A routine chemical procedure was developed at the Ede Hertelendi Laboratory of Environmental Studies (HEKAL), in Debrecen which can measure the dissolved organic radiocarbon content of groundwater as well as the inorganic and total fraction. The typical background of this non-purgeable dissolved organic radiocarbon preparation is 0.73 ± 0.14 percent modern carbon (pMC), using a carbon contamination correction on fossil dissolved material (potassium hydrogen phthalate) samples.

This paper presents new radiocarbon dates for two Aboriginal archaeological complexes situated on the cliff-lines of the Murray River in South Australia (SA); at Pooginook Flat and Tanamee. These dates represent the first age estimates for archaeological sites within the Upper Gorge section of the Murray River. The dates ranged from ca. 11 cal ka to the Late Holocene. The research supports previous evidence which has indicated that sites located along the Murray cliffs preserve much of the oldest evidence of Aboriginal peopling along the Murray River corridor in SA. The new dates also allow us to contribute to discussions concerning broader chronological trends in Aboriginal lifeways within the Murray-Darling Basin (MDB). Specifically, the new ages add some insight into the nature and timing of early Aboriginal occupation along the Murray River corridor in SA and further evidence that the LGM acted as a significant inhibitive factor for intensive occupation of this riverscape. The conservation of these significant and informative cliff-top sites remains precarious, however, and there is an imperative to continue to record and sample the extant sites.

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.

Cremated bones are a commonly preserved material and often found in burial environments where unburned bone may not be preserved. As such direct radiocarbon dating of cremated bone could be essential in determining the chronology of an event. Pretreatment of cremated bone exploits the structural carbonate component of the bone which survives cremation. However, due to the low abundance (ca. 0.1%) of this component, the extraction of an amount of endogenous carbon sufficient for radiocarbon dating may represent a challenge. Here we investigate two modifications to the phosphoric acid digestion protocol used during the preparation of cremated bones at the Oxford Radiocarbon Accelerator Unit (ORAU). The first of these was to use ultrasonication to release evolved CO2 from the viscous phosphoric acid and cremated bone mixture that is formed during digestion. The second was to double the amount of time during which evolved CO2 was removed from the reaction vessel by transfer into a cryogenically cooled ampoule. Ultrasonication of the digestion mixture failed to produce a significantly higher carbon yield, while double-time collection resulted in an average 21.5±13.8% increase of C yield without affecting the measured age. Extending the collection time can better enable reliable dating of small (less than 1 g) samples.

Despite chronicles from the 16th century describing fertile alluvial plains and densely populated wetlands, archaeology in western Mexico has been little studied. The Directorate of Archaeological Salvage (DSA) of National Institute of Anthropology and History (INAH) has initiated a study of two sites in Costa Canuva, at the southern part of Nayarit state: Becerros and Naranjos. Thirty charcoal and shell samples were radiocarbon (14C) dated to determine occupation history. A Bayesian approach was used to build a chronological modeling from charcoal samples. Charcoal and shell samples found in the same context allowed us to calculate the ΔR values of marine offset for this period. In general, the archaeological sites of this area are divided into three major periods: Formative, Classic, and Postclassic. The 14C dating of Becerros recovered materials provided a chronological framework for the site’s occupation, from cal AD 169–1025, corroborating the ceramic studies in the sense that human settlement activities date from the Formative (300 BC–AD 600) to the Early Postclassic (AD 900–1200). Naranjos started in the Classic period and reached its occupancy peak in the Late Classic. The site’s occupation may have persisted for at least two centuries after the conquest of the Altiplano in 1521. The comparison of charcoal dates and associated shell samples from the Naranjos Unit gave a probability distribution for ΔR, that ranged from 118.5 to 199.5 with a mean value of 159 ± 4, slightly higher than other values obtained at nearby sites.

