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Neanderthals had complex land use patterns, adapting to diversified landscapes and climates. Over the past decade, considerable progress has been made in reconstructing the chronology, land use and subsistence patterns, and occupation types of sites in the Rhône Valley, southeast France. In this study, Neanderthal mobility at the site of Payre is investigated by combining information from lithic procurement analysis (chaîne evolutive and chaîne opératoire concepts) and strontium isotope analysis of teeth (childhood foraging area), from two units (F and G). Both units date to the transition from Marine Isotope Stage (MIS) 8 to MIS 7, and show similar environmental conditions, but represent contrasting occupation durations. Level Gb (unit G) represents a long-term year-round use, in contrast to short-term seasonal use of the cave in level Fb (unit F). For both levels, lithic material and food were generally collected from a local to semi-local region. However, in level Gb, lithic materials were mainly collected from colluviums and food collected in the valley, whereas in level Fb, lithic procurement focused primarily on alluvial deposits and food was collected from higher elevation plateaus. These procurement or exchange patterns might be related to flint availability, knapping advantages of alluvial flint or occupation duration. The site of Payre is located in a flint rich circulation corridor and the movement of groups or exchanges between groups were organized along a north-south axis on the plateaus or towards the east following the river. The ridges were widely used as they are rich in flint, whereas the Rhône Valley is not an important source of lithic raw materials. Compared to other western European Middle Palaeolithic sites, these results indicate that procurement strategies have a moderate link with occupation types and duration, and with lithic technology. The Sr isotope ratios broadly match the proposed foraging areas, with the Rhône Valley being predominantly used in unit G and the ridges and limestone plateaus in unit F. While lithic reconstructions and childhood foraging are not directly related this suggests that the three analysed Neanderthals spend their childhood in the same general area and supports the idea of mobile Neanderthals in the Rhône Valley and neighbouring higher elevation plateaus. The combination of reconstructing lithic raw material sources, provisioning strategies, and strontium isotope analyses provides new details on how Neanderthals at Payre practised land use and mobility in the Early Middle Palaeolithic.

The cranium from Broken Hill (Kabwe) was recovered from cave deposits in 1921, during metal ore mining in what is now Zambia.sup.1. It is one of the best-preserved skulls of a fossil hominin, and was initially designated as the type specimen of Homo rhodesiensis, but recently it has often been included in the taxon Homo heidelbergensis.sup.2-4. However, the original site has since been completely quarried away, and--although the cranium is often estimated to be around 500 thousand years old.sup.5-7--its unsystematic recovery impedes its accurate dating and placement in human evolution. Here we carried out analyses directly on the skull and found a best age estimate of 299 [plus or minus] 25 thousand years (mean [plus or minus] 2[sigma]). The result suggests that later Middle Pleistocene Africa contained multiple contemporaneous hominin lineages (that is, Homo sapiens.sup.8,9, H. heidelbergensis/H. rhodesiensis and Homo naledi.sup.10,11), similar to Eurasia, where Homo neanderthalensis, the Denisovans, Homo floresiensis, Homo luzonensis and perhaps also Homo heidelbergensis and Homo erectus.sup.12 were found contemporaneously. The age estimate also raises further questions about the mode of evolution of H. sapiens in Africa and whether H. heidelbergensis/H. rhodesiensis was a direct ancestor of our species.sup.13,14. Analyses of the hominin skull from Broken Hill, Zambia, place it at an earlier date than previously thought, confirming that later Middle Pleistocene Africa was home to at least three lineages of hominin., Author(s): Rainer Grün [sup.1] [sup.2] , Alistair Pike [sup.3] , Frank McDermott [sup.4] , Stephen Eggins [sup.2] , Graham Mortimer [sup.2] , Maxime Aubert [sup.2] [sup.5] , Lesley Kinsley [sup.2] [...]

Two fossilized human crania (Apidima 1 and Apidima 2) from Apidima Cave, southern Greece, were discovered in the late 1970s but have remained enigmatic owing to their incomplete nature, taphonomic distortion and lack of archaeological context and chronology. Here we virtually reconstruct both crania, provide detailed comparative descriptions and analyses, and date them using U-series radiometric methods. Apidima 2 dates to more than 170 thousand years ago and has a Neanderthal-like morphological pattern. By contrast, Apidima 1 dates to more than 210 thousand years ago and presents a mixture of modern human and primitive features. These results suggest that two late Middle Pleistocene human groups were present at this site--an early Homo sapiens population, followed by a Neanderthal population. Our findings support multiple dispersals of early modern humans out of Africa, and highlight the complex demographic processes that characterized Pleistocene human evolution and modern human presence in southeast Europe. Detailed comparative analyses of two fossil crania from Apidima Cave, Greece, indicate that two late Middle Pleistocene human groups were present at this site; first an early Homo sapiens population followed by a Neanderthal population., Author(s): Katerina Harvati [sup.1] [sup.2] [sup.3] , Carolin Röding [sup.1] , Abel M. Bosman [sup.1] [sup.2] , Fotios A. Karakostis [sup.1] , Rainer Grün [sup.4] , Chris Stringer [sup.5] , [...]

