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

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

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

Ostracods and lithofacies close to the Eifelian-Givetian boundary (Devonian) at Aisemont (Namur Synclinorium, Belgium)

The paper presents the sedimentological analysis and the ostracod study of the upper part of the Rivière Fm. and of the stratotype of the Névremont Fm. in the Aisemont section, the reference section for the Eifelian-Givetian boundary (Devonian) in the southern border of the Namur Synclinorium, Belgium.Thirteen major microfacies types are defined. Their stratigraphic succession records the transition from a mixed siliciclastic-carbonate ramp (upper Eifelian) to a carbonate platform (lower Givetian). About 6,350 ostracods were extracted. Forty species (19 in open nomenclature) are recognized in the Rivière Fm. and 48 species (27 in open nomenclature) in the Névremont Fm. They belong exclusively to the Eifelian Mega-Assemblage and their distribution is controlled mainly by water energy and salinity variations.The sedimentological analysis and the study of ostracods are in good agreement with recent conodont study of GOUWY & BULTYNCK (2003). Our work confirms the position of the Rivière and Névremont formations boundary and highlights a gap of the major part of the Hanonet and Trois-Fontaines formations of the southern Dinant Synclinorium. This hiatus is probably associated with the lowstand systems tract at the Eifelian-Givetian boundary interval in northern France and southern Belgium (PRÉAT, 2004).The presence of Quassilites fromelennensis and Jenningsina heddebauti, indicates that a great part of the transitional zone of GOUWY & BULTYNCK (2003) is of Givetian age

Ostracodes et sédimentologie du sommet de l'Eifelien et la Base du Givetien, à Couvin (bord sud du Bassin de Dinant, Belgique)

About seventy ostracod species are present in the upper part of the Hanonet Formation (Upper Eifelian) and in the base of the "Trois-Fontaines" Formation (Lower Givetian) of the "La Couvinoise" quarry at Couvin (southern border of Dinant Basin, Belgium). The ostracods belong to the "Eifeler Okotyp" and four associations are recognized which characterize successively a quiet open marine environment on the outer ramp (ecozone III), a shallow marine environment with increasing of water turbulence on the mid- and inner ramps (ecozone II), an open lagoonal environment on the upper part of the inner ramp (ecozone I) and a restricted lagoonal environment on the platform (ecozone 0). This sequence is the same as in the Resteigne quarry (50 km E of Couvin) studied by CASIER & PREAT (1990 & 1991) and is closely related to environmental variations. The principal ecological factors controlling the composition of the ostracod fauna are water movement in the Hanonet Formation (Eifelian), and water movement and salinity in the Trois- Fontaines Formation (Givetian). Two new species are erected: Condracypris? covinumensis n. sp. et Microcheilinella? hanonetensis n. sp

Ostracods, rock facies and magnetic susceptibility of the Hanonet Formation / Trois-Fontaines Formation boundary interval (Early Givetian) at the Mont d’Haurs (Givet, France)

Approximately 870 carapaces, valves and fragments of ostracods were extracted from 26 samples collected in the Hanonet Formation (= Fm) and Trois-Fontaines Fm in a section located along the southwestern rampart of the historically entrenched military camp at the Mont d’Haurs (Givet, France). Forty-eight species belonging to the Eifelian Mega-Assemblage have been identified and three new are proposed: Coryellina? audiarti nov. sp., Cavellina haursensis nov. sp. and Parabolbinella coeni nov. sp. The ostracod assemblages are generally indicative of shallow marine well-oxygenated environments, except at the base of the Trois-Fontaines Fm where ostracods indicative of semi-restricted and even of lagoonal water conditions are reported.The sedimentary record represents a transition from mixed siliciclastic-carbonate open-marine ramp system to restricted carbonate platform with deposition in low-energy peritidal and lagoonal settings frequently affected by subaerial exposition. A general trend follows a shallowing-upward and a relative sea-level decrease from the Hanonet Fm toward the Trois-Fontaines Fm.High-energy characterized the ramp setting and destroyed most of the stromatoporoid and coral buildups, which occur as floatstone and rudstone accumulations forming a thick biostrome. Girvanella and issinellid shoals developed also in this high-energy environment. The low-field magnetic susceptibility (=MS) log plotted against the lithological column reveals four magnetic sequences. The MS log and microfacies are moderately correlated mainly due to the evolution of sedimentary environments from a ramp to a platform. The MS values of the Trois-Fontaines Fm are very low in the biostromal unit whereas restricted lagoonal facies are characterized by the highest values of MS. A high-resolution stratigraphic correlative pattern is proposed here between the Mont d’Haurs section and the 40 km distant Baileux section despite the greater thickness. The MS signal is strongly controlled by minerals of ferromagnetic characteristics with a minor contribution of paramagnetic phases. The lagoonal sediments of the Trois-Fontaines Fm are characterized also by the highest values of normalized viscosity coefficient and a IRM loss. These results confirm the occurrence of a significantly high proportion of ultrafine magnetic grains which may be formed during diagenesis by chemical remanent magnetization processes.The list of the Givetian ostracods figured by Coen (1985) and recently lodged at the Department of Paleontology at the Royal Belgian Institute of Natural Sciences is reported in annex with new inventory numbers