Stratigraphie, paléoécologie et foraminifères du paléogène des Alpes Maritimes et des Alpes de Haute-Provence (Sud-Est de la France)

Paleogene sedimentation in the Alpes Maritimes and Alpes de Haute Provence regions is composed of one complete sedimentary sequence. This sequence begins with the continental Formation from Microcodium and continues with the Cerithium layers, the Calcaires Nummulitiques and the Marnes Bleues, which are overlaid by the turbidites of the Grès d’Annot Formation. Sedimentation starts in the Nummulites perforatus zone close to the base of ‘the Truncorotaloides rohri zone (P 14) and ends in the Cassigerinella chipolensis-Pseudohastigerina micra zone (P 18) and the NP21 zone in the upper part of the Grès d’Annot. More biomarkers were used in order to define a more detailed local biozonation (biozones AMP 1 to AMP 7). Four local zones were also defined by the last occurrence of Nummulites millecaput and N. perforatus-N. ptukhiani and then by the first appearance of N. retiatus (AMGF 1-4). The evolution of benthic foraminiferal assemblages shows an increase in bathymetry from the internal platform in the Cerithium layers to the calcareous platform with large foraminifers, then to the external platform and the deep offshore environment of the Marnes Bleues and Grès d’Annot. Low faunal diversity in the Grès d’Annot together with the predominance of agglutinated species indicates a poorly oxygenated, organic rich and turbidite environment. Seven steps (SD 1 to SD 7) in the Eocene marine transgression are shown from East to West by detailed local biozonation and sequence analysis. Grès d’Annot sedimentation is also diachronous, beginning within the Truncorotaloides rohri zone (P 14, AMP 1) in the East and ending within the Pararotalia opima opima zone (P 20, middle Rupelian) in the West (Barrême). Small foraminifer Paleogene fauna from the Alpes Maritimes and Alpes de Haute Provence was studied from 400 samples. It is composed of 378 species. Two new taxa are proposed: Fissurina niceana n. sp. and Globocassidulina alpina n. sp. The species from the Escarène and Gorbio neighborhood described by M. von Hantken (1884) were re-examined.     

Matière organique sédimentaire et paléoenvironnements du Tithonien inférieur quercynois (France)

The Solen 98 well corresponds to the limestones of the Lower Tithonian Cazals Formation (Gigas Zone). The iterative succession of six sedimentary terms expresses a cyclic peritidal dynamic. Limited by two emersion surfaces, each sequence evolves from an upper subtidal lagoon to a tidal flat, upper intertidal or supratidal environment, and ends with open sea depositional bioclastic and oolitic shoals deposits. Hierarchical ascendant classification applied to palynological data define 6 palynofacies types associated with different depositional facies. Type 1, characterizing open marine deposits, shows a diversified and balanced assemblage. The blade-shape woody particles are abundant and the amorphous organic matter is absent. Types 2 and 3 are linked to lagoonal and skeletal shoals deposits. Then microfossil population is dominated by Corculodinium or long-spine Micrhystridium. The Shannon-Weaver and the equitability indices are moderate. Type 4 is associated with the upper tidal flat, lagoonal and skeletal shoal deposits. When microfossils are present, the algal assemblages are more balanced than in type 5. This type, observed in all the palaeo-environments except the open marine, is enriched in elements attributed to the Hyalinsphaeridia complex. The marine component assemblages are balanced. The amorphous organic matter is relatively abundant and the oxydized woody particles absent. Type 6, mainly composed of amorphous organic matter and phytoclasts, is principally associated with the stromatolitic facies of tidal flat deposits. The example of the Solen 98 well, shows that hierarchical ascendant classification method is well suited for identification of palynofacies     

Les industries paléolithiques du bassin de Bose (Chine du Sud)

About eighty Paleolithic sites are presently known in Bose basin (West of Guangxi autonomous region, South China). The sites are extensively spread on the fourth terrace of the Youjiang River. They are dated to 0.8 my, thanks to the presence in the archaeological layers of tektites, residues from a major meteoritic event, in association with the archeological materials. Only about twenty sites have been actually excavated and handaxes have been very recently discovered in stratigraphic context. The archeological material exclusively includes lithic industry which is mainly constituted by unifacial pebble tools made on coarse grain rocks: choppers, but also handaxes and picks. The technology used is very simple and there are no spheroids which usually characterize a lot of Chinese sites of this period. Bose handaxes, thought their number is quite low, remind of the western Acheulian.     

