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Geophysical surveys in the Lakes Tazenat, Aydat, Chambon and Lacassou combined with a multiproxy study of sediment cores highlight Late Holocene abrupt environmental changes in the northern part of the French Massif Central (FMC). Dating landslide-induced dust layers and subaqueous slope failures impacting lake basin sedimentary fills suggest regional triggering by palaeo-earthquakes (cluster of events) either in the Puy-de-Sancy volcano area, or along the regional Limagne fault. In the present study, a cluster of palaeo-earthquakes occurring in the Sancy area between AD 1243 and 1270 are documented in the Lakes Montcineyre, Chauvet, Pavin and Guery, as well as by the formation of Lake Lacassou following the last emplacement of the Dent du Marais landslide in the Chaudefour glacial valley around AD 1250 ± 30. Former cluster of earthquakes occurring near the Limagne fault between AD 580 and 650 are evidenced in Lake Tazenat and in maar Lake Pavin. Lake Pavin present lake-level was similarly favoured by the cluster of earthquakes between AD 1243 and 1270 and the occurrence of a slump and an outburst flood event resulting in the bypassing of a palaeo-outlet. Holocene earthquakes near the Limagne fault are suggested in maar Lake Tazenat by coeval mass wasting deposits (MWDs) around 2250 ± 50 cal. BP and around 2730 ± 30 cal. BP. A landslide-induced dust layer dated between 2760 and 2520 cal. BP at the transition from paludal to lacustrine deposits in the Chaudefour glacial valley is suggesting that the formation of Lake Chambon resulted from a first emplacement of the Dent du Marais landslide. Radionuclides and radiocarbon dating in Lake Tazenat suggest variable sedimentation rates over the last millennia due to: (i) floods during the Little Ice Age, (ii) coeval MWDs at the basin edges and an erosive turbidite in the central basin between AD 575 and 625, and (iii) lake eutrophication since AD 1945. More gravity cores are needed to directly sample and date the youngest generation of coeval MWDs detected on seismic profiles in order to test the impact in this lake of the cluster of major historical earthquakes in the FMC between AD 1450 and 1490 near the Limagne fault.

International audience; Lake Bottom oxbow is a partially-filled oxbow lake within an alluvium filled sandstone canyon reach of the Dolores River in eastern Utah, USA. Two adjacent sediment cores were obtained from the Lake Bottom oxbow to better understand the depositional and environmental history of the site and region. Depositional ages were determined using radiocarbon dating (14C) of pollen extracts, optically stimulated luminescence (OSL) of sand, concentration of 137Cs and 210Pb radioisotopes, and the first occurrence of pollen from human-introduced crops (Zea mays) and trees and shrubs (Tamarix) found in the oxbow sediments. Age control from OSL, short-lived radioisotopes, and pollen are stratigraphically consistent and fit the geomorphic character of the partially-filled oxbow, which suggests it is a late Holocene feature. In contrast, the 14C results appear to be contaminated by old carbon and produced age overestimates of 3000–12,000 years. Our findings suggest that multiple dating methods should be employed when applying radiocarbon dating to settings that are susceptible to contamination by recycled old carbon, especially when dating pollen extracts that are difficult to determine organic purity. The OSL results suggest initial oxbow formation by 860 ± 270 yr (±2σ) and then rapidly infilled with fluvial sediment. The OSL age control indicates the oxbow formed during the Medieval Climate Anomaly, a time of enhanced summer moisture and active flooding in the Dolores River watershed. Similar low-elevation records in the arid Colorado Plateau are rare, making this site an important contribution to the regional paleoenvironmental record.

We present results for three sections with a representative loess record of the end of the Late Pleistocene from the south-east of Western Siberia. These sections are characterized by different structure and formed in different geomorphological position of Ob Loess Plateau and Cis-Salair plain. The age of deposits within MIS 1 - MIS 3 is determined by radiocarbon and OSL dating. Data on the quartz grain morphology confirmed that aeolian processes were the main factor in the accumulation of studied profiles, the influence of cryogenic weathering was also noted. Evidence of the MIS 2 warmings have been recorded in the northwestern Salair region (Ust’-Chem section), presented by two weakly developed Late Glacial paleosols formed 14.9–12.3 kyr ago. The distribution of magnetic susceptibility and grain size records in the Lozhok and Klyuchi sections reveals a period of relatively long term aridization with an increase in atmosphere dustiness in the lower part of the Eltsovka loess (MIS 2). The trend of increase in humidity with decrease in the atmosphere dynamics is observed during the second part of MIS 2. An event of activation of local aeolian processes with dune formation took place 47 kyr ago (the first half of the Karga interstadial; MIS 3) in the Klyuchi section. It is supposed that the geomorphological situation and the presence of nearby material available for local redeposition was a significant agent in the formation of the lower layer of Klyuchi and Ust-Chem sections. It was formed by combined deposition of silt material from the atmosphere flow and by the local aeolian transportation of sand. Permafrost-solifluction event was established in the northeastern part of the Ob Loess Plateau at about 23 ka.

Following a major revision of the Sartan ice sheet limits, Velichko et al.’s (2011) view of northwestern Siberia as a cold arid desert during MIS 2 (27.8–11.7 ka) has been prominent in regional scholarship. Our article presents the analysis of a series of sandy sediments associated with MIS 2 polygonal ice-wedge pseudomorphs (PIWPs) located in the Lower Nadym, the Middle Nadym, and the Siberian Uvals regions. Whereas Velichko et al.’s cold desert hypothesis was based on optical morphoscopy, our research relied on the scanning electron microscope technology (in conjunction with sedimentological, soils, and radiocarbon data). Our morphoscopic analysis of three wedge fill – host sediment pairs suggests that none of the MIS 2 surface sediments can be unequivocally associated with desert dune environments, but instead resemble alluvial deposits that have been moderately to substantially reworked by aeolian and cryogenic (freeze-thaw) processes. While the environmental characteristics varied between different sub-regions, northwestern Siberia likely resembled a sparsely vegetated tundra during MIS 2. AMS radiocarbon dates obtained from the organic matter of paleosols discovered inside of PIWPs indicate that the climate warming in northwestern Siberia began around 13.5–13 ka cal BP (end of MIS 2). This climatic shift was associated with a more pronounced warm season, as evidenced by the surface sediments experiencing more intensified freeze-thaw cycles in all of the examined locations. Judging from our analysis of sandy deposits, aeolian activity intensified in the Siberian Uvals in the middle MIS 2, compared to early MIS 2. Aeolian activity also intensified in the Middle Nadym in the second part of MIS 2, compared to the first part of MIS 2. Besides the intensified freeze-thaw processes at the end of MIS 2, surface deposits of the Lower Nadym region remained relatively stable throughout the Sartan cryochron.

This review serves as an explanatory note to the sketch map of loessoids, i.e. loess and various loess-like deposits. The map is a byproduct of the ongoing project of Quaternary Map of the Russian Federation, scale 1:2,500,000 in GIS-format. The primary information is derived from the standard National Geological Map scale 1:1,000,000 of the last two generations supplemented by literary data. The map polygons present all mappable loessoid units, including thick southern carbonate loess with paleosols, loess-like silts of northern terrains, intercalations of loessic sediments with waterlain facies and icy silts of the Arctic and Subarctic type. The loessoid formations are classified according to their stratigraphic intervals: 1) the radiocarbon dated Upper Pleistocene of northern terrains, 2) the Middle plus Upper Pleistocene of central Russia, 3) the late Lower Pleistocene to Upper Pleistocene series of southern regions and 4) the Lower Pleistocene red clays of the south. The distribution of diverse loessoids is an imprint of: i) the diverse sedimentary environments of the basically arid periglacial zones of the Pleistocene and ii) the modern geographical zonality changing from subtropics to the icy High Arctic and responsible for post-depositional alteration of subaerial dust. Whatever the origin of the primary dust and geographical varieties of the diagenesis, all loessoids share the same fundamental feature – paleosols, whether numerous and expressive or scarce and weak. They underline the climatically driven intermittent process of loessoid formation – basically subaerial and independent of any aqueous agencies.

