Radiocarbon Dating Research Articles

Despre problema datarii mormantului cx. 20A de la Pecica-Duvenbeck ai a semnelor de cruce pe vasele ceramice din Bazinul Dunarii mijlocie / On the Question of Dating the Tomb CX. 20A from PECICA-Duvenbeck and the Signs of the Cross on Ceramic Vessels from the Middle Danube Basin

Rescue excavation from Pecica-Duvenbeck from the year 2018 unearthed 582 complexes related to various periods, among them two groups of graves datable in the 7/8‒9th centuries. In a grave, complex no. 20A, there has been identified a pot, which has under the throat an incised cross sign. The skeleton, partially disturbed at the time of its robbery, seems to have been a woman adultus/maturus, with an estimated age of over 30 years. Besides presenting this interesting discovery, we also proposed a debate on the problem of the radiocarbon dating of the grave, because the same samples of the skeleton were analysed in two laboratories getting antagonistic results. However, in the light of typo chronology and the results of the other 8 samples from other graves in this funerary site, we can conclude that the grave can be dated at the end of the 7th and the first half of the 8th century. Out of the ceramic pot of the grave from Pecica, in only two cases we have been able to document cross-shaped marks on the wall of vessels in the Avar funerary environment (7–8th centuries); even cross-shaped marks were found in such non-Christian funerary contexts. Therefore, we think that the cross-shaped mark on the Pecica pot – in an environment dominated by a cultural habitus entirely different from the Christian world – was not a Christian symbol, but an interpretation as an apotropaic, i.e. as a symbol adopted and transformed according to the pagan mentalities of the 8th century, is a more plausible explanation.

Radiocarbon Dating of Cremated bone samples from the Site of the Hungarian Church at Pauca, Sibiu County

Archaeological research in the site of Pauca - Hungarian Church started in 2010, and between 2012-2023 has uncovered over 116 graves, some being simple cremation graves with a deposit of remains in the urn, others being double graves (with two urns) and one being a mixed double grave (incineration and inhumation). The dating of the five samples from the cemetery would suggest that the beginnings of the Păuca cemetery is contemporary with the late Germanic period (Gepids) and the early Avar period. Admitting that it is more accurate to date closer to the upper limit of the range (7th century), the cemetery at Pauca could be connected with historical events that occurred between 567 and 630, i.e. the establishment and consolidation of Avar power in the Pannonian-Transylvanian space. The C14 dating of the cremated bones from the Păuca cemetery (Sibiu county) reopens the discussion on the need for more samples of C14 data from the cremation cemeteries attributed cemetery to the so-called Mediaș group and simultaneously may represent a turning point in the evaluation of the chronology of the period between 6th and 8th centuries A.D.

Understanding the local dynamics

This study addresses the dynamics of the Neolithic expansion in the Central Balkans by reconstructing its direction and speed of spread. The Inverse Distance Weighting (IDW) method is applied to the earliest radiocarbon dates from Starčevo culture sites in Serbia. Local speed estimates are derived from the earliest dates within specified spatial bins. The results confirm the assumed south-to-north direction, revealing rapid progression, particularly in the southernmost region. The possibility of pioneering scouting groups was also discussed. The results confirm the arrhythmicity of the Neolithization processes and higher local spread rates while offering new insights into Starčevo culture mobility.

Los Enebrales rock-shelter (Tamajón, Guadalajara, Spain): First Gravettian site in central Iberia

The stratigraphy and materials from a survey carried out in 1994 and 1995 in a rock-shelter in Tamajón (southwestern Iberian Central Range) are studied here. The Pleistocene deposits were generated by high-energy channelled fluvial flows and dense currents of debris flow and mud flow type. The recovered lithic industry, created mainly in low-quality local materials, can be associated with Gravettian technocomplexes. Three radiocarbon dates obtained from the stratigraphic sequence are located in a temperate interstadial of OIS 3a and in a cold episode at the beginning of OIS 2. The faunal remains, which come from human consumption, display cut and percussion marks. They reveal a predominance of equines, followed by deer, in a mosaic environment. A shale plaque-pendant, worked and decorated, was found outside the stratigraphy. The human occupations of the shelter must have been sporadic, but reflect, with the growing evidence nearby, a thriving population in this area of anatomically modern humans. The association of pre-Solutrean archaeological materials, together with the dates obtained, establishes the human occupation of the Los Enebrales shelter as the oldest evidence of the Upper Palaeolithic in the inner Iberian Plateau.

