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International audience; Borehole CDB1 (675.05 m) crosses the deepest Cenozoic sedimentary basin of the Armorican Massif, the Rennes Basin, to reach the underlying basement at a depth of 404.92 m, made up of the Late Neoproterozoic to Early Cambrian Brioverian Group, weathered down to 520 m depth. The basin's Cenozoic deposits are divided into seven formations, ranging from Early–Middle Bartonian to Late Pliocene in age. Coastal sediments at the very base, along with a thick Priabonian lacustrine episode, imply a major revision of the regional palaeogeography, whilst a very steady and low-energy lacustrine-palustrine environment throughout the Priabonian and Early Rupelian argue for an aggradational system associated with uniform subsidence. Palynological assemblages attest to environmental and climatic changes through the Eocene and Early Oligocene, in accordance with regional and global trends (Eocene–Oligocene Transition).

International audience; The northern part of the N–S-trending basin of the Limagne graben, located in the northern part of the Massif Central (France), contains Oligocene and Miocene calcareous lacustrine deposits. The area is known for its stromatolite reefs surrounded by marl, clay and uncemented carbonate sand with oncolites. Because the origin of the carbonate accumulated by cyanobacteria has long been debated, the clayey deposits associated with the stromatolites were analysed using XRD, SEM and K–Ar dating methods. The results show a monotonous assemblage of carbonates, dioctahedral smectite, illite–smectite (Reichweite) R=0, glauconitic illite and abundant orthoclase. Detrital minerals such as quartz and detrital illite are found near the basin's borders but are very scarce in its central part, indicating a lack of detrital input from the regional basement. Hence, the abundant orthoclase found in all the clayey deposits of the Limagne Basin cannot be linked to erosion of the surrounding Hercynian basement. The SEM analysis showed the orthoclase crystals to have a tabular morphology with sharp boundaries and to be embedded within a clay matrix, whilst the K–Ar dating of the orthoclase and glauconitic illite yielded ages ranging from 90 to 66±2 Ma, i.e. Turonian to Maastrichtian. These two results clearly indicate that the fill of the Limagne Basin, composed mainly of carbonate, clay and orthoclase, must have been partly due to the erosion of an Upper Cretaceous sedimentary blanket once covering the Massif Central basement. This cover was probably constituted of chalk, dioctahedral smectite, I/S and glauconitic illite, associated with authigenic orthoclase and flint. Flints are found reworked in the alluvial formations of the Late Pliocene Lower Bourbonnais sands and clays (‘Sables et argiles du Bourbonnais') and in the Pleistocene terraces. Moreover, relicts of the Upper Cretaceous cover were preserved during the sedimentary filling of the Cenozoic Limagne Basin. Authigenic orthoclase of similar shape has been described in the Chalk Group of the Paris Basin and from localities in northern France and Belgium. The mineral is rare in the Turonian chalk but increases rapidly at the base of the Coniacian to Campanian chalk; it has also been noted that the number of orthoclase crystals increases as the quantity of clastic components decreases. Similar orthoclase crystals were found associated with dioctahedral smectite in the decarbonated residues of the Coniacian to Santonian chalk from Fécamp and Etretat (northern France). Moreover, our results are consistent with other data from within and around the Paris Basin, such as the palaeogeography and facies distribution of the Chalk formations, the residual flints in the clay-with-flints of the southern Paris Basin and around the Morvan, and apatite fission-track thermochronology data from the Hercynian basement of the Massif Central and the Morvan. All these data indicate a major connection between the Paris Basin and the Tethys, and an extensive palaeocover on the Massif Central and Morvan basement.