The Gulf of Mexico coastal plain contains one of the largest dune systems in Mexico. These dunes and particularly their paleosols contain valuable paleoenvironmental information, however this aspect has been poorly studied. Here, we present the preliminary results obtained from buried paleosols of coastal dune ridges in Veracruz with the aim to reconstruct the environmental conditions during their formation as well as the phases of stability (pedogenesis) and instability (sedimentation) of the landscape. Three profiles were studied in the areas of Punta Delgada, PD (in the north), Palma Sola, PS, and La Mancha, LM (in the south). The chronological frame was constructed by radiocarbon dating of paleosols organic matter and pedogenic carbonates, and by Optical Stimulated Luminiscence (OSL) dating for the dune sediments. For each section several paleosols levels were identified whose properties permitted the differentiation of pedogenetic trends as well as their periods of formation. Nevertheless, the three sections did not provide for a continuous record of pedogenesis and sedimentation, as most of the paleosols are truncated by erosion. PS is the most complete profile which is formed from Marine Isotope Stage (MIS) 5c to MIS 1, with especially well-developed Holocene paleosols. LM includes only paleosols developed during MIS 4 and MIS 3, and PD shows only one paleosol originated during MIS 2. Although, the chronology is not complete as it has been constructed with a few dates, we consider each section contains information from different chronological windows. The results demonstrate that the oldest paleosols formed under more humid conditions during MIS 5c to 5a and probably MIS 4. As the MIS 4 to MIS 2 paleosols contain pedogenic carbonates, we interpret drier climates or with higher evapotranspiration rates. Paleosols from the early Holocene exhibit vertic properties probably formed by seasonal climates. Soils from the Middle-Late Holocene are less developed, due to the activation of the dune sedimentation. The results found here are compared at a regional scale with the dune system in the northern Gulf of Mexico and Yucatan peninsula, revealing both synchronous and asynchronous systems of eolian dynamics. The major asynchrony relates to the Wisconsinian stage (MIS 4 to MIS 2) for which high intensity of dune development is documented in the Veracruz and northern coasts whereas no dunes of that age are found in the Yucatan peninsula.

The INQUA Dunes Atlas project has developed a global digital database of chronological information for periods of inland or continental sand dune accumulation and stabilization. The database comprises information on the site location (including coordinates), dune type, and stratigraphic context, pertinent analytical information (e.g. luminescence procedures), and literature citations to the original data source. This paper discusses the background to the project, the concept and structure of the chronologic database that forms its core, and gives some examples of the scope of the database and ways in which it can contribute to greater understanding of the spatial and temporal variability in dune development. Fil: Lancaster, Nicholas. Desert Research Institut; Estados Unidos Fil: Wolfe, Stephen. Canadian Geological Survey; Canadá Fil: Thomas, David. University of Oxford; Reino Unido Fil: Bristow, Charlie. Birkbeck University; Reino Unido Fil: Bubenzer, Olaf. Universitat Zu Köln; Alemania Fil: Burrough, Sallie. University of Oxford; Reino Unido Fil: Duller, Geoff. Aberystwyth University; Reino Unido Fil: Halfen, Alan. University of Kansas; Estados Unidos Fil: Hesse, Paul. Macquarie University; Australia Fil: Roskin, Joel. University of Haifa; Israel Fil: Singhvi, Ashok. Physical Research Laboratory; India Fil: Tsoar, Haim. Ben Gurion University of The Negev; Israel Fil: Tripaldi, Alfonsina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Basicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Basicas, Aplicadas y Ambientales de Buenos Aires; Argentina Fil: Yang, Xiaoping. Chinese Academy of Sciences; República de China Fil: Zárate, Marcelo Arístides. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina

Intensive stratigraphic work on a horizontally extensive but shallow sample of early Holocene archaeology at Ntloana Tsoana rockshelter in western Lesotho has revealed a complex social history of waxing and waning occupation sandwiched between, and overlapping with, two distinct flood events. Bayesian models of radiocarbon and OSL ages are critical, enabling robust temporal ranges to be assigned to stratigraphic phases despite considerable challenges. This, in turn, means that site-specific happenings can be linked to broader ecological and cultural processes, including early Holocene warming and the emergence of southern Africa's small scraper tradition. By emphasising the duration of human activity, these results also show how specific hide working practices were repeated there by successive generations. Questions arise about the separation of scales that has characterised explanation in Later Stone Age archaeology and the largely overlooked role of persistent places in hunter-gatherer history. It is argued that repeatedly occupied rockshelters and their enduring sedimentary, bone and lithic residues would have been active entities in the past, anchoring people in time and space and may have led to an ontological merging of practice and place. Related ways of thinking about our own practice reveals that archaeologists can also benefit from thinking about sedimentary deposits as active and enduring as well as sequential.

This study examined temporal changes in the archaeological records of the Pleistocene/Holocene transition in Hokkaido, northern Japan, based on assemblage composition, radiocarbon ages, projectile point flaking pattern, and site distribution, with a particular focus on the lithic reduction technique. It explained the formation processes of Jomon society in response to climate change as follows. In Hokkaido, pottery emerged during the Late Glacial (LG) warm period (ca. 15,000–13,000 cal BP) because the Incipient Jomon people migrated from Honshu to the north. The Incipient Jomon communities coexisted with the Terminal Upper Paleolithic (TUP) people that had continued to occupy the region since the stage prior to the LG warm period, but the Incipient Jomon population was relatively small. During the LG cold period (ca. 13,000–11,500 cal BP), the subsistence and settlement strategies adopted by the Incipient Jomon people could not continue in Hokkaido. There is currently no reliable evidence of human activity during the LG cold period. Nevertheless, the analysis of stone tool-making patterns has revealed that stone tool making originating among the TUP people is found in an early Initial Jomon assemblage from the Taisho 6 site. It has an accepted date range of 11,000–10,000 cal BP. This indicates that TUP people's more mobile lifestyle might have enabled them to adapt to the LG cold environment. In the initial Holocene, there was a change in subsistence strategy evidenced in the increase in pottery vessels and the emergence of tools for processing of plant foods. The dramatic warming at the beginning of the Holocene is thought to have significantly changed the TUP people's subsistence strategies and lifestyles.

s Two opinions exist regarding the appearance of the oldest pottery in the Transbaikal Region, Russia— (1) in the early Neolithic during the Holocene Atlantic optimum (6.5–5.5 ka Cal yr BP), or (2) during the Taymir Warm period of the Sartan Glacial (12.0–10.8 ka Cal yr BP)— both derived from the same archaeological component, Cultural Layer 9, at the Studenoe 1 Site. Here we scrutinized data related to the geochronology of early ceramic-yielding layers at Studenoe 1. Results show that the radiocarbon dates between 15,080 and 12,720 Cal yr BP contradict site stratigraphy which consists of vertically accreting overbank deposits and buried soil horizons that developed during periods of landscape stability. Palynological and stable-carbon isotope analyses also show inconsistencies with the calibrated radiocarbon dates. We do not yet know the reason for these anomalies, however, it may be that alpine glacier and permafrost thawing, and the subsequent supply of older carbon into the Chikoi River, ceased during cold periods, but accelerated during terminal Pleistocene and early Holocene warm periods, causing a systematic error of older radiocarbon dates.

In Southwest Asia, early ceramics are generally associated with sedentary farming communities. This is unlike many other parts of Asia, where ceramics were first manufactured by hunter-gatherers. Radiocarbon evidence indicates that sustained production of ceramic containers (pottery) began at several sites in Anatolia, Upper Mesopotamia and the northern Levant around 7000 BC or slightly later, although there are indications that very small-scale production of pottery sometimes occurred at even earlier dates. In other regions (e.g. the southern Levant, Cyprus) pottery does not become common until centuries later. This paper examines Southwest Asian ceramic production in terms of its timing, technology and use, as well as its social and economic contexts. It also considers the legacy of early archaeological studies of Southwest Asian pottery for our general understanding of the emergence of ceramics. For example, Gordon Childe's concept of a ‘Neolithic package’ promoted a close association between the emergence of farming and pottery, which cannot be supported for many parts of Asia.

