http://bibli-cloud15.segi.ulg.ac.be/1374-8505 fr http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7357 In the loess stratotype of Belgium, in Romont quarry (Bassenge), minerals of a volcanic ash-fall deposit are dispersed in large quantities as a cryptotephra within a fossil humic horizon dating back to the end of the Weichselian Early Glacial. Chemical analysis of pyroxenes and amphiboles indicates that those minerals belong to the Rocourt Tephra as described in another four reference localities. The stratotype of this tephra is thus maintained in this quarry, as it is the only site of high chronostratigraphic value where it is still accessible. Dans le stratotype des loess de Belgique, dans la carrière du Romont (Bassenge), des minéraux d’une retombée volcanique sont dispersés en fortes quantités sous forme de cryptotéphra dans un horizon humifère fossile qui remonte à la fin du Début Glaciaire weichsélien. L’analyse chimique des pyroxènes et amphiboles démontre que ces minéraux appartiennent au Téphra de Rocourt tel qu’il a été décrit dans quatre autres localités de référence. Le stratotype de ce téphra est maintenu dans cette carrière car c’est le seul site à haute valeur chronostratigraphique où il est encore accessible. Sun, 14 Jun 2026 00:00:00 +0200 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7357 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7349 The merit of the low-field magnetic susceptibility as proxy parameter is concisely reviewed. In many geological samples it is a composite consisting of a diamagnetic, paramagnetic, and ferromagnetic (sensu lato) contribution that varies with rock type. For weakly magnetic samples, the diamagnetic and paramagnetic contributions are an appreciable portion of the measured susceptibility. In such materials equating the measured susceptibility with the ferromagnetic susceptibility is not warranted. Before a susceptibility record is geologically interpreted, the underlying drivers of its variation must be understood. This is achieved by integrating susceptibility data with an extended magnetic property analysis, geochemical information, and a paleomagnetic assessment of the timing of the acquisition of the natural remanent magnetization as the magnetic minerals may post-date the sedimentation age. Measuring the susceptibility at several frequencies and in varying low applied fields provides important information on the grain-size distribution in the ultrafine grain end and, to a lesser extent, on the magnetic mineralogy. Examples discussed include research into loess/paleosol records and high-resolution time scale development. Variable surficial oxidation of magnetite particles and potential remagnetization complicate the interpretation of a susceptibility record in terms of paleoclimate. Fri, 05 Jun 2026 00:00:00 +0200 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7349 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7339 Sun, 28 Dec 2025 00:00:00 +0100 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7339 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7327 Three drill holes in the Mons Basin yield together 350 m of Coniacian to Campanian chalk cores. Detailed geological logging was conducted on the well-known Trivières Chalk, Saint-Vaast Chalk, and Maisières Chalk formations. A thorough sedimentological characterization was performed, from macrofacies to SEM microtexture. Petrographic observations and geochemical analysis indicate eogenetic calcite cementation and phosphatization in two benchmark levels, already known for their high glaucony content, namely in the Trivières Chalk Formation and the Maisières Chalk Formation. Upwelling currents, prevalent during the Late Cretaceous, are likely the source of the phosphates, and the cause of reduced sedimentation rates. Strong anoxic currents resulted in the formation of hardgrounds, the development of glaucony pellets and pyrite formation within shallow subtidal sediments. Multiple conglomeratic chalk intervals were identified in the Trivières Chalk Formation. They likely result from local sediment destabilization due to extensional tectonic activity. Moreover, the identification of deformation bands attests to synsedimentary tectonic activity within the basin. Overall, this research unravels various phenomena, including marine currents, sea-level fluctuations, and tectonic activity, that influenced chalk deposition in the Mons Basin. This research enables enhanced comprehension and forecasting of the heterogeneities in chalk and its spatial variability. Tue, 23 Dec 2025 00:00:00 +0100 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7327 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7317 Three tests of the holasteroid echinoid Hemipneustes striatoradiatus from the Belgian-Dutch type area of the Maastrichtian Stage preserving evidence of vertebrate-invertebrate interactions are documented and analysed. One specimen exhibits adoral pentagonal puncture marks and a large aboral scar from a mosasaur attack, with Mosasaurus hoffmannii as the presumed predator. A second test preserves evidence of two separate attacks, the first by a mosasaur, presumably Plioplatecarpus marshi, leaving both a pentagonal adoral scar and a large aboral one, and the second by a shark, leaving non-penetrating small, deep triangular pits with tapering tails. A similar pitting is seen on the third test, arranged in clusters and here interpreted as a shark bite from above followed by a second bite subsequent to a 90° rotation of the echinoid. These finds provide the first unambiguous evidence of mosasaur predation on Hemipneustes and add to the sparse record of shark-echinoid interactions, suggesting that predation on large holasteroids by vertebrates was more frequent than previously recognised. All three tests also exhibit syn vivo and post-mortem invertebrate interactions, including also an undescribed serpulid. Fri, 19 Dec 2025 00:00:00 +0100 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7317 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7310 The elasmobranch fauna of the middle Lutetian Asse Clay Member (the lower part of the Maldegem Formation) has been updated and complemented with new material from a temporary outcrop at Papenboskant (Wolvertem), about 20 km north of Brussels. This faunal assemblage, which exclusively comes from its coarse-grained glauconitic base, traditionally known as the bande noire, comprises 22 taxa. Fourteen are mentioned for the first time in this horizon, including Abdounia lapierrei, which has never been recorded in Belgium before, and Casierabatis spp. The latter comprises dental morphologies deviating from these of the two nominal Casierabatis species known to date, although it is currently unclear if these reflect