En Normandie occidentale, seule la région du Cotentin a conservé une épaisse série sédimentaire cénozoïque (environ 280 m), bien qu’en partie cachée sous les terrains holocènes. Dès l’Éocène, le bassin du Cotentin est ouvert sur le domaine atlantique, protégé par des hauts‑fonds rocheux paléozoïques, chenalisant les eaux et accélérant les courants tidaux. Selon les époques, c’est une morphologie de baie ou de couloir tidal, encadrée par les reliefs du Nord et Sud Cotentin. Les dépôts sédimentaires cénozoïques correspondent à des périodes de haut-niveau eustatique, lors du recouvrement de l’Armorique sous des eaux atlantiques (Lutétien moyen à Bartonien ; Oligocène inférieur ; Miocène moyen ; Plio-Pléistocène), transportant des sables et graviers coquilliers marins côtiers (faluns) ou des sables quartzeux tidaux. Cette série cénozoïque se caractérise également par de très nombreuses lacunes stratigraphiques (Paléocène, Éocène inférieur et moyen, Oligocène moyen et supérieur, Miocène inférieur et supérieur, Pliocène inférieur) qui témoignent de plusieurs déformations, émersions et érosions. Les transgressions atlantiques recouvrant le Massif armoricain s’avancent également à plusieurs reprises en mer de la Manche, puis dans la vallée de la Seine (Haute-Normandie) et finalement dans la cuvette parisienne. Elles expliquent le dépôt de sables marins coquilliers ou quartzeux, dans la vallée de la Seine dont bon nombre ont été ensuite érodés et remaniés au Plio-Pléistocène inférieur. Dans le même temps, la paléo-Seine drainant la partie nord du Massif central s’écoule dans ce couloir, y déposant des sables quartzeux grossiers entre le Pliocène inférieur et le Pléistocène inférieur. In the NW Normandy, only the Cotentin peninsula has preserved record of a thick Cenozoic sedimentary series (about 280 m) covered partially by Holocene sediments. As late as the Eocene, the Cotentin basin was open toward the Atlantic Ocean and separated from it by Paleozoic rocky shoals which controlled the tidal currents. During the Cenozoic times, it was a bay or a tidal estuary between the North and the South Cotentin reliefs. The Cenozoic sedimentary series may be explained by the high eustatic sea-levels due to repetitive transgressions of Atlantic Ocean over the Armorican massif (Middle Lutetian to Bartonian; Lower Oligocene; Middle Miocene; Plio-Pleistocene) which transported shelly sands and gravels (faluns) or tidal quartzose sands. The Cenozoic sedimentary series are also characterized by few sedimentary gaps (Paleocene, Lower to Middle Eocene, Middle to Upper Oligocene, Lower to Upper Miocene, Lower Pliocene) which may be due to deformations, uplifts and erosions. The repetitive Atlantic transgressions over the Armorican massif were extended through the Channel basin to the present-day Seine valley and finally to the Paris basin. These repeated transgressions can account for the presence of shelly or quartzose marine sands in the Seine valley of which few were eroded or remained during the Plio-Pleistocene times. At the same times, the paleo-Seine river drained the North margin of the Massif Central, transported and deposited the fluvial coarse-grained sands in this gateway between the Pliocene and the Lower Pleistocene.

Resume Anterieurement attribuees a l'Albo-Aptien et considerees comme resultant du diapirisme des evaporites triasiques, les breches de Bosmendiette se seraient, pour certains auteurs recents, mises en place au Selandien (Paleocene), dans des canyons sous-marins etablis au sein d'un profond sillon, le long de la chaine des Pyrenees, du Roussillon jusqu'a l'Atlantique. Leur âge serait fonde sur la decouverte d'une riche microfaune pelagique de globigerinides. Nos recherches montrent qu'azoiques a leur base, pourvues de radiolaires et de rares foraminiferes benthiques au sommet, ces breches resultent en realite de la destruction de boucles de slumps affectant l'« Infralias ». Recouvertes en onlap par les calcaires et marnes de l'Albo-Aptien, elles traduisent, conformement a nos precedentes interpretations, l'effondrement par collapse et le glissement vers le nord, en milieu marin graduellement ouvert, de la plate-forme jurassique, lors de la mise en place du diapir de Beloscare–Apoura, au cours du Cretace inferieur. Pour citer cet article : J. Canerot et al., C. R. Geoscience 336 (2004).

Recent deep boreholes Γ1 (205 m) and AIG 10 (1001 m), performed in the Aigion area, bring new information on syn-rift deposits. MIS1/Holocene (11.8–4.3 ka BP) and Upper Pleistocene are identified in the upper part of the boreholes. Below Holocene deposits, the borehole AIG 10 crossed successively a detrital system with fine intercalations and a thick development of clay. No specific dating was possible on this lower formation, so the age of the local basal syn-rift deposits is discussed. To cite this article: F. Lemeille et al., C. R. Geoscience 336 (2004).