New excavations in Sulawesi, where in situ stone artefacts associated with fossil remains of megafauna have been recovered from stratified deposits between 200,000 and 100,000 years ago, suggest that Sulawesi was host to a long-established population of archaic hominins. Sulawesi is the largest and oldest island within Wallacea, a vast zone of oceanic islands separating continental Asia from the Pleistocene landmass of Australia and Papua (Sahul). By one million years ago an unknown hominin lineage had colonized Flores immediately to the south.sup.1, and by about 50 thousand years ago, modern humans (Homo sapiens) had crossed to Sahul.sup.2,3. On the basis of position, oceanic currents and biogeographical context, Sulawesi probably played a pivotal part in these dispersals.sup.4. Uranium-series dating of speleothem deposits associated with rock art in the limestone karst region of Maros in southwest Sulawesi has revealed that humans were living on the island at least 40 thousand years ago (ref. 5). Here we report new excavations at Talepu in the Walanae Basin northeast of Maros, where in situ stone artefacts associated with fossil remains of megafauna (Bubalus sp., Stegodon and Celebochoerus) have been recovered from stratified deposits that accumulated from before 200 thousand years ago until about 100 thousand years ago. Our findings suggest that Sulawesi, like Flores, was host to a long-established population of archaic hominins, the ancestral origins and taxonomic status of which remain elusive., Author(s): Gerrit D. van den Bergh [sup.1] [sup.2] , Bo Li [sup.1] , Adam Brumm [sup.3] [sup.4] , Rainer Grün [sup.3] , Dida Yurnaldi [sup.1] [sup.5] , Mark W. Moore [...]

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Rock art is found in many different regions of the world, with ages dated from late Palaeolithic period to the present. However, determining the precise ages for such artworks with direct chronological methods is challenging. U-series dating of secondary carbonates can constrain the age of rock art if these carbonates stratigraphically connected to the art. Hitherto, U-series isotope-dilution analyses with multi-collector inductively-coupled plasma mass spectrometry (ID-MC-ICPMS) has been increasingly used for rock art dating. This approach can achieve U–Th isotope-ratio quantification at the per-mille or submille level, but requires chemical pretreatment using isotope spikes and results in a relatively low sampling resolution. While in situ U-series dating using laser ablation-MC-ICPMS (LA-MC-ICPMS) is significantly less precise than ID-MC-ICPMS analysis, it allows to collect spatially resolved data sequences on very thin samples (<1 mm). This is important for identification of open systems and the chronological integrity of the analyses. Therefore, we developed a new method for high spatial resolution U-series in situ analysis. A piece of homogeneous stalagmite was selected as an in-house standard (RM-C1) for U-series in situ dating analysis. RM-C1 contains high U (17.3 ± 1.0 μg/g) and low Th concentrations (<5 ng/g). The 234U/238U and 230Th/238U activity ratios of 1.0116 ± 0.0006 and 0.9525 ± 0.0013, respectively, corresponding to a U-series age of 303.5 ± 1.5 ka, were determined by the ID-MC-ICPMS analyses (n = 10). Using the RM-C1 standard, we were able to date the Dansgaard–Oeschger (D/O) 19 event (with an expected age of 68.9 to 70.3 ka) in a stalagmite to a range from 68.0 ± 2.0 to 71.2 ± 2.5 ka, with an average age of 69.6 ± 1.5 ka (n = 15). This demonstrates the accuracy and reproducibility of our dating protocol. Subsequently, we conducted U-series in situ dating of secondary carbonates associated with rock paintings with two samples from the Cangyuan shelter (CY2-4 and CY2-7) and two samples from the Wanrendong Cave (SL3-A and SL5-A) in Yunnan Province, southwestern China. These samples had high U-concentration (>4 μg/g) and negligible environmental Th. The carbonate layers immediately overlying the pigments of CY2-4 and CY2-7 were dated to 3.7 ± 0.3 and 3.2 ± 0.2 ka, respectively, suggesting that the Canyuan rock paintings belongs to a late Neolithic culture of this area. The pigment layer sandwiched in the sample SL3-A was bracketed to between 8.7 ± 0.3 and 10.1 ± 0.3 ka and in SL5-A to between 10.4 ± 0.3 and 10.8 ± 0.4 ka, implying that the Wanrendong rock paintings probably were created by a hunting-gathering population during the early Holocene. [ABSTRACT FROM AUTHOR]

Strontium isotope ratios (87 Sr / 86 Sr) of biogenic material such as bones and teeth reflect the local sources of strontium ingested as food and drink during their formation. This has led to the use of strontium isotope ratios as a geochemical tracer in a wide range of fields including archaeology, ecology, food studies and forensic sciences. In order to utilise strontium as a geochemical tracer, baseline data of bioavailable 87 Sr / 86 Sr in the region of interest are required, and a growing number of studies have developed reference maps for this purpose in various geographic regions, and over varying scales. This study presents a new data set of bioavailable strontium isotope ratios from rock and soil samples across Israel, as well as from sediment layers from seven key archaeological sites. This data set may be viewed and accessed both in an Open Science Framework repository (10.17605/OSF.IO/XKJ5Y, Moffat et al., 2020) or via the IRHUM (Isotopic Reconstruction of Human Migration) database. [ABSTRACT FROM AUTHOR]

