Search results for "CHRONOLOGY"
showing 10 items of 338 documents
Tree-Ring Amplification of the Early Nineteenth-Century Summer Cooling in Central Europe
2015
Abstract Annually resolved and absolutely dated tree-ring chronologies are the most important proxy archives to reconstruct climate variability over centuries to millennia. However, the suitability of tree-ring chronologies to reflect the “true” spectral properties of past changes in temperature and hydroclimate has recently been debated. At issue is the accurate quantification of temperature differences between early nineteenth-century cooling and recent warming. In this regard, central Europe (CEU) offers the unique opportunity to compare evidence from instrumental measurements, paleomodel simulations, and proxy reconstructions covering both the exceptionally hot summer of 2003 and the ye…
Landsat TM/ETM+ and tree-ring based assessment of spatiotemporal patterns of the autumnal moth (Epirrita autumnata) in northernmost Fennoscandia
2010
Abstract We used fine-spatial resolution remotely sensed data combined with tree-ring parameters in order to assess and reconstruct disturbances in mountain birch ( Betula pubescens ) forests caused by Epirrita autumnata (autumnal moth). Research was conducted in the area of Lake Tornetrask in northern Sweden where we utilized five proxy parameters to detect insect outbreak events over the 19th and 20th centuries. Digital change detection was applied on three pairs of multi-temporal NDVI images from Landsat TM/ETM+ to detect significant reductions in the photosynthetic activity of forested areas during disturbed growing seasons. An image segmentation gap-fill procedure was developed in orde…
Considerations on an integrated biochronological scale of Italian Quaternary Mammals
2011
Viene analizzato il lavoro di MASINI e SALA (2007) sull’approccio integrato della distribuzione dei grandi e piccoli mammiferi dell’Italia continentale del tardo Pliocene e del Pleistocene, tenendo conto della nuova definizione del Quaternario, mettendo in risalto i punti di forza e quelli deboli della scala proposta. Vengono inoltre aggiunti nuovi dati sulla biocronologia a mammiferi del Pleistocene Superiore. The paper of MASINI and SALA (2007) regarding an integrated approach on the stratigraphic distribution patterns of large and small mammals in the late Pliocene and Pleistocene of the Italian peninsula is analysed, showing the weak and strong points. New data are presented on the mamm…
Multi-isotopic and trace element evidence against different formation pathways for oyster microstructures
2021
Geochimica et cosmochimica acta 308, 326-352 (2021). doi:10.1016/j.gca.2021.06.012
Timing of deformational events in the Río San Juan complex: implications for the tectonic controls on the exhumation of high-P rocks in the northern …
2013
An integrated structural, petrological and geochronological study was undertaken to constrain the tectonic history and controls on the exhumation of the high-P rocks of the Río San Juan complex in the northern Caribbean subduction–accretionary wedge. In the main structural units of the complex, microtextural analyses were performed to identify the fabrics formed at peak ofmetamorphismin eclogite-facies conditions and during the main retrogressive event toward the low-P amphibolite or blueschist/greenschist-facies conditions. U–Pb SHRIMP dating on zircon rims (71.3 ± 0.7 Ma) coupled with 40Ar–39Ar analyses on phengite (~70– 69 Ma) in felsic sills placed temporal constraints on the exhumation…
From intra-oceanic subduction to arc accretion and arc-continent collision: Insights from the structural evolution of the Río San Juan metamorphic co…
2013
The Río San Juan metamorphic complex exposes a segment of a high-pressure subduction-accretionary complex built during Caribbean island arc-North America continental margin convergence. It is composed of accreted arc- and oceanic-derived metaigneous rocks, serpentinized peridotites and minor metasediments forming a structural pile. Combined detailed mapping, structural and metamorphic analysis, and geochronology show that the deformation can be divided into five main events (D1eD5). An early subduction-related D1 deformation and M1 metamorphism produced greenschist (mafic rocks of the Gaspar Hernández peridotite-tectonite), blueschist and eclogite (metamafic blocks in the Jagua Clara mélang…
Radiocarbono y estadística Bayesiana: aportaciones a la cronología de la Edad del Bronce en el extremo oriental del sudeste de la península Ibérica
2014
La investigación arqueológica desarrollada en las últimas décadas ha permitido evaluar que en los valles de los ríos Segura y Vinalopó se dirimió el contacto entre dos sociedades de la Edad del Bronce de la península Ibérica: el grupo Argárico y el grupo del Prebético Meridional Valenciano. Las excavaciones realizadas en tres yacimientos de este ámbito - Terlinques, Cabezo Pardo y Cabezo Redondo- y las dotaciones de radiocarbono obtenidas permiten por primera vez evaluar la diacronía del proceso histórico que envolvió el desarrollo de ambos grupos arqueológicos a lo largo del II milenio cal BC, así como determinar diversos momentos socialmente significativos en su devenir histórico. Para el…
Une crise dans la production métallique de l’âge du Bronze final autour de 900 av. J.-C.
2023
La fin du Xe siècle av. J.-C. correspond à une subdivision mineure au sein des principaux systèmes chronologiques d’Europe continentale (transition Bronze final IIIa-IIIb ou Ha B1-B2/3). Il s’agit pourtant d’une période de rupture majeure dans les productions métalliques. L’aspect des objets en bronze, notamment ceux de la sphère personnelle (épées, parures, couteaux…), change radicalement. La riche ornementation graphique répandue jusqu’alors laisse place à des objets beaucoup plus épurés et standardisés. Ce changement rapide doit être mis en relation avec des variations au sein des systèmes de production et le développement de l’utilisation de moules permanents, auparavant réservés à la p…
Composantes culturelles et Premières productions céramiques du Bronze ancien dans le sud-est de la France
2012
The collective research project "Cultural components of the first pottery productions of the Early Bronze Age in Southeast France" derives from renewal of documentation on the Early Bronze Age in the southeast Rhodanian region and new approaches to the Bell Beaker period, particularly in the southern part of Southeast France. In 1998, the Riva del Garda conference constituted a high point in Bell Beaker research at a European scale, of which the consequences and questions motivated the collective project for an overview of the transition from the end of the Neolithic to the Early Bronze Age in a large southeastern quarter of France. In these regions, issues relating to the future of Bell Be…
Lignées morphologiques et techniques dans la production des épées à poignée métallique de l'âge du Bronze en Europe nord-alpine : continuités…
2021
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