Resume Le Pleistocene superieur et l’Holocene d’Aigion ont livre une microfaune abondante dont 35 especes d’Ostracodes. Le Pleistocene du forage d’Aigion contient generalement des Ostracodes de milieu oligohalin a Cyprideis torosa, Candona angulata et Tyrrhenocythere amnicola tandis que dans l’Holocene dominent les especes marines infralittorales a Cytheridea neapolitana, Carinocythereis whitei, Loxoconcha ovulata et Cytherois frequens. La sedimentation marine s’effectuait a des profondeurs de quelques metres a quelques dizaines de metres. Selon la coupe d’Aghios Constantinos, les niveaux, a caractere lagunaire, oligohalins, sont caracterises par la presence d’Euxinocythere schuldtae et d’une espece naine de Xestoleberis. Un changement radical d’environnement se produit donc a la limite Pleistocene–Holocene et pourrait concerner l’ensemble du golfe de Corinthe.

A 205 m-deep borehole drilled in the Aigion harbour crosses three main sedimentary units: a lower deltaic unit, interbedded with lagoon brackish layers attributed to sea level high stands of marine isotopic stages 5 and 3, an intermediate brackish unit and an upper marine Holocene unit. Environmental conditions of sedimentation are determined by palaeontological studies. 14C ages and correlations with published sea level curves yield preliminary results on subsidence and sedimentation rates. Subsidence rates are close to those inferred from palaeoseismological studies (1.5–), whereas sedimentation rates are variable (1.5–13.8 ). These rates will allow estimating the activity of nearby faults. To cite this article: F. Lemeille et al., C. R. Geoscience 334 (2002) 497–504.

On behalf the CINERGY project, a 675m-long borehole was cored through the sedimentary column (405 m) and the basement (270 m). The studied interval encompasses 3 lithostratigraphic units, from 66m to 405m depth. The chronostratigraphic framework of the sedimentary series relies on benthic foraminifera and palynology. Palaeoenvironmental reconstruction is based on sedimentology, pollen analysis and clay mineralogy. 95% of the series deposited continuously from the Early-Middle Bartonian to the Rupelian, including 290 m-thick lacustrine shaly organic deposits, alternating open and closed system depending on the floatting vegetal mats extension. Climate evolution is illustrated by palynological content. The Eocene climate evolves from a from warm and humid condition to a more contrasted seasons. the EOT is marked by a short drier and fresher period, the Rupelian is characterized by disappearance of megathermic taxa but back to more humid condition. Clay mineralogy changes more abruptly at the E/O boundary (~200 m depth), from an almost pure kaolinitic content to a kaolinite-smectite dominated assemblage. Whether the sudden mineralogical change across de E/O boundary is related to a change in source material or to a change in the hydrolysis in soil clay production, a climatic origin is very likely.

Razin Philippe, Roger Jean, Bourdillon Chantal, Serra-Kiel Josep, Philip Jean, Al-Suleimani Z. Paleogene carbonate systems at the Arabian platform margin (Oman). In: Géologie Méditerranéenne. Tome 28, numéro 1-2, 2001. Anatomy of Carbonate Bodies / Anatomie des corps carbonates. International Meeting / Colloque international. Marseille, 9-12 mai 2001, France, sous la direction de Marc Floquet, Jérôme Hennuy et Jean-Pierre Masse. pp. 145-148.

A new assemblage of marine vertebrates from northern Saudi Arabia, east of the Nafud, leads us to reconsider the age of the top unit of the Aruma Formation, the Lina Member, hitherto referred to the Maastrichtian. This assemblage contains the remains of a dozen selachian and actinopterygian fishes, as well as those of a giant sea turtle representing a new dermochelyid taxon. It suggests a Late Paleocene to Early Eocene age for this unit. This new dating and a revision of the stratigraphic position of the Lina Member demonstrate the existence, on a regional scale, of an important hiatus at the K-T boundary.

8 p, 5 fig.; International audience; During the Cenozoic, in the western Paris Basin, atmospheric weathering of the chalks with flints of the Upper Cretaceous led to the creation of clay with flints. A reconstitution of the chalks lost to dissolution is proposed and is based on the determination of the age of the parent chalks of the clay with flints and the quantification of the thickness of dissolved chalk. The chalks affected by weathering range in age from Turonian to Maastrichtian, thus confirming the deposition of calcareous sediments in the western Paris Basin up to the Maastrichtian. Chalk weathering took place in situ, as indicated by the preservation of the stratigraphic succession of the chalk in the clay with flints profiles. Weathering led to the dissolution of 20-200 m of chalk, with regional variations. The weathering rate varies between 2.1 and 14.5 m/Ma.