This paper describes a personal journey in ESR dating and gives some insights of the progress made over 35 years in ESR dating of tooth enamel. When I started, samples were irradiated with four additive dose steps of 5, 10, 15 and 20 krad and the linear extrapolation yielded the dose value. An assumed dose rate of 100 mrad/a yielded the age of the sample. Since then I learned that one actually has to measure the dose rate. I also learned that the dose response can be described by a single saturating function, or perhaps two, and that errors can be appropriately calculated. Rather than having a single anisotropic CO 2 − radical, tooth enamel consists of two anisotropic CO 2 − radicals and two isotropic CO 2 − radicals, one stable, one unstable. Also, the dose response shows spatial differences in the production of these different radicals in response to beta and gamma rays. Then there is the problem of uranium uptake over time. We solved this by combining ESR and U-series analyses. We can even measure appropriate beta attenuation factors including sequential laser ablation U-series analyses. Even better, all analyses can be carried out on small enamel fragments, which can be glued back into their original position with little to no visible damage. Still, when using the most sophisticated dose rate calculations, they're often close to 1000 μGy a−1. [ABSTRACT FROM AUTHOR]

Kiacatoo Man, a large, rugged Aboriginal adult buried in the Lachlan riverine plains of southeastern Australia, was discovered in 2011. Laser‐ablation uranium series analysis on bone yielded a minimum age for the burial of 27.4 ± 0.4 ka (2σ). Single‐grain, optically stimulated luminescence ages on quartz sediment in which the grave had been dug gave a weighted mean age of 26.4 ± 1.5 ka (1σ). Luminescence samples from the grave infill and from sediment beneath the grave exhibit overdispersed dose distributions consistent with bioturbation or other disturbance, which has obscured the burial signal. The overlap between the minimum (U‐series) and maximum (luminescence) ages places the burial between 27.0 and 29.4 ka (2σ). Luminescence ages obtained from the channel belt of between 28 ± 2 and 25 ± 3 ka indicate that fluvial sedimentation was occurring before the Last Glacial Maximum, which is consistent with the broader geomorphic setting. Together, these results are internally and regionally consistent, and indicate that Kiacatoo Man was one of the more ancient individuals so far identified in Australia. His remains are important to our understanding of patterns of biological variation and other processes that have shaped people in the Murray‐Darling Basin through time. Copyright © 2019 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This review is a follow up to Grün et al. (2006): Direct Dating of Human Fossils. Since that time there has been progress on the experimental side of the geochronological analyses, which are detailed for uranium-series isotope and ESR dating. Also, many new human fossils, including several new species (e.g., H. naledi, H. luzonensis, and H. longi) have been discovered, named and dated. Direct dating of human fossils has contributed to some major revisions in our understanding of human evolution. For example, the enigmatic Homo floresiensis has been dated to >60 ka instead of ∼18 ka as was originally published. This put an end to the heated debate about how H. floresiensis could have survived the arrival of H. sapiens on Flores for several tens of thousands of years. From Africa, results are presented for Swartkrans, Thomas Quarry, Broken Hill (Kabwe), the Rising Star sites Djebel Irhoud, Florisbad and Omo Kibish. In western Asia, human fossils from Mislya, Tabun, Qafzeh and Al Wusta were analysed and in Europe from Payre, Moula Guercy, Lezetxiki, Apidima, El Sidron and Atapuerca (Sima de los Huesos and Gran Dolina). From Asia and Oceania we discuss the results from Denisova, Penghu, Harbin, Liujiang, Liang Bua, Mata Menge, Callao, Ngandong, Sambungmacan, Wajak, Niah and Tabon, while from Australia WLH50 is added to WLH3. We describe the dating procedures for each site. All published data were re-evaluated. The systematic analysis of the U-series isotopic data led to new insights, particularly with respect to detailed U-diffusion processes (provenance of the uranium, leaching, secondary overprints etc.), which altered the interpretation of the ages for some of the sites. For example, we can show that the minimum age of H. luzonensis is 134 ± 14 ka, covering the transition of MIS6 to MIS 5 (younger dates were the result of secondary U-overprints), and that Apidima 1 and 2 have significantly different isotopic characteristics, refuting claims of initial contemporaneous burials. We discuss the implications of the results for our present understanding of human evolution. • Critical assessment of U-series and ESR dating. • Dating the earliest occurrences of Homo sapiens in Africa, the Levant and Europe. • The ages of new human species found since 2000: H. floresiensis, H. luzonensis, H. nadeli, H. longi. • Updated summary of our present understanding of human evolution. [ABSTRACT FROM AUTHOR]

It has been estimated that up to 25% of Indigenous human remains held in Australian institutions are unprovenanced. Geochemical tracers like strontium isotope ratios (87Sr/86Sr) have been used globally for over 40 years to discern human provenance and provide independent data to aid in repatriation efforts. To reliably apply this technology, landscape 87Sr/86Sr isotope ratio variability must be quantified. In Australia, only a few studies have used this technique and they are lacking in detail. Here, we present Australia's first regional strontium isotope ratio variability study. We measured strontium isotope ratios in soil, plant, water, and faunal material throughout Cape York, Queensland, the most northerly point of mainland Australia. Results show a close correlation between surface soil leachates, vegetation, surface water, and faunal 87Sr/86Sr results with extremely high values (0.78664) associated with ancient Precambrian geology. Our study suggests that measuring 87Sr/86Sr in soil and plant samples offer a reliable approach for assessing regional Sr isotope distribution, although the inclusion of mammal and freshwater samples is also important to assess exogenous inputs. This study provides an important tool for modern and prehistoric provenance studies and may aid in answering some of Australia's most enduring archaeological questions. [ABSTRACT FROM AUTHOR]

