Les forages de Juzanvigny (Aube, France): lithobiostratigraphie des formations du Barrémien à l'Albien moyen dans l'est du bassin de Paris et datations par les ammonites

RESUME Dans le departement de l'Aube, region stratotypique de l'etage Albien, plusieurs forages realises en 2013 ont traverse la plus grande partie des Argiles tegulines de Courcelles ou « Gault » auct. (Albien inferieur et moyen), les Sables verts de l'Aube (Aptien superieur), les Argiles a Plicatules (Aptien inferieur), les Sables et argiles bariolees (Barremien superieur) et la partie superieure des Argiles ostreennes (Barremien inferieur). Une description lithologique detaillee de la succession est realisee dans le but d'ameliorer la connaissance du Cretace inferieur de la bordure orientale du bassin de Paris dont les affleurements sont peu nombreux et discontinus. En ce qui concerne l'…

La baie de Wissant et la carrière de Lottinghen (Pas-de-Calais) : deux coupes de références dans l'Albien du nord de la France.

14 pages; National audience

Lower Cretaceous formations (Berriasian/Valanginian to Albian) from the East of the Paris Basin: lithostratigraphy and depositional environments.

The Paris Basin is a Meso-Cenozoic intracontinental basin characterised during the Early Cretaceous by a continental evolution. However, in its southeastern part, due to transgres­sions originating from the Tethys, the Lower Cretaceous conti­nental deposits were occasionally interrupted by the deposition of marine sediments. In this area, the sedimentary succession includes above the Lower Tithonian “Calcaires du Barrois”, the transgressive “Sables de Soulaines” Formation on the Late Jurassic emersion surface. This formation showing facies characteristic of a tidal flat is reputed to be Valanginian in age, but there is no dating element and could as well begin in the Late Berriasian. Above,…

Notice explicative de la carte géologique de la France (1/50000).

Les affleurements du Saumurois (partie occidentale du stratotype).

24 pages; National audience

Stratigraphie et corrélations de l’Albien (Crétacé inférieur) du Sud-Est du bassin de Paris.

27 pages; National audience

Romaniceras (Yubariceras) ornatissimum (Stoliczka, 1864) : une ammonite rare dans les craies du Turonien moyen de l'Aube (France).

9 pages; International audience

Gastroplites cantianus Spath, 1937: an arctic ammonite in the Upper Albian from the anglo-Paris basin (Wissant section, northern France).

Gastroplites cantianus Spath, 1937, an ammonite from the arctic province of the boreal realm, is described in the Upper Albian ofWissant, Pas-de-Calais (northern France). The occurrence of this exotic ammonite in the anglo-Paris basin, which itself belongs to thenorth european province of the boreal realm, is linked to an overall rise of the sea level (transgressive interval of a third-order eustaticcycle superimposed on a second order cycle). It is probably a shell that drifted post-mortem to Europe. This discovery allows to clarifythe correlations between the northern european and arctic provinces of the boreal realm.

Les récifs des gardes dans la baie de Wissant (Pas-de-Calais) : des barres rocheuses albienne, aptienne et tithonienne.

Environmental and climatic controls of the clay mineralogy of Albian deposits in the Paris and Vocontian basins (France)

18 pages; International audience; High-resolution clay mineral analyses were performed on lower and middle Albian deposits from the Paris and Vocontian basins in order to specify the weathering conditions that prevailed at that time. The clay mineral assemblages are composed of small proportions of chlorite and vermiculitic clays associated with abundant illite, R0 type illite-smectite mixed-layers (smectite) and kaolinite. Clay minerals originated from the physical alteration and chemical weathering of rocks and soils outcropping on the Variscan massifs bordering the studied areas. In the Paris Basin, the covariation of illite and kaolinite suggests the reworking of these latter minerals f…

Ammonite faunas from condensed Cenomanian-Turonian sections (‘Tourtias’) in southern Belgium and northern France

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…

The Albian clays from Saint-Florentin (Yonne): stratigraphic markers and sequences in a condensed sedimentary succession. Mineralogy and climato-eustatic control.