In order to better characterise carbonaceous components in atmospheric aerosols and to assess the contributions of fossil carbon (FC) and non-fossil carbon (NFC) sources and their seasonality in the Eastern Mediterranean, we collected fine (PM1.3) aerosols at a remote marine background site, the Finokalia Research Station, Crete, Greece, over a period of one-year. PM1.3 samples were analysed for elemental carbon (EC), organic carbon (OC), water-soluble OC (WSOC), and stable carbon isotope ratio (δ13CTC) and radiocarbon content (14CTC) (pMC) of total carbon (TC). All the parameters, i.e., PM1.3, δ13CTC and 14CTC showed a clear temporal pattern with higher values in summer and lower values in autumn. The 14CTC ranged from 54.7 to 99.1 pMC with an average of 74.5 pMC during the entire year. The FC content in TC (FCTC) was found to be slightly lower in winter and almost stable in other seasons, whereas the NFC contents (NFCTC) showed a clear seasonality with the highest level in summer followed by spring and the lowest level in winter. Based on these results together with the seasonal distributions of organic tracers, we found that biomass burning (BB) and soil dust are two major sources of the fine aerosols in winter. Although biogenic emissions of VOCs followed by subsequent secondary oxidation processes are significant in summer followed by spring and autumn, pollen is a significant contributor to TC in spring. This study showed that emissions from fossil fuel combustion are significant (25.5%) but minor compared to NFC sources in the eastern Mediterranean.

This brief review describes the discovery of cosmic rays by Victor Hess from the Vienna Radium Institute and the later contribution of Marietta Blau through her observation of “disintegration stars” in photographic emulsion plates exposed to cosmic-ray bombardment. Marietta Blau, a nearly forgotten cosmic-ray pioneer from the Vienna Radium Institute, developed the nuclear emulsion technique for studying nuclear reactions, eventually discovering the disintegration of nuclei through high-energy cosmic rays. Blau survived the Holocaust by escaping to Mexico City from 1939 to 1944. Starting in 1948 at Columbia University, later as a staff member of Brookhaven National Laboratory and then University of Miami, she performed fundamental and original research with nuclear emulsions exposed to 3-GeV protons at the Brookhaven Cosmotron and to 6-GeV protons at the Berkeley Bevatron. Blau returned to Vienna in 1960, where at the Radium Institute a classical β-decay counting facility for radiocarbon dating had been installed, which was finally superseded by the Vienna Environmental Research Accelerator (VERA), a modern versatile accelerator mass spectrometry facility.

This work presents the integration of an elemental analyzer (EA) and an isotope ratio mass spectrometer (IRMS) into the 6 MV AMS system at the Institute for Nuclear Physics, University of Cologne. The AMS measurement of δ13C values for IAEA-C6 reference material resulted in –11.39(226)‰, compared to –10.28(32)‰ obtained by IRMS. The EA-IRMS system was also tested with IAEA-C3, IAEA-C5, and IAEA-C7 reference materials, yielding –24.79(9), –25.18(15), and –14.76(18)‰ respectively. Compared to the IAEA information values given as –24.91(49), –25.49(72) and –14.48(21)‰ respectively. To investigate an observed sample mass dependency, environmental samples from Spitzbergen were examined, showing δ13C values of –25.17(55), –25.80(31), and –26.17‰ in Cologne, while Hamburg recorded –24.8(1), –25.5(1), and –26.2(13)‰. In summary, this new setup could enable online analysis and quasi-simultaneous measurements of 14C, δ13C, and δ15N for ultra-small samples, utilizing precise δ13C values from IRMS for fractionation correction of the 14C/14C isotopic ratio.

While recent genomic and isotopic information show that migration has been pervasive along human history, southern Andean archaeology has largely overlooked its importance in shaping human trajectories of sociocultural change. Building on previous isotopic research that identified the presence of migrant farmers in the Uspallata Valley (Mendoza, Argentina), we present chronological and bioarchaeological results that help to characterize the timing and mode of human migrations in the southern Andes. The burials with migrants show the representation of the different age classes, including a high abundance of children, as well as both men and women, suggesting that family groups were likely involved. The Bayesian modeling of 16 direct dates for migrants indicates that these migrations started between 1210–1275 CE (median 1255 CE) and finished at 1320–1425 CE (median 1360 CE), indicating that there is nearly no overlap between the commencement of this migration phase and the southwards expansion of the Inka Empire. The model defines a diachronic process that lasted between 55 and 195 years, implying that migration to Uspallata was a multi-generational process that involved between two and eight generations (median of four generations). Our contextual, bioarchaeological and chronological evidence indicates that the conditions fostering migration to Uspallata were sustained through time, inviting to explore persisting push-pull dynamics acting during this period. 87Sr/86Sr results show that migration occurred across the daily territories of these groups and may have involved movement across social or ethnic frontiers.

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.

