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.

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.

Despite the continuous reporting of radiometric chronology of lithic assemblages in the Korean peninsula, systematic evaluation of reliable radiocarbon (14C) dates and discussion on the lithic technological variability have not been adequately presented. This paper attempts to address the issue reviewing the available data on the Early Upper Paleolithic (EUP) of Korea, with a focus on 14C chronology and lithic technology. Also, these recent advances in Paleolithic studies in Korea provide interesting aspects of the transition to Upper Paleolithic (UP) technology in East Asia. The transition to the UP is characterized by two key developments: the emergence of blade technology and tanged points, and the use of quality raw material that had been previously disregarded. Reliable 14C dates published recently indicate that this transition began around 43,000–40,000 cal BP. We propose that the emergence of the UP tradition on the Korean peninsula can be explained by focusing on the mobility, regional exchange networks and population dynamics of hunter-gatherers rather than the continuing resort to the simple unidirectional dispersal.

This study examines settlement evidence from south-eastern Norway during the Late Neolithic and Bronze Age, revealing unique aspects of regional architectural and social organization. Notably, smaller and uniform house sizes suggest a divergence from the monumental power displays seen in southernmost Scandinavia. The uniformity in house sizes and significant spatial distances between contemporary houses imply a social structure akin to segmentary societies with symmetrical power relations, reliant on mobility and mixed subsistence practices. Changes in settlement patterns and house sizes during the Late Bronze Age could have been the result of increased social stratification or responses to population growth. Overall, the settlement patterns and house sizes in south-eastern Norway reflect a society that, while connected to the broader Nordic Bronze Age world, developed distinct social and economic strategies. These findings highlight the importance of considering regional variations and responses to environmental and social challenges in prehistoric societies.

The stratigraphic record of the Early Holocene in the Nebraska Sand Hills suggests dry climatic conditions and periods of sustained aeolian activity, which resulted in several well-documented instances of sand dunes blocking river drainages in the western Sand Hills. Here, we present evidence that drainage blockage by migrating sand dunes also occurred in the central Sand Hills, where precipitation is higher and dune morphology differs. The South Fork Dismal River valley contains a sequence of aeolian, alluvial, and lacustrine sediments that record a gradual rise of the local water table following a sand dune blockage of the river valley around 11,000 years ago. After the initial development of a wetland, a lake formed and persisted for at least 2000 years. Increased groundwater discharge due to a warm, moist climate in the region after 6500 years ago likely caused the breaching of the dune dam and eventually resulted in the decline of the local water table. Through a careful examination of the intricate relationships between ground water, surface water, and sand movement in a dune field setting, we discuss the hydrologic system's complex response to climate change. We use diatoms to reconstruct the lacustrine environment and optically stimulated luminescence and radiocarbon dating to provide chronological control, based on a careful evaluation of the strengths and limitations of each method in varied depositional environments.

The excavation of a stratified sequence of deposits spanning the Initial Late Formative period (250 BC–AD 120) at Iruhito, in the upper Desaguadero Valley of Bolivia, provides insight into this previously unrecognized, four-century period separating the well-documented Middle Formative (800–250 BC) from the Late Formative (~AD 120–590) period. By tracking subtle shifts in ceramic, architectural, lithic, and faunal data, we can explore tempos of change in social life during this dynamic time. These data lead us to suggest that, rather than being a “transitional” period or a “hiatus” in regional occupation, the Initial Late Formative period was a distinct mode of sociality characterized by the realignment and expansion of interaction networks, on the one hand, and rejection of the decorative aesthetics, monumentality, and public-oriented performances of earlier periods, on the other. We argue that the Late Formative period centers emerging after ~AD 120 intentionally cited architecture and aesthetics that were distant in time and space, constituting a sophisticated political strategy. Finally, these data suggest that the chronological schemata we use to build regional histories often obscure social variability.

Burial 10 is a unique Manteño (AD 650–1532) burial from Buen Suceso, Ecuador, dating between AD 771 and 953. This burial included the remains of a young female, pregnant at the time of death and buried with an elaborate array of goods, including anachronistic spondylus ornaments, green stones, and shell eye coverings. Perimortem trauma, including a cranial fracture and cutmarks on hand bones, perimortem removal of the hands and left leg, and other body manipulation suggest she was sacrificed, a rare event for coastal Ecuadorian peoples.

El objetivo del presente trabajo es analizar el registro de Chenopodium recuperado en el poblado pukara El Carmen 1, sector centro-occidental del valle de Santa María, Tucumán (ca. 1200-1450 dC). Para ello se trabajó con una muestra de 310 macrorrestos provenientes de las excavaciones realizadas en el poblado alto (recinto 13, sector VI). El predominio y alta densidad de granos de Chenopodium quinoa Willd. y Chenopodium cf. quinoa Willd. con evidencias de procesamiento en la estructura de combustión, podría corresponder a prácticas de tostado y/o hidratación en el marco de preparaciones culinarias. La ubicación del recinto 13 en el espacio de mayor jerarquía dentro del sitio y su posición centralizada dentro del sector, sugieren la importancia de la quinoa para los habitantes del poblado y llevan a pensar en su rol en el marco de encuentros, ceremonias o eventos rituales en los que el procesamiento y la elaboración de comidas y/o bebidas adquieren importancia.