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…

Les ammonites.

Quel avenir pour le stratotype ?

2 pages; National audience

Parcours géologiques au sein du stratotype Turonien.

19 pages; National audience

Une coupe lithologique synthétique dans l'Albien-type de l'Aube, France.

17 pages; National audience

L'historique du tunnel sous la manche : une brève revue des contributions les plus marquantes

The Channel Tunnel is the largest underground geotechnical project undertaken in Europe during the 20th century. There have been numerous proposals since the early 19th century, especially by Thomé de Gamond (1867), Potier and de Lapparent (1877), and Destombes and Shephard-Thorn (1971). This paper discusses the history of the most important geological investigations for the Channel Tunnel bored in the Lower Cenomanian Chalk Marl.

The global bio-events at the Cenomanian-Turonian transition in the reduced Bahloul Formation of Bou Ghanem (central Tunisia).

In central Tunisia, the thickness of the Bahloul Formation varies generally between 20 to 40 m such as for example, respectively, at wadi Smara near Kalaat Senan and at wadi Bahloul near Maktar. The thickness is also of several tens metres at Koudiat el Azreg near Jerissa and at Tajerouine. In these sites where the thickness of the Bahloul Formation is dilated, in addition to five geochemical events (d13C), nine bio-events were defined near the Cenomanian-Turonian transition, successively in ascending order: 1. LO Rotalipora cushmani, 2. Heterohelix bio-event, 3. FO Pseudaspidoceras pseudonodosoides, 4. LO P. pseudonodosoides, 5. LO Thalmanninella multiloculata, 6. “filaments” bio-event, Ce…

First record of early Aptian Oceanic Anoxic Event 1a from the Paris Basin (France) - Climate signals on a terrigenous shelf

Abstract In 2013, Andra (French National Radioactive Waste Management Agency) drilled boreholes to the south-east of the Paris Basin, to characterise Aptian and Albian clayey formations, including the ‘Argiles a Plicatules’ Formation dated as early Aptian. One of these boreholes intersected this formation with an excellent recovery allowing detailed biostratigraphy (ammonites), sedimentology, clay mineralogy, isotope geochemistry (δ13Corg) and Rock-Eval analyses to be performed. The base of the formation corresponds to transgressive dark-grey silty clays with iron oolites and plant debris indicating a coastal environment evolving up-section to upper offshore environments. Higher in the succ…

The Albian (Vraconnian)-Cenomanian boundary at the western Tethyan margins (Central Tunisia and southeastern France).

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…

Le Turonien du Saumurois et de la Touraine dans les collections.

8 pages; National audience

Les Argiles albiennes (Gault) de la Baie de Wissant (Pas-de-Calais) : nouvelles observations lithologiques.

L’Albien type de l’Aube (France) : première description litho- biostratigraphique de la totalité des Argiles tégulines de Courcelles.

16 pages; National audience

Zones d'ammonites et de foraminifères du Vraconnien au Turonien : Une comparasion entre les domaines boréal et téthysien (NW Europe / Tunisie centrale)

International audience; Depuis la fin du 19ème siècle, l'intervalle comprenant l'Albien supérieur élevé, le Cénomanien, le Turonien et le Coniacien basal a été subdivisé d'abord en zones d'ammonites puis, à partir du milieu du 20ème siècle, en zones de foraminifères planctoniques, deux groupes de macro- et de microfossiles particulièrement efficaces en bio-chronostratigraphie grâce à leur taux d'évolution rapide. Toutefois, des différences de compositions fauniques entre le domaine boréal (Europe du Nord-Ouest) et le domaine téthysien (Méditerranée) ont longtemps empêché des corrélations précises entre ces deux domaines. Aujourd'hui, dans un intervalle de temps couvrant environ 16 millions …

Support for a Vraconnian Stage between the Albian sensu stricto and the Cenomanian (Cretaceous System)

