The green tree python is quite a favorite pet for sale on the international market. The species is therefore protected by the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES). Since the illegal poaching of large numbers of specimens in the wild might lead to the detriment of native populations, and wildlife breeding farms were found to be serving as conduits to funnel wild-caught green tree pythons out of Indonesia, a forensic tool to distinguish wild-caught from captive-bred specimens could support the enforcement of CITES protections. To disrupt the illegal trade of green tree pythons, we have developed an effective tool to distinguish the animals supposedly bred in captivity from those caught in the wild, based on the strontium isotope composition in conjunction with trace element data. Like in human hair, 87Sr/86Sr values seem to vary according to the relative contribution of endogenous and exogenous sources. Thus, we infer that if there is enough sustainable strontium available for the analysis, it might be possible to use the 87Sr/86Sr values in parallel with trace elements to distinguish wild-originated specimens from the in captivity-bred ones. Indeed, our pilot study on the shed skins of animals where the geographic origin was either the Czech Republic or Indonesia, confirms that shed skins can be effectively used for further forensic Sr radiogenic isotope analyses.

Five unknown Holocene flank eruptions from the Masaya caldera are reported here. These eruptions comprise basaltic lava flows emplaced in Masaya’s northern rift zone along the Cofradía fault zone, east of Managua City. The lava flows were defined as Mosintepe, Portillo, Gorgonia, Campuzano, and Martha units. Paleosol samples were collected below each lava flow, and radiocarbon AMS analyses were performed, yielding ages of 2250 ± 30, 1610 ± 30, 1600 ± 30, 1140 ± 30, and 790 ± 30 yrs BP, respectively. Calibrated age intervals are 285–229 cal BC for Mosintepe, 496–534 cal AD for Portillo, 496–535 cal AD for Gorgonia, 914–976 cal AD for Campuzano, and 1226–1268 cal AD for Martha; all stratigraphically consistent. These eruptions emitted magma bulk volumes between 0.02 and 0.51 km3, reaching up to 8 km from their eruptive vent and 13 km from Masaya’s polygenetic system summit crater. Their mineral paragenesis, and major and trace element geochemical fingerprint reveals a common volcanic provenance from the Masaya caldera due to lateral magma draining. This study demonstrates that basaltic lava flow flank eruptions are common in the Masaya caldera along its northern volcanic rift zone. Therefore, this information should be considered in future hazard and risk assessments.

As the capital of medieval Makuria, Old Dongola, Sudan was one of the largest sites in the region and a center of religious and cultural importance. The annex to the monastery on Kom H at Old Dongola, functioning from the 6/7th through 14/15th c. CE, contains three distinct burial crypts that have been proposed as having been utilized for the burials of social elites, quite likely Makurian Church or monastic officials. Each crypt contains multiple burials, ranging from five (Crypt 3) to seven (Crypts 1 and 2), bringing forth questions of temporality and re-use. Medieval Makurian burials do not typically contain grave goods or personal items, reducing the possibility of establishing temporality through relative dating. In the absence of substantial grave goods allowing for seriation and temporal affiliation of interments, and with only the epitaph of Georgios providing a date of 1113 CE, it has thus far not been possible to differentiate the timeframes of interment for the individuals interred within Crypts 1–3 on Kom H at Old Dongola nor the establishment of these crypts in relation to the monastery. To gain further insight to the periods of use of these crypt burial spaces, 18 human bone collagen samples were submitted for radiocarbon dating at Poznań Radiocarbon Laboratory. The results of radiocarbon dating provide novel insights to the use of Crypts 1–3 at the Kom H monastery, allowing for periodization of this burial environment in relation to the larger adjacent medieval cemetery and Old Dongola community.