The Amur River basin is widely known as one of the regions where the earliest pottery first appeared, however few are aware that it happened simultaneously in two separate areas associated with two different archaeological complexes -the Gromatukha and Osipovka. This duality is confirmed here through three lines of inquiry. The first section reviews the most recent general data on both complexes including radiocarbon ages and stone tool assemblages, the second gives detailed descriptions and analysis of both cultures’ pottery including composition, forming, and decorating techniques, and the third provides data on their changes over time. The primary distinctions between the two complexes are stressed including the distribution area, pottery and stone tool production, chronological discrepancies, complex origins, and affiliations. Based on these observations we conclude that the Osipovka and Gromatuka pottery are likely produced by different cultural groups in distinct regions, with little cultural interactions. These observations provide a more complex view of the invention and development of pottery within a smaller regional setting, facilitating future comparisons of the general context of pottery invention and opening new pathways for the reconstruction of human behavioral reactions to cultural, climatic, and environmental challenges in the past.

A number of AMS radiocarbon dates, accumulated since the 1990's, reveal that ceramic technology first developed among non-agricultural, hunter-gatherer societies in the late Pleistocene of East Asia. Specifically, on the Japanese Archipelago the radiocarbon chronology indicates a diverse trajectory of pottery adoption. The earliest adoption of pottery here was by mobile hunter-gatherers, regardless of region and climatic event. On the other hand, pottery culture suddenly started to flourish later along the warmer Pacific coastline region of southwestern Japan just after the onset of climatic warming of the Late Glacial, and spread throughout the archipelago by the onset of the Holocene. Climatic amelioration, therefore, did not induce the ‘beginning’ of pottery use, but prompted the ‘development’ of sedentary lifestyles accompanying intensified use of pottery. This complicated situation clearly means that motivation and context of pottery adoption do not follow a simple explanation. However, recent studies of chemical and isotope analyses of charred residues on pottery indicate similar use of early pottery throughout the archipelago in the late Pleistocene and the early Holocene. This paper critically re-evaluates these issues through examining synchronic and diachronic archaeological contexts. Existing data indicate that there is great inter-regional variability in technology, subsistence, paleoenvironment, and adaptation associated with pottery, therefore the motivation for the adoption of pottery is distinct within various geographical, environmental, and temporal contexts in the archipelago.

New investigations of the Krasnaya Gorka site suggest the emergence of pottery in the Late Pleistocene-Early Holocene in the Transbaikal region. Several new AMS dates obtained for the early ceramic cultural layer 2 indicate an age between 13900-10500 cal BP. The results of palynological studies of the Krasnaya Gorka deposits are given in the paper for the first time, and the Late Pleistocene-Holocene environmental changes were reconstructed. Pollen data obtained from the Krasnaya Gorka profile showed cold and dry Late Pleistocene environmental conditions. The regional climate became milder and more humid around 13900–12700 cal BP, which corresponds to the Allerod interstadial thus corroborating the radiocarbon age results. The warmest interval of the Late Pleistocene occurred around 13500 cal BP. Between 12700 and 11800 cal BP, cooling probably corresponds to the cold and dry event of the Younger Dryas. There is some stratigraphical in deposits of the Krasnaya Gorka archeological site. The deposits forming in the early Holocene and beginning of the middle Holocene most likely were removed by erosion. Warming and increased humidity occurred in middle of the late Holocene (2700-1800 cal BP). During the late Holocene, the climate was unstable. Beginning 400 cal BP, the vegetation of the region acquired its modern appearance. Some published materials concerning reconstructions of paleoclimate in the region of Ust’-Karenga XII, Studenoe I, and Ust’-Menza I are considered in the context of general characteristics of the region. Therefore, both palynological reconstructions and radiocarbon dates place the earliest ceramics from Krasnaya Gorka within the final stage of the Late Pleistocene – Early Holocene between 13900-10500 cal BP.

Despite its long-standing assumption of the spread of early pottery innovated by the Late-Glacial hunter-gatherers in Japan, cultural diffusion as an explanatory model has not explicitly tested. This study addresses the question of the extent to which cultural diffusion played a role in proliferating the innovated early pottery technology across the Japanese Archipelago by employing the distance decay model of cultural diffusion. Based on the assembled dataset of the Late-Glacial assemblages with early pottery radiocarbon dates, distances between the presumed core where the earliest dates were obtained (i.e., Odaiyamamoto I) and the adopted sites do not exhibit the time-progressive pattern. In contrast, frequencies of potsherds relative to lithic artifacts increases as time progressed, implying that early pottery technology was gradually accumulated nearly by the end of the Younger Dryas, ca, 11,000 cal. BP. This study demonstrates that cultural diffusion does not fully explain the emergence and spread of early pottery in Japan, while the Late-Glacial travel and exchange networks enabled hunter-gatherers to transmit and accumulate knowledge of pottery use.

Soft-sediment deformation structures (SSDSs) are widely developed in the lacustrine sediments of paleo-dammed lakes in tectonically active regions and contain a wealth of information on regional fault activity. In this study, multiple SSDSs (load structures, small-scale slump structures, droplets, diapir and pillow structures, silty-clay pillars and large-scale slump structures) were identified in the strata of the Late Pleistocene lacustrine sediments in the Tashkorgan River drainage in northeastern Pamir. The deformation mechanisms of the SSDSs were related to the liquefaction, fluidization and thixotropic behaviors. The regional tectonic settings and SSDS features point toward a trigger mechanism with seismic activities and indicate that the seismogenic faults were possibly related to the southern part of the Kongur Shan extensional system. Accelerator mass spectrometry (AMS) radiocarbon dating data showed that the SSDSs in the Tashkorgan lacustrine sediments formed 30,221-29,932 cal BP and 25,825-25,317 cal BP. The results of this study improve our understanding of fault activity and geodynamic processes in northeastern Pamir during the Late Pleistocene.

Multilayer sections in lake bottom sediments and continental sections of loose sediments in Mongolia and the Baikal region provide rich palaeontological material and radiocarbon dating for palaeoenvironmental reconstructions of the Late Pleistocene (Late Glacial) to Holocene. Multidisciplinary data from lacustrine bottom sediments provide evidence of past lake level and vegetation dynamics in the watersheds. Palaeontological data from terrestrial deposits indicate a mosaic landscape structure and a temperate warm and humid climate during the Late Glacial and Holocene, with some regional variability. Global and regional climatic changes at the end of the Pleistocene resulted in the mass extinction of components of the Mammoth faunistic complex, such as the woolly mammoth, cave lion, cave hyena, and big-horned deer; the number of tundra species decreased and migrated to the north, and arid animal species migrated to the south. During the Holocene, four vegetation types (steppe, forest, taiga, and desert) did not show radical changes, but their ratio and spatial distribution changed. Steppe landscapes were replaced by desert steppes during the arid phases of the Holocene. In contrast, the area of taiga forests expanded during humid Holocene phases, but the steppe landscapes remained dominant in the studied territory.

Uranium (U) contamination in groundwater from geogenic sources affects water quality globally. Here, we use a multifaceted isotopic and geochemical approach to elucidate U sources and controls on g...