Dating Perishables to Refine the Chronology of Shrine Cave Use, the Goggle-eye Motif, and other Jornada and Mimbres Mogollon Iconography

Professional and avocational archaeologists have recovered thousands of perishable artifacts from caves and rockshelters across the southern US Southwest, but few have been radiocarbon dated. This article reviews thirty AMS radiocarbon dates obtained on perishable items from nine shrine caves in the Jornada and Mimbres Mogollon regions of south-central New Mexico and west Texas. Dates were obtained from fragments of tablitas, effigies, prayer sticks, projectile point foreshafts, and flat curved sticks. Several convey iconographic elements of the Jornada Style of rock art while others are implements and weapons, but all were deposited in shrine caves. Problems inherent in the dating of shrine cave deposits and perishable artifacts are reviewed and technical matters involving contamination, curation, context, and sample materials are discussed. Analysis reveals several significant trends, one of the most salient being that the Goggle-eye motif, a signature element of Jornada and Mimbres iconography, has greater antiquity than previously assumed.

Analysis of summed probability density functions (PDFs) of radiocarbon and luminescence dates from discontinuous profiles of river deposits against the background of climate changes recorded in the NGRIP core

Analysis of summed probability density functions (PDFs) of radiocarbon and luminescence dates from discontinuous profiles of river deposits against the background of climate changes recorded in the NGRIP core

Новые данные по радиоуглеродной хронологии неолитических комплексов Виловатовской стоянки

Introduction. The article presents some latest absolute dates for Neolithic pottery from the Vilovatoye site, the latter being characterized by a most impressive pottery collection from the Middle and Late Neolithic across the forest-steppe Volga River basin. Goals. The work shall introduce a series of radiocarbon dates for Neolithic patterns of the Vilovatoye site. To facilitate this, the paper shall describe the vessels that yielded such radiocarbon dates, analyze and interpret the absolute values, compare the latter to those of the Middle Volga culture. Materials and methods. In 2018–2019, shards from a total of fourteen Neolithic vessels excavated in the site of Vilovatoye were selected. Four of them were decorated with pricks of different shapes, one bore pricks combined with blackened lines, and nine vessels had comb stamps. Radiocarbon dating by liquid scintillation was conducted at the Radiocarbon Laboratory of Herzen University. Results. The pricked vessels of the Vilovatoye site dated from the third quarter of the 6th millennium BC to the second quarter of the 5th millennium BC. These results tend to well correlate with dates yielded by pricked pottery of the Middle Volga culture. The shards of the vessel decorated with pricks and blackened lines were dated to the first half of 5th millennium BC. The absolute dates for the comb-imprinted pottery cluster within a vast interval — from the last quarter of the 6th millennium BC to the third quarter of the 5th millennium BC. So, the latter dates also well correlate with available radiocarbon values for comb-ornamented pottery of both the Vilovatoye site and the Middle Volga culture. Conclusions. The newly obtained radiocarbon values shall significantly add to the set of dates for the Middle Volga culture. Those are evidence that the traditions of pricked and comb-stamped pottery somewhat co-existed — on the Vilovatoye site in particular, and within the Middle Volga culture at large.

Transformation and aging of organic matter during degradation and preservation in marine sediment of the northern South China Sea