Abstract Many samples used for luminescence and ESR dating show complex mineralogical structures, resulting in heterogeneous beta dose rates. Ideally, the beta dose rate distribution could be reconstructed using softwares like DosiVox, which can both upload 3D-scans recorded with X-ray tomography and distributions of radioactive elements. However, some minerals often exhibit only small X-ray contrasts making them difficult to distinguish in 3D-scans. For example, quartz and plagioclase have closely similar X-ray characteristics, which limit the applicability of this approach. Here, we introduced a Monte Carlo simulation of beta particles in two dimensions, in order to calculate the dose rate from 2D images. The simulation results are compared between 2D modelling, 3D modelling and standard calculation. The implications for beta dose rate heterogeneity in grains are discussed. Using the "DosiVox-2D" software, we show that 2D scans may characterize complex heterogeneous 3D beta dose rate distributions. This approach could lead to a better understanding of micro-dosimetric phenomena and the improvements in the accuracy of dose rate calculation for heterogeneous samples. Highlights • We set up a new method of beta dose rate modelling for trapped charge dating. • A 2D representation of the sample is created from mineral mapping. • Beta dose rate is simulated in 2D and calculated for the different minerals. • 2D-modelling provides equivalent results to those of 3D-modellings. • 2D-modelling is easier to set up than 3D-modellings although less accurate. [ABSTRACT FROM AUTHOR]

Abstract Accurate evaluations of beta dose rates are crucial in luminescence and electron spin resonance (ESR) thermochronology. Most igneous rocks are heterogeneous and have complex mineralogical structures that render them unsuitable for the conventional methods of beta dose rate calculations based on infinite matrix assumptions. The recently developed software DosiVox-2D provides a Monte-Carlo approach for calculating beta dose rates in realistic heterogeneous geometries. In this paper, we present 2D simulations of uniform and layered igneous rocks. For the modelling, mineral distribution maps were obtained by QEM-EDS (quantitative evaluation of minerals using energy dispersive spectroscopy) and radionuclide concentrations in minerals were determined by laser ablation (LA) ICP-MS. The results show that the skewness of beta dose rate distributions in quartz reduces as the K concentration in a rock increases, and the estimation of the beta dose rate can be critically influenced by the U and Th concentrations and distributions. Highlights • QEMSCAN® provides realistic 2D mineral mapping for heterogeneous rocks. • A single set of radionuclide concentrations cannot be representative for some U and Th enriched minerals. • Selections of representative slices, mapping resolution and size are essential to obtain reliable beta dose rate. • Beta dose rate calculation can be critically influenced by the U and Th concentrations and distributions. • DosiVox-2D enables to estimate beta dose rate in single-grain level. [ABSTRACT FROM AUTHOR]

A limestone cave on the lower slopes of the southeastern Australian high country reveals a deep, stratified deposit dated from ca. 14,000 to 2000 cal. BP and rich in predominantly non-cultural faunal remains. Located in a sensitive ecological area between the Australian Alps and the Southern Tablelands, the site provides a valuable chronological archive for the interpretation of local environmental change using the faunal record as a proxy, in particular native rodents and other small mammals. Inferred palaeoenvironmental trends include the cessation of periglacial conditions in the surrounding ranges during the Terminal Pleistocene; a shift to warmer conditions and the establishment of forest and wetland habitats from around 13,500 to 10,000 cal. BP, with a significant decline in cold-adapted species at ca. 11,500 cal. BP and a period of significant taxon fluctuation and extinctions corresponding to a possible peak in warm and moist conditions (a 'Holocene Optimum'), beginning around 8000 cal. BP and lasting perhaps 1500 to 2000 years. Complications to the relatively steady and continuous chronostratigraphy, formed from an AMS radiocarbon sequence from sedimentary charcoal, arose from the presence of several teeth of extinct sthenurine megafauna. These were resolved with direct U-series analysis to establish their much greater antiquity and comparison of the sthenurine teeth with teeth of extant macropodids from the same deposit through fluoride absorption analysis, which also identified the megafauna teeth as anomalous to the sequence. The site provides an important case study for the interpretation of megafauna remains in stratified sedimentary deposits, especially for sites that appear to contain evidence for the co-occurrence of megafauna and humans in primary contexts. [ABSTRACT FROM AUTHOR]

