi-phase UNESCO-listed Timios Stravros church at Pelendri, including a terminus post quem for the celebrated liturgical wooden cross, are approximately dated across the 11th to 16th centuries AD.

Biobased content analysis is a well-established, analytically independent, standardized method to determine the biobased content of fuels and plastics, based on differences of the specific radiocarbon (14C) activity of fossil and recent biogenic compounds. This biogenic content analysis can be useful for the producers as a quality assurance tool, for the customers as feedback about the truly biobased products and for the control organizations as an independent analytical tool to prove the biological origin. More than 100 commercially available foods, cosmetics, and drug samples have been used for biobased carbon content analysis by accelerator mass spectrometry (AMS) 14C measurement to demonstrate the potential of this technique. Our results show that this measurement technique is a unique tool for the determination of biocontent in foodstuff and medical products. Most of the tested materials were nearly or completely biobased (≥ 98 pMC), and no completely fossil-based final product was detected. The lowest biogenic compound was measured in a vanilla aroma flavor. In 45 of the 102 samples selected a wide range (2–98%) presented fossil-based carbon content. The method can be applied for monitoring raw materials and final products for biobased content in the industry and consumer protection as well.

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%.

Analysis of 20 calibrated accelerator mass spectrometry radiocarbon (AMS 14C) ages reveals a chronology for the habitation of a unique peripheral settlement at Zahrat adh-Dhra‘ 1 (ZAD 1), Jordan during the Middle Bronze Age of the Southern Levant. Bayesian modeling distinguishes three phases of occupation between the first settlement at ZAD 1, perhaps as early as about 2050 cal BCE, and its abandonment by 1700 cal BCE. ZAD 1 represents a marginal community, both environmentally and culturally, on the hyperarid Dead Sea Plain, and exemplifies the peripheral settlements that are envisioned as important elements of Bronze Age Levantine society. Most importantly for this study, it is the only peripheral site in the Southern Levant that provides a Bayesian model for its habitation during the growth of Middle Bronze Age urbanized society. The timing of ZAD 1’s constituent phases, early in Middle Bronze I, across the Middle Bronze I/II transition and in Middle Bronze II, correspond well with emerging chronologies for the Middle Bronze Age, thereby contributing to an ongoing reassessment of regional social and settlement dynamics.

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 paper focuses on the Pleistocene deposits in Perspektywiczna Cave, southern Poland, related to cave hyena (Crocuta crocuta). We used direct radiocarbon dating of hyena fossils supported by genetic and stable isotope analyses to infer the paleobiology of this population. Radiocarbon dating of 19 hyena remains suggests long inhabitation of the region during early MIS 3, around 50–34 ky cal BP. The youngest among our dates, 34,355–33,725 cal BP (1σ, combined of two dates for the same specimen) points out the latest appearance of a cave hyena north to Carpathians. Beside this long period of occupation, the Perspektywiczna Cave hyenas stayed ecologically stable, but their genetic structure changed. Two mtDNA haplogroups were present, one typical for other Late Pleistocene European populations and the other one known so far only from recent African populations.