Organic matter (OM) preservation in marine sediments is an important sink in the carbon cycle and the isotopic records of the preserved OM provide useful information on the sources, biodegradation, and transformation of organic carbon during early diagenesis. Here, we present radiocarbon data combined with stable carbon isotope measurements of total organic carbon (TOC) and four organic fractions, namely, total lipids, hydrolysable amino acids (THAAs), humic acids (HAs), and acid-base insoluble OM, separated from four sediment cores collected from the South China Sea (SCS), to reveal their sources and transformation. The total lipids, THAAs, HAs and acid-base insoluble OM fractions account for 1.1 ± 0.4%, 3.1 ± 1.6%, 12.7 ± 9.4% and 61.6 ± 10.0% of the TOC (the percentages of organic fraction in TOC), respectively, and the acid-base insoluble OM is the dominant fraction of TOC preserved in the sediments. Distinct differences in both 13C and 14C values are found among these organic fractions. The δ13C values are more depleted in total lipids and HAs (−23.1‰ to −30.2‰) than in THAAs and the acid-base insoluble OM (−15.3‰ to −20.6‰), which indicates that HAs could be polymerized from lipid-like materials. The acid-base insoluble OM has the lowest Δ14C values (−848‰ to −358‰), with the oldest 14C ages (mean of 7330 years before present) compared to total lipids (−574‰ to −253‰, 3860 years), THAAs (−331‰ to −66‰, 1527 years) and HAs (−569‰ to −168‰, 2916 years) in these sediment cores. The δ13C and Δ14C values of THAA in the sediment are similar to those of pore-water dissolved organic carbon (DOC), indicating that THAA is preferentially degraded and converted to DOC. These results reveal that OM derived from marine and terrestrial sources decompose selectively and contribute differently to the organic fractions during early diagenesis and preservation in marine sediment. The very aged acid-base insoluble fraction is likely formed as a complex of the most refractory OM during microbial degradation and alteration of TOC, representing a major mechanism of OM sequestration in marine sediments.

Late Quaternary Dynamics of Landscape and Climate in the North of the West Siberian Plain Revealed by Paleoecological Studies of Peat and Lake Sediments

West Siberian mires covering more than 50% of area in the subarctic are still poorly investigated despite their thick peat sediments suitable for paleogeographic research of past long-term landscape and climatic changes. In this research, a combination of paleoecological methods were used, including the analysis of pollen, spores, diatoms, NPPs, and macrofossils, the measurement of peat humification, and quantitative paleoclimate reconstruction. This multi-proxy approach was applied to study a palsa bog (frost peat heave mound) located in the north of western Siberia on the border of the northern taiga and forest–tundra (65°18′56″ N, 72°52′27″ E). Chronology is based on 21 radiocarbon dates, which were calibrated in CLAM. Studies have shown that sediments of palsa bog Nadym of a 1050 cm thickness were formed both in the Holocene and earlier periods of the Quaternary. Radiocarbon dating worked well for peat sequences (610 cm thick), but failed for underlying lacustrine and mineral sediments (440 cm thick). Numerous remains of salt-water diatoms and exotic Neogene pollen were found in the lacustrine sediments (650–850 cm). The oldest sediments (850–1050 cm) have signs of secondary epicryogenic diagenesis in the form of cryogenic iron-enriched granules. Both lacustrine and bottom sediments contain abundant coniferous pollen. At the same time, spore–pollen complexes dated to the Last Glacial Age were not found in low sediments because of failed dates. To explain this, the authors turn to the hypothesis of glyacioisostatic compensation, according to which the study area was uplifted during the Last Glacial Age and the ancient deposits underwent secondary diagenesis in subaerial conditions. Holocene lacustrine sedimentation began to form about 9800 cal. a BP. These lacustrine sediments turned out to be enriched in redeposited Neogene pollen and diatoms. It was interpreted as an influence of excess humid climate in combination with geological subsidence of landscape in the study area during the Early Holocene. This caused lake formation and introduction of exotic microfossils via surface run-off from higher-relief areas in the catchment. Syngenetic sedimentation in the Nadym section is associated only with peat-mire deposits covering the last 8400 cal. a BP. For this time, the dynamic of vegetation cover and quantitative changes in paleoclimate were reconstructed using spore–pollen, macrofossil, humus, and NPP data as well as the information–statistical method of V.A. Klimanov. The spore–pollen analysis revealed four main phases in the development of vegetation cover: 1. Spruce–birch forests with open meadows and lakes (8400–7600 cal. a BP); 2. Dominance of spruce forests and thawed eutrophic (minerotrophic) mires (7600 to 6500 cal. a BP); 3. Coniferous–birch forests and thawed mesotrophic mires (6500 to 4500 cal. a BP); 4. Birch–pine forests and oligotrophic (ombrotrophic) bogs with permafrost mounds—palsa bogs (approx. the last 4500 years). Quantitative reconstructions of paleoclimate based on pollen data show that in most cases the periods of a sharp decrease in mean January and mean July temperatures coincided with episodes of low solar activity. The assumption was made about the determining influence of solar activity on the formation of permafrost in the soils and mires of the study area. Sun minima caused permafrost formation in the mire periodically since 8400 cal. a BP in study peatland, but complete freezing of the peat mire and formation of the palsa bog occurred at c. 2800 cal. a BP.

