Radiocarbon Dating Research Articles

Terminal Pleistocene–Early Holocene human occupation in north-central Chile

While a clear human presence may be recognised in the Andes by 12 000–11 000 cal BP, most archaeological research has focused on occupation of the Andean highlands. To understand the initial occupation of inland areas of South America, the authors consider regional connections and spatial exploitation strategies of hunter-gatherers highlighted in a recent survey of Andean sites. Focusing on north-central Chile, artefacts and radiocarbon dates from three rock shelters suggest sporadic and brief occupation during the Terminal Pleistocene–Early Holocene. Co-occurrence of marine and montane resources, the authors argue, demonstrates a strategy of high mobility and local adaptation in early Andean occupation, using rock shelters as landmarks to navigate and learn new landscapes.

Radiocarbon chronology and settlement patterns in the Bronze Age of the Qaidam Basin, Northwestern China.

Prehistoric settlement patterns on the Tibetan Plateau, particularly in the Qaidam Basin, have drawn significant scholarly interest. Yet, limited data have hindered a comprehensive understanding the Bronze Age chronology and landscape exploitation in this region. This paper presents 24 newly obtained radiocarbon dates from eight archaeological sites within the Qaidam Basin on the Tibetan Plateau. Integrated with existing 14C data and spatial analysis, these findings reveal an overall continuous occupation of the basin from ca. 3600-2500 calBP, with a gradual shift from expansive lowland settlements to smaller, ephemeral high-altitude structures, identified around 3350 calBP. This change is consistent with demonstrated periods of climate degradation which likely drove strategic adaptations in landscape management and subsistence methods. Overall, this research not only establishes a more robust chronology for the Qaidam Basin's Bronze Age, but also advances the discussion on human-environment interactions in high-altitude areas during late prehistory.

Evidence for the oldest Middle Palaeolithic cave occupation in the Romanian Carpathians

ABSTRACTThe Middle and Upper Palaeolithic sites in the Carpathians and Danube lowlands constitute key contexts for tracing the dispersal of Homo sapiens into central‐western Europe and the replacement of Homo neanderthalensis. Surprisingly, the Romanian archaeological inventory lacks transitional technologies and only a few sites have been systematically excavated and numerically dated, explaining the incomplete understanding of the Middle Palaeolithic and hence Neanderthal population dynamics. Here we present new age constraints for the Abri 122/1200 and Peștera Mare caves in the Romanian Carpathians, obtained by radiocarbon dating of charcoal and bone and by optically stimulated luminescence (OSL) dating of cave sediments. Methodological issues and the method's upper limit cause grossly underestimated radiocarbon ages for charcoal from Abri 122/1200 and provide only minimum ages (>41–60 14C ka bp) for bones from Peștera Mare cave. However, the OSL ages suggest Middle Palaeolithic cave occupation in the Carpathians since early Marine Isotopic Stage (MIS) 7 and lasting at least until MIS 5. These ages reinforce the vast potential of Carpathian cave sites in solidifying our understanding of Neanderthal dynamics in the region and their habitats. We discuss the reliability of this new chronology and the archaeological implications for the Middle Palaeolithic of neighbouring areas.

Prehistoric communities in the Bayuda Desert, Sudan

Abstract Large-scale field research is providing extensive data on the prehistoric settlement history of the Bayuda Desert in Sudan. The authors briefly examine notable outputs from the project, including some of the more than 100 radiocarbon dates that permit a more nuanced understanding of the chronology of settlement pattern changes.