The stratigraphy of the Late Paleocene-Early Eocene has been revised in Avesnois thanks to drillings supporting a geological mapping project. Detailed sampling and analyses were performed along selected drillings, among which sedimentological, mineralogical, chemostratigraphic (δ13Corg), biostratigraphic and palynological data have been obtained. New Mbs/Fms are defined around the Paleocene-Eocene boundary (PEb) and compared to the lithostratigraphic nomenclatures of the Belgian and Paris Basins (Steurbaut, 1998; Aubry et al., 2005). Biostratigraphy based on the study of foraminifera and mammal fauna, palynological content and chemostratigraphy enable correlation to be established between adjacent basins as well as sea level and landscape evolutions to be refined during this critical interval. Upper Thanetian marine units In the AVE 007-drilling (Mormal Forest, Locquignol, between Englefontaine, Landrecies and Maroilles villages), the Coniacian chalk is overlain by a flint conglomerate, whose sandy-clayey matrix contains Thanetian pollen and dinocysts. Widespread in Avesnois and containing often reworked Upper Cretaceous foraminifera and occasionally glauconite, this unit constitutes the Vervins Mb (cf. 'Argile a silex de Vervins' interpreted as a marine conglomerate by Gosselet, 1879). It is often overlain by the Mondrepuis-Bettrechies Sand Mb (cf. 'Sable verts de l'Avesnois'), a thin sandy glauconiferous unit, more clayey and silty westward (cf. 'Tuffeau de Valenciennes' Mb). The three Mbs constitute the Hainaut-Valenciennois Fm and can be correlated to the Belgian Grandglise Mb (upper part of the Hannut Fm) and Bois-Gilles Fm, and to the Paris Basin Châlons-sur-Vesles and Bracheux Fms, all Thanetian in age. Uppermost Paleocene to lowermost Eocene terrestrial units In AVE 007 the Vervins Mb is unconformably overlain by flint gravels (Mormal Mb), then a pyritic sand (Le Quesnoy Sand Mb, cf. 'Sables et Gres du Quesnoy' of Gosselet, 1890), and a lignitic clay (Locquignol Mb), silty and ochreous at the top. All but the top ochreous paleosol contain spores and pollen grains and are devoid of dinocysts, they were thus probably deposited in terrestrial environments. The Carbon Isotope Excursion (CIE) of the PEb begins below the top of the sandy unit and continues in the lignitic clay. The palynological study confirms the Locquignol Mb's earliest Eocene age and allows correlation with the base of the Tienen Fm. To the East of AVE 007 along the Belgium-France border, fluvial fossiliferous gravels and sands have been studied in past sand quarries (Erquelinnes Sand Mb). Above a sharp unconformity, they i) overly Upper Thanetian marine sands (Bois-Gilles Fm, NP9a, then Grandglise Mb, NP8), ii) contain a mammal fauna referred as MP7 in the Mammalian biochronological scale for the European Paleogene (Missiaen et al., 2013) and iii) record the first part of the CIE onset in the basal fossiliferous gravel and marl beds. Three km west of Erquelinnes and toward AVE 007 a few drillings have recognized a sandy and pyritic unit containing resinite fragments, lignite and peat beds (Vieux Reng Mb), overlying a thin basal flint gravel bed (Mormal Mb). These five Mormal, Le Quesnoy, Locquignol, Vieux-Reng and Erquelinnes Sand Mbs form the Sambre Fm. Such fluvial gravels and sands, more or less lignitic, clayey or marly are widespread in northern France and southeastern Belgium. They belong to the so-called Upper "Landenian" and are correlated to the Tienen Fm. In AVE 007, they record the CIE onset marking the PEb and 2.5 m of Upper Paleocene fluvial units, in contrast with Belgian drillings such as Doel and Kallo where a hiatus is present at the PEb. Lower Ypresian hiatus and marine units In AVE 007, a laminated silty unit overlies the Locquignol Mb, contains dinocysts Wetzeliella sp. and agglutinated foraminifera similar to those of the base of the Orchies Clay Mb. Widespread in Avesnois-Valenciennois that marine unit is named Avesnois Mb, it is locally richer in very fine sand, and correlated to the base of the Kortrijk Clay Fm (Ieper Gp). In Avesnois, Sparnacian lagoonal units are absent