共查询到20条相似文献,搜索用时 0 毫秒
1.
L'ensemble des Spongiofaunes du Crétacé moyen offre des affinités évidentes avec celles du Crétacé inférieur et même avec celles du Jurassique supérieur. Mais surtout elles annoncent l'énorme développment de la spongiofaune du Crétacé supérieur, en particulier celui des Lithistides, dont la répartition était jusque là restée assez discrête.On peut considérer que, au Crétacé, la signification bathymétrique et thermométrique des Spongiaires était acquise et que leur comparaison avec les faunes actuelles apporte des renseignements valables.Cretaceous sponge associations in Europe are useful for determining the palaeobathymetrical zones of temperature and depth; this is particularly so for the Tethyan Albian-Cenomanian transgression. Important sponge associations of the Albian to Turonian are reviewed. 相似文献
2.
Plusieurs synthèses concernant la distribution stratigraphique des kystes de Dinoflagellés dans différentes régions du monde ont été publiées. Pour le Crétacé moyen (Albien à Turonien) européen, l'obtention d'une échelle biostratigraphique précise, ainsi que sa mise en parallèle avec celle des Ammonites (ou celle des Foraminifères planctoniques par exemple), nécessitera encore de nombreuses études de sédiments bien datés, notamment en domaine mésogéen. La relative abondance de données pour le secteur occidental du domaine boréal, en particulier pour le Bassin de Paris, permet de dresser un tableau de la répartition verticale des principales formes de dinokystes (66 espèces ou sousespèces) et d'acritarches (1 espèce). Six “épisodes” biostratigraphiques sont ainsi mis en évidence et corrélés avec les zones d'Ammonites. Enfin, l'important renouvellement des espèces de Dinoflagellés au cours de l'Albien supérieur est souligné. 相似文献
4.
A partir de données bibliographiques et des observations personnelles des différents auteurs un inventaire et une mise à jour taxonomique des ostracodes du Crétacé moyen européen sont effectués. Plusieurs tableaux présentent la répartition stratigraphique des ostracodes dans les pays les mieux étudiés. Il ressort de cette synthèse une grande hétérogénéité des connaissances selon les pays. Les faunes sont relativement homogènes pendant l'Albien et le Cénomanien inférieur et marquent un net provincialisme au cours du Cénomanien supérieur et du Turonien.From bibliographic data and the authors' observations, an inventory and taxonomic updating of European Mid-Cretaceous ostracods are given. Several charts present the stratigraphic distribution of the ostracods in the best studied countries. This synthesis shows great heterogeneity in coverage for the different countries. Faunas are relatively homogeneous during the Albian and the Lower Cenomanian but show clear provincialism during the later part of the Cenomanian and the Turonian. 相似文献
5.
A. V. Dhondt 《Cretaceous Research》1981,2(3-4)
Parmi les Bivalves, les groupes dont les coquilles ont une assez forte teneur en calcite, se retrouvent très fréquemment dans les dépôts du Crétacé. En général, il s'agit de Ptériomorphes, et au Crétacé moyen particulièrement d'huîtres (Ostreacea), de peignes (Pectinidés s.l.), de Spondylidés, de limes (Limidés), de plicatules et d'Anomidés.Le rapport présenté ici reprend assez complètement les Limidés et les Pectinidés d'Europe, d'Afrique du Nord et du Texas; pour les huîtres une sélection a été faite en essayant d'y inclure des espèces utilisées en stratigraphie. Je me suis basée uniquement sur des examplaires étudiés personnellement. Certains ont été récoltés sur le terrain, mais la majeure partie a étéétudiée dans les collections de nombreux musées d'Europe et d'Amérique du Nord—les énumérer serait fastidieux et la liste n'en est pas incluse. Cependant l'objectivité scientifique m'oblige à préciser que les données pour le domaine tempéré d'Europe et pour la Téthys du Texas sont plus nombreuses que celles obtenues pour le domaine mésogéen d'Europe et d'Afrique du Nord; surtout, dans une partie des collections téthysiennes que j'ai pu étudier les indications stratigraphiques manquaient de précision; ceci pourrait expliquer certaines anomalies dans les résultats.Les subdivisions stratigraphiques utilisées