Search results for "IDE"

Depositional mechanism of the upper Pliocene-Pleistocene shelf-slope system of the western Malta Plateau (Sicily Channel)

2021

Abstract A high resolution seismic stratigraphic study of the western edge of the Malta Plateau (central Mediterranean Sea) was conducted to reconstruct the depositional mechanisms of the shelf-slope system since the end of the Messinian salinity crisis (MSC; 5.3 Ma). The accurate interpretation of a large grid of variable-resolution seismic reflection profiles (multichannel and Sub Bottom) allows us to identify and map a Plio-Quaternary sedimentary sequence overlying the Messinian evaporites. The stratal pattern of this sequence is the result of a clinoform prograding system that constitutes the internal structure of a sedimentary shelf developed in a ramp about 2° slope with bathymetries …

Accelerated transgressive processes in a Mediterranean coastal barrier: Subsidence, anthropic action and geomorphological changes since the Little Ic…

2020

Abstract Subsidence, changes in sediment supply and environments, sea storms, current sedimentary deficit and recent anthropic action are factors determining coastal geomorphological processes and evolution of a transgressive Mediterranean coastal barrier. At a longer timescale, the barrier landward migration is partially due to local subsidence of tectonic origin. Peatmarsh remains under seawater at around 100 m from the present-day coastline (4821–4566 and 4874‒4820 cal BP) show evidence of the more advanced position towards the sea of the late Holocene coastal barrier, which has not been preserved. Furthermore, behind the present gravel barrier, wide sandy washover fans dating about 665 …

Regional Tectonic Setting and Geological Structure of the Rhenish Massif

1983

This chapter contains an outline of the geological history of the Rhenish Massif and the development of its margins and surrounding areas. Section 2.2 gives some main aspects of the development of the Variscan geosyncline and orogeny and a short description of the pre-Variscan geological history of this region. Since the end of the Variscan orogeny many different epeirogenetic processes have occurred here (Sect. 2.3). During these long geological times uplift and subsidence changed in the different parts of the Massif and in the surrounding areas.

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…

Carbon-isotope records of the Early Jurassic (Toarcian) Oceanix Anixic Event from the Valdorbia (Umbria-Marche Apennines) and Monte Mangart (Julian A…

2009

The Toarcian oceanic anoxic event (ca 183 Ma) coincides with a global perturbation marked by enhanced organic carbon burial and a general decrease in calcium carbonate production, probably triggered by changes in the composition of marine plankton and elevated carbon dioxide levels in the atmosphere. This study is based on high-resolution sampling of two stratigraphic successions, located in Valdorbia (Umbria-Marche Apennines) and Monte Mangart (Julian Alps), Italy, which represent expressions of the Toarcian oceanic anoxic event in deep-water pelagic sediments. These successions are characterized by the occurrence of black shales showing relatively low total organic carbon concentrations (…

Systematic review of the effects of chemical insecticides on four common butterfly families

2017

Safeguarding crop productivity by protecting crops from pest attacks entails the wide use of plant protection products that provide a quick, easy and cheap solution. The objective of this study is to understand the effects of insecticides used in agriculture on non-target butterflies, specifically on the families Lycaenidae, Nymphalidae, Hesperiidae, and Papilionidae. To achieve this goal, a formal systematic review was performed according to European Food Safety Authority (EFSA) guidelines, by entering a combination of keywords on 3 online databases. Three reviewers independently extracted information on study characteristics and quality. The main results were collected and grouped by the …

Applicability and consequences of the integration of alternative models for CO<sub>2</sub> transfer velocity into a process-based lake mo…

2019

Abstract. Freshwater lakes are important in carbon cycling, especially in the boreal zone where many lakes are supersaturated with the greenhouse gas carbon dioxide (CO2) and emit it to the atmosphere, thus ventilating carbon originally fixed by the terrestrial system. The exchange of CO2 between water and the atmosphere is commonly estimated using simple wind-based parameterizations or models of gas transfer velocity (k). More complex surface renewal models, however, have been shown to yield more correct estimates of k in comparison with direct CO2 flux measurements. We incorporated four gas exchange models with different complexity into a vertical process-based physico-biochemical lake mo…

The influence of lipid content and taxonomic affiliation on methane and carbon dioxide production from phytoplankton biomass in lake sediment

2021

How ocean acidification can benefit calcifiers.

2017

Reduction in seawater pH due to rising levels of anthropogenic carbon dioxide (CO2) in the world's oceans is a major force set to shape the future of marine ecosystems and the ecological services they provide [1,2]. In particular, ocean acidification is predicted to have a detrimental effect on the physiology of calcifying organisms [3]. Yet, the indirect effects of ocean acidification on calcifying organisms, which may counter or exacerbate direct effects, is uncertain. Using volcanic CO2 vents, we tested the indirect effects of ocean acidification on a calcifying herbivore (gastropod) within the natural complexity of an ecological system. Contrary to predictions, the abundance of this cal…

Ectosymbiosis associated with cidaroids (Echinodermata: Echinoidea) promotes benthic colonization of the seafloor in the Larsen Embayments, Western A…

2011

7 pages; International audience; Ice-shelf collapses in the Larsen A and B embayments along the Weddell side of the Antarctic Peninsula resulted in new open-water areas that are likely reorganizing benthic communities. It is a natural laboratory to assess colonization of the sea bottom under new conditions. We tested the hypothesis that the epibionts associated to cidaroid echinoids could promote or enhance the colonization of hard surfaces. In fact, being vagile, cidaroids might improve dispersal capabilities of the sessile animals that are attached to their spines, e.g., promoting the colonization of areas where the fauna has been eradicated by iceberg scouring. If this hypothesis is corr…