Lumineszenzdatierung glazifluvialer Sedimente im nördlichen Alpenvorland

Das nördliche Alpenvorland gilt als klassische Region der Quartärforschung. Hier wurde das System der quartären Eiszeiten anhand der Terrassenstratigraphie entwickelt (PENCK & BRÜCKNER 1901/1909). Die drei letzten Eiszeiten sind die Mindel-, die Riss- und die Würm-Eiszeit. Während das Alter der Vergletscherungen bis heute mit Sauerstoffisotopengehalten in marinen Sedimentbohrkernen korreliert wird, erlauben neuere Datierungsmethoden eine direkte Altersbestimmung der Sedimente. Ziel dieser Untersuchung war es, erstmals eine unabhängige Chronologie der quartären Schotterkörper im Alpenvorland mittels optischer Datierung zu erstellen. Dazu war eine detaillierte methodische Analyse der Lumineszenzeigenschaften der Proben notwendig. Die vergleichende Datierung der Quarz- und Feldspatfraktion derselben Probe diente der Validierung der Ergebnisse. Die Datierungsergebnisse weisen auf zeitlich voneinander zu unterscheidende Terrassenakkumulationen hin. Darüber hinaus haben die vielfältigen experimentellen Untersuchungen zu wichtigen neuen Erkenntnissen bezüglich des Lumineszenzverhaltens der Sedimente im Alpenvorland geführt, die in Zukunft zur Etablierung einer eigenständigen Chronologie der pleistozänen Ablagerungen im Alpenvorland genutzt werden können

Aeolian sedimentation in the Rhine and Main area from the Late Glacial until the Mid-Holocene

Äolische Sedimente (sandiger Löss, Flugsand) wurden durch pedologische und geochronologische Methoden (OSL) mit dem Ziel untersucht, hieraus Aussagen zur stratigraphischen Abfolge und zum Ablagerungsalter zu gewinnen und diese Ergebnisse auf die Ergebnisse der archäologischen Ausgrabung zu beziehen. Die Ergebnisse zeigen, dass die Ablagerung des Lösses im Spätglazial auf einer älteren Lage von Windkantern erfolgte und dieser am Ende des Pleistozäns von äolischem Sand überdeckt wurde. Untersuchungen der fundführenden Schichten ergaben eine mittelholozäne Datierung (6.9 ka), die mit einer lokalen Störung durch äolische Sedimentumlagerungen in Folge anthropogener Landschaftsveränderungen während des Neolithikums erklärt werden. Diese Untersuchungsergebnisse werden vor dem Hintergrund vergleichbarer äolischer Stratigraphien und Fundplätz im Rhein-Main-Gebiet diskutiert.researc

The Trade-off Between Income Inequality and Carbon Dioxide Emissions

Based on a substantially larger data set (in both regional and temporal coverage) than the existing literature, we investigate the theoretically ambiguous link between income inequality and per capita emissions using cross-country panel data. We find that the relationship depends on the level of income. Using an arguably superior group-fixed effects estimator, we show that for low and middle-income economies, higher income inequality is associated with lower carbon emissions while in upper middle-income and high-income economies, higher income inequality increases per capita emissions. The result is robust to the inclusion of plausible transmission variables as well as different data sources or aggregations

Infrared Radiofluorescence (IR-RF) of K-Feldspar:An Interlaboratory Comparison

Infrared Radiofluorescence (IR-RF) is a relatively new method for dosimetric dating of the depositional timing of sediments. This contribution presents an interlaboratory comparison of IR-RF measurements of sedimentary feldspar from eight laboratories. A comparison of the variability of instrumental background, bleaching, saturation, and initial rise behaviour of the IR-RF signal was carried out. Two endmember samples, a naturally bleached modern dune sand sample with a zero dose and a naturally saturated sample from a Triassic sandstone (~250 Ma), were used for this interlaboratory comparison. The major findings of this study are that (1) the observed IR-RF signal keeps decreasing beyond 4000 Gy, (2) the saturated sample gives an apparent palaeodose of 1265 ± 329 Gy and (3) in most cases, the natural IR-RF signal of the modern analogue sample (resulting from natural bleaching) is higher than the signal from laboratory-induced bleaching of 6 h, using a solar simulator (SLS). In other words, the laboratory sample bleaching was unable to achieve the level of natural bleaching. The results of the investigations are discussed in detail, along with possible explanations