sont celles présentées pour le WG9 du MCE.Au Crétacé moyen les Ptériomorphes se différencient partiellement entre les domaines téthysien et tempéré-boréal. De l'Albien au Turonien les dépôts présumés boréaux sont relativement rares; ils se retrouvent cependant à Bornholm, en U.R.S.S., et dans certains dépôts du Cénomanien supérieur du bassin anglo-parisien (Plenus marls) comme il a été démontré par Jefferies (1962).Les Ptériomorphes les mieux connus se trouvent dans le domaine tempéré. La diversité des faciès et les adaptations à ces faciès par les groupes étudiés, peuvent expliquer le grand nombre d'espèces reconnues (une liste des faunes est donnée).Among the Pelecypods, the groups with rich calcite shells are abundant in the Cretaceous deposits. In general, they belong to the Pteriomorphia and, especially in the middle Cretaceous, to oysters (Ostreacea), Pectinids s.l., Spondylacea, Limacea, Plicatula and Anomiacea.This report resumes the study of Limacea and Pectinids of Europe, North Africa and Texas. From among the oysters a selection has been made, trying to include species with a stratigraphical use. I have based my work only on specimens studied personally. Some of them were collected in the field, but most were studied in the collections of numerous European and North American Museums. I cannot enumerate all these forms, and the list is not included. Nevertheless, for scientific objectivity it must be specified that the data from the European temperate realm and from the Tethyan Texas are more abundant than those from the European and North African mesogean realms. Above all, a part of the Tethyan collections studied shows a lack of stratigraphical precision, which could explain some anomalies in the results.Stratigraphical subdivisions used are those of the WG 9 of the MCE.During the middle Cretaceous the Pteriomorphia are differentiated between the Tethyan and the temperate-boreal realms. From Albian to Turonian, the presumed boreal deposits are relatively rare; they still exist in Bornholm, the U.S.S.R. and in some upper Cenomanian deposits from the anglo-Paris Basin (Plenus marls), as was proved by Jefferies (1962).The well known Pteriomorphia are in the temperate realm. The variety of the facies and the adaptations to these facies for the groups studied can explain the great number of recognized species (a list of the fauna is given). 相似文献
6.
M. Feist 《Cretaceous Research》1981,2(3-4)
La découverte de nouveaux gisements dans le Sud de la France révèle la persistance, dans le Cénomanien, d'Embergerella cruciata, Atopochara restricta et A. brevicellis (Clavatoraceae). Une parenté entre les genres Embergerella (Barrémien-Cénomanien) et Septorella (Maastrichtien) est envisagée sur la base d'une nouvelle interprétation de la structure de l'utricule. Pour la première fois, des représentants de la famille des Characeae sont décrits dans le Cénomanien: Peckisphaera revesti n. sp. et le Turonien: Mesochara fusiformis n. sp. Indications biostratigraphiques: dans l'état actuel des connaissances sur les flores de Charophytes du Crétacé moyen, seul le Cénomanien est bien caractérisé, par A. multivolvis à laquelle s'ajoute maintenant une nouvelle association de quatre espèces; l'Albien et le Turonien, pour lesquels des précisions sont apportées, restent toutefois encore mal individualisés.The discovery of new localities in the South of France shows that Embergerella cruciata, Atopochara restricta and A. brevicellis (Clavatoraceae) continued into the Cenomanian. A relationship between the genera Embergerella (Barremian-Cenomanian) and Septorella (Maastrichtian) is suggested on the basis of a new interpretation of the structure of the utricle. Representatives of the family Characeae are described for the first time, Peckisphaera revesti n. sp. in the Cenomanian and Mesochara fusiformis n. sp. in the Turonian. Biostratigraphic information: in the present state of knowledge of Middle Cretaceous Charophyte floras, only the Cenomanian is well characterized, by A. multivolvis to which is now added a new association of four species. Although new information is presented on the Albian and Turonian, they are still inadequately understood. 相似文献
7.
