ESR-dating of a flowstone core from cova de sa Bassa Blanca

[eng] A flowstone core from the Cova de Sa Basa Blanca (SBB), Mallorca, was dated by means of ESR. This systematic investigation shows that the precipitation of this flowstone took place in several time-periods. It began at about 700,000 a and finished at the end of the penultimate interglaciation at about 200,000 a.[spa] Una muestra de material estalagmítico parietal procedente de la Cova de Sa Bassa Blanca (testigo n.º21/campaña de muestreo de marzo-81) ha sido datada mediante la técnica de Resonancia de Spin Electrónico (E.S.R.). Las investigaciones realizadas sistemáticamente sobre dicha muestra han puesto de manifiesto que la precipitación de esta secuencia de espeleotemas tuvo lugar en varios períodos de tiempo; habiendo comenzado en torno a los 700.000 años y acabando hacia el final del penúltimo inter- glacial, hace alrededor de 200.000 años

Jeux différentiels stochastiques à information incomplète

L'objectif de cette thèse est l'étude des jeux différentiels stochastiques à information incomplète. Nous considérons un jeu à deux joueurs adverses qui contrôlent une diffusion afin de minimiser, respectivement de maximiser un paiement spécifique. Pour modéliser l'incomplétude des informations, nous suivrons la célèbre approche d'Aumann et Maschler. Nous supposons qu'il existe des états de la nature différents dans laquelle le jeu peut avoir lieu. Avant que le jeu commence, l'état est choisi au hasard. L'information est ensuite transmise à un joueur alors que le second ne connaît que les probabilités respectives pour chaque état.Dans cette thèse nous établissons une représentationduale pour les jeux différentiels stochastiques à information incomplète. Ici, nous utilisons largement la théorie des équations différentielles stochastiques rétrogrades (EDSRs), qui se révèle être un outilindispensable dans cette étude. En outre, nous montrons comment, sous certaines restrictions, cette représentation permetde construire des stratégies optimales pour le joueur informé. Ensuite, nous donnons, en utilisant la représentation duale, une preuve particulièrement simple de la semiconvexité de la fonction valeur des jeux différentiels à information incomplète.Un autre partie de la thèse est consacré à des schémas numériques pour les jeux différentiels stochastiques à informationincomplète. Dans la dernière partie nous étudions des jeux d'arrêt optimal en temps continue, appelés jeux de Dynkin, à information incomplète. Nous établissons également une représentation duale, qui est utilisé pour déterminer des stratégies optimales pour le joueur informé dans ce cas.The objective of this thesis is the study of stochastic differential games with incomplete information. We consider a game with two opponent players who control a diffusion in order to minimize, respectively maximize a certain payoff. To model the information incompleteness we will follow the famous ansatz of Aumann and Maschler. We assume that there are different states of nature in which the game can take place. Before the game starts the state is chosen randomly. The information is then transmitted to one player while the second one only knows the respective probabilities for each state. In this thesis we establish a dual representation for stochastic differential games with incomplete information. Therein we make a vast use of the theory of backward stochastic differential equations (BSDEs), which turns out to be an indispensable tool in this study. Moreover we show how under some restrictions that this representation allows to construct optimal strategies for the informed player.Morover we give - using the dual representation - a strikingly simple proof for semiconvexity of the value function of differential games with incomplete information. Another part of this thesis is devoted to numerical schemes for stochastic differential games with incomplete information. In the last part we investigate continuous time optimal stopping games, so called Dynkin games, with information incompleteness. We show that these games have a value and a unique characterization by a fully non-linear variational PDE for which we provide a comparison principle. Also we establish a dual representation for Dynkin games with incomplete information.BREST-SCD-Bib. electronique (290199901) / SudocSudocFranceF

Th-230 / U-234- sowie ERS-Altersbestimmungen einiger Travertine in Ungarn

Dreizehn Travertinproben von den Lokalitäten Tata, Vértesszöllös, Dunaalmás und Buda werden mit Hilfe zweier neuerer Absolutdatierungsverfahren untersucht, der Th-230/U-234- und der ESR-Methode. Für acht der untersuchten Proben ergibt sich eine gute Übereinstimmung zwischen den Th/U- und den ESR-Altern, zwei Proben waren aufgrund extrem hoher Mangan-Gehalte nicht ESR-datierbar und in drei Fällen ergaben sich deutliche Diskrepanzen. Travertine aus dem Riß/Würm Interglazial haben ein Alter von ca. 100.000 a, die des vorletzten Interglazial zeigen ein Alter von 200.000 a und etwas darüber die des drittletzten Interglazials weisen ein Alter von über 300.000 a auf.researc