L’ambre cénomanien d’Anjou : stratigraphie et paléontologie des carrières du Brouillard et de Hucheloup (Ecouflant,Maine-et-Loire)

The Ecouflant area (Maine-et-Loire, France) shows the last outcrops from the Anjou region that allow the study of early Cenomanian lignites and the associated amber. The quarry of Le Brouillard was historically the most studied locality, but it is now partly covered by bulky waste. No fossil arthropod has been found in the amber collected in this locality, and only a few bacterial filaments and plant fragments were detected among the microinclusions. The quarry of Hucheloup shows a wider exposure. Amber is poor, but fossil plants and bivalve are frequent. Based on the sedimentological series and the palaeontological contents of the lignitic clay, we suggest that it corresponds to estuarine to coastal depositional environments with variable salinity.     

Un biofacies à Trilobites Homalonotidae dans I'Ordovicien de la marge nord-gondwanienne: implications paléobiologiques et paléogéographiques

During the Llandeilo, the sandy lithological units which develop locally in the Armorican Massif, Spain and Morocco, are all characterized by similar trilobite associations in which endobenthic homalonotids. well adapted to shallow water and sandy substrate, are predominant. During the Llandeilo, on the northern Gondwanan margin, the wide geographical distribution of most of the trilobites, controlled by environmental factors, shows that the existence of a 'Proto-Tethys' ocean is unlikely. □ North Gondwana, Trilobita, Homalonotidae, Ordovician, Llandeilo. palaeoenvironment.     

Stratigraphie et sédimentologie des « Couches rouges » continentales du Jurassique-Crétacé du Haut Atlas central (Maroc) : implications paléogéographiques et géodynamiques

In several synclines of the central High Atlas, the “Redbeds” following the closure of the marine Tethyan Atlasic trough during the Middle Jurassic are constituted by three successive formations or units of continental deposits dated recently with biostratigraphical elements. Some micropaleontological markers, mainly charophytes and ostracods, allow to precise the stratigraphy in agreement with a Bathonian-?Callovian assignment for the lower unit (Guettioua Formation), and in dating the middle and upper units. The Upper Jurassic, mainly the Kimmeridgian, is developed in the lower part of the middle unit (Iouaridene Formation). The Barremian has been recognized in this middle unit and in the upper unit (Jbel Sidal Formation). The Jurassic/Cretaceous boundary is thus delimited for the first time with micropaleontological data. These new data are very significant for the Atlasic history during the Mesozoic. The basaltic flows inserted in the continental Jurassic-Cretaceous deposits of the central High Atlas result from two separate events in the Middle Jurassic and in the Barremian. The tectogenesis in the basins is characterized by a polyphase process including notably a synsedimentary tectonic activity conspicuous in the Barremian. The evidence of marine to brackish intercalations allows moreover to date the first Cretaceous transgressive event on the NW boundary of the High Atlas during the Lower Barremian and to consider an Atlantic paleogeographical interaction. SW margin of the Tethyan trough in the Lower and Middle Jurassic, the central High Atlas is merged with the margin of the central Atlantic Ocean during the Lower Cretaceous.     

Algues et microfossiles problématiques du Dévonien Moyen du « Fondry des Chiens » (bord sud du Synclinorium de Dinant, Belgique) : implications paléobathymétriques

This study is concerned with the distribution of algae and microproblematica observed in a regressive sequence of carbonate rocks that accumulated open marine to lagoonal palaeoenvironments. The basal algal microflora is reduced to a few chlorophytes (Udoteacean, Dasycladales), but increases rapidly in number and diversity in the flanks of the bioconstructions, then explodes in the restricted facies (“Pseudo-udoteaceans”). An attempt to estimate the bathymetry is based on the palaeoecological constraints of the identified algae. We conclude that the maximum water depth did not exceed the twenty meters. The regressive sequences being made of around sixty meters (of reefal, perireefal and lagoonal carbonates), subsidence is believed to be the main mechanism controlling accommodation space.     

Ostracodes de la Formation de Bhanness,Kimméridgien (Jurassique supérieur) du Liban central : taxonomie,paléoécologie et paléobiogéographie

A microfauna composed of 11 species of ostracodes belonging to 11 genera have been recovered from the Bhanness Formation of Kimmeridgian age, in Central Lebanon. Four species are new and are described herein: Ektyphocythere dahressawanensis nov. sp., Dicrorygma (Orthorygma) libanensis nov. sp., Citrella? elongata nov. sp. and Procytherura inflata nov. sp. From a palaeobiogeographical standpoint, this fauna characterizes the North Gondwana province which differs from the South Gondwana province, particularly by the presence of the genus Schuleridea and the absence of the genus Majungaella.     

