Search results for "NiTi"
showing 10 items of 53731 documents
Community replacement of neritic carbonate organisms during the late Valanginian platform demise: a new record from the Provence Platform.
2012
24 pages; International audience; The Valanginian is marked by amajor platform demise inducing a hiatus in the northern Tethyan neritic carbonate record from the top of the lower Valanginian to the lower Hauterivian. New biostratigraphic and chemostratigraphic data from the Ollioules section (Provence Platform, southern France) are presented here, demonstrating that a large part of the upper Valanginian is preserved in an inner platform environment. The thick, upper Valanginian, aggrading carbonate succession is observed in an aborted rift domain, implying relatively low subsidence. In this context, a relatively long-term sea-level rise was required to sustain a keep-up style of carbonate p…
Pottery techniques as exchange indicators: a preliminary analysis in the Upper Rhine Valley at the dawn of the Iron Age (9th century BC)
2015
International audience; Technological analysis of 236 pots from the Upper Rhine Valley, dating from the Late Bronze Age, reveals a shared technical background, but also brings to light original forming sequences in the Kaiserstuhl micro-region. These behaviours throw light on local socio-economic networks at the dawn of the Iron Age.; L'étude technologique de 236 poteries du Bronze final IIIb issues de 12 sites de la vallée du Rhin supérieur démontre un fondement technique commun, ainsi que des séquences de façonnage originales dans la micro-région du Kaiserstuhl. Ces pratiques sont révélatrices des réseaux socio-économiques de proximité à la veille du premier âge du Fer.
A North American ammonite fauna from the late Middle Turonian of Vaucluse and Gard, southern France: the Romaniceras mexicanum, Prionocyclus hyatti a…
2016
Abstract An unusual, exotic, ammonite fauna including Romaniceras mexicanum Jones, 1938, Prionocyclus hyatti (Stanton, 1894) and Coilopoceras cf. springeri Hyatt, 1903 is recorded from the late Middle Turonian of Vaucluse and Gard, southern France. It is the first record of this ammonite association outside the Gulf Coast region and the Western Interior of the United States of North America. Up to present, these species were considered as endemic to the Western Interior sea-way. The migration of numerous ammonites from North America to western Europe during the late Middle Turonian suggests it is linked to a transgressive event or to a short sea-level high.
A tale of two gorges: Late Quaternary site formation and surface dynamics in the Mula basin (Murcia, Spain)
2018
Abstract We present a case-study in Palaeolithic archaeology focusing on formation processes at cave- and rock-shelter-sites in a Mediterranean context and on the correlation between site deposits, Quaternary surface sediments and the morphology of the surrounding land. We study three sites located in the basin of River Mula (Murcia, Spain): the cave-site of Cueva Anton and the rock-shelters of Finca Dona Martina and Abrigo de la Boja, in the Rambla Perea valley. They are examined through an integrated geoarchaeological approach that takes into account geomorphological, stratigraphic and soil micromorphological data. The three sites are found within a short distance and cover similar time s…
Transient metazoan reefs in the aftermath of the end-Permian mass extinction
2011
5 pages; International audience; Recovery from the devastating Permian-Triassic mass extinction about 252 million years ago is usually assumed to have spanned the entire 5 million years of the Early Triassic epoch1,2. The post-crisis interval was characterized by large-scale fluctuations of the global carbon cycle and harsh marine conditions, including a combination of ocean acidification, euxinia, and fluctuating productivity3. During this interval, metazoan-dominated reefs are thought to have been replaced by microbial deposits that are considered the hallmark of the Early Triassic4-7. Here we use field and microscopic investigations to document Early Triassic bioaccumulations and reefs f…
Direct terrestrial–marine correlation demonstrates surprisingly late onset of the last interglacial in central Europe
2011
AbstractAn interdisciplinary study of a small sedimentary basin at Neumark Nord 2 (NN2), Germany, has yielded a high-resolution record of the palaeomagnetic Blake Event, which we are able to place at the early part of the last interglacial pollen sequence documented from the same section. We use this data to calculate the duration of this stratigraphically important event at 3400 ± 350 yr. More importantly, the Neumark Nord 2 data enables precise terrestrial–marine correlation for the Eemian stage in central Europe. This shows a remarkably large time lag of ca. 5000 yr between the MIS 5e ‘peak’ in the marine record and the start of the last interglacial in this region.
Unknown Deformations on the Facades of the Pyramid of Khafre at Giza Pyramid Complex in Egypt
2016
Abstract The pyramids of Giza in Egypt are the architectural heritage of ancient civilizations and for many thousand years served as great examples of ancient design, planning and construction solutions. Their scale is grandiose and the attempts of ancient architects to find perfect forms to ensure the structure stands for eternity are admirable. The initial geometry of the structures, their form, proportions and symmetry, was adapted to construction material and technologies available at that time. However, during more than 4500 years these monuments were damaged and partly destroyed; some pyramids were razed to the ground due to construction faults and seismic activity. The second largest…
Bioavailable 87Sr/86Sr in different environmental samples — Effects of anthropogenic contamination and implications for isoscapes in past migration s…
2012
(87)Sr/(86)Sr reference maps (isoscapes) are a key tool for investigating past human and animal migrations. However, there is little understanding of which biosphere samples are best proxies for local bioavailable Sr when dealing with movements of past populations. In this study, biological and geological samples (ground vegetation, tree leaves, rock leachates, water, soil extracts, as well as modern and archeological animal teeth and snail shells) were collected in the vicinity of two early medieval cemeteries ("Thuringians", 5-6th century AD) in central Germany, in order to characterize (87)Sr/(86)Sr of the local biosphere. Animal tooth enamel is not appropriate in this specific context t…
Permian-Triassic extinctions and rediversifications.
2015
Ammonoids were a major component of Permian marine faunas, but were on the verge of extinction during the Permian-Triassic crisis ~ 252 myr ago. Despite the severity of this extinction, their recovery was explosive in less than 1.5 myr. By Smithian time, they had already reached levels of taxonomic richness much higher than those of the Permian. The causes for the rapid Early Triassic diversification and proliferation of these organisms still remain elusive, but the evolution of their spatio-temporal diversity and disparity patterns closely correlates with the numerous environmental changes recorded during this time interval.
Raw material, gestures, artefacts. An approach to the work of bone and ivory in the Iron Age in the Iberian peninsula
2018
Abstract This work seeks to give visibility to the industry of hard animal materials that is documented during the Iron Age in the Iberian peninsula. We focus on the analysis of three common artefacts within the bone and ivory industry in the Iberian culture (between the 6th to the 1st Century BC): pins, perforated plates and combs. We have studied these objects from a technological point of view, thanks to a series of experimental work carried out in order to meet different operational chains, necessary to manufacture each one of these items and tools that could be used for this purpose. So, we searched the archaeological tool models to work bone and ivory, and whenever it has been possibl…