J. Mdus 《Cretaceous Research》1981,2(3-4)
L'homogénéïté floristique de l'Europe de l'Ouest (boréale et mésogéenne) est remarquable au Crétacé moyen. Les limites des unités unités floristiques majeures sont controllées par des facteurs climatiques: la variation la plus importante étant située à la limite Cénomanien-Turonien.Western Europe (Boreal and Tethyan) was marked by floristic unity during the Mid-Cretaceous. The limits of the major floristic units were controlled by climatic factors, with the most accentuated variations at the Cenomanian-Turonian boundary. Stratigraphical accuracy is higher within basins than between geographical entities. 相似文献
8.
Sediments of two studied Quaternary cores from the north-eastern Atlantic Ocean were rich in coccoliths. Some species were chosen, and are briefly discussed. In addition to Emiliania huxleyi and Pseudoemilicinia lacunosa , the importance of the Gephyrocapsa genus and especially the smallest forms of the group (G. aperta var. 1 and 2, G. ericsonii, G. protohuxleyi ) is shown. A summary of the morphological variations of the coccoliths of G. caribbranica and of Coccolithus doronicoides completes the study.
The main qualitative and quantitative variations correspond to twenty stratigraphic events of the last 1,300,000 years. The same floral associations follow in succession in the two cores, which are located in different geographic and climatic areas, so it is possible to use them as a true biostratigraphy of the middle and upper Pleistocene of the north-eastern Atlantic Ocean. 相似文献
The main qualitative and quantitative variations correspond to twenty stratigraphic events of the last 1,300,000 years. The same floral associations follow in succession in the two cores, which are located in different geographic and climatic areas, so it is possible to use them as a true biostratigraphy of the middle and upper Pleistocene of the north-eastern Atlantic Ocean. 相似文献
9.
Groupe de Travail Europen des Grands Foraminifres A. Arnaud P. -Y. Berthou L. Brun A. Cherchi M. Chiocchini P. De Castro E. Fourcade A. Garcia Quintana M. Hamaoui M. Lamolda E. Luperto Sinni M. Neumann B. Prestat R. Schroeder G. Tronchetti 《Cretaceous Research》1981,2(3-4)
Le Groupe de Travail Européen des Grands Foraminifères présente un tableau de répartition stratigraphique de 42 espèces bien définies du Crétacé moyen de la région méditerranéenne. La répartition stratigraphique proposée pour chaque espèce est fondée soit sur des propres observations soit sur des données de la littérature supprimer et est contrôlée par la présence d'Ammonites ou de Foraminifères planctoniques.A summarizing account is presented of the deliberations of the research group for Large Foraminifers of the IGCP Project “Mid-Cretaceous Events”. Large Foraminifers are of incontestable value for dating carbonate platform sequences owing to the absence of many other diagnostic groups of organísms. A table of stratigraphical distributions for 42 species is presented. 相似文献
10.
11.
J. Philip 《Cretaceous Research》1981,2(3-4)
Dans un premier temps on délimite les plates-formes à rudistes de la province méditerranéenne occidentale, au sein de laquelle on distingue, en fonction des particularités paléogéographiques locales, quatre sous-provinces. On souligne ensuite l'importance et la nature des événements paléogéographiques du Crétacé moyen qui ont joué un rôle dans la distribution et le développement des formations à rudistes; on distingue fondamentalement des événements eustatiques et tectoniques. Les événements biologiques sont caractérisés par un déclin ou une disparition des rudistes éocrétacés, un développement des Caprinidae et des Radiolitidae à l'Albo-Cénomanien, l'apparition des Hippuritidae et le déclin des Caprinidae au Turonien. On analyse les causes, les circonstances et les faits majeurs de l'évolution et de la paléoécologie des rudistes au cours de cette période.The rudistid platforms of the western Mediterranean embrace four palaeogeographical sub-provinces. The palaeogeographical events that decided the distribution and development of the rudistids are discussed. Of significance are eustatic and tectonic events.There was a decline or a disappearance of Early Cretaceous rudistids, a development of the Caprinidae and Radiolitidae around the Albian-Cenomanian, the appearance of the Hippuritidae and a decline of the Caprinidae in the Turonian. Factors of evolutionary and palaeoecological significance are reviewed. 相似文献
12.
