The stratigraphic position of the lower Miocene Kiel Sand Member of the Berchem Formation in the Antwerp area (northern Belgium) is not well constrained and its depositional environments are poorly known. Due to a spatial limited decalcification front, the Kiel Sand Member is completely decalcified in southern Antwerp and gradually becomes fossiliferous to the north-east of the city. The stratigraphy and palaeontology of the fossiliferous sediments in three temporary exposures are presented. The dinoflagellate cyst analysis of fossiliferous horizons shows the relative progress of a transgression in the southern North Sea Basin during the early–middle Burdigalian, that probably initiated in the late Aquitanian. The Kiel Sand Member contains an important mollusc fauna, with several species reported for the first time from this member. The taphonomy and fauna of the shell beds indicate a shallow marine, high energetic depositional environment, strongly influenced by storms, currents, waves and a rather low sedimentation rate. The climate was warm-temperate to subtropical. In all studied sections, the Kiel Sand Member could be clearly distinguished from the Antwerpen Sand Member: similarities and differences are discussed. Moving to the north of Antwerp, the erosive base of the Antwerpen Sand Member cuts deeper into the Kiel Sand Member. The Early Miocene Unconformity (EMU) is suggested at this contact.
The glauconitic sands in the upper part of the lower-middle Miocene Berchem Formation are subdivided into the Kiel and Antwerpen Members. Although lithological differences between both members are well known from temporary outcrops in the Antwerp city area, they are difficult to distinguish in boreholes, which hinders regional mapping of these units. In this study, we investigate whether both members can be distinguished on cone penetration tests (CPTs). For this purpose, we correlated multiple outcrops-in which the Kiel and/or Antwerpen Members have been identified-with nearby CPTs. On the CPTs, the boundary between the Kiel and Antwerpen Members is clearly identifiable as it coincides with an abrupt upwards decrease in cone resistance (q c ). The lower q c of the basal part of the Antwerpen Member is probably related to the finer grain size with more clayey admixture compared to the underlying Kiel Member. This change to a finer grain size is caused by a decrease in depositional energy and sedimentation rates as the region was transgressed during the eustatic sea-level rise at the start of the Mid-Miocene Climatic Optimum. On the CPTs, several spikes in q c values were observed within the Antwerpen and Kiel Members. These spikes could be correlated to shell beds, three horizons with sandstones and possibly a hardground. The sandstones appear to be discontinuous, whereas some of the shell beds could be traced across the entire study area. Most shell beds probably represent storm deposits within an otherwise relatively low energetic sedimentary environment. A phosphatic shell bed above the base of the Antwerpen Member is interpreted as the maximum flooding surface, lying in a zone with the lowest q c values for the Antwerpen Member, which might reflect maximum fining. The shell beds and interlayered sands of the Antwerpen Member thin in a southern direction, indicating reduced accommodation space in this direction.
The enigmatic megamouth shark is a rare occurrence in both Recent oceans and in the fossil record. A temporary construction site in the city of Antwerp (NW Belgium) gave the opportunity to study the poorly known early Miocene Kiel Sand Member of the Berchem Formation. In this Burdigalian deposit, a previously unknown fossiliferous horizon with Glycymeris and Cyrtodaria was sampled which contained a single Megachasma tooth. This specimen, attributed to Megachasma aff. pelagios by its resemblance with extant M. pelagios, is the first in situ record from un-reworked strata in Belgium. Only around a dozen fossil Megachasma teeth have been reported from Europe. It is concluded that a circumglobal megamouth population existed during the Burdigalian. Some evolutionary remarks are made.
Firefighters are exposed via multi-route exposure to a multitude of chemicals (PAHs, VOCs, flame retardants, dioxins, etc.) that may cause acute and long-term health effects. The dermal absorption of contaminants is a major contributor to the overall exposure and can be reduced by wearing appropriate personal protective equipment. As leather firefighters’ gloves cannot be decontaminated regularly by wet cleaning, many Belgian firefighters wear supplementary undergloves made of nitrile butadiene rubber (NBR) to protect against the accumulation of toxicants. However, the safety of this practice has been questioned. In this commentary, the current practice and risks are outlined for the first time, assessed by an interdisciplinary working group of the Belgian Superior Health Council. As NBR sticks to the skin more at high temperatures, the contact time on removal will be prolonged, posing an additional risk for deeper burns. However, based on the physicochemical properties of NBR and the existing experience of firefighters and burn centers, it is estimated that such incidents occur relatively rarely in practice. On the other hand, the risk of repeated exposure to contaminated gloves if no undergloves are worn is unacceptable. Despite the slightly increased risk for deeper burns, it is concluded that wearing disposable NBR gloves under regular firefighters’ gloves is an appropriate and effective preventive measure against toxic contamination. The nitrile butadiene rubber must always be fully covered to avoid any contact with the heat.
Cross-border correlations of the Pliocene–Pleistocene successions in the southern Netherlands and northernmost Belgium are problematic, because biostratigraphic markers are often lacking. Correlation is further hampered by the poor age constraints of the Belgian Merksplas Formation. To address these issues, sedimentary, mollusc and dinoflagellate cyst analyses are combined to characterise the lithostratigraphic units in the Huijbergen borehole (The Netherlands) and to provide age estimates. Subsequently, the Huijbergen borehole was correlated with nearby boreholes in Essen and Kalmthout (Belgium). The Piacenzian intervals of the Dutch Oosterhout Formation can be correlated with the Belgian Lillo Formation, with the latter’s threefold borehole log signature appearing virtually continuous across the border between both countries. The Dutch Maassluis and Waalre formations are correlated with the shell-bearing lower part and the unfossiliferous higher part of the Merksplas Formation respectively. Although dinocysts are not age-diagnostic for the Maassluis and Waalre formations in borehole Huijbergen, characteristic interglacial marine shells provide a Gelasian age assessment for the Maassluis Formation. By correlation, this age estimate can also be applied to the lower part of the Merksplas Formation, thereby elucidating the Pliocene–Pleistocene transition near the Dutch-Belgian border.
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