intraspecific variability or represent taxonomic novelties. The new records from Papenboskant consist predominantly of small-toothed taxa, mainly batoids, which are absent from the historical handpicked museum collections of the Wemmel Sand and Asse Clay members reviewed in this study. The composition of the elasmobranch fauna indicates that during the middle Lutetian, the area north of Brussels was covered by a tropical to warm-temperate shallow sea with sandy to muddy bottoms and an open connection to deeper waters. The pronounced similarities between the assemblages of the Belgian, Hampshire, and Paris basins indicate that, during the middle and late Lutetian, these three subareas of the southern North Sea remained interconnected and maintained marine exchange with the Atlantic Ocean, not only through the northern seaway but also via the southwestern English Channel. Virtually all of the newly recovered elasmobranch taxa existed over a considerable period of time and were reported from several Ypresian and/or Lutetian deposits across the North Sea Basin. Abdounia lapierrei appears to possess biostratigraphic significance, being so far confined to Lutetian strata. This may also apply to certain representatives of the Casierabatis species group, although this remains to be confirmed. The single tooth of Notorynchus figured in Leriche (1905) and recovered from the Wemmel Sand Member at Neder-Over-Heembeek is re-examined and refigured. This specimen represents the first occurrence of Notorynchus kempi in Belgium. Thu, 18 Dec 2025 00:00:00 +0100 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7310 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7298 Two Devonian asteropygine trilobite specimens exhibiting rare cases of encrustation are recorded. An almost fully articulated exoskeleton of Rhenops australocustos from the lower Emsian in Luxembourg carries hederelloid colonies on its cephalon and thorax. The colonies are interpreted to have attached syn vivo (i.e. to the living trilobite) and the relation with their host was likely commensal. A cephalon of Philonyx philonyx from the upper Emsian in Germany exhibits five putative morphotype encrusters identified as hederelloids, auloporid corals, cornulitids, bryozoans and foraminifers. This is the first documented evidence of a foraminifer on a trilobite host. This cephalon is either a moult or a carcass. Fri, 28 Nov 2025 00:00:00 +0100 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7298 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7287 In the Neufchâteau–Eifel Synclinorium (southern Belgium), remnants of the spoil heap of the disused and now flooded underground Sainte-Barbe Quarry (Warmifontaine) yielded an invertebrate Pragian assemblage occurring in the dark monotonous slates of the La Roche Formation (Martelange Member). This locality is considered as a new Belgian Konservat-Lagerstätte (fossil conservation deposit) due to the presence of both biomineralised and soft-bodied organisms. Two specimens from the Sainte-Barbe Quarry Biota are described and assigned to two distinct classes of extinct echinoderms. The first one corresponds to an almost complete, flattened and distorted dendrocystitid solutan, which is tentatively identified as Dehmicystis? sp., based on similarities with D. globulus from the Hunsrück Slate (Emsian) of Germany. The second echinoderm specimen is a well-preserved, flattened, fully articulated and almost complete mitrate stylophoran, morphologically close to Mitrocystites? styloideus-like peltocystidans from the Lower and Middle Devonian of Germany. Taphonomic attributes of the two echinoderms from Warmifontaine (e.g. both fully articulated; mitrate with its aulacophore preserved in feeding position) suggest they were probably killed and entombed by obrution deposits in an otherwise quiet and deep setting. Other echinoderms (asteroids, crinoids, blastoids, cyclocystoids, ophiuroids) reported from the Lower Devonian of Belgium are also briefly discussed and illustrated (e.g. holotypes). Wed, 12 Nov 2025 00:00:00 +0100 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7287 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7277 Though the Neogene deposits of northern Belgium yielded many marine vertebrate remains, including cetaceans, the fossil record of several clades remains scarce. Among echolocating toothed whales (Odontoceti), cranial fossils of early delphinidans generally referred to the family Kentriodontidae are surprisingly rare in the Miocene units of the Antwerp area. Recently, a large construction pit excavated in the city centre of Antwerp allowed for the lithostratigraphic description of a section in the Kiel and Antwerpen members of the Berchem Formation. In addition to an elasmobranch assemblage of 13 species, a well-preserved, tiny odontocete cranium was discovered in the lower part of the Antwerpen Member (Middle Miocene, lower Langhian). Representing a young individual, this rare fossil displays strong anatomical similarities with the small kentriodontid Kentriodon pernix, originally found in upper Lower to Middle Miocene deposits of the Atlantic Coastal Plain (USA). It is referred here to Kentriodon cf. K. pernix, contributing to the improvement of the scant fossil record of early delphinidans in the North Sea. Associated to a degree of tooth wear that is unexpected in such a young individual, highly unusual anatomical traits, especially in the orbit region, are interpreted as resulting from a malformation that occurred relatively early during cranial development. Wed, 29 Oct 2025 00:00:00 +0100 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7277 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7272 The homalonotid trilobite Burmeisterella delattrei is recorded from the early Emsian Ruisseau de la Forge Formation in Belgium (southern limb of the Dinant Synclinorium), somewhat lower than its previously recorded first occurrence in the overlying Vireux Formation. The species may be considered an index fossil for the German Singhofen and Vallendar groups along with the homalonotids Burmeisterella armata and Digonus ornatus ornatus. A pygidium of B. delattrei from the Clervaux Formation in Luxemburg with one of the dorsal spines in place on the first pleural rib, allows a minor modification of current reconstructions of the dorsal exoskeleton to be proposed. The holotype and two paratypes (pygidia) of B. delattrei from the Vireux Formation in northern France are refigured. In total, four species of Burmeisterella, namely B. aculeata, B. armata, B. delattrei (= B. vixarmata) and B. quadrispinosa, are now recognised in the upper Pragian to lower Emsian of Belgium. Tue, 17 Jun 2025 00:00:00 +0200 http://bibli-cloud15.segi.ulg.ac.be/1374-8505/index.php?id=7272