Biostratigraphie des foraminifères du Toarcien du Moyen Atlas Central, Maroc Biostratigraphy of the Toarcian foraminifera of the Central Middle Atlas, Morocco

International audienceLes dépôts toarciens du Moyen Atlas central, généralement de type hémipélagiques, indiquent des conditions de plate-forme et de bassin ; ils sont marneux et confinés dans les dépocentres, calcaro-marneux et condensés dans les dépoaxes. L'étude micropaléontologique des foraminifères benthiques a permis de suivre l'extension biostratigraphique des dif-férentes espèces rencontrées. Quatre biozones sont établies (biozone à Lingulina gr. tenera et Marginulina gr. Prima ; biozone à Lenticulina obonensis mg P. ; biozone à Lenticulina pennensis mg. M., Ichtyolaria hauffi, Dentalina utriculata, Citharina longuemari et spectre Lenticulina chicheryi ; biozone à Lenticulina d'orbignyi mg L. et Nodosaria pulchra). Les associations ou les espèces indicatrices de paléoenvironnements particuliers sont soulignées. Pour répondre aux conditions des milieux de vie, ces espèces adoptent généralement des stratégies exprimées par des tendances mor-phologiques particulières concernant, entre autres, la taille du test, son aplatissement et son déroulement. The Toarcian sediments of the Central Middle Atlas show hemipelagic facies deposited in platform to basinal envi-ronments. They are represented by marly thick sections which accumulated in troughs under restricted conditions and by condensed sections of marly limestones encountered rather on high ridges. The micropalaeontological study of benthic foraminifera allowed us to establish the biostratigraphic extension of the different encountered species. Four biozones were thus established (biozone with Lingulina gr. tenera and Marginu-lina gr. Prima; biozone with Lenticulina obonensis mg P.; biozone with Lenticulina pennensis mg. M., Ichtyolaria hauffi, Dentalina utriculata, Citharina longuemari and spectre Lenticulina chicheryi; biozone with Lenticulina d'orbignyi mg L. and Nodosaria pulchra). Both typical associations and paleoenvironmental marker species are described. In response to envi-ronmental change, significant morphological variations have evolved in these species (e.g. size, flattening and uncoiling of the test)

Stratégies adaptatives des foraminifères benthiques toarciens du Moyen Atlas (Maroc) : implications paléoécologiques. Adaptive strategies of the Toarcian Benthic Foraminifera of the Middle Atlas (Morocco) : paleoecological implications

International audienceAu Toarcien, dans le Moyen Atlas, l'analyse quantitative et qualitative des associations de foraminifères benthiques montre une adaptation aux conditions du milieu qui influent sur la diversité, la fréquence et les modifications morphologiques (forme et taille). Plusieurs taxons appartenant essentiellement aux Nodosariidés, aux Cératobuliminidés et aux Agglutinés adoptent des formes et des tailles particulières qui leur permettent de subsister et parfois de proliférer dans des niches où les conditions écologiques sont difficiles (déficit en oxygène, fonds vaseux, etc.). Quantitative and qualitative analysis show that, as a whole, associations of Foraminifera adapt with the conditions of the envi-ronment which influence diversity, frequency fluctuations and morphological modifications (form and size). Several species belonging primarily to Nodosariidea, Ceratobuliminidea and Agglutinea adopt particular forms and sizes which enable them to remain and sometimes to proliferate in niches where the ecological conditions are difficult (e.g. oxygen deficit, muddy funds, ...)

La figue de Barbarie: valorisation d’un produit de terroir issu d’une culture adaptée aux défis climatiques dans la région d’OuledDlim - Sud du Maroc

21-23 octobre 2014International audienc

Huellas terópodas gigantes en el Jurásico Superior de Marruecos. Yacimiento de Aït Mazight (Atlas Central)

A new small site, not always outcropping, with large and giant theropod tracks in the Upper Jurassic of the Central High Atlas of Morocco is described. The ichnites and the typology of the rocks of the site are similar to those of the Iouaridène sites with which there is no cartographic continuity. The particular characters of the tracks and trackways are analyzed and highlighted and a hypothesis of distribution of this type of dinosaurs is pointed outSe describe un nuevo yacimiento pequeño, no siempre aflorante, con huellas terópodas grandes y gigantes en el Jurásico Superior del Alto Atlas Central de Marruecos. Las icnitas y la tipología de las rocas en las que yacen son similares a las de los yacimientos de Iouaridène con los que no hay continuidad cartográfica. Se analizan y destacan los caracteres particularesde las huellas y rastrilladas y se apunta una hipótesis de distribución de este tipo de dinosaurio

