The suitability of marine limpet shells for radiocarbon dating may depend on potential offsets due to diet and habitat, especially with regard to grazing mollusks on carbonate substrates (Dye 1994; England et al. 2013). A previous study on one grazing limpet species on the coast of Ireland found no offsets from carbonate substrates (Allen et al. 2019), but a similar study from mediterranean coasts found significant offsets on carbonate substrates (Ferguson et al. 2011). We carried out a new study of radiocarbon and stable carbon isotopes, using multiple species of mollusks collected live from the coasts of Gibraltar and Sardinia, from both carbonate and non-carbonate substrates. The 14C results indicate that one species, inhabiting the upper shore, has a significant offset at the carbonate locations. This species, Patella rustica, has adapted to tolerate desiccation and may have biological traits that result in higher metabolic-derived carbon incorporated in its shell. The results of this preliminary study imply that selected species of grazing mollusks are suitable for radiocarbon dating, even in areas of carbonate geology.

Chronological studies are pivotal for understanding different dimensions of the past. Latin America has embraced various archaeometric dating methods, including radiocarbon (14C) dating. This article reviews the development and challenges of radiocarbon databases and datasets in Latin America, analyzing their integration with global projects and highlighting regional disparities. While global databases like IntChron and CARD often marginalize Latin American data, local projects such as ArqueoData, AndesC14, MesoRAD, SAAID and ExPaND focus on regional needs. The fragmentation of radiocarbon data across publications, technical reports, and limited-access archives hinders accessibility and collaboration. This article underscores the necessity of transitioning from static datasets to dynamic web applications, utilizing APIs to enhance data interoperability, incorporating FAIR principles (findability, accessibility, interoperability, and reusability). This article proposes embedding Latin American initiatives within stable, local institutions to ensure sustainability, establishing classification standards for both radiocarbon dates and associated archaeological contexts. Interdisciplinary collaboration between archaeologists and computer scientists is crucial to developing robust, interoperable databases. By embracing these strategies, Latin America can bridge technological and economic gaps, strengthening its contribution to global archaeological research and fostering new insights into the region’s past.

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.

Archaeological investigations in the Prut-Dniester region during the Roman Imperial Period have yielded numerous Sarmatian culture necropolises and isolated graves. Establishing a precise chronology for these remains has long been a challenge due to the limitations of typological dating alone. This study integrates radiocarbon (14C) analysis of 11 human bone samples from selected funerary contexts with traditional typological methods, refining the chronological framework of the Sarmatian culture in this region. The radiocarbon analyses were subjected to Bayesian modeling, which allowed for the delineation of these samples into distinct phases, thereby adjusting and improving the periodization established through traditional methods. The results not only confirm but also refine previously established chronologies, offering deeper insights into the cultural, social, and economic dynamics of Sarmatian communities in the Prut-Dniester Barbaricum. These findings represent a significant contribution to the broader understanding of the Roman Imperial Period beyond the Eastern Limes.

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.

Recent archaeological studies carried out at Morro de Arica, on the Pacific coast of the south-central Andean area, traditional burial core of the Chinchorro culture (∼7000−3000 cal BP), have enabled a comparative analysis of radiocarbon dates from burial and domestic spaces, considering the differences between dated marine and terrestrial samples. Consequently, we refined the chronological sequence of the Chinchorro culture and obtained a delta reservoir effect of up to 176±113 years, allowing for interpretation of the impact of stratigraphic alterations and pottery fills on the archaeological site’s formation.

The study provides a radiocarbon sequence for the Iron Age occupation in the elevated areas of the Phoenician settlement of Lisbon, located in the Tagus estuary (Portugal). The dataset is based in ten animal and human samples recovered during archaeological excavations at Largo de Santa Cruz do Castelo. These samples are associated with distinct phases of the Iron Age, dated by the ceramic findings between the 7th and 5th century BCE, as well as a latter sample from the Roman Republican Period (2nd half of the 2nd century BCE). Despite the challenges posed by the 1st millennium BCE radiocarbon calibration, this dataset proves valuable for establishing a more detailed chronological framework. It represents a significant contribution to refining the timeline of Lisbon’s Iron Age settlement and provides a stronger basis for interpreting local developments within the broader regional context.

