502 research outputs found
Les Ostracodes des Sédiments envasants du récif de la Carrière Beauchâteau, à Senzeilles (partie supérieure de Frasnien, Bassin de Dinant)
This study indicates that the red marble reef of the Beauchâteau quarry (Dinant Basin, Belgium) was formed in a shallow marine environment. The enclosing sediments probably overlap the Favulella lecomptei / Svantovites lethiersi Interval Zone and the S. lethiersi Zone of the zonal sequence established on Metacopida. Two new species, Bairdiocypris bellicastellana n. sp. (PODOCOPIDA) and Rozhdestvenskayites senceliensis n. sp. (PALAEOCOPIDA) are described
Contribution à la connaissance des ostracodes du frasnien de la belgique
Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe
La zone à Svantovites Lethiersi n. sp., zone nouvelle d’Ostracodes de la fin du Frasnien et du début du Famennien des bassins de Namur et de Dinant
The species Svantovites lethiersi n. sp. is described in detail. This speciesgives its name to a new zone of the upper part of the Frasnian andlowermost Famennian — Eoparaphorhynchus triaequalis triaequalis Zone— of the Namur and Dinant Basins. The Favulella lecomptei Sub-zone iselevated to full zonal status
Les Ostracodes des Schistes à aspect « Matagne » de la partie supérieure du Frasnien de l’affleurement protègede Boussu-en-Fagne, Belgique
Fourteen species, eleven of which are Entomozoacea, are described.Two are new : Entomozoe (Nehdentomis) buxutumensis n. sp. andEntomoprimitia (Entomoprimitia) sartenaeri n. sp. This last species issynonymous with E. (E.) variostriata (CLARKE, J., 1884) sensu A. RABIEN,1954. The base of the outcrop belongs to the Bertillonella (Rabienella)reichi (MATERN, H., 1929) Zone, and the Upper part perhaps to theB. (R.) reichi (MATERN, H., 1929) / Entomoprimitia (Entomoprimitia)splendens (WALDSCHMIDT, E., 1885) Interval
Les Entomozoacea (Ostracodes) du Frasnien de l’extreme occidentale du bord sud du bassin de Dinant, Belgique
An abundant and relatively well-preserved Frasnian entomozoid fauna occurs in the westernmost sequences of the southern part of the Dinant Basin. Fifteen species have been identified of which five are described. The zonal sequence established by A. RABIEN in 1954 for Germany is applicable also to the Belgian faunas and one super-zone, four zones and two intervals are recognized
Paléoécologie des Ostracodes au niveau de la limite des étages Frasnien et Famennnien, à Senzeilles
Study of the ostracods of the Frasnian-Famennian boundary in Senzeilles (Dinant Basin, Belgium) confirms the existence of shallow, poorly oxygenated waters in Palaeotethys during the late Frasnian. These environments are responsible for the disappearance of mud-mounds and for the sedimentation of the so-called « Matagne Shales » which are rich in Entomozoacea and Cypridinacea. The faunal change on which the Frasnian-Famennian boundary was defined in last century by GOSSELET corresponds to Ihe gradual colonization of such an environment after ihe improvement of the oxygen supply. The extinction rate of the OStracods near the Frasnian-Famennian boundary is not abnormal
Description et étude des ostracodes de deux tranchées traversant la limite historique Frasnien-Famennien dans la localité type
Study of two new trenches dug at Senzeilles shows the sudden change from a dysaerobic to a well oxygenated environment at the boundary between shales with "Matagne" aspect and transition shales. This event located 3.5 m below the base of Senzeilles shales seems the same as the event observed at the top of the Kellwasserkalk in Kellerwald and Harz. The dysaerobic community contents numerous ostracods belonging to Entomozoacea and Cypridinacea super-families. The faunal renewal begins with the appearance of a very abundant benthonic ostracod fauna and crinoïds, 2.5 m below the first appearance of the brachiopod macrofauna on which GOSSELET fixed last century the Frasnian-Famennian boundary. The mode of life of the Entomozoacea is discussed in answer to GROOS-UFFENORFE & SCHINDLER's recent paper (1990)
Evolution sédimentaire et Ostracodes de la base du Givetien à Resteigne (bord sud du Bassin de Dinant, Belgique)
