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.

Archaeological investigations have documented an ideological and occupied frontier in the Lower Tagali Valley along the southern margins of the Highlands of Papua New Guinea. Open-area excavations document two types of house structure associated with Huli occupation of the Lower Tagali Valley landscape, a women's house (wandia) and a lodge and ceremonial complex associated with a bachelor cult (ibagiyaanda). Excavation revealed the complete floor plan of the women's house site and multiple structural elements of the ceremonial complex. Radiocarbon dating provides a chronology for both sites that accords with genealogical histories for the colonization of this landscape by Huli during the early nineteenth century, or approximately eight generations ago. These archaeological findings are consistent with the strategies still employed today by Huli in the initial ideological incorporation of new territory and anchoring of expansionary claims through subsequent settlement and cultivation.

The possibility to conduct new fieldwork projects in previously largely unexplored Iraqi Kurdistan during the past decade has reinvigorated research into the transformative fifth to third millennium BCE (Chalcolithic to Early Bronze Age) in southwest Asia when human societies grew from small, autonomous villages to centralized states with urban centers. Major efforts to synchronize stratigraphic sequences from various sites in order to reach a consensus on archaeological periodization and to identify the absolute chronology of societal transformations necessarily focused on available datasets from Syria, Turkey, and Iran. However, increased understanding of differences in communities’ adoption, adaptation, or rejection of new forms of technologies and social organization demands the need for constructing region-specific absolute chronological models for comparative analysis. Such work is particularly challenging in the case of Iraqi Kurdistan where sites frequently have major hiatuses in occupation. The site of Kani Shaie (Sulaymaniyah Governorate) offers the rare opportunity to investigate the Chalcolithic to Early Bronze Age with a largely uninterrupted sequence of occupation from ca. 5500 to 2500 BCE. This paper presents a series of fourteen radiocarbon dates, representing every archaeological period in this timeframe, as a first step toward the construction of a regional absolute chronology.

LiDAR coverage of a large contiguous area within the Mirador-Calakmul Karst Basin (MCKB) of northern Guatemala has identified a concentration of Preclassic Maya sites (ca. 1000 b.c.–a.d. 150) connected by causeways, forming a web of implied social, political, and economic interactions. This article is an introduction to one of the largest, contiguous, regional LiDAR studies published to date in the Maya Lowlands. More than 775 ancient Maya settlements are identified within the MCKB, and 189 more in the surrounding karstic ridge, which we condensed into 417 ancient cities, towns, and villages of at least six preliminary tiers based on surface area, volumetrics, and architectural configurations. Many tiered sites date to the Middle and Late Preclassic periods, as determined by archaeological testing, and volumetrics of contemporaneously constructed and/or occupied architecture with similar morphological characteristics. Monumental architecture, consistent architectural formats, specific site boundaries, water management/collection facilities, and 177 km of elevated Preclassic causeways suggest labor investments that defy organizational capabilities of lesser polities and potentially portray the strategies of governance in the Preclassic period. Settlement distributions, architectural continuities, chronological contemporaneity, and volumetric considerations of sites provide evidence for early centralized administrative and socio-economic strategies within a defined geographical region.

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.

La jerarquización de recursos constituye uno de los procedimientos más empleados para evaluar la subsistencia de los cazadores-recolectores en el pasado. Para el Centro Occidente Argentino (COA) esta jerarquización se fundaba en el tamaño corporal de las presas. Aquí incorporamos datos sobre los costos de manejo, generando el primer ordenamiento de recursos para la región que contempla los elementos requeridos por los modelos de optimización (Kcal/tiempo post-encuentro). Luego del guanaco (Lama guanicoe) —presa de mayor rendimiento— este ranking situó en segundo y tercer lugar a los huevos de Rheidae y los armadillos (Dasypodidae), respectivamente, resaltando la importancia de presas tradicionalmente consideradas de bajo rendimiento. Siguiendo la teoría de aprovisionamiento óptimo, elaboramos el modelo de amplitud de dieta (MAD) para los desiertos más representativos de Nordpatagonia: el de Monte y el patagónico. En este último, la mayor disponibilidad de guanacos tornó menos ventajosa la incorporación de nuevos ítems a la dieta. Para el Monte, la dieta óptima se amplió, incluyendo recursos menores como ciertos peces (i.e., Percichthys trucha). En definitiva, el MAD permitió reinterpretar tendencias temporales en la subsistencia humana, sosteniendo una ampliación en el espectro de recursos explotados hacia el Holoceno tardío en el COA. En general, las expectativas del MAD son confirmadas con el registro zooarqueológico regional.