Holocene history of Fiskesø, Prinsesse Ingeborg Halvø, eastern North Greenland

Sediment cores up to 92 cm in length were recovered with gravity and Russian peat corers from Fiskesø, Prinsesse Ingeborg Halvø, eastern North Greenland, during the summer 2014. The correlated sediment succession consists of clastic sediments that are interspersed in the upper part with layers of organic material and likely record the environmental history of the lake since deglaciation. The paucity of macrofossil remains hampered radiocarbon dating of the sediments from Fiskesø. According to published data, the deglaciation of the region took place c. 10 cal. ka BP. Relative sea-level reconstructions from the region suggest that the Fiskesø basin, which is today located at 33 m above sea level, was characterised by marine conditions until c. 8.1 cal. ka BP. Marine fossils in the lower part of the sediment succession support the prevalence of marine conditions. A reliable radiocarbon age from 5 cm above the isolation horizon in Fiskesø sediments indicates an age of 6.1 cal. ka BP and supports the isolation of the basin prior to this time. Cooling is indicated in the upper part of the sediment succession and is reported to have taken place in the region stepwise shortly after 6.1 cal. ka BP and at c. 4.5–4.0 cal. ka BP. Despite the poor chronology the data from Fiskesø support existing terrestrial and marine reconstructions from the region.

Fauna and landscapes of the Southern Minusinsk basin (southern Siberia) at the end of the late pleistocene

The paleolandscapes of the first half of MIS 2 or the Last Glacial Maximum (LGM) were reconstructed based on the study of the first mammoth fauna locality in the Abakan River valley and comparison with other localities in the South Minusinsk Basin. The sediments in the geological section of Uytag are represented by interlayers of silts, underlain and overlain by sandstone rock slack fragment, interpreted as weakly eroded deluvium. The study of the Uytag locality made it possible to clarify the time and range of distribution in southern Siberia of some mammal species Ovis ammon, Equus ferus, Marmota baibacina, Sicista subtilis, Lagurus lagurus and Microtus gregalis, as well as Pleistocene bird Aquila chrysaetos. The age of the locality is confirmed by radiocarbon dating. The species composition of the fauna is similar to other localities in the region of this age. All known localities and single finds of faunal remains indicate a wide development of open steppe landscapes in the South Minusinsk Basin during the LGM.

Lake sediments on the Adamawa Plateau (Central Cameroon) as archives of climate change and the Bantu impact during the last 4000 years BP

AbstractThis study investigates Late Holocene environmental changes in Central Cameroon induced by the combined effects of climate and human impact. For this purpose, sediments from lakes Dang, Massote, Fonjak and Ngaoundaba were studied through lithologic analysis including mineralogical composition and organic geochemistry combined with radiocarbon dates. From these analyses, the sediments at the base of lakes Massote and Dang cores are respectively dated to 4680–3530 and 4220–3580 cal yr BP, whereas the sediments of lakes Fonjak and Ngaoundaba seem to be younger, respectively dated to 3210–3000 and 1870–1740 cal yr BP. Lake sedimentation is dominated by organic matter (OM) poor deposits (OM < 3%) in the lower sections and OM-rich deposits (OM: 5–54%) in the upper sections. This shift from OM-poor to OM-rich sedimentation induced by climate variations occurred at $$\sim $$ ∼ 2800–2400 cal yr BP. The mineral assemblage is predominantly composed of kaolinite with minor contributions from chlorite, smectite, chlorite/smectite, illite/smectite, quartz, K-feldspar, gibbsite, plagioclase, siderite, hematite and goethite. These sediments are clastic, except for Lake Fonjak core sediments which correspond to peat intercalated with carbonate clay and clastic deposits. Age-depth models suggest that the sedimentation rate was 0.2 mm yr-1 for lakes Dang and Massote before $$\sim $$ ∼ 690–560 cal yr BP and $$\sim $$ ∼ 660–470 cal yr BP, respectively. Thereafter, it increased to 0.8 mm yr-1 in Lake Dang and 0.7 mm yr-1 in Lake Massote. Finally, Late Holocene environment changes in Central Cameroon consisted of the shift of open water lakes to marshy fringes with abundant vegetation induced by human activities and facilitated by increasing seasonality.

