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Stratigraphic context and dating of the Middle and Late Eocene vertebrate localities of the Fayum.
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The Fayum Oasis and surrounding areas in Egypt include a number of exceptionally rich and important fossil vertebrate sites. These include the Wadi Al-Hitan World Heritage Site, made famous by the abundance of archaeocete whale remains, and the site BQ-2 with its diverse terrestrial mammals, including primates. Despite the importance of this area, the stratigrapby is poorly understood and there has be little agreement in the dating of the fossiliferous units. This is in large part due to the extreme diachroneity of some of the rock units and paucity of biostratigraphically useful fossils within the shallow water facies. Platform carbonates are overlain by condensed open marine mudstones of the Gebannam Formation. These span the Bartonian-Priabonian boundary, with a diverse offhore marine fauna being present throughout, including marine mammals. Four units of shoreface sandstone of the Birkel Qarun Formation overlie and partly pass into the Gehannam Formation. The lowest of these sandstone units is dated to nannofossil zone NP19/20, and hence 'mid' Priabonian, and contains the oldest archaeocetes described from the region. Diverse fossils, including abundant whales, are present throughout the Birket Qarun Formation, but these are especially concentrated at the top of the lowest sandstone (lowstand systems tract) and in the transgressive lower part of the third sandstone and its lateral equivalent within the Gehannam Formation (transgressive systems tract). The overlying Qasr el Sagha Formation is a very rapidly deposited deltaic/lagoonal complex. Tidal channels from two to over 40 metres deep are present throughout. The lower part of this formation is still in nannofossil zone NP19/20. INterchannel deposits contain a fully marine, but probably shallow water, assemblage. Larger channels also include deeper water elements near the base, with transported terrestrial and quasimarine elements being present within the uppermost part of a small channel fill at quarry BQ-2. The transition to the non-marine units above is sharp but conformable and coincides with the base of the Oligocene. The clastic succession indicates the initiation of Nile-type drainage and coincides with the uplift of East Africa, preventing drainage to the east. It is likely that clastic successions in the Qattara Depression and Libya can be related to the same sedimentological episodes. This is largely based on, and dedicated to, the work of Chris King, who passed away earlier this year.
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RBINS Staff Publications
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Stratigraphic Correlation by calibrated well logs in the Rupel Group between North Belgium, the Lower-Rhine area in Germany and Southern Limburg and the Achterhoek in The Netherlands.
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RBINS Staff Publications
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Stratigraphical reinterpretation of Devonian strata underlying the Mons Basin based on cuttings from the Saint-Ghislain borehole, Hainaut, Belgium
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It is revealed that the lowest 1010 m of the Saint-Ghislain borehole (-4393 to -5403 m), of which cuttings are available, constitutes a crucial source of information to investigate, amongst others, the deep geothermal potential within the Brabant Parautochthon, underlying the Mons Basin, Hainaut. The lithological succession of this interval was reconstructed based mainly on visual analysis and calcimetry of 852 cutting samples as well as four core samples. Additionally, palynological, magnetic susceptibility and X-ray diffraction analyses were conducted in order to complement the dataset. The lower section of the investigated borehole sequence mainly consists of grey calcareous shale while the middle section is dominated by blue-grey shaly limestone and the upper section is mainly composed of green shale. Palynomorphs found at -5261 m suggest an uppermost Givetian–Lower Frasnian age. A new lithostratigraphical interpretation of the deepest part of the Saint-Ghislain borehole is proposed. The lower calcareous shale from -5403 m to -5100 m is interpreted as the Bovesse Formation (Lower Frasnian) and at its base possibly uppermost Givetian. The overlying limestones from -5100 to -4790 m can be attributed to the Rhisnes Formation (Upper Frasnian), and the green shale between ca. -4393 and -4790 m, to the Bois de la Rocq Member (Famennian). These results open new insights regarding the geological interpretation of the basement underlying the Mons Basin. They also present a promising approach and example regarding interpretations based on cuttings. KEYWORDS: Brabant Parautochthon, Mons Basin, Frasnian, Famennian, geothermal energy, Saint-Ghislain borehole