This study from the Accelerator Mass Spectrometry Laboratory at the Center for Physical Sciences and Technology (FTMC), Vilnius, Lithuania, presents a detailed description of the sample preparation methods employed in the laboratory, with a focus on two AMS systems: a single-stage accelerator mass spectrometer (SSAMS) and a low energy accelerator (LEA). A pivotal aspect of this article is our participation in the GIRI intercomparison test, demonstrating our commitment to precision and accuracy in radiocarbon dating, with the average z-score values of the GIRI test being 0.16 ± 1.66 for SSAMS and –0.04 ± 1.52 for LEA. The outcomes from this participation validate the meticulous sample preparation procedures at Vilnius Accelerator Mass Spectrometry Laboratory and offer significant insights into the efficiency and reliability of SSAMS and LEA systems, contributing to a better understanding of their capabilities in radiocarbon analysis.

In this paper a part of a new multi-proxy results obtained from the Kotoń landslide fen deposits (the Beskid Makowski Mountains, the Outer Western Carpathians, S Poland), including loss on ignition analysis, plant macrofossil analysis and radiocarbon dating is presented. The aim of the study was to verify whether the reconstructed local palaeoecological stages of the Kotoń fen development could be correlated with the Bølling-Older Dryas-Allerød sequence and to verify whether the rarely recognised short GI-1d/Older Dryas climate cooling affected the regional and local palaeoecological record of the Kotoń deposits. Results showed that four palaeoecological stages of development (poor-in-vegetation waterbody, waterbody with aquatic succession, calcareous extremely rich fen and moderately rich fen) determined for the Kotoń landslide fen deposits between ca. 14,600–13,500 cal BP stay in agreement with the earlier pollen division of the Kotoń deposits and with the extraregional chronology of the Greenland ice cores. The influence of GI-1d/Older Dryas climate cooling on the surrounding and regional vegetation was recognised for the deposits of Kotoń and other localities in a form of open-space habitats with herbs, shrubs and sparse tree stands, e.g. steppe-tundra, reflecting the cold and dry climatic conditions. In case of local vegetation and palaeohydrological changes, the Older Dyas climatic oscillation was recorded as a shallowing of the existing palaeo-waterbodies. Although for other localities this process was attributed to the dry climatic conditions, in case of Kotoń site more detail multi-proxy research is necessary to distinguish the climatic impact from the autogenic succession.

Bone and tissue fractions, obtained in 2017 following hip replacement surgery on a healthy Caucasian male, born in 1944, reflect in their 14C concentrations the integrated effect of the lifetime metabolic uptake and replacement of atmospheric bomb 14C at different tissue-specific turnover rates. The 14C content of hair and nails reflects recent carbon uptake. The 14C values in healthy cartilage and bone collagen/apatite correspond to those of the “local” atmosphere during the 2005–2009 Northern Hemisphere growing seasons, while those from damaged areas of the femur head correspond to the atmosphere in 2013–2014. A simple bone growth and regeneration model used in combination with the NH atmospheric 14C concentrations indicates remodelling rates around 9% per year in the healthy bone and a doubling to tripling in the damaged area depending on the model chosen. The differences in 14C concentration observed in the fractions provide both a caveat for sample selection for the 14C dating of archaeological bones and an indication of its potential in forensics and as a diagnostic tool for turnover rates in medical studies.

A reassessment of radiocarbon counting statistics in accelerator mass spectrometry (AMS) at the Andre E. Lalonde National Facility revealed that the traditionally assumed Poisson distribution may not always apply. An extensive analysis of 2.5 years of 14C and 12C data was conducted on a MICADAS™ AMS. This study found that only 63% of results adhered to Poisson statistics, while 34.2% showed slight deviations, and 2.8% exhibited strong non-Poisson behavior. This finding challenges the classic assumption that radiocarbon AMS is inherently a Poisson process. This study recommends considering non-Poisson models, specifically quasi-Poisson and negative binomial models, to better account for internal error and improve the accuracy of the reported error. Integrating 12C current noise into error calculations is also suggested as it plays a significant role in measurement variability. We would like to ignite curiosity on other AMS laboratories to test the non-Poisson error framework with the broader aim of assessing its applicability in improving conventional statistical models, error expansion methods, and in ensuring more accurate and reliable 14C results.