New dinosaur ichnological sites from the carixian. South of central High Atlas Mountains (Goulmima. Morocco)

On the nor th of the Goulmima-Tinerhir line three new dinosaur ichnological sites were discovered. The new ichnites and sites (21 and 3) are added to the 23 footprints and 4 outcrops known until now. All sites are in the Aghbalou Formation (Carixian) being those described in this work, older that previously known. Eubrontes, other not identified theropod and possibly sauropod ichnites are described in the new localities. The litology and the direct and indirect structures accompanying of the footsteps also suppose a contribution for the extension of variation both in the sedimentary materials and morphologic ichnological types in the regio

Marcas de cola de cocodrilos y huellas de dinosaurio. Bathoniense?-Calloviense. Imilchil. Alto Atlas Central. Marruecos

Three types of ichnites from a new site discovered in Imilchil were studied and described. The structures of pes and manus prints and tail traces of tetrapods provide data to separate: real ichnites (theropod footprints and crocodile tail drag marks); and sauropod’ subtraces. Most of the theropod footprints are deformed by collapse of their walls, the sauropod subtraces show the strong deformation of about ten well-stratified sedimentary levels. The surface on which we can see theropod and crocodile ichnites is the tracking surface, i. e. the original surface on which they were printedSe estudian tres tipos de icnitas de un nuevo yacimiento descubierto en Imilchil. Las estructuras de las huellas de pies, manos y cola de tetrápodos proporcionan datos para separar: icnitas reales (pisadas terópodas y marcas de arrastre de cola de cocodrilos) y calcos saurópodos? La mayor parte de las huellas terópodas están deformadas por colapso de sus paredes, y las subhuellas saurópodas muestran la fuerte deformación de unos diez niveles sedimentarios bien estratificados. La superficie en la que se encuentran las huellas terópodas y las icnitas de cocodrilo son la superficie de marcha, es decir la superficie original sobre las que se imprimiero

Bioestratigrafía de Foraminíferos del Toarciense del Atlas Medio (Marruecos). Correlación con las regiones vecinas

Los depósitos del Toarciense del Atlas Medio, generalmente de tipo hemipelágico, presentan características de plataforma y de cuenca. Son depósitos margosos, confinados en los depocentros, y depósitos condensados calcáreo-margosos, en los altos de la cuenca. Los estudios micropaleontológicos de foraminíferos bentónicos nos permiten seguir la extensión bioestratigráfica de las diferentes especies encontradas. Se han establecido las siguientes cuatro biozonas: biozona con Lingulina. gr. tenera y Marginulina gr. prima; biozona con Lenticulina obonensis mg Planularia; biozona con Lenticulina pennensis mg Marginulinopsis, Ichtyolaria hauffi, Dentalina utriculata, Citharina longuemari var. angusta-gradata y espectro de Lenticulina chicheryi; y biozona con Lenticulina d’orbignyi mg Lenticulina, Astacolus y Planularia, Nodosaria pulchra y Lenticulina ferruginea mg Falsopalmul

Paleoichnological explorations in the west part of the Iouaridène syncline (Hight Atlas. Morocco). Inventory of the sites and ichnite number

The Iouaridène syncline is a is famous palaeontological site among the ichnologists for several reasons: i) the time of the site is known - the first footprint paper were published in 1937; ii) the discovery of the sauropod trackway Breviparopus, Dutuit and Ouazzou, 1980 used as narrow gauge morphotipe by Farlow (1992); iii) the succesive discussions about the age of the “red beds” where the ichnites were found, and in consequence, the variations in the footprint age attributions; and iv) the discussion about the swimmer dinosaurs in manus-only sauropod trackways. The exploration on the area and the bibliographical review have allowed to verify many of the former suppositions and to adjust the age of the mentioned sauropod trackway, fact of great importancy in the dinosaur palaeoichnolog