Infrared radiofluorescence (IR-RF) dating:A review

International audienceLuminescence dating methods on natural minerals such as quartz and feldspars are indispensable for establishing chronologies in Quaternary Science. Commonly applied sediment dating methods are optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). In 1999, Trautmann et al. (1999a, b) proposed a new related technique called infrared radiofluorescence (IR-RF). IR-RF denotes the infrared luminescence signal of feldspar resulting from exposure to ionizing radiation and potentially offers a significant methodological advance compared to OSL and IRSL regarding luminescence signal stability, dating range and required measurement time. The method has rarely been applied due to a lack of commercially available measurement equipment but experienced a revival during the last years. The present article provides a state-of-the-art overview of the physical background of IR-RF, its challenges, applications and the potential as a dating method. The paper particularly addresses practical considerations for applying IR-RF dating, including signal bleachability and saturation behaviour, and summarizes proposed solutions

Abrigo de la Quebrada Level IV (Valencia, Spain): Interpreting a Middle Palaeolithic Palimpsest from a Zooarchaeological and Lithic Perspective

The Abrigo de la Quebrada (Chelva, Valencia) stratigraphic succession comprises nine Middle Palaeolithic levels. Human selection of this rock shelter for occupation owes to its favourable location—at the gates of a blind valley where the trapping of large herbivores would have been practicable. The immediate environment is varied, with both abrupt and flat terrain, and would have supported a wide range of prey animals. Radiocarbon-dated charcoal samples from level IV, which is characterised by a high density of lithic (> 18,000) and bone (> 100,000) remains, yielded results of 43,930 ± 750 BP (Beta-244002) and > 51,6 ka BP (OxA-24855). There is no evidence of modification by carnivores or birds of prey, so this level’s faunal remains must be anthropogenic in the main. Relative to the inhabited space, the location of level IV’s many combustion features shows little variation. The level’s typical palimpsest structure results from frequent, repeated occupations with intense on-site processing in a context of low sedimentation rates. The study of seasonality, carcass exploitation, taphonomy, stone tool refitting and raw material provenience patterns supports the notion that the different occupations subsumed in the level IV deposit were all short term. The comparison of our results with coeval contexts from the central area of Mediterranean Iberia sheds additional light on the adaptations of western Europe’s Neanderthal groups.info:eu-repo/semantics/publishedVersio

Site formation and chronology of the new Paleolithic site Sima de Las Palomas de Teba, southern Spain

The newly identified Paleolithic site Sima de Las Palomas de Teba hosts an almost seven -m-thick sediment profile investigated here to elucidate the rock shelter's chronostratigraphy and formation processes. At its base, the sediment sequence contains rich archeological deposits recording intensive occupation by Neanderthals. Luminescence provides a terminus ante quem of 39.4 ± 2.6 ka or 44.9 ± 4.1 ka (OSL) and 51.4 ± 8.4 ka (TL). This occupation ended with a rockfall event followed by accumulation of archeologically sterile sediments. These were covered by sediments containing few Middle Paleolithic artifacts, which either indicate ephemeral occupation by Neanderthals or reworking as suggested by micromorphological features. Above this unit, scattered lithic artifacts of undiagnostic character may represent undefined Paleolithic occupations. Sediment burialagesbetweenabout23.0±1.5ka(OSL)and40.5±3.4ka(pIRIR)provideanUpperPaleolithicchronology for sediments deposited above the rockfall. Finally, a dung-bearing Holocene layer in the upper most part of the sequence contains a fragment of a human mandible dated to 4032 ± 39 14C yr BP. Overall, the sequence represents an important new site for studying the end of Neanderthal occupation in southern Spain

Environmental change during MIS4 and MIS 3 opened corridors in the Horn of Africa for <i>Homo sapiens</i> expansion

Archaeological findings, numerical human dispersal models and genome analyses suggest several time windows in the past 200 kyr (thousands of years ago) when anatomically modern humans (AMH) dispersed out of Africa into the Levant and/or Arabia. From close to the key hominin site of Omo-Kibish, we provide near continuous proxy evidence for environmental changes in lake sediment cores from the Chew Bahir basin, south Ethiopia. The data show highly variable hydroclimate conditions from 116 to 66 kyr BP with rapid shifts from very wet to extreme aridity. The wet phases coincide with the timing of the North African Humid Periods during MIS5, as defined by Nile discharge records from the eastern Mediterranean. The subsequent record at Chew Bahir suggests stable regional hydrological setting between 58 and 32 kyr (MIS4 and 3), which facilitated the development of more habitable ecosystems, albeit in generally dry climatic conditions. This shift, from more to less variable hydroclimate, may help account for the timing of later dispersal events of AMH out of Africa