As one of the most extensive prehistoric entities of western Iran, Dalma culture belonging to the Zagros Chalcolithic, flourished in vast areas of the Central Zagros and Northwest Region of the country. This culture is defined essentially by its characteristic ceramic assemblages that show a marked uniformity in terms of technology, vessel forms, and painted designs throughout its territory. One of the main issues regarding this culture is its chronology, which was largely based on comparative studies, a few radiocarbon (14C) dates analyzed in the 1960s–1970s, or a few confusing thermoluminescence dates. In this paper, a series of 15 charcoal samples from a recent salvage excavation at Nad Ali Beig, a single-period site dated to Dalma period, is presented that provide the first reliable absolute dates for a part of the Middle Chalcolithic period of the Central Zagros region. Based on these new dates we may suggest that Dalma culture flourished between ca. 5200/5100–4600 BCE. Furthermore, based on these dates it is now possible to determine the order of appearance of different types of the Dalma culture ceramic assemblage, including the Ubaid-related painted buff ceramics.

14CO2 activity in air samples collected at Kakrapar Gujarat Site, India, was measured, and site-specific dilution factor for 14CO2 has been evaluated. 14CO2 activity in air samples was monitored for 72 different sampling events at onsite stack of Nuclear Power Plant (NPP) and at ESL meteorology laboratory (at 1.6 km from NPP stack). 14CO2 activity in air at stack of NPP and at ESL meteorology laboratory was observed to 0.10–0.18 TBq (GWe.year)–1, with mean value 0.12 TBq (GWe.year)–1 and ≤0.04–0.13 Bq m–3, with mean value 0.08 Bq m–3 respectively. The results were correlated with meteorological parameters. Site specific dilution factor for 14CO2 in air was evaluated at 1.6 km and was found to be in the range of 4.6E-05 to 21E-05 s m–3. Inter angle (degree) between plume direction and fixed sampling location and rainfall (mm) are found to be the important influencing parameters for dilution factor of 14CO2 in air.

Prehistoric shell mounds can be useful for the quantification of the radiocarbon marine reservoir effect (MRE) and, at the same time, knowledge about the MRE allows for the establishment of robust chronologies for these sites. This creates a loop in which the archaeological setting has a dual role: it is part of both the method and the application. Therefore, it is paramount to address these sites from both archaeological and environmental perspectives, investigating their origin and diagenesis in order to overcome biases caused by post-depositional alterations. In this study, samples of bone, charcoal and shell from a Late Holocene shell mound in Southern Brazil, the Sambaqui de Cabeçuda, were analyzed following a multidisciplinary approach to disentangle the complex relationships between archaeology and the environment. We performed X-ray diffraction, radiocarbon dating, stable isotopes (δ13C, δ18O, δ15N) and anthracology analyses as well as Bayesian Chronological Models and Isotope Mixing Models to assess the local MRE and to reconstruct the diet of Cabeçuda builders. Our results reveal a negative local correction for the MRE (ΔR = –263 ± 46 14C yr), expected for the lagoon next to the site, and diets with considerable intakes of marine proteins. We examine the implications of these results for the chronology of the site and discuss a series of complications when performing MRE studies using shell mound sites.

This article discusses radiocarbon dating results of documents preserved at the Central Library of the University of Tehran (hereafter, CLUT) as part of the project “Irankoran.” The paper adds new evidence to an ongoing campaign of dating Qurʾāns and Oriental manuscripts by the Corpus Coranicum Project. The dated manuscripts include one kūfī fragment of the Qurʾān on parchment (no. 10950) and a selection of Islamic and Persian manuscripts, all from the second millennium: the Arabic dictionary Muǧmal al-Luġah (Meškāt no. 203), the medical encyclopedia Ḏaḫīrah-ye Kh w ārazmšāhī (no. 5156), the epic Panǧ Ganǧ of Neẓāmī (no. 5179), the book of wisdom Ādāb al-Falāsifah (no. 2165) attributed to Ḥunayn b. Isḥāq (d. 873 CE), and one of the oldest extant manuscripts of the Avesta Wīdēwdād (no. 11263). Although the authenticity of their colophons is disputed, radiocarbon dating supports the dates of the colophons; even in cases where they were suspected of being tampered with, they most likely present the accurate original dates of the corresponding manuscripts. Only in the case of Ādāb al-Falāsifah (no. 2165), radiocarbon dating of the parchment has identified the manuscript as non-authentic. Inconsistent carbon dating results of two samples taken from Ḏaḫīrah-ye Khwārazmšāhī (no. 5156) and Panǧ Ganǧ (no. 5179) provide evidence of later replaced/added leaves.