Dating the Egyptian Old Kingdom: The reign of Djedkare (5th dynasty)

Abstract This study aims to discuss the chronology of the Egyptian 5th dynasty of the Old Kingdom and the tentative date of accession of king Djedkare based on material from his royal necropolis at South Saqqara and non-royal cemetery of Abusir South, Egypt. A series of radiocarbon (14C) dates were established through analysis of archaeological material from several monuments at the necropolis, including the king’s pyramid complex, pyramid complex of his queen, and two elite tombs (Isesiankh and Khuwy). In addition, two samples from non-royal tombs in the Abusir South cemetery, were taken into consideration for further precision during the modeling, associated with king Huni (end 3rd dynasty) and king Niuserre (5th dynasty). The contextualized 14C dates together with re-evaluation of historical evidence on Djedkare’s rule, results in a new model of temporal probability density which can be further refined with any new data from archaeological research. It shows that Djedkare’s reign can be currently modelled between 2503 and 2449 BCE (95.4%), thus slightly older than expected by literature. This presented model provides a more precise chronological frame for the late 5th dynasty period of Egyptian history, which was period of a significant socio-economic transformation.

Archaeology on the edge: radiocarbon chronologies for Aboriginal cliff-top sites of the Murray River, South Australia

Abstract This paper presents new radiocarbon dates for two Aboriginal archaeological complexes situated on the cliff-lines of the Murray River in South Australia (SA); at Pooginook Flat and Tanamee. These dates represent the first age estimates for archaeological sites within the Upper Gorge section of the Murray River. The dates ranged from ca. 11 cal ka to the Late Holocene. The research supports previous evidence which has indicated that sites located along the Murray cliffs preserve much of the oldest evidence of Aboriginal peopling along the Murray River corridor in SA. The new dates also allow us to contribute to discussions concerning broader chronological trends in Aboriginal lifeways within the Murray-Darling Basin (MDB). Specifically, the new ages add some insight into the nature and timing of early Aboriginal occupation along the Murray River corridor in SA and further evidence that the LGM acted as a significant inhibitive factor for intensive occupation of this riverscape. The conservation of these significant and informative cliff-top sites remains precarious, however, and there is an imperative to continue to record and sample the extant sites.

Radiocarbon ageing of Indigenous culturally‐significant trees for bushfire management on Minjerribah (North Stradbroke Island), southeast Queensland

SummaryPartnerships between Indigenous People and governments for joint management of ancestral lands, designated as protected conservation areas for biodiversity and cultural heritage, provide an opportunity to leverage accumulated traditional land management knowledge with emerging science. In Australia, veteran or large old trees in natural landscapes are of significant ecological importance, and among the Indigenous communities, they are living monuments to historical cultural practices, but their survival, endurance and long lives are rarely acknowledged to afford them protection. In sub‐tropical Australia, the lack of consistent annual growth rings in stem wood makes it difficult to estimate the age of large trees using methods such as the periodic diameter increment. Ngugi et al., 2020 published radiocarbon (14C) dates using wood core (‘pith‐wood’) samples from 12 Indigenous culturally‐significant trees covering five species on Minjerribah (North Stradbroke Island). Due to the imprecise calendar age results of the single samples used in the original study (Ngugi et al., 2020), subsequent radiocarbon dating of an additional three wood core samples from each tree was undertaken to age the trees more precisely. The revised tree ages ranged from 63 to 531 years and suggest an important role of past Indigenous land management practices into protecting Bugari (Cypress Pine, Callitris columellaris F. Muell.) from deadly crown scorching fires. These results underscore the importance of incorporating Indigenous practices in current fire management strategies and plans. Estimating tree ages based on the periodic diameter increment method overestimated the age relative to that derived from radiocarbon dating. New bias correction factors were developed for adjusting the recorded periodic tree diameter increments.