Cosmogenic 7Be and 10Be are effective tracers for studying atmospheric dynamics and Earth’s surface processes, with over 90% of these isotopes reaching the surface via wet deposition. However, the characteristics and influencing factors of 7Be and 10Be wet deposition remain unclear in different regions, limiting the precision of these nuclides as tracers of environmental change. This study analyzes the annual variation of 7Be and 10Be wet deposition in Xi’an and examines the impact of precipitation on their deposition. Ultra-trace levels of 7Be and 10Be in precipitation were synchronously measured using state-of-the-art accelerator mass spectrometry. One-year (July 30, 2020 to September 3, 2021), high-frequency (individual rain events) and time-synchronized series of observations of 7Be and 10Be wet deposition data (n = 49) were analyzed. The total annual wet deposition fluxes of 7Be and 10Be in central China (34.22°N, 109.01°E) for 2020/21 were (218 ± 24) × 108 atoms·m–2·yr–1 and (314 ± 16) × 108 atoms·m–2·yr–1, respectively. Precipitation amount, intensity, and duration were quantitatively analyzed for their effects on total wet deposition flux, mean concentration, washout ratio, deposition velocity, and scavenging coefficient of 7Be and 10Be during individual rain events. The results indicate that precipitation amount is the most significant factor influencing the wet deposition flux of both nuclides.

Sulfur stable isotope ratios (δ34S) have become increasingly common in archaeology for studying paleodiet, especially in occasions where there is a need to identify aquatic resource consumption more accurately. This is particularly relevant in the Baltic Sea region, where brackish conditions tend to mask “typical” marine carbon isotopic signals. Here we report new δ34S values for 126 human bone collagen samples which will be analyzed together with previously published data to investigate the potential of sulfur isotopes as an alternative proxy for aquatic resource consumption in historic period Estonia (ca. AD 1100‒1800). Bayesian statistical programming was used to provide quantitative dietary estimates, suggesting that the diet of the general population was predominantly terrestrial. The inclusion of δ34S as an additional dietary proxy produced generally comparable model results to the scenario that excluded δ34S. A sub-selection of samples was also radiocarbon dated and calibrated to take into account potential reservoir effects. For burials of commoners, the average contribution of 10% fish to dietary carbon does not significantly alter calibrated date ranges, even in the occasion where data on local reservoir effects is insufficient. This study has demonstrated both the potential and the pitfalls of using δ34S in this temporo-spatial context, and the new stable isotope and 14C data have shed light onto individual site-histories but also to broader cultural processes and changes that occurred during these turbulent times in this region.

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.

Radiocarbon dating is a widely used method in archaeology and earth sciences, but the precision of calibrated dates from single radiocarbon measurements can be difficult to understand. This study investigates the precision of calibrated radiocarbon dates depending on the uncertainties of the measurement and the details of the calibration curve. Using data for the Holocene epoch and the IntCal20 calibration curve, over 1,000,000 hypothetical radiocarbon measurements were calibrated and analyzed. The study shows that high-precision measurements can yield calibrated date ranges from less than 50 years to more than 200 years (at the 95.4% probability) depending on the specifics of the calibration curve. This research may serve as a tool for planning future studies and assessing whether high-precision measurements are beneficial for proposed case.

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.

The recovery of nearly 250 burials at the El Olivar site provided the opportunity to address questions regarding the groups inhabited coastal settings of the semiarid north of Chile between the 800 and 1540 AD. Stable isotopes of carbon, nitrogen, and oxygen were analyzed from 60 human samples. Radiocarbon (14C) analyses were conducted in 20 samples from camelids and 42 human samples. Subsequently, a sample of 25 individuals exhibiting diagnostic cultural features of the Las Ánimas Cultural Complex (LACC) and the Chilean Diaguita Culture (CDC) was selected for the purpose of assessing differences in their diet and mobility and clarifying their chronology. The δ13C and δ15N values obtained revealed the existence of a small group of individuals (n=6) with a diet based on C3 plants and terrestrial protein, and another major group (n=33) with values compatible with the consumption of C4 plants and marine resources. Four of the six individuals of the small group presented Ánimas diagnostic features, and in the major group were identified both Ánimas and Diaguita individuals. The δ18O values exhibited a similarity between the Ánimas and Diaguita individuals, suggesting coastal-to-inland mobility in both groups. Calibrated 14C dates indicate that El Olivar was occupied for a period of nearly 380 years, spanning between 1150 and 1536 AD, and that between the 1300 and 1400 AD, Ánimas and Diaguita individuals coexisted at El Olivar. These findings call into question the current thought that the CDC emerged from the LACC around 1000 AD, and that both represent different archaeological entities.

