Search results for "Cenomanian"
showing 10 items of 37 documents
Ammonite faunas from condensed Cenomanian-Turonian sections (‘Tourtias’) in southern Belgium and northern France
2011
AbstractIn southern Belgium (Mons Basin and Tournai region) and northern France (area between Lille, Valenciennes and Maubeuge), condensed sequences have been referred to as ‘tourtias’ since the start of the nineteenth century. These levels correspond to a succession of trangressive systems tracts and generally appear as dark green, glauconitic and microconglomeratic facies. They are distributed all along the base of the more important transgressive systems tracts of the Cenomanian and basal Turonian from the Boulonnais (northwest France) to the Mons Basin (southern Belgium), through the Artois and Douaisis. Their age can now be determined more accurately by identification of their ammonite…
Stratigraphy and stage boundaries in reference sections of the Upper Cretaceous Chalk in the east of the Paris Basin: the “Craie 700” Provins borehol…
2005
Abstract The Provins boreholes (Poigny: Craie 701, and Sainte-Colombe: Craie 702) drilled in 1999 as part of the “Craie 700” project initiated by the Paris Basin Geologists' Association provide reference sections for the Upper Cretaceous of the eastern part of the Paris Basin. The lithology of the Cretaceous drilled at Poigny and Sainte-Colombe is presented in two logs displaying major litho-events that provide lines of correlation. Bio-events are expressed by the appearance/disappearance of index species of fossils. Foraminifera give a biozonation close to that defined by previous work on the Anglo-Paris Basin. Some of these bio-events provide a second set of lines useful for correlation. …
Les ammonites du Niger (Afrique occidentale) et la transgression transsaharienne au cours du Cénomanien-Turonien
1992
Resume Notre travail s’inscrit dans le cadre d’une revision de la paleontologie des ammonites liees a la transgression transsaharienne du Cenomanien-Turonien et d’un affinement de la biostratigraphie dans le bassin sedimentaire des Iullemeden (Niger occidental et meridional: Mt Iguelela et Damergou). Plus de 700 ammonites ont ete recoltees avec precision dans 8 localites, Il a ete ainsi possible de mettre en evidence une serie de 9 horizons biostratigraphiques et de decrire egalement 3 taxons nouveaux. En particulier, la presence de Metoicoceras geslinianum (d’ Orbigny ), associe aux Nigericeras gadeni ( Chudeau ) permet de mieux correler les niveaux a N. gadeni avec le nord-ouest de l’Euro…
Astérides du Cénomanien de Charente-Maritime (SW France)
1993
Resume Des restes d'Asterides (plaques infero- et superomarginales) ont ete trouves dans les sediments du Cenomanien deCharente-Maritime (Sud-Ouest de la France). Ils appartiennent a 17 taxons, dont la nouvelle espece Calliderma moreaui nov. sp., et correspondent a 5 familles differentes: Goniasteridae, Pycinasteridae, Stauranderasteridae, Sphaerasteridae et Astropectinidae. Leur description est suivie d'une breve analyse de leurs repartitions stratigraphique et paleobiogeographique.
L'évolution paléoenvironnementale des faunes de poissons du Crétacé supérieur du bassin du Tafilalt et des régions avoisinantes (Sud-Est du Maroc) : …
2001
Abstract A critical revision of published data along with new field data allow to draw up the succession of the fish faunas from the Lower Cenomanian to the Lower Turonian in the Tafilalt basin and surrounding areas (southeast Morocco). The analysis of these faunas shows changes from freshwater to marine palaeoenvironments. The palaeogeographic distribution of some taxa is discussed. It shows that the crossing of strictly freshwater organisms between Africa and South America was likely impossible at the time of the formation of the deposits resting around the Tafilalt basin and named ‘Kem Kem beds’. The Cenomano-Turonian transgression reached the Erfoud–Errachidia carbonate platform from th…
The Albian (Vraconnian)-Cenomanian boundary at the western Tethyan margins (Central Tunisia and southeastern France).
2008
AbstractThrough the description and interpretation of the position of macro- and microfossils in several sections of the Albian-Cenomanian boundary in SE France and Central Tunisia, a comparison is made between the north and south margins of the Tethyan Ocean by using the occurrences of marker bioevents. For the planktonic foraminifera, the criterions applicable for the accurate determination of Thalmanninella globotruncanoides (Sigal) – the marker species for the base of the Cenomanian stage – are discussed. The species Th. globotruncanoides and the intermediate forms with its ancestor Th. caroni (Ion) are illustrated. For the ammonites, two subjects are new. Firstly, the species Stoliczka…
Zonation by ammonites and foraminifers of the Vraconnian-Turonian interval: A comparison of the Boreal and Tethyan domains (NW Europe / Central Tunis…
2008
International audience; Since the end of the 19th century the interval comprising the uppermost Upper Albian, the Cenomamian, the Turonian and the basal Coniacian has been subdivided, first into ammonite zones, then, beginning in the middle of the 20th century, into zones of planktonic foraminifera. These two groups, one macrofossil, the other microfossil, are particularly effective for bio-chronostratigraphy thanks to their rapid rates of evolution. But differences in the faunal makeup between the Boreal domain (northwestern Europe) and the Tethyan domain (Mediterranean) have for a long time hindered precise correlation of the two domains. Today, in a time interval covering about 16 millio…
Early Aptian corals from Peñascal (Bilbao, N Spain)
2020
From two horizons in the lower Aptian Peñascal limestone Formation south of Bilbao 22 coral species are reported. The corals belong to the scleractinian families Actinastraeidae, Eugyridae, Haplaraeidae, Latomeandridae, and Solenocoeniidae, and the octocorallian family Helioporidae. The stratigraphic distribution of the species lies between the Berriasian to Cenomanian, but most species have a distribution between the Barremian and Albian. The faunas show most palaeobiogeographical relationship to faunas from the Hauterivian to Albian of the European Boreal, the Western Atlantic and the Western Tethys.
Late Cretaceous palaeoenvironments expressed by the clay mineralogy of Cenomanian–Campanian chalks from the east of the Paris Basin
2005
Abstract The clay fraction of Cenomanian–Campanian chalks cored at Poigny and Sainte-Colombe, close to Provins (east-south-east of Paris), includes variable proportions of smectitic minerals, illite and kaolinite. The smectitic sediments (which constitute the background of low-terrigenous supply throughout the stratigraphic interval) resulted mainly from the warm, humid climate and high sea level that prevailed during Late Cretaceous in this area. During the Late Turonian, the smectitic sedimentation was interrupted by significant detrital inputs of illite and kaolinite. This reflected tectonic rejuvenation of landmasses coeval with an explosive volcanism expressed by the occurrence of bent…
Rare earth elements in limestone/marlstone couplets from the Albian-Cenomanian Cismon section (Venetian region, northern Italy) : assessing REE sensi…
1997
Abstract We have studied the REE distribution through the Albian-Cenomanian interval of a stratigraphic succession (Cismon section, Scaglia Variegata Formation, Venetian Prealps) consisting of rhythmically alternating carbonate-rich and carbonate-poor strata which are the sedimentary expression of systematic variations of surface fertility and bottom-water redox conditions in the depositional basin. Limestone semicouplets show seawater-like shale-normalized patterns (HREE-enriched, with negative Ce anomalies and high Er/Nd ratios) indicating a clear dependence on the REE chemistry of surface seawaters. Marlstones and shales exhibit flatter patterns, more moderate Ce anomalies and low Er/Nd.…