Radiocarbon (14C) activity in aquatic environments is usually different from that of the atmosphere, the result being that organisms that grow in these different environments will have different 14C ages, even though they are contemporary. This age offset in marine samples is known as the “marine reservoir effect.” The marine calibration curve takes this effect into account as a global approximation, but local variations due to ocean dynamics and other factors must be individually studied and corrected for. With a littoral of more than 11,000 km and a great interest in dating malacological marine samples, Mexico has scarce local reservoir effect studies. Most of the available data come from studies done in the 1960s and 1990s. In this study, we present new reservoir effect corrections for four sites in the Pacific Ocean with positive ΔR values as expected, and one from the Caribbean Sea with a negative average value of ΔR. The results were obtained by dating known-age shells from the malacological collection of the Natural History Museum Felipe Poey, in Havana, Cuba. This new data will be useful to do more precise reservoir effect corrections to malacological samples of the region, with special interest in contexts where it is difficult to date other kinds of organic samples, due to difficulties in their preservation.

The date of the Thera eruption has been a subject of intense debate since the mid-20th century. In recent years, the disagreements have escalated with the introduction of IntCal20. The increased number of annual measurements around the time period of the eruption has highlighted potential fluctuations in the atmospheric radiocarbon record, shedding new light on the date of the disastrous event. The Centre for Isotope Research in Groningen has already contributed data from this time period to IntCal20, and here, we report a new set of annual data of approximately 90 radiocarbon measurements between 1660 and 1507 BCE. We investigate the potential anomalies in the calibration curve and compare our dataset with those from other leading laboratories. Although we do not find compelling evidence of any rapid increases in radiocarbon production during this period, the results do point to the presence of minor differences between datasets which could be species, region or laboratory pretreatment related. By quantifying such offsets, we assess their impact on chronological models related to the eruption of Thera.

The Nerja Cave is a key archaeological site in the Southern Iberian Peninsula. It was inhabited by humans from the Upper Palaeolithic until recent Prehistory (30 and 3.7 ka cal BP). Various excavation campaigns performed in its external chambers (Vestíbulo, Mina and Torca) have recovered evidence of its use as habitat and burial site. Multiple studies on these matters have been published, but, until now, no Bayesian chronological modeling that utilized radiocarbon dates of the three chambers has been performed. To do so, all the available radiocarbon dates and stratigraphic and archaeological data have been compiled. These comprehend ample and diverse information about which, firstly, individual phase models based on the stratigraphic sequence of each one of the chambers have been created. After critically evaluating the results for each of the chambers, a general phase model for the prehistoric occupation of the external chambers has been created considering the cultural adscription of the samples. This has enabled the identification of 11 phases which correspond to the different technocomplexes of the Gravettian, Solutrean, Magdalenian, Epipalaeolithic, Mesolithic, Neolithic and Chalcolithic. Still pending are the refinement and improvement of the model for the Neolithic horizon among other phases of the sequence. The individual and the general models have evidenced important differences between the different archaeological phases in radiocarbon information as well as in the occupation of the three chambers.

This study presents the initial results of carbon-14 dating after performing sample preparation and graphite production processes at the Federal University of Bahia (UFBA) in an intercomparison with the same processes performed at the Radiocarbon Laboratory of the Fluminense Federal University (LAC-UFF). Both laboratories are located in Brazil. The accelerator mass spectrometry (AMS) system at LAC-UFF was used for radiocarbon measurements. To verify any possible contamination sources during sample preparation, we initially performed swipe tests at UFBA, which were subsequently processed and the graphite samples were produced at LAC-UFF. After UFBA, several reference materials (IAEA-C1, -C2, -C6, -C9, and OXII standards) were prepared and converted into graphite. In addition, the sample material was first partially prepared at UFF and UFBA and then analyzed with the AMS system at LAC-UFF. Subsamples were prepared for additional measurements of the δ13C composition with an elemental analyzer coupled to an isotope ratio mass spectrometer (EA–IRMS) in LFNA-UFBA to study the isotopic fractionation and yield of the graphitization reaction. The obtained values closely aligned with the reference values, demonstrating reproducibility and quality and indicating minimal contamination during chemical and graphitization processes. In the future, samples from different matrices will be prepared at UFBA for application in paleoenvironmental and archaeological studies.