Longevity Estimates of Canary Palms and Dragon Trees via Radiocarbon Dating: Initial Results.

Correctly estimating the maximum lifespan of plant species is a necessary component of demographic and life-history studies, which, in turn, are needed for understanding climatic impacts. Arboreal monocotyledons, which can grow to >30 m in height and >5 m in trunk perimeter, are difficult to age because they do not undergo seasonal dormancy; hence, their longevity has been estimated using various size-related methods. In this study, we tested radiocarbon (14C) dating with Accelerator Mass Spectrometry (AMS) as an additional tool for determining the age of two iconic monocotyledons: the Canary Island palm and the dragon tree. A total of 25 samples were collected from the basal stem of four palms and five dragon trees on Gran Canaria and Tenerife and then processed using the most advanced 14C-AMS analysis available. Calibration curves provided by the "IntCal group" were used to determine the oldest possible age of each sample, and 16 of them were found to be "modern", i.e., formed after the 1950s. Nine samples that were either collected from exterior, but lignified, palm tissues or from interior, and lignified, dragon tree tissues suggested ages > 300 years. Given the constant improvement of 14C-AMS tools, they can contribute to the further refinement of existing scientific knowledge on Macaronesian charismatic megaflora.

Technology from hunting blinds: A study of lithic assemblages in Late Holocene stone structures from Patagonia (Argentina)

Stone structures called parapetos are a highlighted feature of the archaeological record in central-western Santa Cruz, Patagonia. More than 500 have been registered so far with varied sizes and shapes and clustered in different amounts. They are located in basaltic plateaus, over 700 masl. These hunter-gatherer structures are believed to be mainly related to hunting activities though some sites have revealed a more general function. Radiocarbon dates reveal that they are a typical Late Holocene technology.
 This work discusses the characteristics of lithic materials recovered in these particular sites with a specific spatial and temporal distribution in Patagonia. We evaluate the existence of variability in lithic artefacts related to stone structures recovered in different areas: Pampa del Asador (Cerro Pampa), Guitarra Plateau, Asador Plateau and the Strobel Plateau. Diverse types of hunting blind sites have been included: isolated structures and grouped ones located in different topographic and ecological contexts. Materials were recovered from inner and outer surfaces of structures as well as from stratigraphic contexts. The sample includes tools, debitage and cores; more than 10000 lithic artefacts are included.
 Results show that there are similarities in the characteristics of artefacts discarded in parapetos from different areas. However, variability in the type and characteristics of artefacts in each assemblage could account for a wider array of activities being carried out in parapetos from the northern sector of the region under study. Thus, strategies for occupying highlands during the Late Holocene differed.
 The evidence discussed summarises more than 20 years of on-going investigations in the region. It provides exceptional information based on systematic analysis of a significant sample of lithic artefacts in hunting blinds.

Neuroanatomy and pneumaticity of the extinct Malagasy "horned" crocodile Voay robustus and its implications for crocodylid phylogeny and palaeoecology.