Taphonomie des plantes et interprétations paléoécologiques. Une synthèse

The taphonomy is a powerful and requisite tool for environmental reconstructions of ancient plant communities. Necrobiotic processes, which lead to the production of plant fragments, inform us on fossil plant physiology. Among the processes that can be drawn from necrobiotic studies is the retention of leaf organs on plants, the relative quantity of pollen grains produced by different fossil species or the significance of wildfire dynamics in ancient plant communities. Biostratinomy examination is a fundamental tool for elucidating fossil plant habitats. Numerous experimental data allow paleobotanists for evaluating the role of transport in the origin of fossil assemblages. Autochthonous plant assemblages, which are characterised by the preservation of fossil rooting structures, are relatively rare in the nature. In consequence, the search for palaeoecological information from parautochthonous to allochthonous assemblages has been a priority in taphonomy. As a result, taphonomic models have been elaborated in well-known sedimentological contexts, such as small lacustrine deltas, which allow for the distinction between riparian or perideltaic plant remains. Lithospheric processes modify plant debris after burial. The differences in the degrees of transformations (or alterations) during the diagenesis provide for information about the original morphology and biochemical composition of the plant tissues, which are also paleoecologically useful. Thus, amber diagenesis modifies resin biochemistry into new molecules that are still informative from the chemotaxonomical point of view.     

Euxinocythere (Ostracoda, Cytheridae, Leptocytherinae) du Miocène supérieur du Bassin de Turiec (Slovaquie) : taxonomie et paléoécologie

Eight new species of the family Cytheridae have been identified in the Upper Miocene deposits of the Turiec Basin (Slovakia), a small isolated intermountain depression. Six species are new - Euxinocythere aphroditae, E. delicata, E. lactea, E. minuscula, E. quadricostata, E. satyrica - and two are kept in open nomenclature. Their attribution to the genus Euxinocythere is based on arrangement of the hinge elements and of anterior marginal zone. This genus is known from brackish ostracod assemblages of the Paratethys and the Eastern Mediterranean while the species from the Turiec Basin are associated to fresh-water assemblages. The Euxinocythere have been found in littoral as well in deep limnic environment.     

Le « nucléus Donggutuo » et sa signification dans l’industrie du paléolithique inférieur de Donggutuo, bassin de Nihewan, Chine du Nord

As one of the most important Lower Pleistocene sites of the Nihewan basin in North China, Donggutuo (DGT) site is well known for its fine retouched small tools and characters of flake industry. However, new excavations still reveal some new discoveries and educe some new issues to us. For example, the “DGT core” introduced in this article is a new discovered typotechnology and indicates new economic strategy of the local people, which was never known before in this area at the time of 1.1 Ma B.P. The paper provides general background and statistic analysis of DGT industry including special method applied to the “DGT core” and discusses possible influence of environmental change for the emerging of the “DGT core”. The “DGT core” shows a germinated microlithic tradition and reflects a cultural diversity of early humans in the Lower Paleolithic in North China.     

Heterosteginapapyracea Seguenza du Miocène du Corridor Sud-Rifain (Maroc) : biométrie et particularités paléoécologiques

Biometric study of the inner features of Heterostegina specimens preserved in tortonian sediments of the oued Yhoudi member allows to confirm the presence of species Heterostegina papyracea Seguenza, 1880. Analysis of both large and small components of the foraminiferal assemblage in all examined samples establishes the dominant character of species Heterostegina papyracea Seguenza (more than 60% of total benthic foraminifera). The assemblage of small benthic foraminifera associated with the Heterostegina is different from that described from Recent sediments, as well as from Miocene sediments of Calabria and Spain. In order to explain this result, two hypotheses can be put forward: (1) the Tortonian Heterostegina from Morocco proliferated abundantly in very shallow environments in association with small foraminifera (i.e. abundant Ammonia beccarii). (2) Because of powerful tidal currents in the South Rifian Corridor, Heterostegina tests were probably transferred after death. This transfer could possibly be due to the narrowness of the South Rifian Corridor in the Early Late Tortonian and its position between the Atlantic and the Mediterranean. Similar cases foraminiferal displacements are also known from modern basins. This study illustrates the difficulties in reconstructing the paleogeography of the studied area and the importance of considering all available components of the assemblage.     