Pahñu is an archaeological site belonging to the Xajay culture, which inhabited north-central Mesoamerica in 350–1000 AD. Human burials contained in three pairs of contiguous cists were discovered inside a ceremonial structure at Pahñu during excavations conducted between 2019 and 2022. The walls of the cists separated groups of skeletal remains, so the stratigraphic units containing them did not overlap. Stratigraphically speaking, the six groups of remains could have been contemporary and each of the cists could have been used during periods of different durations. Therefore, the analysis of excavation data could not produce a precise temporal sequence of the events that took place in the cists. However, radiocarbon dating by accelerator mass spectrometry (AMS) of representative samples of bones, teeth, and charcoal, allowed us to refine the temporal sequence of their placement in each cist and thus have a better understanding of the funerary practices of the Xajay.

Holocene environmental changes on the Paraty coastal plain in southeastern Brazil unfolded under dynamic sea-level fluctuations and shifting sedimentary regimes. Continental and marine palynomorph analyses, combined with calibrated radiocarbon dating from two sediment cores (JBS1 and JBS2), reveal a continuous depositional record spanning approximately 7800 to 1000 cal yr BP. Sandy mud and muddy sand sequences reflect variable coastal energy conditions through out the mid to late Holocene. Dinoflagellate cyst assemblages indicate a transition from open marine to marginal marine environments, with maximum marine influence between 7000 and 5000 cal yr BP. Terrestrial palynomorphs show a concurrent shift from grassland-dominated landscapes to mixed vegetation including ombrophilous forest taxa. A marked increase in pollen concentration in the upper stratigraphic layer suggests coastal progradation, enhanced continental input, and reduced marine influence during the late Holocene regression. Bayesian age-depth models demonstrate uninterrupted but variable sedimentation rates, with no evidence for erosional surfaces or depositional hiatuses. The results align with regional sea-level reconstructions and under score the role of transgressive-regressive processes and delta infilling in shaping vegetation dynamics. This integrated micropalaeontological and chronostratigraphic approach offers a robust framework for interpreting Holocene palaeoenvironmental evolution in tropical coastal settings.

The Pelagatos volcano is situated within the Sierra Chichinautzin Volcanic Field (SCVF), 20 km southeast of Mexico City. Previous radiocarbon (14C) dating has revealed that the age of the Pelagatos volcano ranges from 2.5 ± 0.1 to 14.1 ± 0.2 ka BP (1σ). The analysis of additional cosmogenic radionuclides, such as in situ 10Be, facilitates the confirmation of the geochronology of any geological phenomenon by determining exposure ages in quartz minerals. This study proposes a new chronology for the exposure of the Pelagatos volcano rocks by in situ analysis of 10Be in olivine samples collected from five locations. The average 10Be ages in olivine from Pelagatos rocks range from 3.95 ± 0.97 ka to 5.7 ± 1.4 ka (1σ), with a mean age of 4.6 ± 0.9 ka and 4.9 ± 0.9 ka for flow 1 and flow 2, respectively. These results are consistent with previously reported 14C ages, confirming the reliability of the 10Be exposure ages obtained in this study. The in situ dating of 10Be in olivine minerals presents a viable alternative for elucidating the volcanic history and estimating the timing of the next eruption in this volcanic field.

Quantifying marine reservoir effects (MREs) across time and space is crucial for establishing accurate archaeological chronologies, including the activities of past hominines. Although the northern Iberian Peninsula shows a high density of Upper Paleolithic sites and marine shells are frequently found in these assemblages, quantification of MREs in this coastal region remains limited. We performed Bayesian modeling of radiocarbon measurements from both terrestrial (Capra pyrenaica, Cervus elaphus and other herbivores unidentified at species level) and marine (Littorina littorea Linnaeus, 1758 and Patella vulgata Linnaeus, 1758 taxa) archaeological samples recovered from the Tito Bustillo cave (Asturias, Spain) in order to determine the ΔR values for northern Iberia during the Lower Magdalenian period (ca. 20–17 ka cal BP). For the time span between 18.6 and 18.2 ka cal BP we estimated ΔR values of –298±44 14C yr and –495±122 14C yr for the periwinkle L. littorea and the common limpet P. vulgata, respectively. This finding has significant implications for future archaeological research in the northern Iberian Peninsula, as researchers must apply distinct ΔR values depending on the mollusk species selected for radiocarbon dating. Furthermore, the consistency between our calculated ΔR value for P. vulgata and previously recorded data for the same taxon from a neighboring coastal region (Cantabria, Spain) suggests remarkable stability in the marine environment of this area during the Lower Magdalenian period.