Late pleistocene exploitation of Ephedra in a funerary context in Morocco

The active compounds found in many plants have been widely used in traditional medicine and ritual activities. However, archaeological evidence for the use of such plants, especially in the Palaeolithic period, is limited due to the poor preservation and fragility of seed, fruit, and other botanical macro-remains. In this study, we investigate the presence and possible uses of Ephedra during the Late Pleistocene based on the analysis of exceptionally preserved plant macrofossils recovered from c. 15 ka year-old archaeological deposits at Grotte des Pigeons in northeastern Morocco. This cave has yielded the earliest carbonized plant macrofossils of Ephedra, which were found concentrated in a human burial deposit along with other special finds. Ephedra is a plant known to produce high amounts of alkaloids, primarily ephedrine and pseudoephedrine, which have been utilized in traditional medicine. Direct radiocarbon dates on both Ephedra and the human remains indicate that they were contemporaneous. To understand the uses of Ephedra by people at the site, we discuss the different pathways through which plant remains could have arrived. We suggest that the charred cone bracts of Ephedra likely represent residues of the processing and consumption of the plant’s fleshy cones, which may have been valued for both their nutritional and therapeutic properties. Furthermore, we interpret the presence of Ephedra and its deposition in the burial area as evidence that this plant played a significant role during the funerary activities.

A rapid dispersal of maize from the Great Plains to northeastern North America

Northern Flint maize (Zea mays ssp. mays) is a distinct landrace that was common throughout early historical northeastern North America. It is likely represented archaeologically as Eastern 8-row maize, the dominant form there after 1200 CE. Genetic analyses indicate that Northern Flint is most likely derived from maize in the American Southwest. Evidence for maize in the form of phytoliths and starch recovered from directly radiocarbon dated cooking residues occurs in the Northeast by 290 BCE. Until recently there has been no substantiated evidence for maize of similar or older age in the Great Plains, through which maize is likely to have dispersed from the Southwest. A recent report of early microbotanical evidence for maize from the central Plains allows Bayesian modeling of radiocarbon dates to estimate the amount of time that elapsed before maize spread from the Plains to the Northeast. Results indicate only a short amount of time elapsed, from a few to less than 170 years.

Fenland Fields: Evolving Settlement and Agriculture on the Roddon at Viking Link Substation, Bicker Fen, Lincolnshire

Archaeological mitigation undertaken by Headland Archaeology (UK) Ltd at Bicker Fen, Lincolnshire, uncovered the remains of two distinctly different enclosure systems situated on a raised roddon (the dried raised bed of a watercourse). The earliest of these systems was characterised by a series of inter-linked enclosures that formed part of a larger complex farmstead developing around the mid-2nd century AD. The enclosure system subsequently evolved through phases of maintenance and expansion, potentially following changes in agricultural practice or as a result of environmental influences. Features in the northern part of the excavation provide some evidence for industrial activity, including iron smithing and bone working, within the settlement. Zooarchaeological evidence, however, suggests that the main economic focus of this rural community was beef production. It seems that the farmstead remained occupied until at least the 4th century AD, with radiocarbon dates suggesting continued activity of some kind into the 5th century. The Saxon field system was situated to the east of the Roman settlement and is geographically independent. The system is less substantial in nature than the Roman enclosures, characterised by curvilinear boundaries and irregular enclosure sizes. Radiocarbon dating suggests that activity took place between the 6th and 10th centuries AD. During this phase, the focus appears to have been pastoralism. This, together with the transient nature of the system and many maintenance phases, suggests seasonal or otherwise ad hoc land use away from the core of any settlement.

