Search results for "Sedimentary"
showing 10 items of 455 documents
Summer air temperature, reconstructions from the last glacial stage based on rodents from the site Taillis-des-Coteaux (Vienne), Western France.
2014
AbstractThe oxygen isotope composition of phosphate from tooth enamel of rodents (δ18Op) constitutes a valuable proxy to reconstruct past air temperatures in continental environments. This method has been applied to rodent dental remains from three genera, Arvicola sp., Microtus sp. and Dicrostonyx sp., coming from Taillis-des-Coteaux, Vienne, France. This archaeological site contains an exceptionally preserved sedimentary sequence spanning almost the whole Upper Palaeolithic, including seven stratigraphic layers dated from 35 to 17 cal ka BP. The abundant presence of rodent remains offers the opportunity to quantify the climatic fluctuations coeval of the various stages of human occupation…
Structural contacts in subduction complexes and their tectonic significance: the Late Palaeozoic coastal accretionary wedge of central Chile
2007
Understanding the contact between the very low-grade metagreywacke of the Eastern Series and high-pressure metamorphosed schist of the Western Series in the Late Palaeozoic accretionary wedge of central Chile is fundamental for the understanding of the evolution of ancient accretionary wedges. We show the progressive development of structures and finite strain from the least deformed rocks in the eastern part of the Eastern Series of the accretionary wedge to high-pressure schist of the Western Series at the Pacific coast. Upright chevron folds of sedimentary layering are associated with an axial-plane foliation, S1. As the F1 folds became slightly overturned to the west, S1 was folded abou…
Land use change, soil erosion and alluvial dynamic in the lower Doubs Valley over the 1st millenium AD (Neublans, Jura, France)
2003
International audience; Geochemical and particle size analyses, surface scanning magnetic susceptibility, microscopic charcoal counting and pollen analysis, have been carried out on two cores from the lower Doubs valley in order to reconstruct the land use history. The interpretation of anthropogenic pollen indicators and micro-charcoal deposits is discussed in relation to the lithological variation of sedimentary accumulation and evolution of the settlement. The environmental changes which occurred during the 1st and the 6th century AD reflect the impact of human activities on the landscape in the immediate surroundings of the site. Multiproxy indicators indicate that soil erosion as a con…
Earliest salt working in the world: From excavation to microscopy at the prehistoric sites of Ţolici and Lunca (Romania)
2018
Abstract Since the Early Neolithic, salt has played an important role in the social and economic development of populations. Consequently, the study and comprehension of salt management strategies have become a significant component of current archaeological research. This study is part of an interdisciplinary research program consisting of excavations and detailed analyses on two Early Neolithic salt working sites situated in the sub-Carpathian region of Romania, Lunca and Ţolici (county Neamţ). These remarkably well-preserved sites are characterised by stratified deposits several meters thick. Detailed stratigraphic descriptions were followed by optical microscopy analysis (soil micromorp…
Fires at Neumark-Nord 2, Germany: An analysis of fire proxies from a Last Interglacial Middle Palaeolithic basin site
2016
Few sites with evidence for fire use are known from the Last Interglacial in Europe. Hearth features are rarely preserved, probably as a result of post-depositional processes. The small postglacial basins (
Combined Electrical Resistivity Tomography (ERT), Direct-Push Electrical Conductivity (DP-EC) Logging and Coring - A New Methodological Approach in G…
2016
Non-invasive geophysical methods have been increasingly applied in geoarchaeological research commonly showing the need of data calibration based on stratigraphical information deduced from outcrops or sediment cores. In this contribution, a methodological approach combining two-dimensional (2D) electrical resistivity tomography (ERT) and stratigraphical data based on coring and, for the first time in geoarchaeological research, direct-push electrical conductivity (DP-EC) logging is presented and discussed. The approach yields high resolution data based on studies of two different types of archives, the Holsterburg site in central Germany located in a fluvio-terrestrial zone and the Corfu C…
Record of latest Barremian-Cenomanian environmental change in tectonically controlled depressions from the Jura-Burgundy threshold (Jura Mountains, e…
2019
Abstract The area of the western Jura Mountains constitutes the former Jura-Burgundy threshold between the Tethys Ocean and the epicontinental Paris Basin Sea. During the Barremian, the area was covered by a shallow-water Urgonian carbonate platform. Tectonic processes influenced the architecture of the Urgonian platform and were notably responsible for the formation of fault-related depressions on top of the Urgonian series, which were subsequently transformed into incised valleys and then to marine depocenters. Their sedimentary infills are mostly represented by the Perte-du-Rhone Formation and record stepwise environmental change on the innermost platform, which was strongly influenced b…
Drowning of a carbonate platform as a precursor stage of the Early Toarcian global anoxic event (Southern Provence sub-Basin, South-east France)
2011
The Toarcian Oceanic Anoxic Event is well-known as coinciding with a carbonate crisis, coupled with organic matter accumulation and perturbation of the carbon cycle expressed by carbon-isotope excursions. In this palaeoenvironmental setting, the present research attempts to better constrain the palaeoenvironmental conditions leading to the drowning of a carbonate platform during Late Pliensbachian to Early Toarcian times. This study is based on the integrated sedimentological, diagenetic and geochemical (stable isotopes and Rock-Eval pyrolysis) analysis of several stratigraphic successions located in the Southern Provence sub-Basin (South-east France). Eodiagenetic ferroan calcite cements b…
Late Quaternary palaeoenvironmental reconstruction of sediment drift accumulation in the Malta Graben (central Mediterranean Sea)
2018
The Malta Graben is a deep tectonic depression in the Sicily Channel, bounded by NW-SE normal faults and filled by thick Pliocene-Quaternary deposits. A previous analysis of a giant piston core (LC09) from the Malta Graben had revealed a wide range of sedimentary features (carbonate turbidites, bioturbated mud and scours), although the chronostratigraphic constraint of the stacking pattern has remained elusive. After establishing a reliable chronological framework based on seven radiocarbon dates for a shorter core from the Malta Graben (ANSIC03-735), a down-core analysis of planktonic foraminifer and coccolith abundance, stable isotopes and sediment grain size was carried out. Since the la…
The relationships between soft-sediment deformation structures and synsedimentary extensional tectonics in Upper Triassic deep-water carbonate succes…
2016
Abstract We describe soft-sediment deformation structures into the Upper Triassic cherty limestone outcropping in the Pizzo Lupo section (Central Sicily, Italy), pertaining to the deep-water palaeodomain of the Southern Tethyan margin. In the study section, mainly consisting of thin-bedded mudstone/marl alternations with bedded chert intercalations, some lithofacies have been separated on the basis of the abundance of the calcium carbonate/clay content and the overall textural features. The deformational structures, displaying different deformational styles as folded and faulted beds, disturbed layers, clastic dikes, and slumps occur mainly in the deformed horizons that involve marl-dominat…