Voay robustus, the extinct Malagasy "horned" crocodile, was originally considered to be the only crocodylian representative in Madagascar during most part of the Holocene. However, Malagasy crocodylian remains have had confused taxonomic attributions and recent studies have underlined that Crocodylus and Voay populations coexisted on the island for at least 7500 years. Here, we describe the inner braincase anatomy of Voay robustus using x-ray computed tomography on four specimens, to provide new anatomical information that distinguishes Voay from Crocodylus, especially features of the brain endocast and the paratympanic sinuses. Geometric morphometric analyses are performed on 3D models of the internal organs to compare statistically Voay with a subset of extant Crocodylidae. Following these comparisons, we build an endocranial morphological matrix to discuss the proposed phylogenetic affinities of Voay with Osteolaeminae from an endocranial point of view. Additionally, we discuss the use of internal characters in systematic studies and find that they can have a major impact on morphological analyses. Finally, new radiocarbon data on Voay and subfossil Crocodylus specimens are recovered between 2010 and 2750 cal BP, which confirm the cohabitation of the two species in the same area for a long period of time. We thus assess several extinction scenarios, and propose a slightly different ecology of Voay compared to Crocodylus, which could have allowed habitat partitioning on the island. Our approach complements information obtained from previous molecular and morphological phylogenies, as well as previous radiocarbon dating, together revealing past diversity and faunal turnovers in Madagascar.

The marine reservoir age of Greenland coastal waters

Abstract. Knowledge of the marine reservoir age is fundamental for creating reliable chronologies of marine sediment archives based on radiocarbon dating. This age difference between the 14C age of a marine sample and that of its contemporaneous atmosphere is dependent on several factors (among others, ocean circulation, water mass distribution, terrestrial runoff, upwelling, and sea-ice cover) and is therefore spatially heterogeneous. Anthropogenic influence on the global isotopic carbon system, mostly through atmospheric nuclear tests, has complicated the determination of the regional reservoir age correction ΔR, which therefore can only be measured in historic samples of known age. In this study we expand on the few existing measurements of ΔR for the coastal waters around Greenland, by adding 92 new radiocarbon dates on mollusks from museum collections. All studied mollusk samples were collected during historic expeditions of the late 19th and early 20th centuries, and besides coastal sites around Greenland, the new measurements also include localities from the western Labrador Sea, Baffin Bay, and the Iceland Sea. Together with existing measurements, the new results are used to calculate average ΔR values for different regions around Greenland, all in relation to Marine20, the most recent marine radiocarbon calibration curve. To support further discussions and comparison with previous datasets, we use the term ΔR13, where the suffix 13 refers to the previous calibration curve Marine13. Our study explores the links between the marine reservoir age and oceanography, sea-ice cover, water depth, mollusk feeding habits, and the presence of carbonate bedrock. Although we provide regional averages, we encourage people to consult the full catalogue of measurements and determine a suitable ΔR for each case individually, based on the exact location including water depth. Despite this significant expansion of the regional reservoir age database around Greenland, data from the northern coast, directly bordering the Arctic Ocean, remain missing.

A multiapproach for solving geoarchaeological problems: inferences from Roman gold mining in the Eria Valley (León)

The Eria River valley exhibits one of the largest gold mining complexes in NW Iberia from Roman age. In this study, a geoarchaeological work is presented, combining a multiapproach based on airborne LiDAR remote sensing, descriptive geology and radiocarbon dating. The studied area is characterized by the presence of a mining infrastructure comprised of hydraulic canals driving the water at different levels to the mines. Mining works were associated with Plio Quaternary raña deposits and Quaternary materials consisting of hillside and periglacial deposits, and fluvial terraces. The washing of the gold deposits used the hydraulic force to break up and drag out the sediment, giving rise to three different types of exploitation depending on the characteristics of the different materials. The results shed light on the geological materials exploited and other geographical aspects that conditioned the exploitation techniques. The work contributes to improving the knowledge about Roman gold mining and its geological context in northwest Iberia.

Environmental and climatic inferences for Marine Isotope Stage 2 of southern Belgium (Meuse valley, Namur Province) based on rodent assemblages