E. Voigt 《Cretaceous Research》1981,2(3-4)
Bien que la durée stratigraphique de la plupart des Bryozoaires crétacés ne soit pas exacterment connue, beaucoup d'espèces caractérisent assez bien les différents étages. Au Crétacé inférieur, dont la faune bryozoologique est plus pauvre que celle du Crétacé supérieur, ce sont les Cyclostomata qui dominent encore, comme au Jurassique. A l'Aptien, citons Chisma, mais aussi Ceata, Meliceritites et Laterocavea apparus au Barrémien. La faune de l'Albien, un peu appauvrie et peu connue, n'a fourni que quelques genres nouveaux encroûtants de Cheilostomata anasca (Rhammatopora, Wilbertopora).Au Cénomanien commence l'explosion des Bryozoaires. Les Cheilostomata les plus anciennes, les Cribrimorpha, les genres “Biflustra”, Cellarinidra, Quadricellaria, Onychocella, “Rhagasostoma”, Stichomicropora, Aechmella et un grand nombre de Cyclostomata (Crisisina, Heterocrisina, Fascipora, Spirentalophora, Marssoniella, Amphimarssoniella, Umbrellina, Exidmonea, Corymbopora, Desmopora, Discocytis, Supercytis, Truncatulipora, etc.) apparaissent. Le Turonien est caractérisé par les genres Cyclostomes (Reticrisina, Bicavea, Homoeosolen), les Cheilostomes (Tylopora, Euritina, Fusicellaria, Reptolunulites) et par de nombreuses Cribrimorpha.Onychocella nerei et Membranipora perincerta sont caractéristiques du Coniacien où l'on trouve aussi les Lunulites et Pavolunulites. Le Coniacien, plus riche en espéces que le Turonien, contient de très nombreux genres et espèces qui se poursuivent dans les étages plus élevés (Santonien-Maastrichtien).This paper deals with the distribution and stratigraphic value of Mid-Cretaceous Bryozoa (Aptian-Coniacian). Research on Cretaceous bryozoa has been neglected during the last decades and knowledge of the stratigraphical range of many Upper Cretaceous genera and species is based mainly on the personal experience of the present author. Accordingly, the range of most species is not exactly known, and the results of these investigations are only preliminary. Many cyclostomate genera (such as Stomatopora, Proboscina, Diastopora, Berenicea and Entalophora) lack easy identifiable specific characteristics, and all the other genera which can be recognized only by their rare ovicells (gonozoids) (such as Plagioecia, Diaperoecia, Microecia, Mecynoecia, Spiropora, Heteropora or Ceriopora, Reptomulticava, Lichenopora and many others) are not particularly suitable as guide-fossils. On the other hand, many characteristic new species have not yet been described.The bryozoa of the Lower Cretaceous are similar to those of the Jurassic. Both are characterized by the absolute predominance of the Cyclostomata and a few very rare primitive Cheilostomata belonging to the encrusting membranimorph Anasca.The Barremo-Aptian fauna, known mainly from England (Faringdon, Berkshire) and eastern and southern France, is characterized by the first Eleidae (Meliceritidae) with Meliceritites and Foricula, the first Ceidae, Clausidae and Horneridae with Siphodictyum and Laterocavea, Chisma furcillatum is known only from the Aptian. Cheilostomata are rare and are represented solely by encrusting membranimorph genera (Rhammotopora, “Membranipora”). The poor Albian bryozoan fauna, although similar to that of the Aptian, is characterized by the appearance of primitive uniserial cheilostomate genera such as (?) Pyriporopsis, Charixa and the genus Wilbertopora. Erect precenomanian Cheilostomata are not known. Albian Bryozoa are little-known and relatively rare.Within the Cenomanian (the plenus-zone included) many new cyclostomate genera Fascipora, Umbrellina, Siphoniotyphlus, Crisisina, Heterocrisina, Discofascigera, Corymbopora, Marssoniella, Amphimarssoniella, Discocytis, Discotruncatulipora, Truncatulipora, Desmepora, Exidmonea, Meliceritella and numerous cheilostomate genera besides “Membranipora” mainly Aechmella, Onychocella, Stichomicropora and