The sedimentological record in the Raciska pecina cave sediment sequence is one of the best-preserved cave records of palaeoenvironmental changes for the last 3.4 Ma. However, as it is typical for cave terrestrial records, it contains many hiatuses in sedimentation. The section study helped to change the state of knowledge and understanding of the long-lasting deposition characteristics in the caves and provided enormous data on environmental changes over time. In the sequence are by magnetostratigraphy well recorded Pliocene/Pleistocene transition at 2.59 Ma, the Matuyama/Brunhes boundary at 0.773 Ma, and the presence of Olduvai subchron between 1.78 and 1.925 Ma. Records of small mammals from the lower part of the section (a molar of Apodemus cf. atavus and dental fragments of Borsodia sp., and Pliomys sp.) suggest MN17 age, Clethrionomys cf. glareolus from the upper part suggests the Late Early or Middle Pleistocene age. Also worth mentioning are records of snail shells Aegopinella sp. and a troglobiont snail Zospeum sp. In the upper part of the section Ursus ex gr. spelaeus was confirmed in the yellow clay layer older than ~72 ka, and soot material at the top of the section was radiocarbon dated on ~11 ka, ~9 ka, and ~3 ka. A detailed chronology of the Raciska pecina section based on magnetostratigraphy and isotopic oxygen stratigraphy was created and correlated with palaeontological, U-series, and radiocarbon results. Before the hiatus 2.6-2.5 Ma ago, the oxygen record was mainly shaped by regional Mediterranean Sea factors. After this boundary, the RP record becomes more similar to the LR04 stack, implying the increased influence of Atlantic Ocean factors.

In the late ninth century, the northern Yatsugatake volcanoes in central Japan experienced a catastrophic collapse, simultaneously causing a debris-avalanche. Such failures have been related to the AD 887 Nin'na earthquake, which occurred along the Nankai Trough. However, supportive evidence of the hypothesis remains unavailable. The present study reports wiggle match radiocarbon (14C) dating of a buried tree excavated from a deep part of the debris deposit. The death year of the buried tree was dated as AD 838 ± 17. The date exactly matches an inference of the AD 887 earthquake obtained from historical documents and field records of archaeological ruins, considering that 14C ages of Japanese trees have a regional offset of ≈30 years greater than the IntCal dataset. Our result suggests that the AD 887 earthquake occurred along about 700 km extending from the western margin of the Nankai Trough to the central segment of the Itoigawa-Shizuoka Tectonic Line.

A multi-proxy study was performed on a gravity core supplemented by acoustics profiles and new radiocarbon dates of macrofossils found in the sedimentation history of the Odra Channel during the Holocene. The channel is located in the western part of Pomeranian Bay and was shaped by a pre-Odra river that flowed northwest along the Peene valley and the eastern part of Rugen Island during a drop in Yoldia Sea level. The acoustic profiling enabled identification of glacial till, the Baltic Ice Lake and Littorina sediments. The studied core penetrated only marine sediments deposited during Littorina and Post-Littorina stages and was the subject of grain size, geochemical and diatom analyses. The age of appearance of a marine environment in the studied area was estimated at 7200 yrs BP. The performed studies enabled division of the core into three phases of environmental evolution: the Littorina I phase occurred during the time span 7200–6000 yrs BP and is described as a shallow water brackish basin with a low rate of sea level rise and favourable conditions for biogenic production, the Littorina II phase dated at 6000–3800 yrs BP reflects a deep marine environment with relatively high salinity and greater current velocity, and the last phase, Post-Littorina, covered the last 3800 yrs BP and turned out to be a strongly energetic environment with decreasing salinity. The change from Littorina II to Post Littorina phase correlates clearly with a change in the acoustic reflection. Core analyses could be associated with extreme stormy cold events known as Bond events dated at 5900–5500 yrs BP and 4200 yrs BP evidencing the final destruction of the Odra Bank barrier.

The present paper deals with the historical evolution of the northern Bay of Cadiz (SW Spain) between the last eustatic maximum (6.5 ka BP) and the present day, by means of a series of independent proxies. The zone is constituted by the tidal estuary of the Guadalete River, filled with saltmarsh sediments during the late Holocene, due to the sheltering of the zone by a confining outer sandy barrier. The northern border of the Bay records an urban settlement of Phoenician Age (first millennium BC), Dona Blanca. A detailed survey was made in the contact between the Phoenician city and the saltmarshes in order to detect other possible urban structures related to the morphological and sedimentary evolution of this environment during historical times. Two campaigns with GPR Stream-X array were carried out as well as aerial imaging and topographic survey with UAV. In parallel, a total of 8 boreholes were made in different parts of the saltmarshes, including radiocarbon dating of selected samples for estimating sedimentation rates in the saltmarshes. Results obtained by georadar prospection and UAV survey revealed the presence of a second urban settlement on the marginal sedimentary plain, very probably installed upon a sandy fluvial island of the Guadelete River. The urban remains, of Punic Age, are partly covered by clay sediments due to the subsequent evolution of these saltmarshes, where sedimentation rates of up to nearly 2.4 mm/yr have been estimated for environments close to fluvial and/or tidal channels and hence more affected by sediment aggradation during flooding episodes. In recent times, river regulation by dams and the artificial desiccation and cropping of the saltmarshes have interrupted the natural trend of the area towards sedimentary silting up.

International audience; This study presents a new precise radiocarbon chronology for the World Heritage site of Sarvestan (SW Iran). The monument is a key construction in the history of architecture because it is a typical Sasanian construction built during the late Sasanian or early Islamic period. Previous attempts to date the monument have suggested the ages ranging from the middle Sasanian (fifth century CE) to early Abbasid (ninth century CE) era. These age estimations are based on the analysis of architectural plans and techniques, and a few radiocarbon dates with very large age uncertainties. This paper presents the results of a systematic radiocarbon dating of timbers in the walls and charcoals in plaster mortars used in the main dome of the monument. It further applies wiggle matching technique and R_Combine function to substantially reduce the age uncertainties in wood sections. The results indicate that a major construction work was undertaken sometime between 658 and 683 CE, the century of the invasion of Fars by Muslim Arabs. This finding pushes back the age of Sarvestan for two centuries and suggests that the monument was built at the transitional period between Sasanian to Islamic era. Sarvestan would have been an architectural project designed andpossibly initiated during the late Sasanian period but mainly accomplished during the second half of the seventh century CE. It can thus be considered a late Sasanian heritage in early Islamic period. Its construction at a time of political unrest further suggests that some areas of Fars may have benefited from certain socio-political stabilities during the expansion of Islaminto the east at mid- to late seventh century CE

Established chronologies indicate a long-term ‘Hoabinhian’ hunter-gatherer occupation of Mainland Southeast Asia during the Terminal Pleistocene to Mid-Holocene (45 000–3000 years ago). Here, the authors re-examine the ‘Hoabinhian’ sequence from north-west Thailand using new radiocarbon and luminescence data from Spirit Cave, Steep Cliff Cave and Banyan Valley Cave. The results indicate that hunter-gatherers exploited this ecologically diverse region throughout the Terminal Pleistocene and the Pleistocene–Holocene transition, and into the period during which agricultural lifeways emerged in the Holocene. Hunter-gatherers did not abandon this highland region of Thailand during periods of environmental and socioeconomic change.