The environmental and climatic conditions of the Late Pleistocene of Southern Belgium are here determined for the final part of Marine Isotope Stage 3 (MIS 3) and for MIS 2 on the basis of a study of rodent assemblages. This paper provides a synthesis of several sets of environmental and climatic data from Late Pleistocene sites, all of which are located in southern Belgium. One has previously been published (Caverne Marie-Jeanne), and seven are unpublished (Cavernes de Goyet, Trou des Nutons, Trou du Frontal, Trou de Chaleux, Grotte la Chefalize, Trou du Chêne, and Trou du Sureau). The habitat weighting and quantified ecology methods are applied to rodent material housed in the Royal Belgian Institute of Natural Sciences (RBINS, Brussels), and previous radiocarbon dates are updated, in order to reconstruct past environments. Among all the sites under analysis, the quantified ecology method shows that Trou de Chaleux corresponds to the coldest temperatures and lowest precipitation. Trou de Chaleux, with a chronology between ca. 15,964–14,014 cal yr B.P., could probably be placed in Greenland Stadial 2 (GS2) or Heinrich Event 1 (HE1). It has a rodent assemblage associated with a predominance of open dry and rocky formations, the most abundant species being the collared lemming and the narrow-headed vole. These data are found to coincide with previous studies carried out on the large-mammal, herpetofaunal, and avifaunal associations of the site, as well as on small-mammal associations from other sites in southern Belgium with similar chronology, such as Grotte Walou. Taken together, this indicates that these latest Pleistocene intervals in southern Belgium were characterized by harsh climatic and environmental conditions. In contrast, the other assemblages under study yielded much more heterogeneous results, frequently inconsistent with an attribution to the Pleistocene. This is likely to be a result of their admixture with Holocene material due to recent intrusions.

Palaeodiet during the pre-dormancy period of MIS 3 Romanian cave bears as inferred from dental microwear analysis

Cave bears (Ursus spelaeus) have been recognized as being predominantly herbivorous. However, Romanian Carpathian cave bears have displayed a flexible diet based on a wide range of δ15N values. In this work, we analyse 97 lower first molars of Ursus spelaeus and contemporaneous Ursus arctos from different sites in this region, using dental microwear analysis to reconstruct their pre-dormancy diets during MIS 3. Newly obtained radiocarbon dates of the individuals are also reported. The short-term diet of all populations studied is identified as omnivorous, with a preference for the consumption of hard objects. For the first time, the widespread presence of puncture pits on U. spelaeus populations has been observed, which could be linked to the intake of seeded and hard-shelled fruits from temperate broadleaf trees. Hence, the dietary patterns of Carpathian cave bears exhibit similarities to those of present-day brown bears inhabiting the same region and suggests that the Carpathians served as an ecological refuge for cave bear specimens. This is reinforced by an early 27.1 cal kyr B.P. date from an individual from Urşilor Cave, which sheds light on the potential dietary continuity of Romanian Carpathian cave bear populations even during the final phases leading up to their extinction.

The vegetation history of Lake Mert and its surroundings for the last 6600 years (Kırklareli, NW Türkiye)

The primary aim of this study is to determine the Middle-Late Holocene vegetation history of the İğneada Longoz (Floodplain) Forests around Lake Mert, located in Kırklareli, using high-resolution palynological analysis conducted on the MRT-04 core. Pollen analyses was performed on sediment samples collected from 67 different levels within the core. Pollen counting and identification were performed using a Leica DM750 light microscope, with a minimum of 500 terrestrial pollen grains counted per sample. The age of the lake was determined to be 6600 years old through radiocarbon dating of the core. According to the findings from the pollen analysis, deciduous mixed oak forests have dominated the region in and around Lake Mert for the past 6600 years. Within these mixed oak forests, Quercus cerris type (deciduous oaks) is predominant, with notable contributions from Fagus, Carpinus, Corylus, and Tilia. This forest composition has displayed a consistent pattern, except for changes attributed to the expansion of temperate species and human influences. The distribution of mixed oak forests began to decline around 1360 BP, coinciding with a significant increase in the presence of Alnus, Fraxinus, and Ulmus. These trees are characteristic species of floodplain forest and indicate the initiation of the formation of the İğneada Longoz Forests after 1360 BP. Furthermore, around 420 BP, there was a substantial decrease in the pollen percentages of Quercus and Fagus. During this period of declining mixed oak forests, Plantago and Ambrosia appeared for the first time in the pollen diagram. The reduction in arboreal plant taxa and the rise of herbaceous taxa such as Plantago, Ambrosia, and Poaceae, which serve as indicators of human impact, signify the conversion of forested areas into agricultural and pasture lands.