several cribrimorphs appear for the first time. The Cenomanian is also characterized by the first erect cheilostomate species such as Onychocella, “Biflustra” or “Vincularia” and the oldest articulated or radicelled cheilostomes (Cellarinidra, Quadricellaria).During the Turonian (excluding the plenus-zone), which is less abundant in Bryozoa than the Cenomanian, the cheilostomes increase (common genera are Onychocella, Euritina, “Rhagasostoma”, bilamellar membranimorphs and cribrimorphs, mainly Rhabdopora) and the first primitive Lunulitidae (Reptolunulites) occur. Among the cyclostomes, represented by numerous species of Meliceritites, Semielea, Foricula, Truncatulipora, Clausa, Petalopora, Heteropora and the first representatives of Homoesolen, Reticrisina, Tervia and Bicavea appear.Within the Coniacian, rich faunas are known from France and England. Although the Cyclostomata are still dominant until the Santonian, considerable progress in the evolution of the Cheilostomata was made mainly by the development of the onychocellids, the erect membranimorphs and the radiation of the different cribrimorph families and genera. The oldest free-living Lunulitidae with Lunulites and Pavolunulites are recorded from the Coniacian. Among the Cyclostomata, the appearance of the genera Diplosolen, Clypeina, Crisina, Filicrisina, Sulcocava, Ditaxia, Pachyteichopora and Cytis is noteworthy. The Coniacian bryozoan fauna is closely related to that of the Santonian and has clearly an Upper Cretaceous character.I refer to the text for comments on single species which may be supposed to be useful as guide-fossils for the Aptian-Coniacian stages. 相似文献
13.
Yolande Razafindrazaka Thogne Randriamananjara Alain Piqu Catherine Thouin Edgard Laville Jacques Malod Jean-Pierre Rhault 《Journal of African Earth Sciences》1999,28(4):949-959
The Majunga Basin is located in the northwestern part of Madagascar with a N45–60°E trending axis. It was filled by almost exclusively continental Karoo Supergroup sediments, which are Permian to Early Jurassic in age, and by younger sequences, mainly marine, that were deposited from the Middle Jurassic to the present.The Karoo Basin geometry is deduced from the analysis of seismic sections. A central northeast trending horst is flanked by two sub-basins. Deposition of the Karoo sequences was controlled by these northeast trending faults. On the contrary, the Middle Jurassic to present sequences witness only a slight tilting of the basement towards the northwest.The development of the Majunga Basin includes, therefore, two successive stages. In the synrift episode, from Permian to Early Jurassic times, the sedimentation was syntectonic, controlled by synsedimentary faulting and the creation of a horst and graben extensive pattern. The postrift episode started during the Middle Jurassic.These two stages of the Majunga Basin development correspond to the geodynamic evolution recorded elsewhere in this part of the Gondwana. 相似文献
14.
Alain Piqu Edgard Laville Grard Bignot Mamy Rabarimanana Catherine Thouin 《Journal of African Earth Sciences》1999,28(4):931-948
In the western part of Madagascar, the Morondava Basin shows the Malagasy Karoo series, made of Late Carboniferous-Mid-Permian (Sakoa), Late Permian-Mid-Triassic (Sakamena) and Late Triassic-Mid-Jurassic (Isalo) sequences. The sedimentary facies are mainly aerial and clastic in the series, and the marine conditions are fully established after Lower Jurassic times, when the strait between Africa and Madagascar was flooded.The Karoo basins where these series were deposited are mainly hemi-grabens. Their filling proceeded from west to east and from south to north. Distinction between the southern and northern part of the Morondava Basin suggests that development of the basin was controlled by old crustal weakness zones trending north-northwest-south-southeast and north-northeast-south-southwest. 相似文献
15.