Corrélation des successions de l'Albien par les ammonites entre la Province Nord-Pacifique et les Provinces européenne et arctique du Domaine boréal : zonation, eustatisme et paléobiogéographie

The vertical distribution of Albian ammonites of the North Pacific Province is described on the basis of several sections located in Northern California. Nine Albian ammonite assemblages are identified, compared to the 4 previously described by Murphy in 1956. Owing to several gaps of observation possibly more assemblages could exist. In the North California Albian history, the first results show a succession of confinement periods - with numerous endemic faunas - followed by periods of open communications with other faunal provinces. As an example, the base of the Middle Albian is marked by exotic ammonites coming from the Tethyan realm (Oxytropidoceras, Lyelliceras) and from the Arctic Province of the Boreal realm (Gastroplites, Pseudopulchellia). These ammonites - except Oxytropidoceras - were not known in that area and are described relatively to their palaeobiogeographical interest. Although rare these migrant faunas give valuable elements to correlate these various provinces. Planktonic foraminifera confirm the existence of open sea communications during the uppermost Albian.With such faunal links, a comparison is proposed between the Albian ammonite zonation of Northern California and the standard and phyletic ones of Europe. This attempt suggests that the major connections between the three faunal provinces are established at second order peak transgressions in the Early and Middle Albian, and during the sea-level high of the Late Albian transgressive period. So, it seems that the vertical distribution of Albian non-endemic ammonites of North California and Europe is largely controlled by global eustatic events. Two palaeobiogeographic maps for Early and Middle Albian and one map for the late Late Albian show the migration outer of these exotic ammonites.     

Lithostratigraphie et biostratigraphie des formations paléocènes et éocènes entre Bayonne et Pau (SW France)

The lithostratigraphy and biostratigraphy of the Paleocene and Eocene formations have been reconsidered on the basis of 18 dated boreholes that intersect the Basque Country, Peyrehorade, Sainte-Suzanne and Sauvelade allochthonous tectonic units, as well as the autochthonous units of the Pey-Saint-Lon anticline, the Arzacq Basin and the North Pyrenean Trough. Correlation of the formations identified in the boreholes and at outcrop has made it possible to outline the sedimentary evolution of this region during the Early Paleogene and to date the various stages of Pyrenean compression on the basis of sedimentary gaps and syntectonic detrital input. The Lasseube Formation is present over the entire study area. Sedimentation becomes differentiated during the Late Selandian-Early Ypresian period. In the North Pyrenean Trough and in the Peyrehorade, Sainte-Suzanne and Sauvelade units, the detrital-clayey Pont-Labau Formation is well developed and all its members are represented (Guillempau, Latapy, Néez, Libaros and Artigueloutan; zones upper P 3b-P 6b; upper NP 5-NP 11). A sedimentary gap showing erosion, and involving zones upper P 3b-upper P 4a and upper NP 5-NP 7, characterises the Basque units, the Pey-Saint-Lon anticline and the western part of the Arzacq Basin. Sedimentation recommences in zone P 8 with middle-bathyal deposits of the Cassoua Member and then continues with the Artigueloutan Member (transition facies towards the Louts Formation) or limestone resembling that of the Meilhan Formation. The Gan Formation shows an east-west polarity. In the east, between the Sainte-Suzanne Unit and the North Pyrenean Trough, the formation is argillaceous with a dominant neritic character, apart from a circalittoral to epibathyal passage in its lower part (zone P 7) containing numerous planktonic foraminifera. The formation is of a detrital and carbonate nature in the west (Sainte-Marie-de-Gosse 1). The bathyal Donzacq Formation appears to transgress a previously deformed surface. Two domains existed during the Lutetian: a continental to neritic domain in the south and a bathyal domain in the north (the Saint-Geours-d'Auribat and Miretrain formations) separated by a variably thick transition zone that is affected by thrust fronts. Two new formations - the Orthez and Sorde-l'Abbaye formations - are proposed, and the Marly limestone formation of Saint-Barthélémy (Douvillé, 1905) is redefined. The Orthez Formation (Sauvelade Unit) is composed of marl and continental conglomerate with neritic carbonate interbedding and belongs to the sub-zones NP 15a and b. The Sorde-l'Abbaye Formation (Peyrehorade Unit and the Basque units p. p.) is composed of neritic carbonate sediments (Lutetian-Priabonian). The Saint-Barthélémy Formation is made up of syntectonic conglomerate, turbiditic limestone and pelagic marl in the central part of the Basque units (NP 15a-NP 16). The Bartonian and Priabonian stages are characterised by carbonate sediments in the Arzacq Basin (Siest Formation). Its base is diachronous: Upper Lutetian (zone SB 16) in the east and Late Bartonian grading to Priabonian in the west (zones SB 17/18 and SB 19). The sediments are argillaceous (Côte des Basques Formation) along the Atlantic coast, in the central part of the Basque units and in the Bayonne-Cauneille syncline. Major thickness variations reflect tectonic phases at the top of the Lasseube Formation in the north (erosion pre NP 8), the Néez Member (NP 7/NP 8 boundary), the Artigueloutan Member (NP 11/NP 12 boundary), and the Gan Formation (P 8/P 9 boundary). The syntectonic conglomerate and breccia indicate the development of thrust fronts in the Libaros Member (NP 8), at the base of the Pillardou and Artigueloutan members (NP 9b, c-NP 10), in the Saint-Geours-d'Auribat Formation (NP 14b) and in the Orthez and Saint-Barthélémy formations (between zones NP 15a and NP 16).     