upon the terrestrial ones described above, again marking a reverse trend when compared with the Belgian and adjacent Basins. This may result from restricted terrestrial environments coinciding with Variscan accidents and structural highs between the Artois anticline and Ardenne Masssif, or to their deposition followed by subsequent erosion prior to the Lower Ypresian marine transgression (cf. sea level drop 2 of Dupuis et al, 2011). Correlations and PETM impact on land All terrestrial units here described fill fluvial channels incised in marine Thanetian and older units such as the Cretaceous or the Variscan basement in Avesnois and Belgium, as already reported elsewhere in northern France (cf. sea level drop 1 of Dupuis et al., 2011). They exhibit locally cross stratification, lignite, flora or vertebrate fauna, for example at Leval, Hoegaarden and Dormaal, and/or are intensively silicified with scarce root or leaf casts. Similar fluvial sediments and silcretes are recognized in the first Sparnacian units and paleogeography of the Paris, Dieppe-Hampshire and London Basins, where the PEb is also present, the CIE being recorded on thicknesses between 3 m (as in AVE 007) to >20 m (as in Sinceny). These features may be regarded now as constant in those Sparnacian landscapes recording the PETM, with very rapid lateral and vertical facies shift, particular paleosols, a few fossiliferous fluvial to lacustrine units and variable deposition rates/sediments preservation. Terrestrial sediments, flora and fauna have been described there before the CIE onset as well, for example at Cobham, Vasterival or Rivecourt (e.g. Smith et al., 2014). Lihons, an intermediate outlier situated between AVE 007 and Sparnacian sites of those basins has further been investigated: marine Thanetian sands are overlain by thin fluvial, lacustrine then lagoonal sediments, the two latter recording the CIE of the PETM on an interval 4 m thick. Here again the basal terrestrial sediments have been deposited before the PEb. In AVE 007, depositional environments are fluvial for the Mormal and Le Quesnoy Mbs, and evolve toward flood plain then palustrine ones for the Locquignol Mb, probably here after the river bed migration, but still recording sporo-pollen fluvial inputs from the hinterland, the whole indicating a rather humid subtropical climate. Compared to the Locquignol Mb, the sporopollinic assemblage of the Mormal and Le Quesnoy Mbs (below the CIE onset) is different, particularly regarding the Normapolles distribution, the Tricolpates, Tricolporates and Monocolpates relative pollen abundances and the pollen ratio of Plicapollis pseudoexcelsus/Juglandaceae. In the three Mbs, rapid vertical variations characterize pollen and fern spores assemblages, with peaks of particular taxa reaching 25% of the total counts, such as for P. pseudoexcelsus, T. platycaryoides, C. dorogensis, P. mcgregorii, T. robustus. They suggest rapid floral changes in the catchment and/or sources changes in the surrounding landscapes compartments for the rivers supplying the fluvial sediments. Resinite particles are irregularly abundant as well as microcharcoals are occasionally abundant, notably slightly before the CIE onset and 1.5 m above it, still within the CIE. The clay mineral assemblage is homogeneous along marine Thanetian units and strongly dominated by Illite-Smectite (IS) mixed layers, whatever the facies, while it is more variable in the marine Ypresian silts (abundant IS, followed by Kaolinite, Illite, Chlorite and Vermiculite). In contrast terrestrial units are dominated by IS followed by Kaolinite, Illite and very rare Chlorite, and no variation is observed across the PEb. Those data would suggest that major environmental changes have regionally begun before the PETM, at the very end of the Paleocene, when terrestrial realm has settled, in relation with a regional uplift. Clay minerals reflect constant reworking of preexisting weathering profiles established upon Cretaceous strata and Variscan basement, while vegetation modifications are subtle and more likely attributable to changes of depositional environments