The present study reports the results of the first direct Electron Spin Resonance (ESR) dating study of Homo antecessor , the oldest known hominin species identified in Western Europe. The analysis of a tooth (ATD6-92) from TD6 unit of Atapuerca Gran Dolina (Spain) following a “semi non-destructive” procedure provides a final age estimate ranging from 624 to 949 ka, which covers all possible uranium uptake scenarios. Last, the additional magnetostratigraphic data collected within TD6 enables to further constrain the initial ESR chronology and to propose an age of between 772 and 949 ka for Homo antecessor , in agreement with previous dating works. Although our new results do not refine the existing chronology of TD6 unit, they nevertheless support the antiquity of H. antecessor , which pre-dates the estimated divergence age of modern and archaic human lineages based on genetic evidence. This work illustrates the challenges of dating human teeth by means of the ESR method, with the main pitfalls that are sometimes inherent to this specific application (e.g., systematic μCT-scanning of fossil hominin teeth; limited knowledge about the original sedimentary environment for teeth coming from old excavations; heterogeneous spatial distribution of the U-series elements in dental tissues). We identified several sources of uncertainty that may directly impact the accuracy of the age result. In particular, a slight contamination of dentine (<6%) in the enamel fragment measured by ESR was found to induce a significant age underestimation (33%) if not taken into consideration. It indeed caused not only a D E underestimation (by about 8%), but also produced a massive internal dose rate overestimation (by a factor of about 3.5). In contrast, other sources of uncertainty, such as the heterogeneity of the sedimentary environment, the variability of the water content over time, the previous μCT-scanning of the tooth or the potential preferential creation of unstable NOCORs in the ESR signal, showed here a limited impact on the final age result. Given our current understanding of the ESR method and the existing uncertainties associated with the evaluation of the D E and dose rate, this is probably as far as we can presently go in the dating study of ATD6-92 sample. [ABSTRACT FROM AUTHOR]

We present here the results of a technological and typological analysis of the Acheulian and early Middle Paleolithic assemblages from Torre in Pietra (Latium, Italy) together with comparisons with the Acheulian small tools of Castel di Guido. The assemblages were never chronometrically dated before. We have now 40Ar/39Ar dates and ESR-U-series dates, within a geomorphological framework, which support correlations to marine isotope stages. The Acheulian (previously correlated to MIS 9) is now dated to MIS 10 while the Middle Paleolithic is dated to MIS 7. Lithic analyses are preceded by taphonomic evaluations. The Levallois method of the Middle Paleolithic assemblage is an innovation characterized by the production of thin flake blanks without cortex. In contrast, the small tool blanks of the Acheulian were either pebbles or thick flakes with some cortex. They provided a relatively easy manual prehension. The choice of Levallois thin flake blanks in the Middle Paleolithic assemblage suggest that the new technology is most likely related to the emergence of hafting. Accordingly, the oldest direct evidence of hafting technology is from the site of Campitello Quarry in Tuscany (Central Italy) where birch-bark tar, found on the proximal part of two flint flakes, is dated to the end of MIS 7. Nevertheless, a peculiar feature of the Middle Paleolithic at Torre in Pietra is the continuous presence of small tool blanks on pebbles and cores and on thick flake albeit at a much lower frequency than in the older Acheulian industries. The adoption of the new technology is thus characterized by innovation combined with a degree of stability. The persistence of these habits in spite of the introduction of an innovative technique underlies the importance of cultural transmission and conformity in the behavior of Neandertals. [ABSTRACT FROM AUTHOR]

We performed dose recovery tests on proto-historic enamel samples that were dosed to approximately 200 Gy to present equivalents of Middle to Late Pleistocene fossil teeth. The experimental results confirmed that the ESR dose response of fossil tooth enamel can be best described by a double saturating exponential (DSE) function. When using a DSE for dose evaluation, it is necessary to irradiate samples to very high doses (at least 20 kGy, ideally up to 50 kGy) and use at least 15 additive dose steps. In past studies, dose estimations were mostly carried out using a single saturating exponential (SSE) function and maximum doses (D max ) in the range of around five to ten times the equivalent dose, usually less than 5 kGy. To address the question whether older dose estimations have to be disregarded as unreliable, we carried out computer simulations using DSE dose response curves which were then fitted with SSEs. Artificial data sets were generated for a wide range of preset dose values between 10 and 5000 Gy. The results indicate a strong correlation between the magnitude of the D E value with systematic and random errors. Reliable doses can be obtained with SSEs for preset dose values of <1000 Gy using 10 exponentially distributed dose points with maximum dose values in the range of up to ten times the D E value. Higher preset doses (>1 kGy) require modified D max values. Although here the application of DSEs is preferable, the use of SSEs can nevertheless provide reliable results with reasonably small systematic errors for doses of up to 2000 Gy, provided D max is adjusted to about 1*D set and measurement precision is better than 0.3%. The overall uncertainty remains acceptable (∼10%) using DSEs for D E values of up to 5000 Gy, provided the measurement precision is better than 0.5% and up to 20 dose steps are used. 5000 Gy is apparently the maximum dose than can be reliably assessed with ESR. Finally, we provide some detailed recommendations to ensure reliable dose evaluations with either the SSE or DSE functions. These recommendations can also be used to evaluate the reliability of previously published ESR dose assessments. [ABSTRACT FROM AUTHOR]

Over the past two decades, the combined electron spin resonance (ESR) and U-series dating method has been widely applied to date fossil teeth for archaeological studies through the use of the US-ESR model. The obtained age, compatible with both the ESR and U-series data determined in all dental tissues and the burial environment, is more flexible and reliable than the parametric uptake ages (by early, linear or recent uptake models), for which selection was often based on the expected age of the site. In this paper, the mathematical basis of the US-ESR model is described in detail, from the U-uptake description to the calculation of accumulation dose in the sample and the US-ESR age determination. An example is used to illustrate the calculation of the US-ESR age, associated dose rates and U-uptake parameters. While the description in this paper is specific to US-ESR model and more largely combined ESR/U-series dating of fossil teeth, we expect that some of the principles can be used in other applications of U-series dating. [ABSTRACT FROM AUTHOR]