Sampling Plants and Malacofauna in 87Sr/86Sr Bioavailability Studies : implications for isoscape mapping and reconstructing of past mobility patterns

Acknowledgments: We thank Annabell Reiner and Sven Steinbrenner (MPI-EVA) for technical and practical support with preparation and analysis of samples. We thank the La Ferrassie Team for support during field sampling and project development, especially Harold Dibble, Shannon McPherron (MPI-EVA), Teresa Steele (UC Davies), Vera Aldeias (MPI-EVA, University of Algarve), Paul Goldberg (University of Wollongong, University Tübingen), Dennis Sandgathe (Simon Fraser University, University of Pennsylvania), Alain Turq (Musée national de Préhistoire, CNRS), and Jean-Jacques Hublin (MPI-EVA), as well as Mike Richards (SFU). Special thanks to Daphne Katranides and Aaron Katranides. We also thank the editor (TP) and two reviewers whose constructive comments greatly improved this manuscript. Funding: This research was funded by the Max Planck Society and a Leverhulme Trust grant to KB (RPG-2017-410), with additional support from Australian Research Council Discovery grants DP0664144 and DP110101417 to RG. KJ thanks the ERC ARCHEIS 803676, and IM thanks Australian Research Council Discovery Early Career Award (DE160100703), for salary support during production of this manuscript.Peer reviewedPublisher PD

The first archaic Homo from Taiwan

Recent studies of an increasing number of hominin fossils highlight regional and chronological diversities of archaic Homo in the Pleistocene of eastern Asia. However, such a realization is still based on limited geographical occurrences mainly from Indonesia, China and Russian Altai. Here we describe a newly discovered archaic Homo mandible from Taiwan (Penghu 1), which further increases the diversity of Pleistocene Asian hominins. Penghu 1 revealed an unexpectedly late survival (younger than 450 but most likely 190-10 thousand years ago) of robust, apparently primitive dentognathic morphology in the periphery of the continent, which is unknown among the penecontemporaneous fossil records from other regions of Asia except for the mid-Middle Pleistocene Homo from Hexian, Eastern China. Such patterns of geographic trait distribution cannot be simply explained by clinal geographic variation of Homo erectus between northern China and Java, and suggests survival of multiple evolutionary lineages among archaic hominins before the arrival of modern humans in the region.This study was supported by grants from the Ministry of Science and Technology, Taiwan (102-2116-M-178-004-) to C.-H.C., the Japan Society for the Promotion of Science (No. 24247044) to Y.K., and Australian Research Council (DP110101415) to R.G

Mapping of bioavailable strontium isotope ratios in France for archaeological provenance studies

Strontium isotope ratios (⁸⁷Sr/⁸⁶Sr) of archaeological samples (teeth and bones) can be used to track mobility and migration across geologically distinct landscapes. However, traditional interpolation algorithms and classification approaches used to generate Sr isoscapes are often limited in predicting multiscale ⁸⁷Sr/⁸⁶Sr patterning. Here we investigate the suitability of plant samples and soil leachates from the IRHUM database (www.irhumdatabase.com) to create a bioavailable ⁸⁷Sr/⁸⁶Sr map using a novel geostatistical framework. First, we generated an ⁸⁷Sr/⁸⁶Sr map by classifying ⁸⁷Sr/⁸⁶Sr values into five geologically-representative isotope groups using cluster analysis. The isotope groups were then used as a covariate in kriging to integrate prior geological knowledge of Sr cycling with the information contained in the bioavailable dataset and enhance ⁸⁷Sr/⁸⁶Sr predictions. Our approach couples the strengths of classification and geostatistical methods to generate more accurate ⁸⁷Sr/⁸⁶Sr predictions (Root Mean Squared Error = 0.0029) with an estimate of spatial uncertainty based on lithology and sample density. This bioavailable Sr isoscape is applicable for provenance studies in France, and the method is transferable to other areas with high sampling density. While our method is a step forward in generating accurate ⁸⁷Sr/⁸⁶Sr isoscapes, the remaining uncertainty also demonstrates that fine-modelling of ⁸⁷Sr/⁸⁶Sr variability is challenging and requires more than geological maps for accurately predicting ⁸⁷Sr/⁸⁶Sr variations across the landscape. Future efforts should focus on increasing sampling density and developing predictive models to further quantify and predict the processes that lead to ⁸⁷Sr/⁸⁶Sr variability.Funding was provided by ARC DP110101415 (Grün, Spriggs, Armstrong, Maureille and Falguères) Understanding the migrations of prehistoric populations through direct dating and isotopic tracking of their mobility patterns. Part of this research was supported by the Australian French Association for Science & Technology through the ACT Science Fellowship program (2013) to M. Willme