Absolute Chronology revisited: Integrating precise Bayesian models from Machu Picchu with Inca ethnohistoric praise narratives

Recent articles provide a captivating set of radiocarbon dates from Machu Picchu and environs, with important ramifications for the site and the Inca Empire more broadly. Here, we present Bayesian models of these dates that incorporate life history details of each dated individual, including age at death, age of tissue formation for dated samples, family relationships, and associated grave goods. We calibrate dates with a bespoke calibration curve mixture specific to Machu Picchu. These model boundaries suggest the site was first occupied ∼ AD 1435 (1410–1455, 95%) and abandoned ∼ AD 1495 (1480–1515, 95%). This is consistent with dates from the region and builds on the consensus that ethnohistoric dates are unreliable. Anchoring Inca history to this radiocarbon chronology allows us to explore the ethnohistoric sources in a new light. We can more plausibly trace the life history of the ruler Pachacutec, including his founding of the Machu Picchu royal estate. Regionally, this approach leads us to reassess the conquest of the earliest and largest Inca conquest, the southern quarter. This area was subject to waves of intense interaction for nearly two centuries by multiple royal houses, possibly starting under Yahuar Huacac, Pachacutec's grandfather, events that were almost completely scrubbed from Inca praise narratives.

First discovery of charcoal-based prehistoric cave art in Dordogne

Archaeologists have long been puzzled by the exact age of Paleolithic cave art in Europe especially in the Franco-Cantabrian region with hundreds of decorated caves because the creation of this parietal art (paintings, drawings and engravings) is closely tied to the appearance of first modern humans in Europe and their ways of life. The Dordogne region, one of the richest regions in terms of Paleolithic cave art in the world with more than 200 cave sites, is currently known to provide figures of cave art solely made with mineral coloring matters that cannot be dated directly. Using in-situ non-invasive Raman spectroscopy combined with portable X-ray fluorescence analysis as well as visible and infrared imaging of the decor of the Font-de-Gaume cave, we show the presence of a large number of charcoal-based Paleolithic figures besides others made of iron and manganese oxides in the main galleries for the first time. The creation periods of the cave art at Font-de-Gaume are mainly attributed to the Magdalenian period and probably more complicated constituted of at least two creation phases than commonly established as shown by the direct or partial superimposition of carbon-based and iron- and/or manganese-based figures. Our new results contribute to a better understanding of the organisation of the ornamentation and thus of the imaginary language of our Prehistoric ancestors. The discovery opens new research possibilities for re-reading of the complex panels and absolute radiocarbon dating.

Identification and tentative removal of collagen glue in Palaeolithic worked bone objects: implications for ZooMS and radiocarbon dating

Collagen glue has been used for nearly two centuries to consolidate bone material, although its prevalence in museum collections is only now becoming visible. Identifying and removing collagen glue is crucial before the execution of any geochemical or molecular analyses. Palaeolithic bone objects from old excavations intended for radiocarbon dating were first analysed using ZooMS (Zooarchaeology by Mass Spectrometry) to identify the animal species, however peaks characteristic of both cattle and whale were discovered. Two extraction methods for ZooMS were tested to identify the authentic animal species of these objects, which revealed that these were originally whale bone objects that had been consolidated with cattle collagen glue. This is the first time animal collagen glue has been identified in archaeological remains with ZooMS, illustrating again the incredible versatility of this technique. Another technique, Fourier Transform Infrared Spectroscopy in Attenuated Total Reflectance mode (FTIR-ATR), was also tested if it could rapidly identify the presence of collagen glue in archaeological bone material, which was not the case. Two other cleaning methods were tested to remove bone glue contamination prior to radiocarbon dating, along with two modified collagen extraction methods for ZooMS. These methods were applied to bone blank samples (FmC = 0.0031 ± 0.0002, (n = 219), 47 336 ± 277 yr BP) that were experimentally consolidated with collagen glue and to the Palaeolithic bone material (ca. 15 000 and 12 000 yr BP). The experimental bone blanks produced excellent 14C ages, suggesting the cleaning methods were successful, however the 14C ages for some of the Palaeolithic material remained too young considering their contextual age, suggesting that the collagen glue contamination had most likely cross-linked to the authentic collagen molecule. More research is needed in order to gain a deeper understanding of the occurrence and elimination of cross-linked collagen-based glues in material from museum collections.