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 Cunene region of southern Angola, especially the area around Xangongo, hosts a large number of African baobabs, including several superlative specimens. Our research reports the investigation of the three biggest specimens from Xangongo Grove, named XG-1 (11 stems; circumference 26.34 m), XG-2 (5 stems; 22.70 m) and XG-3 (9 stems; 27.73 m), and of the largest baobab from Xangongo town, named XT-1 (7 stems; 21.02 m). Several wood samples were collected from these four baobabs mainly as cores from trunks and/or primary branches and then radiocarbon-dated by AMS. The two oldest samples were extracted from two primary branches of baobab XG-1. These have practically identical radiocarbon dates of 1822 ± 19 BP and 1822 ± 10 BP, which correspond to identical calibrated ages of 1785 ± 15 and 1785 ± 10 calendar years. The calculated age of baobab XG-1 is 2100 ± 50 years. Thus, XG-1, which is called by the locals “The biggest baobab of Africa”, becomes the oldest living African baobab with accurate dating results. The results indicate ages of 1100 years for baobab XG-2, 850 years for baobab XG-3 and 550 years for baobab XT-1.

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.

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.

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.

With the development of radiocarbon dating methods in the last decade, the Andean archaeological community has successfully leaned into the problem of the chronology of the expansion of the Inca State. While this chronology was based on ethnohistorical accounts (Rowe 1945), it has been possible to verify its foundations precisely in the last decade. The results from the Maucallacta region are part of these discussions and are intended to add new data from the Inca province of Kuntisuyu, which was neglected in this debate until now. The project encompasses archaeological investigations near the snow-covered volcano Coropuna, frequently mentioned by chroniclers of the 16th and 17th centuries as an oracle worshiped since pre-Inca times. This includes a large complex known as Maucallacta-Pampacolca, located approximately 170 km northwest of Arequipa in the southern highlands of Peru, within the District of Pampacolca, Province of Castilla, Department of Arequipa (LS; 3750 m asl). Due to its location, it holds a unique relationship with the Coropuna landscape. The site is a vast administrative center featuring over three hundred stone buildings, tombs, and ceremonial structures. Among them, the most important is the large ceremonial platform with ushnu and the dumps deposited beneath it. The analysis of ceramics and animal bones, combined with stratigraphic analysis and the results of new calibrations and interpretations of radiocarbon dates, provides a comprehensive picture of the formation and use of ceremonial dumps at the site, making them one of the most thoroughly examined collections in this regard.

In recent times, forensic science has increasingly relied on methods that use stable and radioactive isotope analysis to identify human remains. The use of 14C-AMS dating of dental enamel and dentine of an individual allows the estimation of the year of birth, while that of stable isotopes of carbon and oxygen can provide information on their geographical origin. Isotopic analysis of a tissue complements existing identification techniques, enhancing the capacity to refine, exclude, and affirm investigative approaches directed towards individual identification.

The primary aim of this exploratory study is to amalgamate diverse isotopic methodologies conducive to the prompt and accurate identification of a deceased individual. In this manuscript, we elucidate the application of a rapid processing technique for whole molars from individuals with documented ages, employed to ascertain age through 14C-AMS dating. Furthermore, an investigation was undertaken to assess the capacity of carbon and oxygen-stable isotopes in distinguishing regional disparities. To achieve this, we conducted a comparative analysis of tooth samples sourced from individuals residing in three cities within the Mexican Republic: Mexico City in the central region, Oaxaca City in the southern region, and Tepic Nayarit on the western Pacific coast. The age of dental piece formation, as estimated through 14C-AMS, exhibited a precise correlation with the actual age. By means of the stable isotope outcomes, the data disclosed substantial disparities in 13C and 18O abundances among teeth from individuals residing in the three cities.