The Aghnadarragh site presents the most complete known Midlandian (last cold stage) sequence in Ireland. Above a glacial till and below organic deposits of the Aghnadarragh Interstadial, a unit of poorly sorted gravel and diamicton yielded numerous fossils of woolly mammoth and rarer musk ox, the first record of that species in Ireland. The mammoth molars are of relatively small size and distinctive morphology that probably relate to local environmental conditions. Dating of three mammoth molars by Electron-Spin-Resonance indicates an age for the faunal horizon in the range 109 to 74 ka, corresponding to the later part of MIS 5, presumably MIS 5d or 5b in view of the cold-adapted flora and fauna, or possibly early MIS 4. This in turn suggests that the underlying glacigenic deposits, assigned to the Fermanagh Stadial, formed during a cold stage preceding the last interglacial, rather than being early Midlandian in age as generally assumed. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Over the past decade, we have applied laser ablation ICP mass spectrometry U-series analysis to a large number of bones and teeth. The method is fast and provides high-resolution data of U-series isotopes, which give insights into the complexity of uranium migration into, within and out of bones. In this paper, we present our laser ablation approach in detail, from the experimental set up, to data reduction and uranium diffusion modelling. Laser ablation analysis can now be applied with minimum damage. Complete diffusion data sets can be obtained by laser drilling which leaves a hole of around 200 μm in diameter and 1–2 mm depth. If the natural U-diffusion follows a simple single-stage process, valuable age information can be obtained. In other cases, highly complex U-migrations have been observed, which make any age assessment impossible. Two examples from Wadjak and Callao illustrate the potential of nearly non-destructive laser ablation U-series analysis of human skeletal tissues. The results demonstrate the physical presence of modern humans in south-east Asia at a time when our species just started to migrate into Europe. [ABSTRACT FROM AUTHOR]

Despite numerous sites of great antiquity having been excavated since the end of the 19th century, Middle Pleistocene human fossils are still extremely rare in northwestern Europe. Apart from the two partial crania from Biache-Saint-Vaast in northern France, all known human fossils from this period have been found from ten sites in either Germany or England. Here we report the discovery of three long bones from the same left upper limb discovered at the open-air site of Tourville-la-Rivière in the Seine Valley of northern France. New U-series and combined US-ESR dating on animal teeth produced an age range for the site of 183 to 236 ka. In combination with paleoecological indicators, they indicate an age toward the end of MIS 7. The human remains from Tourville-la-Rivière are attributable to the Neandertal lineage based on morphological and metric analyses. An abnormal crest on the left humerus represents a deltoid muscle enthesis. Micro- and or macro-traumas connected to repetitive movements similar to those documented for professional throwing athletes could be origin of abnormality. [ABSTRACT FROM AUTHOR]

Abstract: Given the interest in dating sediments from numerous caves, lakes and fluvial terraces containing fossils and lithic components in Europe, here we provide a complete revision of the amino acid racemization (AAR) (aspartic acid in dentine) dating method in vertebrates. To examine the reliability of this method, which is based on a straightforward sample preparation (previous 3.5 kDa dialysis), we used a range of dental material. We examined human dentine collagen from living donors and remains from historical (16th and 19th centuries) and prehistorical (Neolithic) periods. On the assumption that genus does not affect collagen racemization rates, we also studied Neanderthal material and material from carnivores (cave bear) and several other mammals. To validate our age calculation algorithm, we used a wide series of radiometric datings (ESR and 14C), along with thermoluminescence and AAR dating on invertebrate (ostracode) samples. Our results demonstrate that AAR shows satisfactory correlation between age and the extent of aspartic acid racemization for material from modern humans and for ancient (Pleistocene) mammal remains (cave bears, horses and Neanderthals) and highlight a strong correlation between ages derived from dentine collagen aspartic acid and other dating methods. However, in samples from burial sites (19th and 16th century and Neolithic samples from Syria), it was impossible to establish age at death. We assume that taphonomic processes (time and geochemistry) greatly contribute to the denaturation of the collagen triple helix and higher order structures, thereby allowing the racemization of peptide-bound aspartic acid. [Copyright &y& Elsevier]

Abstract: The relative ionisation efficiencies of alanine dosimeters and tooth enamel differ greatly between gamma and X-ray irradiations. This can be attributed to the differences in the energy transfer mechanisms. When using Co or Cs sources, the photon energy is transferred to matter via Compton scattering, which shows little dependence on the average Z-value of the absorber. In contrast, the photon energies emitted from X-ray sources are usually much lower and energy is, at least in part, transferred to matter via the photo-electric effect, which has a cubic relationship between energy transfer and average Z-value of the absorber. The decomposition of the ESR spectra of an enamel fragment shows that the X-ray generated distribution of anisotropic radicals is virtually the same as in the natural sample, but quite different to gamma irradiated samples. This implies that X-rays are generally much better suited for ESR dating irradiation procedures than gamma rays. However, exact source calibration will be difficult. [Copyright &y& Elsevier]