The clay assemblages of the Late Jurassic-Early Cretaceous sediments of the Agadir Basin are affected by burial diagenesis. Apparent ages of these formations, from the K-Ar dating of fine grain size fractions (< 2 μm), decrease downward. This indicates an opening of the K-Ar isotopic system of detrital Hercynian minerals during burial. The extent of the isotopic rehomogenisation is more important in sandstones than in clayey marl facies. During burial diagenesis, a temperature of 165°C in clayey marl and 110°C in sandstone can be enough for isotopic rehomogenisation of fine-grained Hercynian illite. The migration of pore water seems to favour the diffusion of radiogenic 40Ar in sandstones. 相似文献
16.
F. Robaszynski 《Cretaceous Research》1981,2(3-4)
Cette note donne une présentation des résultats obtenus par le Groupe de Travail européen des foraminifères planctoniques de 1976 à 1978.The results obtained by the European MCE working group on planktic foraminifera are summarized. A total of 49 species were revised, referable to the genera Planomalina, Rotalipora, Hedbergella, Whiteinella, Archaeoglobigerina, Praeglobotruncana, Dicarinella and Marginotruncana. 相似文献
17.
C. Alvarez-Ramis Ed. Biondi D. Desplats N. F. Hughes J. C. Koeniguer D. Pons M. Rioult 《Cretaceous Research》1981,2(3-4)
Cette note expose un ensemble de synthèses régionales sur les thèmes suivants: les macrofossiles de l'Angleterre; les bois de l'Albien du Boulonnais; les végétaux de Normandie du Crétacé moyen; les milieux forestiers littoraux du Cénomanien inférieur de l'Anjou et des Charentes; les macroflores du Crétacé moyen continental de l'Espagne; les gisements de l'Italie et du Sahara.L'esquisse d'une évolution possible de quelques végétations de ces contrées est proposée, ainsi que les arguments paléoclimatiques que l'on peut en déduire.This paper presents a regional synthesis concerning mid-Cretaceous plant megafossils from England, Normandy, Northern and Western France, Spain, Italy, and the Sahara. A possible evolution pattern is offered for these floras during mid-Cretaceous time; some climatic arguments are presented. 相似文献
18.
MICHELLE CARALP JOSETTE DUPRAT JEAN MOYES ET CLAUDE PUJOL 《Boreas: An International Journal of Quaternary Research》1974,3(1):35-40
Using analysis of marines cores from the Bay of Biscay as a basis, a system of different episodes of the Upper Pleistocene and the Holocene in the area of the Bay is presented. These episodes are characterized by several sedimentological and micropaleontological observations and particularly by the analysis of the coiling ratio of a few species of planktonic foraminifera. From the cores it is thus possible to determine the Holocene, the Würmian with its four glacial and three interglacial stages, and, at the base of the last glacial stage, the Riss-Würm interglacial or its upper level. 相似文献
19.
Prof. A. J. Bernard 《International Journal of Earth Sciences》1974,63(1):41-51
The author summarizes the main arguments in the debate between syngenetic and epigenetic deposits and then underlines the importance of the arguments which prove that the formation of the sediments and of the metalliferous concentrations which they bear are contemporaneous. This is strongly suggested by very early syn-sedimentary reworking of the mineralization. This approach leads to a consideration of metallogenesis of syngenetic sedimentary concentrations both as a supply of metal and a sedimentary trap. The exploitability of mineralized rocks is presently such that only the coincidence of an outstanding supply of metal and a receptive sedimentary environment will yield a workable ore deposit. Reviewing all metalliferous sources which could be contemporaneous with sedimentation (terrigenous, exhalative, marine and possibly also fluidogenic) the author stresses the geological and geochemical characteristic of the surrounding sediments. At the same time, the examination of traps in sandy, shaly and carbonate environments permits to the identification of the main characteristics of the concentration on the scale of the deposit and of the ore itself. The search for an understanding of metalliferous concentrations in the sedimentary cycle becomes a question of defining criteria for the quality of supplies and traps. On the level of the trap these would be the duration and the regulation of parameters which govern the efficiency of the concentrating system: the sedimentary features which result from these concentrating processes must be recognized within the lithologic column during tactical exploration. On the level of the metallogenetic province it is the purpose of strategic exploration to search among the available geological and geochemical data for features which favor each type of supply. These are the basic principles of the indirect method of exploration for sedimentary ore deposits. 相似文献