Search results for "stratigraphy"
showing 10 items of 904 documents
Le cadre géographique et géologique.
2018
2 pages; National audience
A. Céphalopodes - 1. Ammonites oxfordiennes.
2006
18 pages
Stratotype Turonien.
2018
416 pages; National audience; L'Anjou et la Touraine constituent deux des plus belles régions historiques de France, classées au Patrimoine mondial de l'Humanité par l'Unesco. Cette aire géographique est souvent associée dans notre esprit aux châteaux de la Loire, aux vins et à une douceur climatique. Mais c'est également ici qu'est défini un étage du Crétacé supérieur : le Turonien. Si la limite inférieure de l'étage est aujourd'hui prise près de Pueblo dans l'Etat du Colorado aux Etats-Unis, le stratotype, situé en France, garde tout son intérêt patrimonial dans la mesure où il en précise le contenu.Ce volume explique tout d'abord les raisons qui ont conduit au XIXe siècle Alcide d'Orbign…
The Albian clays from Saint-Florentin (Yonne): stratigraphic markers and sequences in a condensed sedimentary succession. Mineralogy and climato-eust…
2020
To the south-east of the Paris Basin, the Albian Gault clays of Saint-Florentin in Yonne department, regionally known as « Argiles desPommerats Formation », are the subject of detailed biostratigraphic (ammonites and inoceramids) and lithological descriptions.Five 3rd order eustatic sequences are identified within the formation which corresponds to the upper part of the « Argiles tégulines deCourcelles Formation » in the Aube department. The comparison with coeval succession of Aube (38,91 m) and Yonne (10,70 m), 75 kmapart, reveals the condensed nature of the Argiles des Pommerats Formation. X-ray diffraction analyses of clay minerals show that theclay assemblages are dominantly composed o…
New sedimentological and stratigraphical data on the Permian and Triassic in northeastern Utah, USA
2021
International audience; We present the Permian to Triassic sedimentological evolution in the Vernal area, northeastern Utah, todetermine: (1) the magnitude of the Permian-Triassic (P-T) unconformity, (2) the depositional environmentsabove the unconformity, as well as (3) their evolution in space and time. Within this area, Permian depositsconsists of the Weber Sandstone, which represents aeolian deposits, overlain by the Park City Formation,composed of silty and sandy marine limestones, dolomites and phosphatic shales. In some places, anunconformity is observed at the top of the Weber Sandstone, which is directly overlain by the MoenkopiGroup. This formation is mostly composed of siltstone,…
The role and contribution of eustasy as a triggering force of the onset of Oceanic Anoxic Events: A case study of the early Aptian OAE1a in the Tethy…
2022
<p>Oceanic Anoxic Events (OAEs) are short-lived global carbon cycle perturbations characterized by significant changes in the chemistry, temperature and circulation of the oceans of the world. The forcing mechanisms behind these events remain a subject of discussion, especially for the Jurassic and Cretaceous periods. Typically, these events are thought to be triggered by a contemporaneous emplacement of a large igneous province (LIP) associated with a significant release of CO<sub>2</sub> into the atmosphere and leading to rapid global warming. In turn, induced sharp climatic change promotes an acceleration of the hydrological cycle which intensifi…
Des géotopes à protéger, l'exemple des carrières des grès triasiques (arkoses) de la Charbonnière (Auxy, Plateau d'Autully, Saône-et-Loire).
2018
8 pages; National audience
Stratigraphie et corrélations de l’Albien (Crétacé inférieur) du Sud-Est du bassin de Paris.
2021
27 pages; National audience
Analyse lithostratigraphique de deux coupes géologiques de puits de mines foncés dans la concession de Chambois (Autunien inférieur du bassin d'Autun…
2019
16 pages; National audience
L’Albien type de l’Aube (France) : première description litho- biostratigraphique de la totalité des Argiles tégulines de Courcelles.
2019
16 pages; National audience