Approche paléontologique de l’évolution du langage : un état des lieux

One of the most influential paleoanthropological approaches to the question of language origins has been the attempt to reconstruct the supralaryngeal vocal tract (SVT) in fossil humans. In particular, the low placement of the larynx was considered to be a uniquely human feature and was interpreted as a specific adaptation to produce human speech. Nevertheless, based on the anatomy of the basicranium and the hyoid bone, various researchers reached different conclusions regarding the placement of the larynx in human fossils, especially in Neandertals. Further, the recent finding of a low placement of the larynx in chimpanzees, calls into question the basic premise on which much of this research has been based. To overcome this, we have proposed and developed a new line of research into the question of speech capabilities in fossil specimens which is focused not on the ability to produce the sounds of spoken language, but on the capacity to perceive them. The modern human auditory pattern is unique among primates in showing a relatively heightened sensitivity to the midrange frequencies between 2-4 kHz, a frequency range which coincides with that of spoken language. Our analysis shows that the preserved skeletal anatomy of the outer and middle ear in the Middle Pleistocene hominids from the site of the Sima de los Huesos is compatible with human-like auditory capacities, and is clearly different from chimpanzees in the midrange frequencies. These results strongly suggest that the anatomical structures which support the modern hum and pattern of intraspecific communication were already present in these human ancestors. Further, the presence of a common condition in both the modern human and Neandertal evolutionary lineages suggests this represents an ancient adaptation within the genus Homo.     

Le paléolithique supérieur au sud du Portugal : le site de Vale Boi

Before the 90s, data on Paleolithic human occupation of southern Portugal was very scarce. During the last decade, the knowledge of the Upper Paleolithic of Algarve increased substantially due to the work of a research team based at the University of Algarve. The present paper is a report on the recent results from Algarve, focusing specially on the site of Vale Boi. It will present the chronology and stratigraphy of different human occupations from the early Upper Paleolithic up to the early Neolithic. It will focus on aspects of zooarchaeology and the exploitation of large and medium mammals as well as on marine fauna. In addition, we will present new data on stone and bone tools. Finally, we will also refer to the social and symbolic aspects present at the site, base on shell and teeth pendants and to an engraved plaquette with animal motifs.     

Découverte de charophytes de l’Albien dans la Formation Kebar (Tunisie centrale) : implications paléoécologiques et paléobiogéographiques

In Tunisia, in the platform domain, the Aptian-Albian transition is associated with a major stratigraphic gap not precisely dated, which is related to the subaerial exposure of the Aptian Orbata platform. Locally, in central Tunisia (Jebel Kebar), this gap is substituted by the sedimentary records of the Kebar Formation. This formation provided a rich association of fossil charophytes, formed by Atopochara trivolvis trivolvis, Clavator harrisii zavialensis and Sphaerochara verticillata which allows attributing it to the late Aptian–early Albian interval (most probably early Albian). In addition, a new variety, Sphaerochara verticillata var. kebariensis, is described. The charophyte assemblage shows significant biogeographic affinities with a coeval flora found in the Iberian Peninsula. The Kebar Formation was previously regarded as exclusively nonmarine, but the presence of the assemblage of charophytes and associated ostracods described rather indicates a fluctuation between margino-littoral (lagoonal) and continental environments.