Mid to late Holocene Indian monsoon variability, aridification and civilization changes in the Deccan Plateau, India

Climate change has been a key driver throughout human history and has frequently been associated with the rise and fall of civilizations. Holocene settlement changes or population displacements were almost always preceded by changes in climate. A high-resolution sedimentary record from the western Bay of Bengal offers insights to centennial-scale mid- to late-Holocene Indian summer monsoon (ISM) variability and its role in the decline of chalcolithic human settlements on India's Deccan Plateau. Increased erosion in the Indian peninsula during the mid to late Holocene, due to aridification and agricultural expansion, is evidenced by higher sedimentation, more magnetic mineral content, coarser magnetic grain size, and increased sand content. The results from mineral magnetic and textural analyses reveal centennial-scale abrupt weak ISM during the Bond events in the core monsoon zone of India. The Deccan Chalcolithic civilizations flourished between ~4.0–3.0 ka BP owing to the favorable climatic conditions, but most of the settlements were deserted after ~3.0 ka BP. We argue that the abrupt weakening of ISM during Bond event 2 (~3.1–2.8 ka BP) caused this collapse of Deccan Chalcolithic. The results from this study together with the published records of number of settlements and summed radiocarbon dates suggest a climate-culture link in the Deccan Plateau. The weak ISM periods in this study are coherent with the records of total solar irradiance record and the percentage of hematite-stained grains from the North Atlantic and suggest solar control on these abrupt climatic events.

Biomolecular analysis of the Epigravettian human remains from Riparo Tagliente in northern Italy

The Epigravettian human remains from Riparo Tagliente in northern Italy represent some of the earliest evidence of human occupation in the southern Alpine slopes after the Last Glacial Maximum. Genomic analyses of the 17,000-year-old Tagliente 2 mandible revealed the oldest presence of a genetic profile with affinities to the Near East in the Italian peninsula, which later became the most widespread hunter-gatherer ancestry across Europe. However, a comparable biomolecular characterization of the Tagliente 1 burial remains unavailable, preventing us from defining its biological relationships with Tagliente 2. Here, we apply paleogenomic, isotopic, and radiocarbon dating analyses on a femur fragment of Tagliente 1 and compare the reconstructed data with previously reported results from Tagliente 2. Despite their different isotopic signatures and non-overlapping radiocarbon dates, we reveal that the two human remains belong to the same male individual. We determine that the distinct isotopic values can be explained by different dietary practices during lifetime, whereas the non-overlapping radiocarbon dates can be caused by minimal radiocarbon contamination, possibly deriving from chemical treatments for conservation purposes. These findings highlight the importance of interdisciplinary biomolecular studies in offering new perspectives on the Palaeolithic fossil record and addressing long-standing bioarchaeological questions.

Radiocarbon Dating of Magnesian Mortars: The Case of San Salvatore Church in Massino Visconti, Piedmont, Italy

This study presents a comprehensive analysis and radiocarbon dating of historical mortar and plaster samples from the San Salvatore—Massino Visconti complex in Piedmont, Northern Italy. Mortar samples and one charcoal sample were collected from various areas within the complex’s lower chapels. Samples were selected and characterized by means of a multi-analytical approach in order to draw inferences about their compositional, mineralogical, and microstructural features. The identification of hydromagnesite and magnesite in the mortar samples suggests the usage of magnesian binder mortar, potentially affecting radiocarbon dating due to its slower carbonation kinetics when compared to calcitic mortars. To mitigate this effect, a purification method was developed involving thermal treatment at 550 °C to isolate datable binding fractions. The results yielded reliable radiocarbon ages consistent with historical context, shedding light on construction materials dating from the 12th to 16th centuries. The study also challenges previous notions by demonstrating the feasibility of radiocarbon dating for magnesian mortars, opening new perspectives for dating such materials. These findings offer valuable insights into the construction history and material composition of the complex, corroborating historical information.

Subsistence and population development from the Middle Neolithic B (2800-2350 BCE) to the Late Neolithic (2350-1700 BCE) in Southern Scandinavia.