The geological scale for the middle Cretaceous currently used throughout the world was proposed by Alcide d'Orbigny in the XIXth century between the years 1842 and 1847 and establishes the succession of stages as Albian, Cenomanian and Turonian. In 1868 Renevier proposed that a supplemental chronostratigraphic division be intercalated between the Albian and the Cenomanian: the Vraconnian stage. This term was not generally accepted and after a period when it was referred to by Breistroffer (1936) as a substage constituting the upper part of the Albian, as an equivalent of the Stoliczkaia dispar ammonite Zone, its abandonment was "recommended" by the Conference on the Lower Cretaceous held in…

Isotopic seawater temperatures in the Albian Gault Clay of the Boulonnais (Paris Basin): Palaeoenvironmental implications

13 pages; International audience; Oxygen isotopes were measured on several types of fossil hardparts from the Gault Clay Formation including benthic and planktonic foraminifera, belemnite guards, and fish small-teeth. Belemnites δ18O values indicate low temperatures (13.5–19.3 °C) with an increase from the Middle to Late Albian. Foraminifera provide variable δ18O values, some too low to be relevant in terms of temperature (until 42 °C). These low values probably result from a diagenetic alteration of the foraminiferal tests even though SEM observations revealed well-preserved microstructures. However, higher foraminiferal δ18O values recorded in some levels indicate temperatures in the rang…

Late Cretaceous palaeoenvironments expressed by the clay mineralogy of Cenomanian–Campanian chalks from the east of the Paris Basin

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…

Zonation by ammonites and foraminifers of the Vraconnian-Turonian interval: A comparison of the Boreal and Tethyan domains (NW Europe / Central Tunisia)

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…

La France au Turonien.

16 pages; National audience

Les autres macrofossiles.

New data on middle Turonian tuffeaux of southern Touraine and on their ammonites faunas.

The knowledge of the Turonian stratotype, “from Saumur till Montrichard“, along the Loire and the Cher valleys waspublished in 2018 by Amédro et alii. Since then, the study of recent collecting of ammonites in southern Touraine provided significant informationto state more precisely the Turonian zonation. New outcrops are described at Bourgueil, Chinon, Loudun, Usseau, Sossay,Marigny-Marmande, Séligny and Ports-sur-Vienne where the following formations were recognized: the Amboise Chalk, the tuffeaux ofArdilliers, of Saumur, of Bourré and the Tuffeau Jaune de Touraine.In these southern countries, it is pointed out that: (1) more than the upper half of the Amboise Chalk appears like the Tuff…

Introduction.

Les affleurements de la Touraine (partie orientale du stratotype).

17 pages; National audience

Lower Aptian climate and recording of the oceanic anoxic event 1a on the terrigenous shelf of the Paris Basin.

A North American ammonite fauna from the late Middle Turonian of Vaucluse and Gard, southern France: the Romaniceras mexicanum, Prionocyclus hyatti and Coilopoceras cf. springeri association

Abstract An unusual, exotic, ammonite fauna including Romaniceras mexicanum Jones, 1938, Prionocyclus hyatti (Stanton, 1894) and Coilopoceras cf. springeri Hyatt, 1903 is recorded from the late Middle Turonian of Vaucluse and Gard, southern France. It is the first record of this ammonite association outside the Gulf Coast region and the Western Interior of the United States of North America. Up to present, these species were considered as endemic to the Western Interior sea-way. The migration of numerous ammonites from North America to western Europe during the late Middle Turonian suggests it is linked to a transgressive event or to a short sea-level high.

Les bioévénements de la limite Albien (Vraconnien) - Cénomanien aux marges nord et sud de la Téthys (S.E. de la France et Tunisie centrale)

International audience; Les bioévénements de la limite Albien (Vraconnien) - Cénomanien aux marges nord et sud de la Téthys (S.E. de la France et Tunisie centrale) [Bioevents at the Albian (Vraconnian) - Cenomanian boundary at the North and South margins of the Tethyan Ocean (SE France and Central Tunisia)]