The Acheulian and early Middle Paleolithic in Latium (Italy): Stability and innovation

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

Last interglacial (MIS 5e) sea-level determined from a tectonically stable, far-field location, Eyre Peninsula, southern Australia

The last interglacial maximum (Marine Isotope Substage 5e [MIS 5e], 128¿116 ka) is a distinctive event in recent Earth history. Shoreline successions of this age are important for calibrating climate models and defining the overall behaviour of the crust¿mantle system to fluctuating ice and ocean-water volumes. In a global context, the recently intensified interest in last interglacial shoreline successions has revealed considerable variability in the magnitude of sea-level rise during this time interval and highlighted the need to examine paleosea-level evidence from tectonically stable, far-field settings. Situated in the far-field of continental ice sheets and on the tectonically stable Gawler Craton, the 300 km coastal sector of western Eyre Peninsula between Fowlers Bay and Lake Newland in southern Australia represents an important region for defining the glacio-eustatic (ice-equivalent) sea-level attained during the last interglacial maximum based on the relative sea-level observations from this region. Low-energy, shoaling upward, peritidal bioclastic carbonate successions of the last interglacial (locally termed Glanville Formation) formed within back-barrier, estuarine¿lagoonal environments in the lee of eolianite barrier complexes (locally termed Bridgewater Formation) along this coastline. The well-preserved shelly successions (coquinas) contain diverse molluscan fossil assemblages including species no longer living in the coastal waters of South Australia (e.g. the Sydney cockle Anadara trapezia and the benthic foraminifer Marginopora vertebralis). The extent of amino acid racemisation (a measure of fossil age based on increasing d/l value) in a range of species, and in particular A. trapezia and Katelysia sp., confirms the time equivalence of the isolated embayment-fill successions, correlated with the informal type section of the Glanville Formation at Dry Creek, north of Adelaide. Preliminary U-series analyses on A. trapezia also suggest a correlation with the last interglacial maximum, but further highlight the complexity in dating fossil molluscs by the U-series method in view of their open-system behaviour. The shelly successions of the Glanville Formation occur at elevations higher than attained by sea-level in the current, Holocene interglacial. A higher sea-level of between 2.1 ± 0.5 and 4 ± 0.5 m above present sea-level is inferred for the last interglacial maximum (MIS 5e) along this coastline based on the elevation of sedimentary successions host to the shallow subtidal¿intertidal fossil molluscs Katelysia sp., and Anadara trapezia. The paleosea-level observations place a lower limit on the sea-level attained during the last interglacial maximum and suggest that caution be exercised in the definition of the upper limit of sea-level during this interglacial

The Age of the 20 Meter Solo River Terrace, Java, Indonesia and the Survival of Homo erectus in Asia

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 546±12 ka (sd±5 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/−17. 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

A new Upper Pleistocene hominin calvarium from West-Turkana (Kenya)

The Upper Pleistocene (UP) African hominin fossil record is extremely scarce. Only two well-preserved specimens dated to 50,000-30,000 years ago are available: the Hofmeyr cranium from South Africa, and the Nazelt Khater 2 (NK2) skeleton from Egypt. Here, we present a new hominin calvarium (NG1) found in 2015 at Ngingolea Idome (West Turkana, Kenya) and directly dated to 30,000-33,000 years ago by U-series. The NG1 calvarium was reconstructed from multiple small fragments which were found on ..