Illegal poaching brought elephant species to the brink of extinction; therefore, international trade in ivory has become regulated by the Convention on International Trade in Endangered Species of Flora and Fauna (CITES). However, the trade is still allowed for antique items, standing for ivory from a period before 1947 within the European Union. This could serve as a loophole for the laundering of modern ivory. In the described case of the Happy Fisherman statuette, the traded item was declared to be antique, but radiocarbon analysis proved a modern provenance, and the statuette was confiscated. The radiocarbon analysis was later confirmed by information from a Chinese newspaper found inside the statuette. Based on the findings, we strongly recommend careful consideration of each individual ivory piece offered for sale, with a thorough inspection of the items and related documentation carried out by a relevant CITES authority. Any exemption of the commercial ban should be granted only to those applicants who meet the criteria of proper evidence in the form of scientific analysis or reliable and trustworthy documentation.

Cellulose of tree rings is often assumed to be predominantly formed by direct assimilation of CO2 by photosynthesis and consequently can be used to reconstruct past atmospheric 14C concentrations at annual resolution. Yet little is known about the extent and the age of stored carbon from previous years used in addition to the direct assimilation in tree rings. Here, we studied 14C in earlywood and latewood cellulose of four different species (oak, pine, larch and spruce), which are commonly used for radiocarbon calibration and dating. These trees were still growing during the radiocarbon bomb peak period (1958–1972). We compared cellulose 14C measured in tree-ring subdivisions with the atmospheric 14C corresponding to the time of ring formation. We observed that cellulose 14C carried up to about 50% of the atmospheric 14C signal from the previous 1–2 years only in the earlywood of oak, whereas in conifers it was up to 20% in the earlywood and in the case of spruce also in the latewood. The bias in using the full ring of trees growing in a temperate oceanic climate to estimate atmospheric 14C concentration might be minimal considering that earlywood has a low mass contribution and that the variability in atmospheric 14C over a few years is usually less than 3‰.

Studies with multiple radiocarbon dates often contain useful information on the relative locations of the dated levels. Such information can be used to obtain robust, integrated site chronologies, with at times more precise ages than those of the individual dates, where outliers can be identified and downweighted, and where the ages of any undated levels can also be estimated. Examples include trees with radiocarbon dates separated by exactly known amounts of yearly tree-rings, or sedimentary sites where ages further down the stratigraphy can be assumed to be older than ages further up. Here we present coffee, an R package for Bayesian models that apply chronological ordering for fossils and environmental events. Coffee runs natively within the popular and versatile R environment, with no need for importing or exporting data or code from other programs, and works with plain-text input files that are relatively easy to read and write. It thus provides a new, transparent and adaptable educational and research platform designed to make chronology building more accessible.

Pottery vessels played a central role in the processing, storage and transport of animal and plant products by prehistoric and historic peoples with their chemical residues surviving for thousands of years. Accurate radiocarbon dating of archaeological pottery vessels by isolating reliable sources of carbon relating to the use of pots has long been a major challenge, but is now possible using compound-specific radiocarbon analysis of absorbed organic residues preserved in the ceramic fabric of the vessel wall. This method involves the radiocarbon dating of single fatty acids most commonly derived from degraded animal fats. These compounds are extracted from the ceramic matrix and isolated from potentially interfering compounds using preparative capillary gas chromatography. When coupled with lipid biomarker and compound-specific stable carbon isotope analyses, this method enables the palaeodietary and chronological information contained in archaeological lipids preserved in ceramic vessels to be interpreted together. From a practical perspective the methodology is challenging and for successful application must adhere to rigorous protocols. We present here guidelines which include (i) consideration of pottery selection, (ii) technical parameters for the isolation of fatty acids then their 14C dating and calibration, and (iii) case studies selected to illustrate the best use of this method.

We report 27 planktonic and 21 benthic radiocarbon ages from the subtropical marine sediment core ODP Site 1063 (Bermuda Rise) for the time range between 30 and 14 ka before present. Despite low abundances of benthic specimens, it was possible to measure radiocarbon ages down to ∼10 µg carbon using a MICADAS and the gas ion source developed at ETH Zurich. Based on a tentative radiocarbon–independent age-model we found that the radiocarbon reservoir of the bottom water varied moderately relative to the analytical and age-model related uncertainties throughout the examined time-period, but larger differences in the radiocarbon reservoir appear to have affected the upper ocean layer. In particular, radiocarbon levels around Heinrich Stadial 2 reveal surface radiocarbon content similar to that of the atmosphere, while during Heinrich Stadial 1 surface waters were significantly depleted in 14C.