International audience; The biostratigraphic revision of the benthic foraminifera present in the coastal Cenozoic quartzose and shelly sands (crags) at Fécamp and Valmont (Seine-Maritime) reveals Early Pliocene (Fécamp) and Early Pleistocene (Valmont) ages. The Tortonian-Messinian thanatocoenosis contained in the Fécamp Crag shows the presence of a former bryozoanrich platform on the floor of the Channel that was reworked during the Lower Pliocene transgression. Tortonian-Messinian and Lower Pliocene deposits have been found in Belgium, England, Brittany, and at Fécamp, but are absent in Cotentin (North-West Normandy), which was uplifted at this period. The Lower Pleistocene tidal sands and crags described in Cotentin, Upper Normandy and the southern North Sea Basin indicate a marine passage between the Channel and the North Sea.

Weathered residual accumulations termed Clay-with-flints (Argiles a silex) overlying Cretaceous deposits are widespread in southern England and northwestern France. Geological and pedological studies and some field surveys indicate their distribution, nature, age and origin. In France, the microfaunas preserved in the hollow flints of the Clay-with-flints demonstrate the preservation of the parent Chalk stratigraphy in the sections studied, i.e. the Clay-with-flints corresponds to in situ weathering profiles. However, in England and in France, an important part of the clay component is derived from a thin veneer of basal Tertiary sediment overlying sub-Tertiary marine erosion surfaces of various Palaeogene transgressions. In England as in France, the youngest generation of Clay-with-flints can be dated from Late Pliocene to Quaternary. It formed after removal of different Cenozoic deposits on many plateaus and during the downcutting of Pleistocene rivers. The most visible effect of subsequent weathering profile development is irregular dissolution of the underlying Chalk to produce deep karstic pipes into which the Clay-with-flints has slumped; other pedological processes include rubification, clay illuviation and cryoturbation. Clay-with-flints also provides evidence of Quaternary palaeoenvironments, Cenozoic continental palaeosurfaces, and their vertical deformation. Copyright © 2003 John Wiley & Sons, Ltd.

National audience; A l'aide de coupes régionales synthétiques des sédiments maastrichtiens et daniens, il est montré que la limite KIT se situe en Europe nord-occidentale, à l'exception du Danemark, au sein d'une lacune de deux Ma comprise entre une surface d'érosion continentale entaillée dans les sédiments d'âge maastrichtien et/ou campanien supérieur et la transgression montienne correspondant au hmlt niveau eustatique TA l 2 de Haq et al, 1987.

7 p, 2 fig. données biostratigraphiques (foraminifères); International audience; Dans le cadre d'une synthèse régionale des altérites de craies à silex du NW du Bassin de Paris, des coupes ont été levées sur les plateaux et interfluves. Des silex, prélevés dans les résidus à silex qui recouvrent les craies et dans des paléo-résidus à silex remaniés à la base des dépôts thanétiens, ont livré une microfaune du Maastrichtien supérieur. Ceci confirme la présence jusqu'ici douteuse de craies à silex du Maastrichtien supérieur dans le Bassin de Paris et l'occultation postérieure de ces dépôts par altération météorique.

Resume Deux gisements a vertebres terrestres (Thaytiniti et Taqah) ont ete decouverts dans la zone meridionale du Dhofar (Sultanat d'Oman) a la base d'une unite marine transgressive, la Formation Ashawq. Des arguments paleomagnetiques et biostratigraphiques permettent de dater ces gisements de l'extreme base de l'Oligocene. De l'ensemble des observations, il resulte que l'un des gisements (Thaytiniti), dans lequel on observe une association d'Invertebres marins et de Vertebres marins, estuariens, dulcaquicoles et terrestres, peut etre date de 35,8 Ma. La faune de Mammiferes recueillie a Taqah et Thaytiniti comprend 11 especes reparties en 5 ordres (Primates, Proboscidea, Embrithopoda, Hyracoidea et Rodentia). Les Primates representes par 4 dents isolees pourraient etre attribuees a un Omomyide et a deux Catarrhiniens (cf. Oligopithecus et cf. Aegyptopithecus). Le stade d'evolution des Rongeurs (Phiomyides) et des Proboscidiens, suggere que les gisements du Dhofar sont plus anciens que ceux de la Formation Qatrani du Fayoum (Egypte).