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RBINS Staff Publications 2020
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Stratigraphie du Frasnien du Massif de la Vesdre (Belgique)
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RBINS Staff Publications
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Stratigraphie et faune d’un puits d’extraction néolithique à Petit-Spiennes
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L'étude de la stratigraphie combinée à celle de la faune d'un puits d'extraction de silex, fouillé entre 1997 et 1999 à Petit-Spiennes, tente de retracer l'histoire détaillée du comblement d'un puits afin d'y rechercher des indices relatifs au travail minier. Elle montre que le comblement ne doit pas être conçu comme un événement synchrone mais doit se mesurer, au minimum, en terme de mois dans un environnement qui, lui, reste stable. La faune - et parmi celle-ci, surtout, les petits vertébrés intrusifs recueillis sur toute la hauteur du puits d'accès ainsi que les gastéropodes, - indiquent un milieu semi-forestier marqué par la présence de la Trouille. La découverte d'éléments fcetaux d'animaux domestiques suggère la pratique de lélevage dans un périmètre relativement proche de la mine e! par là même, celle d'un habitat aux alentours de 4500 8.P., époque du comblement de la structure. La stratigraphie offre, enfin, une illustration de phénomènes de tassement, décrits précédemment dans la littérature, ainsi que dévénements post-dépositionnels particuliers qui posent le problème du déplacement de certains restes dans un espace en théorie colmaté.
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Stratigraphie, nannofossiles calcaires et foraminifères de la coupe du ruisseau de Lespontes à Saint-Lon-les-Mines (Eocène moyen et supérieur d’Aquitaine, France).
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RBINS Staff Publications
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Stratigraphy and depositional environments of the Late Famennian (Late Devonian) of Southern Belgium and characterization of the Strud locality
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The Famennian (Upper Devonian, c. 372 to 359 Ma) strata of Belgium have recently received much attention after the discoveries of early tetrapod remains and outstandingly preserved continental arthropods. The Strud locality has yielded a diverse flora and fauna including seed-plants, tetrapods, various placoderm, actinopterygian, acanthodian and sarcopterygian fishes, crustaceans (anostracans, notostracans, conchostracans and decapods) and a putative complete insect. This fossil assemblage is one of the oldest continental – probably fresh-water – ecosystems with a considerable vertebrate and invertebrate diversity. The study of the palaeoenvironment of the Strud locality is crucial because it records one of the earliest and most important phases of tetrapod evolution that took place after their emergence but before their terrestrialization. It raises the question of environmental and ecological conditions for the Devonian aquatic ecosystem and the selection pressures occurring at the onset of tetrapod terrestrialization. The present study characterized the fluvial facies of the Upper Famennian sedimentary rocks of Strud and the surrounding areas. The exceptional preservation of arthropods and plants in the main fossiliferous layers is explained by rapid burial in the fine-grained sediment of the quiet and confined flood plain environment. Newly investigated fossiliferous sections in the Meuse–Samson area led to the description and correlation of key sections (Strud, Wierde and Jausse sections, complemented by the less continuous Haltinne, Huy and Coutisse sections). Moreover, the investigated sections allowed a review of the age of the fossiliferous horizon, which is now definitely considered to be Late Famennian in age.
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RBINS Staff Publications 2016
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Stratigraphy of an early-middle Miocene sequence near Antwerp in Northern Belgium (Southern North Sea Basin)
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RBINS Staff Publications
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Stratigraphy, sedimentology and palaeoecology of the dinosaur-bearing Kundur section (Zeya-Bureya Basin, Far Eastern Russia)
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RBINS Staff Publications
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Stratigraphy, structure and evolution of the European continental margins
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RBINS Staff Publications 2019