The facies patterns of lower Givetian rocks (Trois-Fontaines, Terres d'Haurs and Mont d'Haurs Formations) at Resteigne quarry (southern border of Dinant Basin, Belgium) reveal a transition from mixed siliciclastic carbonate ramp to gently sloping carbonate platform without any true reefal barrier. Depositional conditions on the ramp were open marine, well circulated, well lit and very near or within wave base. The ramp evolved through a very shallow-subtidal to supratidal, restricted to semi-restricted, quiet stable platform during early Givetian times. A sedimentological model for this succession enables recognition of 12 major microfacies, ranging from open marine, below wave action zone, to reefal complexes, lagoons and supratidal mats. These microfacies define three principal facies belts. Four ecozones belonging to the "Eifeler ökotyp" are recognized in the Givetian of Resteigne quarry. Ecozone 0 is characterized by Leperditicopida in the middle and upper parts of the Trois-Fontaines Formation and indicates a restricted lagoonal environment; three ostracod sub-assemblages can be recorded in term of salinity. Ecozone I is characterized by a few species of Platycopina, Palaeocopina or Eridostraca, each present in large numbers; it indicates an open lagoonal environment in the Terre d'Haurs Formation and, exceptionally, in the middle and upper parts of the Trois-Fontaines Formation. Ecozone II, dominated by large, thick shelled Podocopina, indicates water turbulence at the base of the Trois-Fontaines Formation and in the Mont d'Haurs Formation. Ecozone III is rich in species of Podocopina, Platycopina, Metacopina, Palaeocopina and Eridostraca; it indicates a shallow open marine environment in the Mont d'Haurs Formation and, exceptionally, in the Terres d'Haurs Formation. Water movement and salinity are the principal ecological factors controlling the composition of the basal Givetian ostracod fauna at Resteigne. Their detailed analysis gives more information about the elementary regressive rhythms that produce cyclic patterns on the platform. A new species is erected: Evlanella lessensis n. sp
Sédimentologie et Ostracodes de la Limite Eifelien-Givetien à Resteigne (Bord Sud Du Bassin de Dinant, Belgique)
The global cyclic succession of the microfacies from the Upper Eifelian to Lower Givetian times shows evidence of shallowing from deeper settings, unaffected by storm-reworking, into «proximal» above storm wave base settings, near a shoreline coast. This overall regressive progradational megasequence indicates that deposition could have occurred on a ramp setting without any kind of continuous rims and-or typical lagoonal facies behind them. This general upward-coarsening progradational evolution corresponds probably to a phase of reduced sea-level rise or stillstand on the top of which the ramp setting has evolved into a carbonate progradational accretionnary platform. Forty-one ostracod species are reported and twenty-four described from the Hanonet Formation and from the base of the Trois-Fontaines Formation of the Resteigne quarry. Sixteen are known mainly from Germany and Poland and five of them are closely related to well established species. Sixteen species are placed in open nomenclature, three of which are new, and eight are comparable with previously described data. Aparchites resteignensis n.sp. is described in detail. The ostracod fauna indicates a shallow marine environment and an increase of water agitation near the Eifelian/Givetian boundary
Middle Frasnian (Devonian) ostracods from the Frasnes railway section (Dinant Synclinorium, Belgium); taxonomy, biostratigraphy, paleoecology
Eighty-nine samples have been collected for ostracods, from the stratotypes for the upper part of the Moulin Liénaux Formation and the Grands Breux Formation, in the Frasnes railway section. Forty-seven taxa were recognised, of which 20 have been recorded for the first time in the Middle Frasnian (Devonian) of the Dinant Synclinorium (Belgium). The stratigraphic distributions of a series of already known species are stated more precisely. The investigated part of the section belongs to the Favulella lecomptei Zone. A new species, Bairdiacypris breuxensis nov. sp. is described. The ostracods present in the upper part of the Moulin Liénaux Formation and in the Grands Breux Formation belong exclusively to the Eifelian Mega-Assemblage and their distribution is principally controlled by the energy of the environment, linked to sea level fluctuations
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