Paleocological sequence on the corsican continental slope during the last 100.000 years from Foraminifera and Pteropoda. A core sampled in the S.W. of Ajaccio at 835 m depth shows a very low rate of sedimentation. The sediments attributed to the last interglacial (Tyrrhenian) contain a plantonic Foraminifer, Globigerinoides conglobatus , which is a warm-temperate atlantic species. The glacial (würmian) deposits are characterised by north-atlantic assemblages. This fact emphasizes the importance of water masses displacements in the evolution of the bathyal microfauna during the Quaternary., Une carotte prélevée au S.W. d'Ajaccio, par 835 m de fond, a révélé une vitesse de sédimentation très faible. Les sédiments attribués au dernier interglaciaire (Tyrrhénien) contiennent un Foraminifère planctonique, Globigerinoides conglobatus, qui est une espèce atlantique tempérée chaude. Les sédiments würmiens se caractérisent par des espèces benthiques et pélagiques de type nord-atlantique. Ceci met en évidence le rôle des déplacements des masses d'eaux dans l'évolution des microfaunes bathyales au cours du Quaternaire., Blanc-Vernet Laure, Bourdillon Chantal. Succesions paléoécologiques sur la pente continentale corse pendant les derniers 100.000 ans d'après les Foraminifères et les Ptéropodes. In: Géologie Méditerranéenne. Tome 9, numéro 3, 1982. Formations carbonatées : dynamique, successions paléoécologiques. pp. 279-283.

Dans le cadre du projet CINERGY, un forage carotté de 675 m a recoupé l'ensemble de la série sédimentaire remplissant ce bassin, puis la partie altérée du socle sur plus de 100 m et le socle sain sur 150 m. La série sédimentaire carottée a fait l'objet d'une première étude intégrant biostratigraphie, minéralogie, sédimentologie de faciès et analyse séquentielle, visant à établir le cadre chronostratigraphique, l'évolution des paléoenvironnements et du climat. L'intervalle étudié (66-405 m) comprend 4 unités lithostratigraphiques : - les Marnes à Natica (66-85 m) correspondent à des dépôts laguno-marins argilo-calcaires. La malacofaune et les associations de dinokystes sont typiquement rupéliennes ; - les Sapropèles inférieurs (85-206 m) sont caractérisés par des alternances d'argiles laminées et massives à traces de racines. Le Rupélien inférieur est attesté par la présence du pollen B. hohli. La limite E/O est localisée dans l'intervalle 189-206 m ; - les Argiles à Mohria (206-375 m) ont des faciès similaires, mais particulièrement riches en matière organique. Ces deux formations témoignent d'un environnement lacustre à palustre. Les associations polliniques sont d'âge Priabonien ; - la Formation basale argilo-sableuse (375-405 m) correspond à l'apparition des premiers sables. Les environnements de dépôts fluctuent entre fluvio-lacustre et fluvio-marin. Ces dépôts ont pu être datés par les pollens et les foraminifères du Lutétien supérieur au Bartonien. L'analyse séquentielle de cette succession montre deux MFS majeures, l'une dans les dépôts côtiers vers 380 m, l'autre dans les dépôts très organiques lacustres vers 240 m. A l'échelle de la séquence élémentaire, deux types d'unités génétiques sont définies selon l'environnement lacustre ou lagunaire. La comparaison du bassin de Rennes avec celui de Saffré indique une subsidence nettement plus importante pendant le Priabonien à Rennes. La comparaison avec d'autres bassins ouest-européens place les bassins de Rennes et Saffré dans une dynamique intermédiaire entre les bassins d'effondrement très subsidents comme le fossé rhénan et les bassins intracratoniques parisien, belge ou anglais. L'étude palynologique montre un changement important de la végétation à la fin de l'Eocène avec l'augmentation des Pinacées, puis un changement plus profond du climat à l'Oligocène avec le développement des Herbacées, attestant d'une saison sèche plus marquée, et l'apparition de la chlorite-smectite. A l'échelle ouest-européenne, on constate la simultanéité de ce refroidissement fini-éocène. Une étude à plus haute résolution de cet intervalle clé, particulièrement bien enregistré à Rennes, fournira des réponses sur ce changement global.

The Hawasina napper of the Oman Mountains yielded Permian radiolarians from cherts stratigraphically overlying a thick volcanic basement (Al Jil Formation) at the base of the Hamrat Duru Group. This fauna represents the first Permian radiolarians and radiolarites in the central and western Tethyan realm. A Permain age for pelagic sequences within the Hawasina Complex of Oman has major significance for regional paleogeographic reconstruction. A clear differentiation between platform (reefal sediments) and basin (radiolarites) from the base of the Late Permian (255 Ma) is implied. It suggests a flexure of the platform during Permian time; the present data implies that a zone of rifting was already developed adjacent to the northeast Gondwana platform margin during the Late Permian. The Hamrat Duru Basin corresponds to an opening intracontinental rift area (sphenochasm) between Arabia and northeast Gondwana, a reentrant of the paleo-Tethys.