This paper illustrates the results of research carried out at the archaeological site of Puig Castellar de Biosca (Catalonia, Spain), located in the northeast of the Iberian Peninsula. This Republican military fortress, a castellum, is exceptional due both to its early chronology, which ranges between 180 and 120 BCE, and to the fact that it acted as a long-lasting military installation situated in a pacified area on the periphery of the Celtiberian conflict zone. Work at the site has uncovered a central building on the top of a hill, which due to its Italian features has been identified as the headquarters of the military fortress. If this interpretation is correct, this might be one of the first examples of a Republican military headquarters building documented to date. It could then be considered a predecessor of later praetoria and principia, which have been recorded in the Numantine camps and on the Roman western limes.

Ever since large amounts of Bell Beaker complex pottery were first discovered within megalithic graves in north-western France, the Bell Beaker has been tightly tied to the ‘megalithic phenomenon’. However, the fact of construction of these various kinds of megalithic monument during the Middle to Late Neolithic pre-dates the users of Bell Beakers. While this is a case of the re-use of older funerary monuments, it is assumed that Bell Beaker funerary practices witness a shift from Neolithic collective burial to individual inhumation. For a long time finds from the megalithic graves have constituted our main source of information on the Bell Beaker complex in north-western France. However, these ‘artificial caves’ have biased our understanding of the Bell Beaker complex and, in particular, of its funerary practices. The re-assessment of old finds and recent large-scale excavations have brought to light a large number of new sites, revealing a greater diversity in Bell Beaker funerary practices in the region than had been perceived previously. In the first part, we set the broader picture, stating what we know or can say about funerary practices during the Recent and Late Neolithic (3350–2550 bc), before the beginning of the Bell Beaker phenomenon. We then discuss the different Bell Beaker burial practices (2550–1950 bc), their chronological and regional variabilities, and, above all, the research biases that might have affected their understanding.

Estuaries and deltas are crucial zones to better understand the interactions between continents and oceans, and to characterize the mineralization and burial of different sources of organic matter (OM) and their effect on the carbon cycle. In the present study, we focus on the continental shelf of the northwest Mediterranean Sea near the Rhône river delta. Sediment cores were collected and pore waters were sampled at different depths at one station (Station E) located on this shelf. For each layer, measurements of dissolved inorganic carbon concentration (DIC) and its isotopic composition (δ13C and Δ14C) were conducted and a mixing model was applied to target the original signature of the mineralized OM. The calculated δ13C signature of the mineralized organic matter is in accordance with previous results with a δ13COM of marine origin that is not significantly impacted by the terrestrial particulate inputs from the river. The evolution with depth of Δ14C shows two different trends indicating two different Δ14C signatures for the mineralised OM. In the first 15 cm, the mineralized OM is modern with a Δ14COM = 100 ± 17‰ and corresponds to the OM produced during the nuclear period of the last 50 years. Deeper in the sediment, the result is very different with a depleted value Δ14COM = –172 ± 60‰ which corresponds to the pre-nuclear period. In these two cases, the marine substrate was under the influence of the local marine reservoir effect with more extreme Δ14C results. These differences can be largely explained by the influence of the river plume on the local marine DIC during these two periods.