This commentary aims at raising awareness and fostering a discussion on the need of a new approach to the radiocarbon (14C) dating of historic mortars. Over the last decades, important advancements have been made in the application of the 14C dating methods to lime mortar samples, including the use of lime lumps instead of generic pieces of mortar. However, a relevant number of results in disagreement with the chronological framework of the related archaeological cases are published every year without a clear understanding of the reasons for such results. This suggests that further developments to the methodology are needed. The commentary argues that to further develop this particular application of the 14C dating method, a new, more holistic approach is needed that moves away from the very “applied” approach that dominated the last decades and focuses more on the causes of contamination and the mechanism of the reactions involved. Two actions are suggested that can immediately improve our ability to critically assess the results obtained: the publication of a chemical and mineralogical characterization of the binding fraction for the dated mortars, and the publication of sampling depth for each dated sample.

Accelerator mass spectrometry radiocarbon (AMS 14C) dates (n = 78) from human bone collagen were analyzed in the largest high-resolution chronology study to date at the ancient city of Teotihuacan in central Mexico (ca. AD 1–550). Samples originate from the residential neighborhood of La Ventilla, located in the heart of this major urban center. Here, a trapezoidal model using Bayesian statistics is built from 14C dates combined with data derived from the stylistic analysis of ceramics from burial contexts. Based on this model, we suggest possible refinements to Teotihuacan’s ceramic chronology, at least within the La Ventilla neighborhood. We also explore the abandonment and reoccupation of La Ventilla after the political collapse of Teotihuacan in the Metepec and Coyotlatelco phases. Findings suggest that these ceramic phases began earlier than is currently projected and that the well-documented abandonment period of La Ventilla may have occurred more abruptly than originally estimated.

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.

Absolute dating of plasters and mortars clearly represents a key information to study important structures and buildings that may have undergone a difficult story starting from their construction. This is for instance the case of the architectures in the archaeological site of Hierapolis (Denizli, Turkey). However, when discussing about the possibility to apply radiocarbon (14C) dating, in this site the presence of different sources of contaminants, due to the geological and geochemical conditions and to the used raw materials, prevents the binder dating. As an alternative, we thus decided to focus on the small fragments of straw that had been used as additives in the mortar/plaster matrices. The fragments were identified, selected and dated using a 14C experimental set-up specifically optimized for microgram-sized samples. The obtained results were satisfying, even though the measured 14C ages also pointed out some possible criticalities in dating such small samples collected from a carbonaceous matrix.

The carbon isotope distribution and its relationship with stable N and S isotope ratio values were investigated within a fish assemblage from the shallow lake Tapeliai, which is constantly affected by inflows of 14C depleted water from the surrounding watershed mires. The “conventional” radiocarbon age within the fish from this lake varied from 119 to 693 yr. The 14C/12C and δ13C values correlated significantly (r=0.85 p<0.001), which is not typical in lakes of the temperate zone. There were no observed statistical differences (Kruskal–Wallis ANOVA tests) in the 14C/12C values among different fish species. The radiocarbon dating values and 15N/14N measurements did not correlate. The radiocarbon measurement values also did not correlate with δ34S, however, the distribution of these isotopes in carp (119 yr and 1.3‰, respectively) and roach (344 yr and 4.5‰, respectively) indicated that fish may include allochthonous food sources in their diet.

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.

Archaeological dung pellets are time capsules of ancient herbivore diets and gut flora, informing on past agropastoral activity, ecology, and animal health. Improving multi-proxy approaches is key to maximizing this finite archaeological resource. Through experiments with standard pretreatments used in radiocarbon (14C) dating, we address a fundamental problem in maximal multi-proxy analysis: How to chronometrically date individual caprine pellets while conserving as much as possible for additional analyses? We applied acid-alkali-acid (AAA) or acid-only pretreatments to 37 samples of ancient and recent sheep/goat dung pellets from sites in the Negev desert, Israel, measuring weight-loss due to pretreatment. Shavings of outer surfaces and remaining inner pellets of four pairs were dated and compared. We found that (i) sample-specific factors affect pretreatment survivability, including preservation quality and initial sample size; (ii) given sufficient start weight, AAA can be used to pretreat sheep/goat coprolites; (iii) 100 mg appeared a desirable minimum sample weight before pretreatment; and (iv) shavings of coprolites’ outer surface produced 14C dates equivalent to dates obtained from inner coprolites. Whereas standard coprolite analysis protocols discard shavings removed from outer surfaces to avoid contamination, our findings indicate their efficacy for 14C dating. This offers an important addition to workflows for multi-proxy coprolite analysis.