This study presents new (n=32) and previously published (n=35) human bone 14C AMS dates from 54 individuals interred in 50 burials in the Plinkaigalis cemetery (3rd–7th century AD, Lithuania). The aim of this study is to establish duration of use and identify temporal subgroups within the cemetery. Individuals in group burials were assessed for temporal agreement across individuals and the dates for individuals with multiple dates were combined using OxCal. The Sum command, Interval command, and two Bayesian models (overlapping and abutting periods of use) were used to approximate the use of the site over time and evaluate the chronology of dated burials. An IDW (inverse distance weighted) model was employed to visualize median radiocarbon dates across the cemetery for comparison to earlier IDW interpolations of time at Plinkaigalis. While the two models cannot be distinguished at this time, it can be determined that the site was likely in continuous use from 200–600 cal AD (Sum), 230–560 cal AD (Model 1), 220–550 cal AD (Model 2), or cal 283–508 AD (IDW). The area of the cemetery associated with earliest use shifted east when the IDW model was compared to original data. There was also poor agreement in some group burials and burials with multiple dates. The models generally agree on assignment of burials to phases, but disparate phase assignment was noted across the IDW and Bayesian models. Temporal subgroups cannot be confidently reclassified beyond early/later periods of use based on these models without additional sampling and refinement of the IDW modeling method.

Mollusk shells are often found in archeological sites, given their great preservation potential and high value as a multipurpose resource, and they can often be the only available materials useful for radiocarbon (14C) dating. However, dates obtained from shells are often regarded as less reliable compared to those from bones, wood, or charcoals due to different factors (e.g., Isotope fractionation, reservoir effects etc.). The standard acid etching pretreatment for mollusk shells is the most used in many 14C laboratories, although another protocol known as CarDS (Carbonate Density Separation) was introduced just over a decade ago. We compare these two methods with two newly proposed methods for intracellular organic matrix extraction. We applied all four methods to samples selected from different archeological layers of the well-known Upper Paleolithic site of Vale Boi, rich in mollusk specimens throughout the stratigraphic sequence. Here we compare our results to previous dates to determine which of these pretreatment methods results in the most reliable 14C dates. Based on the results of this study, all four methods gave inconsistent ages compared to previous dates and the stratigraphic attribution.

The Fertile Crescent of Southwest Asia is considered one of the main centers of the first Neolithization worldwide. However, the dating and processes of its spread to neighboring regions have yet to be studied. This study reports new chronological data from the Fars highlands, southeast of the Fertile Crescent. Although the Pottery Neolithic in Fars has long been believed to have started in the late 7th millennium BC, recent excavations at Tepe Rahmatabad have suggested a date half a millennium earlier, raising controversy. Our data from Tol-e Sangi, a stratified site with Pre-Pottery (PPN) and Pottery Neolithic (PN) cultural deposits, support the advent of the Pottery Neolithic at the beginning of the 7th millennium BC. This suggests that despite the late arrival of the food production economy in the Fars highlands, which is dated from the mid-8th millennium BC, subsequent cultural development followed a path similar to that of the eastern wing of the Fertile Crescent.

A new series of 22 radiocarbon dates provides new insights on the origin and distribution of the Early Trypillian archaeological culture in modern-day Moldova and Ukraine. The paper presents data from the sites of preceding groups (5 dates), highlighting gaps in the agricultural settlement of the region, dates related to the Early Trypillia directly (14 dates) and dates from the ceramic hunter-gatherers’ sites that yielded some Early Trypillian pottery (3 dates). The results indicate that the expansion of Early Trypillia into Moldovan and Ukrainian forest-steppe took place during 47–45th centuries BCE and it was a relatively fast colonization likely spanning only 3–5 generations.

Researchers increasingly rely on aggregations of radiocarbon dates from archaeological sites as proxies for past human populations. This approach has been critiqued on several grounds, including the assumptions that material is deposited, preserved, and sampled in proportion to past population size. However, various attempts to quantitatively assess the approach suggest there may be some validity in assuming date counts reflect relative population size. To add to this conversation, here we conduct a preliminary analysis coupling estimates of ethnographic population density with late Holocene radiocarbon dates across all counties in California. Results show that counts of late Holocene radiocarbon-dated archaeological sites increase significantly as a function of ethnographic population density. This trend is robust across varying sampling windows over the last 5000 BP. Though the majority of variation in dated-site counts remains unexplained by population density. Outliers reveal how departures from the central trend may be influenced by regional differences in research traditions, development-driven contract work, organic preservation, and landscape taphonomy. Overall, this exercise provides some support for the “dates-as-data” approach and offers insights into the conditions where the underlying assumptions may or may not hold.