Search results for "BAR"
showing 10 items of 7176 documents
The past distribution of Abies nebrodensis (Lojac.) Mattei: results of a multidisciplinary study
2019
The present study provides a critical review of the available historical data on the distribution of Abies nebrodensis, a fir tree endemic to Sicily. The only (somewhat ambiguous) references to its occurrence on Mount Etna date back to the 1st century bc and refer back to the 3rd century bc. Although the botanical and forestry literature and the very few surviving herbarium specimens do not prove that A. nebrodensis grew outside the Madonie mountain range, several indications suggest its past occurrence on other Sicilian mountain ranges such as the Erei, Nebrodi, and probably also Sicani mountains. The results of the most recent pollen investigations (still ongoing) point to the disappearan…
Human occupation and environmental change in the western Maghreb during the Last Glacial Maximum (LGM) and the Late Glacial. New evidence from the Ib…
2019
With the onset of the Last Glacial Maximum (LGM), hunter-gatherers of the so-called Iberomaurusian techno-complex appeared in what is now the Mediterranean Maghreb. During a period of about seven thousand years, these groups left sandy occupation layers in a limited number of archaeological sites, while at the beginning of Greenland Interstadial (GI) 1, the sudden shift towards the deposition of shell-rich sediments and the increase in number of sites document clear changes in subsistence strategies as well as occupation density. It is highly likely that these shifts in human behaviour are related to paleoenvironmental changes in the area, which, so far, are poorly documented in geological …
Barbegal carbonate imprints give a voice to the first industrial complex of Europe
2019
International audience; The watermill complex of Barbegal is one of the first industrial complexes in the world, and one of the largest such installations known from antiquity. It has been studied through excavations and what is known about the complex, its history and purpose, is based on the remaining stonework of mills and water installations, since no traces of the woodwork or machinery of the mills have been preserved. The archaeological museum in Arles, however, stores 142 pieces of carbonate that formed on the woodwork of the mills. We studied this material by analysis of the shape of the fragments and of stable isotopes and crystallographic fabric of selected carbonate samples. This…
Characterization of the Medieval Climate Anomaly, Little Ice Age and recent warming in northern Lapland
2017
The major climate events of the Common Era (CE) have global imprints but significant variations in their timing and magnitude have been suggested. For reliable assessments of the past climate patterns and their applications for evaluations of the ongoing changes, spatially comprehensive network of high-fidelity paleorecords are necessary. In this study, we reconstruct summer air temperatures of the past 2000 years from northern Lapland (Utsjoki, Finland). We use fossil Chironomidae (Diptera) assemblages from sediments of a remote subarctic lake (Loažžejavri) and the transfer function approach for quantitative temperature reconstruction. The results indicate that the Chironomidae fauna were …
High-resolution clay mineralogy as a proxy for orbital tuning: example of the Hauterivian-Barremian transition in the Betic Cordillera (SE Spain).
2012
11 pages; International audience; The response of clay mineral assemblages to potential orbital forcing is tested in Mesozoic hemipelagic marl- limestone rhythmites of the Río Argos section (Betic Cordillera, Southeastern Spain). Along the section, marls are pervasively enriched in kaolinite and illite, whereas limestones are enriched in smectite-rich illite/smectite mixed-layers, suggesting that marl-limestone alternations are produced by cyclic high-frequency fluctuations of continental runoff. Spectral analyses show that clay mineral assemblages evolve accordingly to precession, obliquity and eccentricity cycles. Durations of ammonite zones are assessed at 535 kyr for the Late Hauterivia…
Problems in the identity of "Crioceras" barremense Kilian, 1895 (Ancyloceratida, Late Barremian), and their proposed resolution
2010
17 pages; The study of "Crioceras" barremense KILIAN was undertaken as a part of the revision of the Hemihoplitidae. This species was considered "classic" and has been used as the index of an Upper Barremian subzone; this usage raises a number of problems. The type specimen from Tyrol was a fragment described and illustrated by UHLIG as Crioceras sp. ind. aff. roemeri. This specimen could not be retrieved, and a topotype could not be collected. Our study revealed that there is both a biostratigraphic hiatus and important differences between conceptions of this species: (1) that ascribed UHLIG's type specimen (Upper Barremian, Tyrol), (2) KILIAN's concept of the specimen he found and named "…
Pseudoshasticrioceras bersaci nov. sp. (Ammonoidea, Gassendiceratinae), and new ammonite biohorizon for the Upper Barremian of southeastern France
2009
International audience; Research in the Feraudianus Subzone of the Sartousiana Zone of the Barremian stage led to the discovery of a new species of Pseudoshasticrioceras: P. bersaci nov. sp. Its study provides evidence concerning the developments of the latest Gassendiceratinae BERT et alii, 2006, and the relationship between the genus Pseudoshasticrioceras DELANOY, 1998, and Gassendiceras BERT et alii, 2006. In particular, this new species is derived from Pseudoshasticrioceras magnini (DELANOY, 1992) by a minor revision in the processes of ontogenesis (retardation of ornamentation - neoteny). However, the evolution towards Pseudoshasticrioceras autrani DELANOY, 1998, implies a "failure" in…
L’origine des Imerites Rouchadze, 1933 : résultat d’une innovation chez les Gassendiceratinae Bert, Delanoy et Bersac, 2006 (Ammonoidea, Ancylocerati…
2009
15 pages; La découverte récente de plusieurs spécimens remarquables d'Imerites dichotomum (Ammonoidea, Ancyloceratina) apporte de nouvelles précisions paléontologiques sur ce genre. L'étude du développement ontogénétique montre que les Imerites dérivent directement du genre Pseudoshasticrioceras. Leur origine se situe donc parmi les Gassendiceratinae et non chez les Heteroceratidae comme il était généralement admis. Par ailleurs, la cohabitation de formes macroconques et microconques au sein des espèces du genre Imerites confirme l'hypothèse du dimorphisme. Les nouvelles données paléontologiques obtenues montrent que le taxon « Crioceras » cristatus est un nomen dubium et qu'il doit être ab…
The owl that never left! Taphonomy of Earlier Stone Age small mammal assemblages from Wonderwerk Cave (South Africa)
2022
Wonderwerk Cave, in South Africa, is an exceptional site that has yielded a large collection of small mammal fossils in a stratigraphic sequence reaching back ca. 2 million years. Taphonomic studies undertaken to date, show that Tytonidae (likely Tyto alba) was the dominant predator during the Earlier Stone Age. They produced masses of pellets that formed a dense carpet-like surface that covered the cave floor at intervals throughout the sequence. This paper compares the taphonomic signatures of five different Earlier Stone Age small mammal assemblages from Wonderwerk Cave, including assemblages not studied before, as well as a modern pellet assemblage collected from inside the cave. These …
Description de Artareites landii nov. (Ammonoidea) du Barrémien supérieur de Majastre (sud-est de la France) et discussion sur les Helicancylidae Hya…
2009
25 pages; Dans le secteur de Majastre (Alpes-de-Haute-Provence, SE de la France), le domaine hémipélagique du Crétacé inférieur est exposé à la faveur du décrochement du Poil. Cette position paléogéographique et paléotectonique a permis la récolte d'une faune d'ammonites diversifiée dans le niveau à « petits Barremites ». Il est précisément daté ici pour la première fois et se place entre la base de la sous-zone à Barremense et la base du biohorizon à Breistrofferi de la biozone à Vandenheckei (base du Barrémien supérieur). Au sein de cette faune, Artareites landii nov. sp. est considéré ici, par ses caractéristiques et sa position stratigraphique, comme issu du genre Dissimilites Sarkar. L…