Search results for "stratigraphy"
showing 10 items of 904 documents
Possible functions of biomineralization of some Textulariid (Foraminifera) species of the Nw Iberian Margin
2016
The main goal of this work is to analyze the elemental composition of the test’s wall of some species/specimens of Textulariids (sub-class Subclass Textulariia), collected in surface sediments of the NW Iberian Margin. The elemental analyses was based on the Energy Dispersive Spectroscopy (EDS) on the Scanning Electron Microscope (SEM; Hitachi, S4100) of Textularia deltoidea, Textularia agglutinans, Sahulia conica, Karrerotextularia flintii, Siphotextularia heterostoma, Karreriella bradyi, Spiroplectammina sagittula and Arenoparrella mexicana . The elelemetal cocnentrations of the species wall were compared with the mineralogical composition (X-Ray diffraction) of the sediments of the stati…
Calcareous nannofossil and planktonic foraminifera biostratigraphy of selected Pliocene and Pleistocene laminites from Southern Italy.
2009
INTEGRATED CALCAREOUS PLANKTON BIOSTRATIGRAPHY OF SELECTED MIOCENE SUCCESSIONS IN THE NORTHERN CALABRIA (ITALY).
2005
An integrated calcareous plankton biostratigraphic approach on six sections cropping out in Northern Calabria allowed to define a revised chronostratigraphic framework for Tortonian-Messinian deposits. Four sections have been investigated in the Amantea Basin (Timpone Napoli, Vallone Salina, Case Vespano, and Cozzo Salice) and two in the Rossano Basin (Vallone Casino and Cozzo Sant'Isidoro). Biostratigraphic analyses have been based on quantitative counting of planktonic foraminifers and semiquantitative counting of nannofossils. The Timpone Napoli and Vallone Salina sections are Late Tortonian in age and referable to the Globorotalia suterae Zone. In terms of nannofossils zonal scheme thes…
Calcareous Nannofossil Biostratigraphy of the Central Mediterranean Basin during the last 430 000 years
2009
Quantitative analyses on over 2300 samples were carried ut on late Quaternary calcareous nannofossil assemblages from a central Mediterranean Sea sedimentary sequence (ODP Site 963A). Our results indicate that Emiliania huxleyi dominated the assemblages between 0 and 45.7 kyr BP; Gephyrocapsa muellerae between 45.7 and 177.3 kyr BP; small Gephyrocapsa between 177.3 and 263.5 kyr BP; Gephyrocapsa caribbeanica from 263.5 kyr BP down to the basal sample of our investigation, at about 430 kyr BP A comparison with similar reports from Atlantic Ocean sites indicates that the boundaries of the acme intervals identified in this study fall within the same Marine Isotopic Stages as the Atlantic Ocean…
Calcareous plankton Biostratigraphy and Chronostratigraphy of selected Pliocene and Pleistocene laminites from Southern Italy
2009
La lumachelle à Cardinia (Bivalves) et Alsatites (Ammonites) du " Revers de Côte Dure " dans l'Hettangien de la couverture sédimentaire du Massif du …
2011
29 pages; International audience; Ce travail est consacré à l'étude d'une faune de l'Hettangien moyen (Chronozone à Liassicus, Sous-Chronozone à Laqueus) qui, relativement peu diversifiée, mais très abondante et bien préservée, caractérise un niveau lumachellique spectaculaire dans la série du Jurassique inférieur, globalement peu fossilifère, de la couverture sédimentaire, du massif du Rochail (Bassin subalpin, zone dauphinoise). Cette faune, qui provient du Revers de Côte Dure (Villard-Notre-Dame, Isère, France), est essentiellement composée de bivalves (e.g., Cardinia, " Astarte ") et d'ammonites (e.g., Alsatites, Saxoceras), mais elle livre aussi, surtout au sommet du banc lumachellique…
Chronologie et périodisation des campaniformes en France méditerranéenne
2012
What is the current state of research, twenty years after the Ambérieu-en-Bugey colloquium, regarding the chronological setitng of the Bell Beaker horizon, the periodisation of pottery styles and the relationships between Bell Beakers and local groups in the late Neolithic in Mediterranean France ? A brief inventory of knowledge from 1992 together with research from the last two decades will allow us to re-evaluate stratigraphic evidence and radiocarbon dates and to examine the evolution of sttlement distribution and the artefact contexts and associations
2021
Abstract. The dynamics of growing collisional orogens are mainly controlled by buoyancy and shear forces. However, the relative importance of these forces, their temporal evolution and their impact on the tectonic style of orogenic wedges remain elusive. Here, we quantify buoyancy and shear forces during collisional orogeny and investigate their impact on orogenic wedge formation and exhumation of crustal rocks. We leverage two-dimensional petrological–thermomechanical numerical simulations of a long-term (ca. 170 Myr) lithosphere deformation cycle involving subsequent hyperextension, cooling, convergence, subduction and collision. Hyperextension generates a basin with exhumed continental m…
The sedimentary series of upper Bajocian-lower Bathonian age and their organization in the Burgundy threshold and its surroundings. Stratigraphy, sed…
1981
Three fundamental features concerning the organization of the bio-sedimentary series of the upper Bajocian-lower Bathonian of the Burgundy threshold environment are retained:- the formations are organized in a bio-sedimentary platform, composed of three sets: a deep SW platform with clay sedimentation, a superficial NE platform, a transition zone- the geochemical characteristics are consistent with the reconstitution of the NE-NW polarized platform- this device has changed over time: a migration and extension of the surface platform to the SW, development of the transition zone, a slight displacement of the deep platform correlated with a more and more opening towards the SW.
Les climats régionaux : observation et modélisation : actes du colloque
2012
6 pages; International audience; L'objectif de cette étude est de caractériser les variations spatio-temporelles des flux sédimentaires de la basse vallée du Mono-Couffo (bassin versant partagé par le Bénin et le Togo), à partir des données de matières en suspension (MES), de débits solides (TSS), de pluie, du débit et des données concernant l'occupation du sol pour mieux apprécier l'impact de la dégradation du couvert végétal sur le flux des sédiments terrigènes. Il ressort de l'analyse une diminution de plus de 60 % des formations naturelles entre les années 1956 et 2000, contribuant à une augmentation des apports spécifiques dans la basse vallée. Une charge solide considérable en matière…