The present study aims to explore the hypothesis of a link between a population increase derived from intensified food production and the development from the widespread cultural diversity of the Middle Neolithic B (MNB) to the cultural unity towards the end of the Late Neolithic (LN) in Southern Scandinavia. We explore this through quantitative modelling of radiocarbon dates, aoristic time series of material culture and palynological data. On this basis, we propose three main results that may explain the transformation: (1) A supra-regional population increase, culminating in the middle of the LN (c. 2100 BCE). (2) A depopulation in Western Jutland at the transition from the MNB to the LN (c. 2400-2300 BCE) counterbalanced by a population increase in North and East Denmark. (3) A population boom in Southern Sweden around 2250-2000 BCE, possibly leading to migrations towards west. Furthermore, we propose an overall decline in population in the final LN (c. 1850 BCE).

ASSESSING A MODIFIED CARBONATE DIGESTION PROTOCOL FOR INCREASED CARBON DIOXIDE RECOVERY DURING CREMATED BONE PRETREATMENT

ABSTRACT Cremated bones are a commonly preserved material and often found in burial environments where unburned bone may not be preserved. As such direct radiocarbon dating of cremated bone could be essential in determining the chronology of an event. Pretreatment of cremated bone exploits the structural carbonate component of the bone which survives cremation. However, due to the low abundance (ca. 0.1%) of this component, the extraction of an amount of endogenous carbon sufficient for radiocarbon dating may represent a challenge. Here we investigate two modifications to the phosphoric acid digestion protocol used during the preparation of cremated bones at the Oxford Radiocarbon Accelerator Unit (ORAU). The first of these was to use ultrasonication to release evolved CO2 from the viscous phosphoric acid and cremated bone mixture that is formed during digestion. The second was to double the amount of time during which evolved CO2 was removed from the reaction vessel by transfer into a cryogenically cooled ampoule. Ultrasonication of the digestion mixture failed to produce a significantly higher carbon yield, while double-time collection resulted in an average 21.5±13.8% increase of C yield without affecting the measured age. Extending the collection time can better enable reliable dating of small (less than 1 g) samples.

Dating the beginning of the Pottery Neolithic in South Iran: Radiocarbon dates from Tol-e Sangi, the Fars

Abstract The Fertile Crescent of Southwest Asia is considered one of the main centers of the first Neolithization worldwide. However, the dating and processes of its spread to neighboring regions have yet to be studied. This study reports new chronological data from the Fars highlands, southeast of the Fertile Crescent. Although the Pottery Neolithic in Fars has long been believed to have started in the late 7th millennium BC, recent excavations at Tepe Rahmatabad have suggested a date half a millennium earlier, raising controversy. Our data from Tol-e Sangi, a stratified site with Pre-Pottery (PPN) and Pottery Neolithic (PN) cultural deposits, support the advent of the Pottery Neolithic at the beginning of the 7th millennium BC. This suggests that despite the late arrival of the food production economy in the Fars highlands, which is dated from the mid-8th millennium BC, subsequent cultural development followed a path similar to that of the eastern wing of the Fertile Crescent.

To date or not to date? A comparison of different 14C pretreatment methods applied to archeological marine shells from Vale Boi (Portugal)

Abstract Mollusk shells are often found in archeological sites, given their great preservation potential and high value as a multipurpose resource, and they can often be the only available materials useful for radiocarbon (14C) dating. However, dates obtained from shells are often regarded as less reliable compared to those from bones, wood, or charcoals due to different factors (e.g., Isotope fractionation, reservoir effects etc.). The standard acid etching pretreatment for mollusk shells is the most used in many 14C laboratories, although another protocol known as CarDS (Carbonate Density Separation) was introduced just over a decade ago. We compare these two methods with two newly proposed methods for intracellular organic matrix extraction. We applied all four methods to samples selected from different archeological layers of the well-known Upper Paleolithic site of Vale Boi, rich in mollusk specimens throughout the stratigraphic sequence. Here we compare our results to previous dates to determine which of these pretreatment methods results in the most reliable 14C dates. Based on the results of this study, all four methods gave inconsistent ages compared to previous dates and the stratigraphic attribution.