Marine radiocarbon (14C) ages are an important geochronology tool for the understanding of past earthquakes and tsunamis that have impacted the coastline of New Zealand. To advance this field of research, we need an improved understanding of the radiocarbon marine reservoir correction for coastal waters of New Zealand. Here we report 170 new ΔR20 (1900–1950) measurements from around New Zealand made on pre-1950 marine shells and mollusks killed by the 1931 Napier earthquake. The influence of feeding method, living depth and environmental preference on ΔR is evaluated and we find no influence from these factors except for samples living at or around the high tide mark on rocky open coastlines, which tend to have anomalously low ΔR values. We examine how ΔR varies spatially around the New Zealand coastline and identify continuous stretches of coastline with statistically similar ΔR values. We recommend subdividing the New Zealand coast into four regions with different marine reservoir corrections: A: south and western South Island, ΔR20 –113 ± 33 yr, B: Cook Strait and western North Island, ΔR20 –171 ± 29 yr, C: northeastern North Island, ΔR20 –143 ± 18 yr, D: eastern North Island and eastern South Island, ΔR20 –70 ± 39 yr.

The Marine20 radiocarbon (14C) age calibration curve, and all earlier marine 14C calibration curves from the IntCal group, must be used extremely cautiously for the calibration of marine 14C samples from polar regions (outside ∼ 40ºS–40ºN) during glacial periods. Calibrating polar 14C marine samples from glacial periods against any Marine calibration curve (Marine20 or any earlier product) using an estimate of ${\rm{\Delta R}}$, the regional 14C depletion adjustment, that has been obtained from samples in the recent (non-glacial) past is likely to lead to bias and overconfidence in the calibrated age. We propose an approach to calibration that aims to address this by accounting for the possibility of additional, localized, glacial 14C depletion in polar oceans. We suggest, for a specific polar location, bounds on the value of ${\rm{\Delta }}{{\rm{R}}_{20}}\left( {\rm{\theta }} \right)$ during a glacial period. The lower bound ${\rm{\Delta R}}_{20}^{{\rm{Hol}}}$ may be based on 14C samples from the recent non-glacial (Holocene) past and corresponds to a low-depletion glacial scenario. The upper bound, ${\rm{\Delta R}}_{20}^{{\rm{GS}}}$, representing a high-depletion scenario is found by increasing ${\rm{\Delta R}}_{20}^{{\rm{Hol}}}$ according to the latitude of the 14C sample to be calibrated. The suggested increases to obtain ${\rm{\Delta R}}_{20}^{{\rm{GS}}}$ are based upon simulations of the Hamburg Large Scale Geostrophic Ocean General Circulation Model (LSG OGCM). Calibrating against the Marine20 curve using the upper and lower ${\rm{\Delta }}{{\rm{R}}_{20}}$ bounds provide estimates of calibrated ages for glacial 14C samples in high- and low-depletion scenarios which should bracket the true calendar age of the sample. In some circumstances, users may be able to determine which depletion scenario is more appropriate using independent paleoclimatic or proxy evidence.

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.

Since 2018, the radiocarbon laboratory of Lanzhou University has been equipped with a compact accelerator mass spectrometer—a 200-KV mini carbon dating system (MICADAS), together with an auto graphitization equipment (AGE III). The laboratory has for a long time prepared graphite targets for 14C dating of plant fossils, charcoal, bones, and bulk organic matter. Herein, we give an overview of the operating status and performance of the dating facility. The long-term measurements of the standard and blank samples indicated that the results for MICADAS in Lanzhou University were accurate and stable and of high sensitivity. Fifteen sets of organic materials collected from archaeological sites in northwest China were selected for an inter-comparison study involving the participation of four specialist laboratories. The 14C dating results for the homogenized archaeological samples from several of the laboratories showed a high degree of consensus. The long-term performance and inter-comparison data for MICADAS confirmed that the radiocarbon laboratory of Lanzhou University could provide stable and accurate 14C dating results. In this context, the 14C dating results for a number of key archaeological/environmental samples were validated.