Abstract: The combined U-series/electron spin resonance (ESR) dating method was applied to nine teeth from two Early Pleistocene archaeological sites located in the Orce area (Guadix-Baza Basin, Southern Spain): Fuente Nueva-3 (FN-3) and Barranco León (BL). The combination of biostratigraphy and magnetostratigraphy places both sites between the Olduvai and Jaramillo subchrons (1.78–1.07Ma). Our results highlight the difficulty of dating such old sites and point out the limits of the combined U-series/ESR dating method based on the US model. We identified several sources of uncertainties that may lead to inaccurate age estimates. Seven samples could not be dated because the dental tissues had (230Th/234U) activity ratios higher than equilibrium, indicating that uranium had probably leached from these tissues. It was however possible to calculate numerical estimates for two of the teeth, both from FN-3. One yielded a Middle Pleistocene age that seems to be strongly underestimated; the other provided an age of 1.19±0.21Ma, in agreement with data obtained from independent methods. The latter result gives encouragement that there are samples that can be used for routine dating of old sites. [Copyright &y& Elsevier]

Abstract: ESR dating of fluvial terraces is usually based on the assumption of sunlight resetting of the Al centres in quartz. Very long bleaching times (months of sunlight exposure) are required to reset this centre to a stable, non-zero ESR intensity. Considering that highly light sensitive optically stimulated luminescence (OSL) analyses of fluvial samples often indicate partial bleaching, ESR dating should be extremely difficult. Two samples were analysed, a fluvial sediment from a Chinese river terrace and an Australian granite. Using a Höhnle sunlight simulator, the Ti centres of both samples were completely bleached within 1 to 65 h, while the Al centre required extreme bleaching times to reach stable residual intensities (∼1000 h). As an alternative to light resetting, tumbler experiments were carried out to simulate fluvial action. The samples were treated under OSL sample preparation conditions. After relatively short tumbling times, corresponding to a few km of fluvial transport, both Al- and Ti-centres were partially reset. In a granite sample, the tumbling reduced the intensity of the Al centre more effectively than light exposure. [Copyright &y& Elsevier]

Abstract: We have produced detailed maps of U and Th isotopes for three cross-sections of an Early Pleistocene equid tooth from the archaeological site of Fuente Nueva-3 (Orce, Andalusia, Spain). This permits us to visualise, for the first time, U migration processes in 3 dimensions. The tooth shows a concentration gradient from the top to the base, indicating the U profile had not equilibrated after >1 Ma. The spatial pattern of 230Th/234U and 234U/238U indicates complex U-mobilisation processes over the last 100 ka, dominated by small-scale redistribution of U. Leaching from the tooth through the pulp cavity started at least 93 ka ago with several later phases in various domains of the dentine and cement. This leaching event could have been triggered by changes in the local hydrological regime associated with periods of increased erosion in the Guadix-Baza basin. The results illustrate the difficulty of dating faunal material from Early Pleistocene sites. They also demonstrate that dental tissues can neither be considered as homogeneous media for U-diffusion, nor behave as closed systems for U-series isotopes because diagenetic alterations seem to trigger U-migration. The results do not support the notion that U-uptake into dental tissues is necessarily of short duration. Nevertheless, rapid laser ablation scanning can be used to identify suitable samples for dating as well as domains within the teeth that may have preserved original isotopic signatures, i.e. domains that have not been affected by recent U-mobilisation process. [Copyright &y& Elsevier]

Background: In recent years the Later Stone Age has been redated to a much deeper time depth than previously thought. At the same time, human remains from this time period are scarce in Africa, and even rarer in West Africa. The Iwo Eleru burial is one of the few human skeletal remains associated with Later Stone Age artifacts in that region with a proposed Pleistocene date. We undertook a morphometric reanalysis of this cranium in order to better assess its affinities. We also conducted Uranium-series dating to re-evaluate its chronology. Methodology/Principal Findings: A 3-D geometric morphometric analysis of cranial landmarks and semilandmarks was conducted using a large comparative fossil and modern human sample. The measurements were collected in the form of three dimensional coordinates and processed using Generalized Procrustes Analysis. Principal components, canonical variates, Mahalanobis D2 and Procrustes distance analyses were performed. The results were further visualized by comparing specimen and mean configurations. Results point to a morphological similarity with late archaic African specimens dating to the Late Pleistocene. A long bone cortical fragment was made available for U-series analysis in order to re-date the specimen. The results (∼11.7-16.3 ka) support a terminal Pleistocene chronology for the Iwo Eleru burial as was also suggested by the original radiocarbon dating results and by stratigraphic evidence. Conclusions/Significance: Our findings are in accordance with suggestions of deep population substructure in Africa and a complex evolutionary process for the origin of modern humans. They further highlight the dearth of hominin finds from West Africa, and underscore our real lack of knowledge of human evolution in that region. [ABSTRACT FROM AUTHOR]