Knowledge of past ice sheet configurations is useful for informing projections of future ice sheet dynamics and for calibrating ice sheet models. The topology of grounding line retreat in the Ross Sea sector of Antarctica has been much debated, but it has generally been assumed that the modern ice sheet is as small as it has been for more than 100 000 years (Conway et al., 1999; Lee et al., 2017; Lowry et al., 2019; McKay et al., 2016; Scherer et al., 1998). Recent findings suggest that the West Antarctic Ice Sheet (WAIS) grounding line retreated beyond its current location earlier in the Holocene and subsequently readvanced to reach its modern position (Bradley et al., 2015; Kingslake et al., 2018). Here, we further constrain the post-LGM (Last Glacial Maximum) grounding line retreat and readvance in the Ross Sea sector using a two-phase model of radiocarbon input and decay in subglacial sediments from six sub-ice sampling locations. In addition, we reinterpret high basal temperature gradients, measured previously at three sites in this region (Engelhardt, 2004), which we explain as resulting from recent ice shelf re-grounding accompanying grounding line readvance. At one location – Whillans Subglacial Lake (SLW) – for which a sediment porewater chemistry profile is known, we estimate the grounding line readvance by simulating ionic diffusion. Collectively, our analyses indicate that the grounding line retreated over SLW 4300-2500+1500 years ago, and over sites on Whillans Ice Stream (WIS), Kamb Ice Stream (KIS), and Bindschadler Ice Stream (BIS) 4700-2300+1500, 1800-700+2700, and 1700-600+2800 years ago, respectively. The grounding line only recently readvanced back over those sites 1100-100+200, 1500-200+500, 1000-300+200, and 800±100 years ago for SLW, WIS, KIS, and BIS, respectively. The timing of grounding line retreat coincided with a warm period in the mid-Holocene to late Holocene. Conversely, grounding line readvance is coincident with cooling climate in the last 1000–2000 years. Our estimates for the timing of grounding line retreat and readvance are also consistent with relatively low carbon-to-nitrogen ratios measured in our subglacial sediment samples (suggesting a marine source of organic matter) and with the lack of grounding zone wedges in front of modern grounding lines. Based on these results, we propose that the Siple Coast grounding line motions in the mid-Holocene to late Holocene were primarily driven by relatively modest changes in regional climate, rather than by ice sheet dynamics and glacioisostatic rebound, as hypothesized previously (Kingslake et al., 2018).

The lake sediments received wide attention for archiving paleoclimate and paleo sea-level variability during the late Quaternary period. It has also been extensively used to disentangle the interrelationships existing among the regional and the global climate systems. In the present study, the applicability of lake sediments has been the major impetus to delineate the mid-late Holocene climate and sea level variability using a ∼10 m sediment core retrieved from a protected freshwater lake-the Vellayani lake, southern Kerala, southwest India. The sediment core was investigated using multiproxy approach and was chronologically supported by AMS radiocarbon dates. The results show monsoon intensification and a high sea level during 6430−4390 cal yr BP led to the formation of a coastal lagoon system in the area. Climatically, a marginal reduction in monsoon during 4390−2600 cal yr BP interspersed by an intensified phase during 3800−2600 cal yr BP was observed while concurrently, a sea regression during4390−2600 cal yr BP restricted sea water influence in the study area. Proxies indicated a significant monsoon reduction during 2600−1000 cal yr BP followed by monsoon intensification post-1000 cal yr BP. After 2600 cal yr BP, a thick pile of alluvial sediments was deposited by the Karamana River which might have hindered the tidal influence and later the basin was transformed into a freshwater lake. The present lake configuration was attained after 440 cal yr BP. Further, comparison of paleoclimate reconstructed from the present study with the global records revealed a teleconnection of Indian monsoon with the global climate system.

Marine reservoir effects (MRE) have the potential to increase the dating uncertainty of humans incorporating marine resources into their diets. Here we attempt a novel dental wiggle-match model to reduce dating uncertainty of seven individuals from the Resmo megalithic tomb (Öland, Sweden) and to test whether this model can be used to calculate MRE from a single tooth. Previous stable isotope ratio studies of these individuals demonstrated that their diets changed, between more or less marine protein, during the early years of their lives. Several incremental samples of dentine from each individual were subjected to radiocarbon dating and stable isotope ratio analysis. An OxCal model was designed that makes use of the known formation sequence of human teeth to reduce overall dating uncertainty. The new dental wiggle-match model is able to reduce overall dating uncertainty in all of the sampled individuals compared to more conventional 14C calibration methods. A utility of the dental wiggle model to estimate marine reservoir effects without associated faunal material is also demonstrated, with promising results.

Due to the marine reservoir effect, radiocarbon dates of marine samples require a correction. Marine reservoir effects, however, may vary among different marine species within a given body of water. Factors such as diet, feeding depth and migratory behaviour all affect the 14C date of a marine organism. Moreover, there is often significant variation within single marine species. Whilst the careful consideration of the Δ R values of a single marine species in a given location is important, so too is the full range of Δ R values within an ecosystem. This paper illustrates this point, using a sample pairing method to estimate the reservoir effects in 17 marine samples, of eight different species, from the archaeological site of Ekven (Eastern Chukotka, Siberia). An OxCal model is used to assess the strength of these estimates. The marine reservoir effects of samples passing the model range from Δ R (Marine20) = 136 ± 41–Δ R = 460 ± 40. Marine reservoir effect estimates of these samples and other published samples are used to explore variability in the wider Bering Strait region. The archaeological implications of this variability are also discussed. The calibrating of 14C dates from human bone collagen, for example, could be improved by applying a dietary relevant marine reservoir effect correction. For humans from the site of Ekven, a Δ R (Marine20) correction of 289 ± 124 years or reservoir age correction of 842 ± 123 years is suggested.

Shell midden sites along the upper Gulf coast of Baja California contain abundant evidence of Indigenous subsistence practices and land use strategies reflecting the long history of local fisheries. Many of these sites contain well preserved faunal remains indicating people utilized a variety of littoral and marine habitats and exploited seasonal runs of the now endangered totoaba (Totoaba macdonaldi). We analyze totoaba otoliths recovered from eight archaeological sites along the upper Gulf coast with adjusted accelerated mass spectrometry (AMS) radiocarbon date ranges spanning ~5700 to 125 cal BP. Integrating geochemical, biological, oceanographic, and archaeological datasets, this study investigates ~5700 years of Indigenous fishing practices and past marine environments by examining totoaba biogeography, population dynamics, season of harvest, and changes in water chemistry. Otolith morphometrics indicate that most (~78%) of the Indigenous catch consisted of yearlings and juveniles, reflecting more sustainable practices than commercial fisheries, which target larger, older, and more reproductively viable fish. Stable isotope results reveal slight oscillations in water chemistry between the Middle and Late Holocene and suggest shifts in salinity due to the extensive damming of the Colorado River in the past century. Our results contribute to regional paleoenvironmental reconstructions, the natural history of totoaba, and the growing body of data that suggest many Indigenous people engaged in localized sustainable fishing practices over thousands of years.

As an extended comment on the paper by Sarnthein et al. (2020), we express strong reservations about the methodology of the so-called 14C plateau tuning (PT) technique used to date marine sediment records and its implications on the determination of 14C marine reservoir ages (MRA). The main problems are linked to: the assumption of constant MRA during 14C-age plateaus; the lack of consideration of foraminifera abundance changes coupled to bioturbation that can create spurious plateaus in marine sediments; the assumption that plateaus have the same shapes and durations in atmospheric and oceanic records; the implication that atmospheric 14C/12C peaked instantaneously from one plateau to the next; that the 14C plateaus represent 82 % of the total time spent between 14,000 and 29,000 cal yr BP, whereas during the remaining 18 % of the time, the radiocarbon clock was running almost 5 times too fast; that the sparsity, combined with the level of analytical uncertainties and additional noise, in both atmospheric and marine data do not currently allow one to reliably or robustly identify plateaus (should they exist) beyond 15,000 cal yr BP; and that the determination and identification of plateaus is reliant upon significant changes in sedimentation rate within the marine sediments which are, a priori, unknown and are not verified with an independent method. The concerns we raise are supported and strengthened with carbon cycle box-model experiments and statistical simulations of pseudo-atmospheric and pseudo-marine records, allowing us to test the ability to identify and tune 14C-age plateaus, in the context of noisy and sparse data.