La Viña rock shelter is a relevant archaeological site for understanding the late Middle and Upper Palaeolithic cultural development in northern Iberia as evidenced by the Mousterian, Aurignacian, Gravettian, Solutrean and Magdalenian bone and lithic industries, parietal engravings and human subsistence remains recovered during the 1980s excavations by J. Fortea in the western and central excavation areas. This paper aims to present 16 new radiocarbon dates, which are added to the previous radiocarbon dates obtained, using different analytical methods on bone and charcoal. These are now 57 dates in total. Bayesian models have been applied to assess and discern the chronology of the archaeological sequence in each sector of the rock shelter. The results provide details on the chronostratigraphy of each excavation area, documenting the duration of the different technocultural phases and confirming in-site postdepositional events.

Although radiocarbon-accelerator mass spectrometry (14C-AMS) is an important tool for the establishment of soil chronology, its application is challenging due to the complex nature of soil samples. In the present study, chemical extraction methodologies were tested to obtain the most representative age of Amazonian soil deposition by 14C-AMS. We performed acid hydrolysis with different numbers of extractions, as well as treatments combining acid and bases and quartered and non-quartered samples. The ages of the soil organic matter (SOM) fractions were compared to the ages of naturally buried charcoal samples at similar depths. The results showed that the age of the non-hydrolyzable inert fraction of soil was closer to the age of charcoal and older than the ages of humin. It was also observed that the quartering process can influence the results, since the dating of the humin fraction showed variability in the results. Our results are important to provide information about the most suitable method for the 14C-AMS dating of soil samples for paleoenvironment reconstruction studies.

Welwitschia mirabilis, a unique gymnosperm native to Namibia and Angola, is a keystone plant species in the Namib Desert. It represents the only extremely long-lived non-clonal plant species occurring under hyperarid desert conditions, yet limited attempts have been made to accurately determine its age. Here, we present radiocarbon dates from a dead, sectioned Welwitschia of moderate size. We find the outer caudex tissue growth to progressively increase in age from the leaf base towards the ground level in this dwarf tree, while the inner cortex tissue becomes younger. Our sampling strategy revealed that the oldest tissue from this Welwitschia, found at the base of the caudex in the middle of the lobe, was dated to 531 ± 20 14C years, suggesting a vertical growth rate of approximately 0.47 to 0.67 mm/year. These findings can serve as a basis for future dating of larger, living individuals.

We present 35 AMS 14C dates from 26 horizons on a 30-cm gravity core from Shira Lake in the republic of Khakassia, Central Russia. The chronology of the core is determined by 210Pb/137Cs dating results and interpretation of elemental geochemistry with historic documents, covering deposition since ca. 1870 CE. This study assesses the old carbon influence (OCI) on organic carbon 14C by comparison with the 210Pb/137Cs dates, sources of carbon, and lake conditions interpreted from elemental proxies. These include elemental concentrations in 0.5N HCl leaches and Aqua Regia dissolution fractions, as well as organic C, N and C/N measurements. From these data we establish a succession of the following six zones: I) (1870∼1900 CE) relatively fresh lake with high lake level, low productivity and high surface runoff (wet conditions); II) (1900∼1940 CE) a “white zone” reflected by high carbonate and low magnetic signal formed in a saline, oxidizing and holomictic lake stage; III) (1940∼1963 CE) reduced carbonate with elevated organic C, N, C/N, Mo and magnetic signal, indicating a stratified and anaerobic lake; IV) (1963∼1994 CE) increased salinity and productivity with the highest observed magnetic signal and elevated heavy metal and Mo contents, implying enhanced anoxic conditions and human impact; V) (1994∼2003 CE) high C/N, organic and carbonate contents suggesting meromictic and anaerobic lake conditions; VI) (2003∼2020 CE) decreased carbonate content with increased organic C and N, and heavy metals showing a deteriorating lake environment under human impact.