Homo erectus was the first human lineage to disperse widely throughout the Old World, the only hominin in Asia through much of the Pleistocene, and was likely ancestral to H. sapiens. The demise of this taxon remains obscure because of uncertainties regarding the geological age of its youngest populations. In 1996, some of us co-published electron spin resonance (ESR) and uranium series (U-series) results indicating an age as young as 35-50 ka for the late H. erectus sites of Ngandong and Sambungmacan and the faunal site of Jigar (Indonesia). If correct, these ages favor an African origin for recent humans who would overlap with H. erectus in time and space. Here, we report 40Ar/39Ar incremental heating analyses and new ESR/U-series age estimates from the "20 m terrace" at Ngandong and Jigar. Both data sets are internally consistent and provide no evidence for reworking, yet they are inconsistent with one another. The 40Ar/39Ar analyses give an average age of 546612 ka (sd65 se) for both sites, the first reliable radiometric indications of a middle Pleistocene component for the terrace. Given the technical accuracy and consistency of the analyses, the argon ages represent either the actual age or the maximum age for the terrace and are significantly older than previous estimates. Most of the ESR/U-series results are older as well, but the oldest that meets all modeling criteria is 143 ka+20/217. Most samples indicated leaching of uranium and likely represent either the actual or the minimum age of the terrace. Given known sources of error, the U-series results could be consistent with a middle Pleistocene age. However, the ESR and 40Ar/39Ar ages preclude one another. Regardless, the age of the sites and hominins is at least bracketed between these estimates and is older than currently accepted. [ABSTRACT FROM AUTHOR]

Abstract: We present a detailed description of the geological setting of the burial site of the WLH 50 human remains along with attempts to constrain the age of this important human fossil. Freshwater shells collected at the surface of Unit 3, which is most closely associated with the human remains, and a carbonate sample that encrusted the human bone were analysed. Gamma spectrometry was carried out on the WLH 50 calvaria and TIMS U-series analysis on a small post-cranial bone fragment. OSL dating was applied to a sample from Unit 3 at a level from which the WLH 50 remains may have eroded, as well as from the underlying sediments. Considering the geochemistry of the samples analysed, as well as the possibility of reworking or burial from younger layers, the age of the WLH 50 remains lies between 12.2 ± 1.8 and 32.8 ± 4.6 ka (2-σ errors). [Copyright &y& Elsevier]

Abstract: Two fossil tooth enamel fragments were irradiated with beta rays, one through the outer surface, the other through the dentine–enamel junction. The angular ESR spectra of the two fragments were decomposed using an automated simulated annealing (SA) procedure, which is particularly well suited to separate overlapping signals. Beta irradiation generated different qualitative and quantitative responses to previous gamma irradiation experiments. Similar to gamma rays, the beta irradiation created both non-oriented and oriented radicals. In contrast to gamma irradiation, which only created orthorhombic oriented radicals, both axial and orthorhombic radicals were extracted after beta irradiation. Furthermore, gamma irradiation created significantly more non-oriented radicals than beta irradiation. Altogether, the radical distribution created by beta irradiation resembled that of the natural sample, which had been exposed to environmental irradiation over several hundreds of thousands of years. The natural sample contained 9% non-orientated radicals and a mix of orthorhombic to axial radicals in the ratio of 35:65. The beta induced spectra of the fragment irradiated through the outer surface contained 9% non-orientated radicals and a mix of orthorhombic to axial radicals in the ratio of 45:55, while for the other sample these values were 19% and 59:41, respectively. The angle between the axial and orthorhombic radicals is around 23° in both natural and beta irradiation components. This indicates that the radicals produced by the different irradiation modes are located in the same positions in the hydroxyapatite crystals. The higher percentage of non-oriented radicals closer to the dentine–enamel junction points to interprismatic zones for their possible location. [ABSTRACT FROM AUTHOR]

Abstract: In the past two years, we have carried out a series of irradiation experiments on fossil tooth enamel fragments, using gamma irradiation for the whole enamel thickness, UV irradiation through the buccal–enamel boundary (BEB) and beta irradiation through the BEB as well as the dentine–enamel junction (DEJ). Using a simulated annealing procedure, the ESR spectra were analysed for three types of CO2 − radicals, consisting of two types of anisotropic CO2 − radicals (AICORs, orthorhombic and axial) plus non-oriented CO2 − radicals (NOCORs). In this paper we complemented the beta irradiation experiments with gamma irradiations on fragments representing the domains close to the BEB as well as the DEJ. The two beta irradiation experiments generated qualitatively similar radical distributions to the natural sample. The effects of gamma irradiation were significantly different. The ESR spectra of both fragments contained only orthorhombic AICORs (non-axial CO2 − radicals) plus a very large amount of NOCORs. Relative to the natural fragments, the domain close to the BEB had eight times more NOCORs and the domain close to the DEJ twenty-nine times more. Heating experiments (at 125°C) showed that NOCORs do not transfer into AICORs but lead to a general decrease of the overall intensity. Orthorhombic CO2 − radicals convert into axial. The strong difference between the beta and gamma irradiations leads to the postulation of two different types of NOCORs, one unstable and decaying without transfer into stable AICORs and a second stable variety converting into AICORs. It seems that beta irradiation resembles gamma irradiation with concurrent heating. A preliminary experiment confirmed elevated temperatures during beta irradiation. The appearance of unstable NOCORs, which are not removed by conventional post-irradiation heating steps or long storage times between irradiation and measurement, has serious consequences for ESR dating. It points to significant age underestimations. For the fragments we have investigated thus far, the underestimation is in the range of 30%. However, at this stage it is not possible to provide a correction that can be easily applied to published results, as there are indications that the offset could depend on age, tooth type (molars versus incisors) as well as species (bovid, horse, hippopotamus, humans, etc.). The implications for ESR dating in general, for published ESR results as well as possible remedies are discussed in detail. [Copyright &y& Elsevier]