International audience; Numerous charcoal kiln remains can still be found throughout the world, evidencing wood harvesting related to former industries. These remains represent effective sources and tools for studying (i) pre-industrial pressures on forest resources and (ii) past strategies related to woodland management. However, radiocarbon dating (AMS), which is the main tool to reconstruct the chronology of past charcoal manufacturing activity, doesn't provide sufficiently accurate dating, especially for the post-1650 period, due to the broad probability range of the dates resulting from wiggles in the calibration curve. In order to overcome the radiocarbon dating limitation and therefore refine the chronology of modern charcoal manufacturing, this paper proposes to apply an integrated approach combining archaeology, micromorphology, anthracology and dendrochronology. To characterise the archaeological record of a target charcoal kiln terrace from the "Forêt de Bernadouze", located in a historical iron production valley of the Northern Pyrenees, we combined classical stratigraphic analysis with a micromorphological study. The results highlight the multiperiod nature of the terrace, i.e. a palimpsest of multiple charcoal production episodes, revealing two major phases marked by an abandonment period between them. Subsequently, we constructed a beech charcoal-ring (n=49) chronology cross-dated with the new "Forêt de Bernadouze" reference chronology from freshly felled, living beech trees (n=24) to obtain the annual resolution of charcoal ring formation. Based on the new reconstructed master chronology covering the 1879-2016 period, we were able to calibrate the charcoal-ring chronology for the 1881-1941 period. Consequently, we (i) dated the charcoal production activity performed on the target terrace during the 1924-1942 period and (ii) identified a shift in the rate of use of the terrace, from one-off to high-intensive use. This study also provides new insights regarding (i) the particular nature of the archaeological record and (ii) the operating and timing of past charcoal-making practices in connection with silvicultural treatments.

Coral skeletal structures can provide a robust record of nuclear bomb produced 14C with valuable insight into air-sea exchange processes and water movement with applications to fisheries science. To expand these records in the South Pacific, a coral core from Tutuila Island, American Samoa was dated with density band counting covering a 59-yr period (1953–2012). Seasonal signals in elemental ratios (Sr/Ca and Ba/Ca) and stable carbon (δ13C) values across the coral core corroborated the well-defined annual band structure and highlighted an ocean climate shift from the 1997–1998 El Niño. The American Samoa coral 14C measurements were consistent with other regional records but included some notable differences across the South Pacific Gyre (SPG) at Fiji, Rarotonga, and Easter Island that can be attributed to decadal ocean climate cycles, surface residence times and proximity to the South Equatorial Current. An analysis of the post-peak 14C decline associated with each coral record indicated 14C levels are beginning to merge for the SPG. This observation, coupled with otolith measurements from American Samoa, reinforces the perspective that bomb 14C dating can be performed on fishes and other marine organisms of the region using the post-peak 14C decline to properly inform fisheries management in the South Pacific.

The development of pre-historic agriculture and its determining factors have been extensively investigated in recent years. Based on the identification of charred seeds and radiocarbon dating, we found that foxtail millet-based agriculture dominated Neixiang County in Central China during the mid-late-Holocene. There were three different farming patterns in the Nanyang Basin, including rice cultivation in the plains, foxtail millet cultivation in the pediment plains, and broomcorn millet cultivation in the valleys. In addition, during the Neolithic-Bronze Age, the distribution of human settlements with rice cultivation matched with the climate pattern at 31.0–36.5° N in China. The emergence of rice cultivation had been facilitated by a significant increase in East Asian summer monsoon and increased precipitation in Central China since 8500 BP and gradually flourished during the Peiligang (8500–7000 BP) and Yangshao (7000–4500 BP) Period, corresponding to a relatively warm and wet climate. However, the average latitude of the human settlements with rice cultivation shifted southward to 33.29° N during the Longshan Period (4500–4000 BP) due to the cold climate brought by the “4.2 ka event.” Afterward, rice cultivation was basically not constrained by climate change, probably owing to the improved farming methods in the Bronze Age.

The vermetidae fossils ofPetaloconchus varians, formed by calcium carbonate, associated with their radiocarbon ages, are the most accurate indicators of paleo sea level due to their restricted occupation in the intertidal zone in the rocky shore. However, the recrystallization of minerals can affect these age calculations and, consequently, the interpretation of the data. The aim of this study is to present new indicators of paleo sea-level changes in Southeast Brazil for the last 6000 years contributing to fill the data gap for the late Holocene. The influence of the recrystallization process was successfully resolved using the CarDS protocol, enabling the separation of the original aragonite fraction by density, prior to radiocarbon dating. This avoids the rejuvenation of ages and ensures greater efficiency for data interpretation. Paleo sea-level indicators were able to show a progressive increase in sea level up to the transgressive maximum of 4.15 m in 3700 BP years, followed by a regression to the current zero. This regression seems to have in addition, here we reinforce the reliability of the use of fossil vermetids as indicators of sea-level fluctuations.

Funerary usage of Galeria da Cisterna (Almonda) and Gruta do Caldeirão began at the onset of the Neolithic and continued until Early Medieval times. At Cisterna, the thin Holocene deposit was unstratified; at Caldeirão, the stratigraphic sequence underwent post-depositional disturbance. Using radiocarbon dating, typological considerations, spatial distribution patterns, and physical anthropological data, these palimpsests can be disentangled to a significant extent. At both sites, the earliest depositions fall in the c. 5250–5500 cal BC interval and are associated with large numbers of beads. Wares extensively decorated with shell and comb impressions are likely to belong in this phase. Another style of decoration – shell impressions forming bands below the rim and garlands between prehension knobs – probably dates to a slightly later time. Burial continued at both sites through the c. 5000–5250 cal BC time range, but which decorative styles were then in fashion remains difficult to ascertain; it is likely that the irregular arrangements of shell impressions seen in some Cisterna vessels are among them. At Caldeirão, non-Cardial impressed and incised wares date to c. 4500–5000 cal BC, while undecorated wares are associated with human bone samples demonstrating two different periods of burial during the c. 3500–4000 cal BC interval. Most if not all of the nine Cardial individuals directly dated at the two sites died coevally with the more recent of the Mesolithic interments found in the shell-midden sites of the Tagus estuary.

During the second half of the Holocene, the Russian Plain experienced several climatic oscillations giving rise to changing vegetation patterns. The spatial variability of vegetation changes and its effects on soils is still a matter of debate. In the present study landscape response to Holocene climatic cycles was analysed on the base of detailed morphological, chemical and microbiomorphic analyses of a paleosol buried under the kurgan of the Abashevo culture (Middle Bronze Age) and a surface soil. Both soils located at the Tokhmeyevo kurgan cemetery (the Middle Volga region, Chuvash Republic, Russia) developed from the same parent material (mantle loam), at the same elevation and in close proximity to each other. Both soils, classified as Retisols, show a similar morphology and key analytical features indicating similar environment. The pollen and phytolith spectra confirm that both buried and surface soils formed under similar forest vegetation. The buried and surface soils at the Tokhmeyevo cemetery could be compared with the previously studied soils of the Sareevo settlement of the Early Iron Age and the Taushkasy kurgan cemetery of the Bronze Age. These studies confirm the stability of the forest environment at the southern boundary of the forest belt since the Bronze Age. At the same time, the buried soil at the Tokhmeyevo cemetery has a thick mollic horizon and black organic coatings overlaying brown clay cutans in the argic horizons, which sets it apart from the surface soil. The radiocarbon dates for the humus in the mollic horizon and black coatings in the argic horizon are surprisingly close to each other (about 5.5 cal ka BP and 5.2 cal ka BP, respectively). The data indicate that the black cutans are derived from degradation of the mollic horizon caused by a sudden increase in humidity during the episodes of extreme summer rainfall events. Our study also prove that the Abashevo people had complicated burial funeral rites. The earth mounds are made of the upper horizons of soils cut off from the surface in the vicinity. The central part of the mound consists of soil bricks with albic material used for the interior, while artificially rumpled material of the argic horizon was used for coverage. The use of albic and artificially rumpled material of argic horizon for earth mound construction implies the similarity between the buried and surface soils since the Bronze Age until today. Thus, the study of such construction techniques is important both for archaeology and paleogeography (paleopedology).