Current scholarship suggests that Neo-Eneolithic systems of settlement and subsistence in Eastern Europe were defined by short-to-medium range migration, while sparsely populated land in peripheral regions allowed for the continual colonization of new territories. We address the Eastern Tripolye Culture (ETC), a sub-group of the Cucuteni-Tripolye cultural complex that flourished ca. 4300–2950 BC by expanding into the forest-steppe ecozone of Central Ukraine. While a general lack of multi-layer sites complicates regional chronology, we resolve several longstanding questions in Ukrainian archaeological discourse by combining traditional relative chronologies of ceramic types with high-precision AMS dating of material from key sites. We offer a revision of the chronology of Tripolye BI and BI-II, which, rather than consisting of distinct “early” and “late” temporal periods, instead constitute a single period characterized by stylistic diversity in material culture. With an absolute chronology established, we then analyze the space-time distribution of sites, revealing a southwest-to-northeast migratory vector across Central Ukraine characterized by punctuated episodes of “leapfrog” colonization. The establishment of this vector by the ETC presages larger-scale population movements by the Western Tripolye Culture (WTC), which led to the establishment of the giant-settlement phenomenon during the first part of the 4th millennium BC.

The aim of this study was a comparative retrospective assessment of radiocarbon (14C) as a tracer, caused by operational emissions of Rivne and Chornobyl nuclear power plants (NPPs), which are equipped with different types of nuclear reactors. For this purpose, 14C was studied in annual tree rings of pine taken at a distance of 1.5 km southwest of the Rivne NPP and at a distance of 3.5 km west-northwest of the Chornobyl NPP, near the Yaniv railway station. As a background, we use the 14C in air data (Hua et al. 2013), which we continue for time interval 2009–2020 with our experimental data for pine tree rings. Tree rings were also collected in a rural area 60 km west of Kyiv, where industrial impact, in our opinion, is absent. 14C in wood samples was determined using the conventional method based on liquid scintillation counting. It was found that the 14C excess in the annual tree-ring samples of pine near the Chornobyl NPP during the observed operation period (1984–2000) was 3.0–13.0 pMC, except for the 1986, the year of the Chornobyl accident, when the 14C value rose sharply to 182.7 pMC (14C excess 62 pMC). After 2000, the content of 14C in the air near the Chornobyl nuclear power plant did not exceed the background values within the uncertainty of the measured data. The concentration of 14C in the samples of annual tree rings of pine near the Rivne NPP for the observation period (1986–2019) corresponded to the background levels within the uncertainty of the measured data. The study of environmental traces of 14C emissions from two NPPs equipped with different types of reactors showed significantly lower emissions of Rivne NPP with VVER compared with emissions from Chornobyl NPP with RBMK reactors.

We compare radiocarbon (14C) ages of coexisting planktonic foraminifera species from sediment cores VM12-107 and KNR166-2-26JPC from the Equatorial Atlantic Ocean for three time periods (Holocene, Heinrich Stadial 1, last glacial maximum). We find a maximum inter-species difference of 1200 14C yr. On average, the 14C ages deviate by ∼300 yr between Globigerinoides ruber and other species. In most cases, this exceeds the analytical uncertainty range of the measurements and thus renders the choice of species for generating age models as important as sample weight. While modern stratified water-column profiles imply an increase in 14C ages with water depth, we observe an expected parallel increase of 14C ages and δ18O only at VM12-107. The mismatch between 14C ages and δ18O at KNR166-2-26JPC likely results from the effects of bioturbation and the hydrographic setting. The largest difference in 14C ages between mixed-layer versus thermocline-calcifying planktonic foraminifera are observed during Heinrich Stadial 1 despite a decrease in upper-ocean stratification at that time. This difference is likely the result of inconsistent increases in 14C reservoir ages during times of reduced overturning circulation masking the potential of 14C ages of coexisting planktonic foraminifera to reflect the density stratification of the water column.

Food production is one of the most significant achievements in Andean history. The domestication of plants and animals presented an enormous challenge, relating to changing technologies, settlement patterns, and social organization. This paper aims to assess Atacama Desert population dynamics and their relationship to the domestication of plants and animals through chronological modeling using kernel density estimation on radiocarbon (14C) dates, assuming that a higher 14C probability density is related to more intense human occupation. The analysis is based on a 14C dataset comprising 1003 14C dates (between 11,000 and 150 BP) from 243 archaeological sites in the Arica and Tarapacá regions of northern Chile, collected from published data. We observed two population-dynamics inflection points for these regions. First, starting at ca. 3000 BP, constant population growth occurred, which was related to horticulture in the Arica region and to agriculture in the Tarapacá region. Second, between ca. 1000 and 400 BP, a general population rise occurred due to the consolidation of intensive agriculture in the lowlands and precordillera altitudinal belts in both regions and the integration of the coast and the altiplano into macro-regional population dynamics.