Abatract More than 80% of marine organic carbon (OC) burial occurs in sediments of marginal seas. Sedimentary OC 14C ages up to several millennia older than co-deposited coastal and pelagic sediments have been well documented but the cause of this phenomenon remains uncertain. We measured 14C and 13C contents of OC, along with the sedimentary content of terrestrial and marine lipid biomarkers, in sediment cores from the East China Sea to evaluate and quantify processes controlling OC ages over the last 14.3 kyr. We find that 14C ages of OC were persistently older than co-deposited sediments by 1930–5530 yr. Temporal variations of the calculated apparent initial radiocarbon ages of total OC (TOC-AIR) mirrored sea level changes, with higher values (4570 ± 1250 yr) during the transgression (14.1–7.8 kyr BP) and lower values (3170 ± 670 yr) during the mid-late Holocene (7.8–0 kyr BP), suggesting that transgression-induced coastline retreat reduced the transport of pre-aged terrestrial OC to the marginal sea. However, bulk OC 14C ages were consistently older than those expected from ternary mixing of Changjiang (Yangtze River), Huanghe (Yellow River) and marine sources based on δ13C and Δ14C end-members. We therefore propose that hydrodynamic processes during sediment transport and the addition of pre-aged OC from land and submerged coast were the main factors contributing to these old 14C ages of OC and their temporal variations. During the transgression, higher TOC-AIR values were observed during times of lower sea-level, which suggests that erosion of coastal deposits during transgression might have contributed old OC. Since sea level stabilized 7.8 kyr BP hydrodynamic processes were the primary cause of high 14C ages of OC. The significant role for hydrodynamic aging processes during the mid-late Holocene is hypothesized to result from longer transport distances between river mouths and sediment depocenters which can accommodate additional deposition-resuspension loops.

The nature of economies and the movement of agricultural crops across Eurasia in the Bronze Age have been the subject of significant research interest in recent years. This study presents and discusses new results of flotation, radiocarbon and carbon stable isotope analyses from the seed assemblage at the Adunqiaolu site (northwestern Xinjiang), in combination with archaeological evidence. Archaeobotanical evidence, including carbonized foxtail millet, broomcorn millet, and naked barley, documents the diversity of local cereal consumption during the mid-second millennium BC. Our results suggest that crops were not grown locally, however, but in the lower Boertala Valley, supporting the argument that Adunqiaolu was a winter camp. These new sets of data constitute an important contribution to the discussion on cereal dispersal across the Tianshan Mountains in the Bronze Age.

In a recent article, Kunz and Mills (2021) report 10 drawn, a speo finished, turquoise blue, IIa40 beads manufactured in Venice and recovered from three late precontact sites in the Alaskan Arctic. They argue that these beads date to the fifteenth century, predating Columbus's arrival in the Americas. This conclusion is certainly in error because beads of this type were not manufactured prior to approximately AD 1560. The historical and archaeological evidence for this dating is substantial. Additionally, the elemental and radiocarbon evidence presented by Kunz and Mills (2021) supports a late sixteenth- to early seventeenth-century date for these beads.

Quantifying the local marine reservoir age (ΔR) and its change over time is critical for precise radiocarbon calibration of marine samples and for the study of the ocean carbon cycle. ΔR values are scarce for the African coast facing the Indian Ocean, and the few values available were obtained from pre-bomb shells collected during the 19th century. Here, the ΔR value for calibrated year 1110 ± 25 (1σ) CE was reconstructed from radiocarbon dating and Bayesian analysis of marine and terrestrial materials coexisting in a tsunami deposit discovered in Pangani Bay (Tanzania, western Indian Ocean coast). The reconstructed ΔR of –8 ± 40 (1σ, n = 3) is similar to pre-bomb regional estimates and provides new information to investigate regional ΔR change over time. The Bayesian analysis of the dated samples revises the age of the tsunami event found in Pangani Bay to 1064–1157 cal CE (95.4% confidence level) or 1110 ± 25 (1σ) cal CE, about one century younger compared to the previous estimate. Our results indicate that the new ΔR value and the proposed calibration approach can be used to refine existing chronologies in the region, with implications for paleo-environmental reconstructions and archaeological studies of Early Swahili societies.

We developed a simple and cost-effective method for extracting carbon from dissolved inorganic carbon (DIC) in water samples without a carrier gas. This method only slightly modifies the existing vacuum line for CO2 purification in radiocarbon research laboratories by connecting several reservoirs and traps. The procedure consists of repeated cycles of CO2 extraction from water into the headspace of the reaction container, expansion of the extracted gas into the vacuum line, and cryogenic trapping of CO2. High CO2 yield (∼98%) was obtained from a variety of water samples with a wide range of DIC concentrations (0.4–100 mmol·L−1, in the case of 1.2 mgC). The δ13C fractionation depended on the CO2 yield, while the 14C concentration was constant within the error range, regardless of the CO2 yield. The average δ13C discrepancy between the results of this method and direct analyses made using the GC-IRMS was 0.02 ± 0.06‰. The standard deviations (1σ) in fraction of modern carbon (F14C) ranged from 0.0002 to 0.0004 for waters below 0.01 of F14C, and below 0.8% of F14C values for waters above 0.1. We conclude that this method is useful for effectively extracting CO2 from DIC in water and yields accurate 14C data.

Shells from Neolithic shell midden sites have been routinely dated in Korea, but they have not been calibrated based on the correction values (ΔR) for the marine reservoir effect (MRE). A lack of proper calibration has left dates on shells incomparable to those on terrestrial samples, and thus unusable in building the chronological sequence of shell middens. Here, we report the two new ΔR values of a pre-bomb (pre-1950) blue mussel from the south coast. We applied the two new and the two previously reported ΔR values to the three dates on marine shells from the Bibongri shell midden in southeastern Korea. Our ΔR adjusted calibration and the comparison to dates on charcoal and bone remains clarify an ambiguity in the stratigraphy and the Early Neolithic chronology at Bibongri. Our contribution is to provide the ΔR values that can be further applied to other Neolithic shell middens along the south coast.

The vast drylands of the Asian interior were an integral part of a transcontinental network connecting east to west, that acted periodically as corridors and routeways for human migration. However, our understanding of the prehistoric human occupation of and interaction with this inhospitable environment has been hindered by a lack of direct evidence from settlements. Here we present the results of the first systematic study of archaeological material and radiocarbon dates from newly-discovered Bronze Age settlements in the hyper-arid Lop Nur region, in the eastern Tarim Basin. The studied settlement (the North Loulan Settlement, NLS), apparently associated with the prehistoric Xiaohe Culture, which is known from the Xiaohe and Gumugou cemeteries, is especially significant for the study of the prehistoric desert-oasis civilization in the drylands of the Asian interior, because it is quite different from any of the contemporary cultures in the surrounding regions. Based on a synthesis of Bayesian-modeled radiocarbon dates, the age of the NLS falls within the range of ca. 2051–1774 BC. Our field investigations indicate that the inhabitants of the site occupied semi-subterranean/semi-cave dwellings on the upper part of high yardangs, suggesting that they were able to utilize island-like yardangs in order to adapt to lake or wetland terrains. The new chronological framework for the Xiaohe cultural sites indicates that the NLS was the first Xiaohe settlement in the Tarim Basin. The earliest settlers, who were influenced by oriental culture, may have migrated to the NLS along the eastern or northeastern corridors. Later, there was the migration of populations westward along rivers.

Isotope analyses on human and faunal skeletal remains from different Swedish Neolithic archaeological contexts are here applied as a means to reconstruct dietary strategies and mobility patterns. The chronological emphasis is on the Middle Neolithic period, and radiocarbon dating constitutes another central focus. The results reveal a food cultural diversity throughout the period in question, where dietary differences in part correspond to, but also transcend, the traditionally defined archaeological cultures in the Swedish Early to Middle Neolithic. Further, these differences, and the apparent continued utilisation of marine resources in several regions and cultural contexts, can only in part be explained by chronology or availability of resources depending on geographic location. Thus, the sometimes suggested sharp economic shift towards an agricultural way of life at the onset of the Neolithic is refuted. Taking the potential of isotope analyses a step further, aspects of Neolithic social relations and identities are discussed, partly from a food cultural perspective embarking from the obtained results. Relations between people and places, as well as to the past, are discussed. The apparent tenacity in the dietary strategies observed is understood in terms of their rootedness in the practices and social memory of the Neolithic societies in question. Food cultural practices are further argued to have given rise to different notions of identity, some of which can be related to the different archaeological cultures, although these cultures are not to be perceived as bounded entities or the sole basis of self-conceptualisation. Some of these identities have been focused around the dietary strategies of everyday life, whereas others emanate from practices, e.g. of ritualised character, whose dietary importance has been more marginal. Isotope analyses, when combined with other archaeological indices, have the potential to elucidate both these food cultural aspects.

The late Pleistocene to early Holocene Champlain Sea provides a unique opportunity to study the development of marine ecosystems in a context of global climatic change. This study presents radiocarbon (14C) dates and stable isotope analyses on 15 vertebrate specimens from Champlain Sea sediments, including the Charlotte Whale, which is Vermont’s State marine fossil. Data are used in an attempt to investigate the timing of colonization and ecological dynamics in this newly formed sea. Using the average marine correction,14C dates on four specimens likely calibrate prior to or possibly synchronous with the accepted origination date for the Champlain Sea, implying larger marine reservoir effects than the average marine correction in the vertebrate tissues. Without knowing the specific marine reservoir offsets, it is not possible to calculate the timing of colonization or its relation to concurrent climatic change. Observed lower δ13C and δ15N values in walruses, a fin whale, and a right whale support consumption of prey from lower trophic levels such as bivalve mollusks, krill, and copepods. Higher isotopic values in beluga whales and a bird, the thick-billed murre, support consuming fish, such as cod and capelin. These isotopic data show comparable values and relationships as observed in modern arctic marine ecosystems.

Este trabajo aborda el estudio de la dinámica poblacional y demográfica de la ocupación prehispánica de Gran Canaria. Para ello se ha recurrido al análisis de la distribución del sumatorio de probabilidad de las dataciones radiocarbónicas procedentes, en este caso, de contextos funerarios. Los resultados obtenidos se compararon con dos modelos teóricos nulos de crecimiento poblacional, tratando de explicarlos teniendo en cuenta la información arqueológica disponible, en relación con los cambios diacrónicos registrados en las fórmulas sepulcrales indígenas, así como a partir de las variaciones detectadas en la ocupación del territorio a lo largo de todo el poblamiento insular. Para precisar el marco temporal sujeto a examen, se llevó a cabo un análisis estadístico formal estimativo del intervalo de confianza para establecer la fecha de poblamiento más temprana de Gran Canaria. Se contribuye también de este modo al renovado debate sobre las fechas de los primeros establecimientos permanentes de población en el Archipiélago. Todo ello ha facilitado una propuesta de marco temporal y social desde el que explicar las particularidades de un proceso de poblamiento insular complejo en el que confluyen dinámicas internas y externas This work addresses the study of the population and demographic dynamics of the pre-Hispanic occupation of Gran Canaria. For this purpose, we have resorted to the analysis of the summed probability distributions of radiocarbon dates from different funerary contexts. The results were compared with two theoretical null models of population growth, explaining them based on the available archaeological information, linked to the diachronic changes recorded in the indigenous burials, as well as the variations in the occupation of the territory throughout the historical sequence of the ancient Canarians. To specify the time frame under examination, a formal statistical analysis was carried out to estimate the confidence intervals to place the earliest date of settlement of Gran Canaria. This work also contributes to the renewed debate on the dates of the first permanent settlements in the archipelago. In sum, this has facilitated the proposal of a temporal and social framework to explain the particularities of a complex process of island population in which internal and external dynamics converge.

The Copper Age cemetery in Varna, Bulgaria, is famous for the earliest known, massive deposition of exquisite golden artefacts. Radiocarbon dating of the Varna i cemetery, excavated in the period 1972–91, places it in the mid-fifth millennium bc and suggests a duration of c 225 years from c 4550 to c 4325 cal bc. Construction work in the adjacent area (2.5 km to the east of Varna i cemetery) in December 2017 led to the discovery of sixteen new graves, whose characteristics are identical to the burials in the cemetery investigated in the last century. This article discusses the AMS dates of ten newly discovered inhumations. The results match well the existing cemetery chronology, showing that the new graves start slightly later and end earlier than Varna i and have a shorter duration of probably no more than a few decades. It is demonstrated for the first time that some areas of burial on the terrace were in continuous use for one or two generations only, suggesting multi-focal depositional activities as opposed to expedient and opportunistic spatial utilisation.

The radiocarbon analysis laboratory at Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI) is equipped with an accelerator mass spectrometer (AMS) MICADAS (MIni CArbon Dating System). The laboratory provides routine 14C analyses on bulk organic matter, plant fragments, dissolved and particulate organic matter, individual molecular lipids, and carbonate (micro-) fossils with the aim to foster international research efforts in vulnerable high latitudes. The AWI MICADAS allows AMS 14C analysis on graphite targets as well as on CO2 samples via gas injection into the hybrid ion source. The laboratory thus provides reliable datasets even if only small amounts of sample material are available, a problem often encountered in polar research. Here we describe the standard operation procedures and sample preparation methods employed, and demonstrate the instrument performance and data quality based on repeat analysis of international reference materials.

International audience; Two millets, Panicum miliaceum and Setaria italica, were domesticated in northern China, around 6000 BC. Although its oldest evidence is in Asia, possible independent domestication of these species in the Caucasus has often been proposed. To verify this hypothesis, a multiproxy research program (Orimil) was designed to detect the first evidence of millet in this region. It included a critical review of the occurrence of archaeological millet in the Caucasus, up to Antiquity; isotopic analyses of human and animal bones and charred grains; and radiocarbon dating of millet grains from archaeological contexts dated from the Early Bronze Age (3500-2500 BC) to the 1 st Century BC. The results show that these two cereals were cultivated during the Middle Bronze Age (MBA), around 2000-1800 BC, especially Setaria italica which is the most ancient millet found in Georgia. Isotopic analyses also show a significant enrichment in 13 C in human and animal tissues, indicating an increasing C 4 plants consumption at the same period. More broadly, our results assert that millet was not present in the Caucasus in the Neolithic period. Its arrival in the region, based on existing data in Eurasia, was from the south, without excluding a possible local domestication of Setaria italica. Today, there are many genetic, archaeobotanical or biochemical resources to track the domestication processes and diffusion of plants and animals. Among them, the millets, Panicum miliaceum and Setaria italica, are two species that have their origins in China, but their path to Europe has been the subject of numerous studies for several years. Across Asia, researchers have looked at millets to describe the dispersal of peoples and languages 1 , to address the concept of food globalization 2 , to understand how these cereals have adapted to different environments 3,4 and to investigate the sedentary, semi-nomadic, or nomadic lifestyles of the early agropastoral communities 5,6. This article focuses on the Caucasus, a region that has hitherto not yet been explored

The paper presents the newly established radiocarbon dates of the Late Upper Palaeolithic (LUP) settlement in Gvardjilas Klde in the Imereti region in Georgia. The analysed samples were collected by Stefan Krukowski in 1916 during his fieldwork in the cave. Krukowski identified two separate UP cultural horizons. The older one was connected with what he called layer 10, and the younger one - with layer 11. The obtained radiocarbon dates confirm the results obtained by Krukowski. The older settlement phase can be dated to 19.7–18.8 ky cal. BP, while the younger one to 15.8–14.7 ky cal. BP. The end of human occupation can be linked to the beginning of the Holocene. Interestingly, the presented probability density models show that Gvardjilas Klde was occupied interchangeably with other sites in the region. There is no other site in the Imereti region with chronology similar to any of the settlement phases in Gvardjilas Klde. The only chronologically corresponding sites are Mezmaiskaya Cave and Badynoko Rockshelter in the Northern Caucasus.