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While geological models traditionally focus on the natural status of the underground, the shallow subsurface has been significantly altered by human activities over centuries. Particularly in urban contexts, ground has been raised, reworked, filled-in or disturbed in other ways. The rationale behind these alterations is as varied as the characteristics of the associated anthropogenic deposits: large-scale structures such as residential and industrial areas built on extensive sheets of filling materials or reclaimed lands are intertwined with smaller-scale features related, for example, to road and railway infrastructures, dikes or landfills. Their composition is equally diverse, ranging from displaced natural materials, such as crushed rocks, gravel, sand or clay, to artificial substances like recycled steel slags, concrete or rubble, or mixtures of these. Gaining knowledge on the presence and characteristics of such deposits is highly relevant, as their physical and chemical behaviour may differ significantly from those of natural deposits. The significance of anthropogenic deposits is increasingly recognized in urban geology. Resolving the geometry and properties of the urban shallow subsurface is essential for anticipating associated risks, for example dealing with pollution, ground stability or distorted water infiltration patterns. Anthropogenic deposits are, however, often scantily archived in permit documentation or represented on (geological) maps. Within the GSEU (Geological Service for Europe) project, the GSB is contributing to the task to develop a common, international vocabulary to describe all aspects of anthropogenic deposits, allowing standardised representation and characterisation in geological models. In parallel, VITO is developing shallow subsurface urban models for the Flemish government (VPO) within the VLAKO-framework, such as the published model of the Antwerp harbour and city. As the anthropogene inherently is part of these models, we are always aiming to better incorporate these deposits into the models. However, modelling the anthropogene presents unique challenges due to its high-resolution variability, scarcity of input data, and dynamic nature. It requires an approach that differs radically from traditional geological modelling techniques, in which depositional concepts related to the sedimentational or structural environment can be incorporated. In this presentation we will outline how we integrate various 1D, 2D and 3D sources to identify and characterize anthropogenic deposits and incorporate these insights in a 3D geological model of the anthropogene. This methodology is applied to the urban periphery of Brussels, where a new 3D geological model is being developed to support infrastructure projects and urban planning with special focus on the ring road (R0) of Brussels. Secondly, we will evaluate current lithological standards, vocabulary and stratigraphic approaches to characterize anthropogenic deposits. We will discuss their applicability in Flanders with practical examples from the periphery of Brussels. Ultimately, improving the representation of the anthropogene in geological models will significantly enhance their utility for urban planning, environmental management, and the sustainable utilization of the subsurface in urban areas.

Nearly every geological subdiscipline relies to some degree on regional geological knowledge. In the introductory section of most geological papers it is standard practice to provide regional geological background information. Stratigraphic terminology is often well defined while other disciplinary concepts rely, at least to some degree, on generally agreed definitions or hierarchical schemes, such as paleontological, structural or magmatic terminology. This, however, is much less the case for the regional geological building blocks. Their names are usually composed of a combination of a geographical locality and a geological term. A few examples from Belgium are Brabant Massif, Campine Basin, Stavelot-Venn Inlier, and Malmedy Graben. Most of these have in common that, although their importance is well recognised, their definitions are vague and sometimes even conflicting, in that their meaning may differ between contexts and authors. Even if their meaning has drifted or become less exact, as a result of their frequent historical use, they commonly remain in use today. This issue is not exclusive to Belgium, but seems to be an altogether historic and worldwide phenomenon. Recently within Europe there is a growing awareness of this issue, resulting in important but rather isolated efforts to better structure and define regional information (Hintersberger et al. 2017; Németh 2021; Le Bayon et al. 2022) which have been brought together through pan-European cooperation (GSEU – Horizon Europe 101075609). The central element that seems to encompass most geologic features, is the lithotectonic unit (a distinct unit based on its partly separate geological history; URI: http://inspire.ec.europa.eu/codelist/GeologicUnitTypeValue/lithotectonicUnit). Grabens, basins and inliers are examples of lithotectonic units. In order to define and describe these units more accurately, lithotectonic limits are introduced. These are planar features, such as faults and unconformities, that correspond to the geologic events that formed the lithotectonic unit (Piessens et al. 2024). All information is organised and linked in vocabularies (thesauri) that together not only adequately define each concept, but also determine the relations between them, placing them in space and geological time (Plašienka 1999). This outlines the core methodology, around which 2D and 3D multi-scale visualisations are built, annotations can be added, existing ontologies can be linked (such as the ICS Geological Time Scale Ontology; Cox and Richard, 2005) and newly developed extensions such as the Modified Wilson Cycle (Németh 2021). As such, the work at Belgian level is closely linked to the ongoing international developments. Making use of the ongoing developments at European level, Belgium was the first country to set up a lithotectonic working group that became operational in 2023. Its first goal is to provide a lithotectonic framework that describes a starting set of main geological units and limits in Belgium, according to emerging European standards (the work at European level is linked to the implementation of INSPIRE and 195 is in communication with the GeoSciML community), by the end of 2024. The working group meets approximately every 2 months, and organisationally resides under the National Commission for Stratigraphy in Belgium. The working group will soon be looking for additional experts (junior and senior) in its continuing effort to identify and define broad superstructures, detail the regional geology to the more local level, to tackle new types of lithotectonic elements, or better address parts of geological history. Potential candidates are encouraged to contact one of the authors or the NCS secretariat. Cox SJD, Richard SM (2005) A formal model for the geologic time scale and global stratotype section and point, compatible with geospatial information transfer standards. Geosphere 1:119. https://doi.org/10.1130/GES00022.1 Hintersberger E, Iglseder C, Schuster R, Huet B (2017) The new database “Tectonic Boundaries” at the Geological Survey of Austria. Jahrbuch der geologischen Bundesanstalt 157:195–207 Le Bayon B, Padel M, Baudin T, et al (2022) The geological-event reference system, a step towards geological data harmonization. BSGF - Earth Sci Bull 193:18. https://doi.org/10.1051/bsgf/2022017 Németh Z (2021) Lithotectonic units of the Western Carpathians: Suggestion of simple methodology for lithotectonic units defining, applicable for orogenic belts world-wide. Mineralia Slovaca 2:81–90 Piessens K, Walstra J, Willems A, Barros R (2024) Old concepts in a new semantic perspective: introducing a geotemporal approach to conceptual definitions in geology. Life Sciences Plašienka D (1999) Definition and correlation of tectonic units with a special reference to some Central Western Carpathian examples. Mineralia Slovaca 31:3–16

1. Abstract The Cretaceous experienced several Oceanic Anoxic Events (or OAEs). Anoxia in these events is indicated by deposits of black shales, enriched in organic matter (OM) compared to the layers below and above, strong carbon isotope perturbations, often with a negative excursion at the onset of the OAEs followed by a positive excursion, and concentration of redox-sensitive trace-elements (RSTE) (Baudin & Riquier 2014). Considered to be the earliest Cretaceous OAE (Baudin & Riquier, 2014), the Faraoni level is a short event first defined in the late Hauterivian sections of the Umbria-Marche Apennines (Cecca et al. 1994). It presents black shales enriched in OM with high concentrations of RSTE but lacks an important positive δ13C excursion (Baudin & Riquier, 2014). This event follows the “Weissert” event, a ca. 2.3 million year carbon isotope perturbation event taking place during the late Valanginian-early Hauterivian (Sprovieri et al. 2006). This latter event is not considered to be an OAE, as anoxia indicators such as RSTE high concentrations or OM-rich layers are not observed at least in the western Tethys (Westermann et al. 2010). In order to link those two seemingly opposite events, sections of Late Valanginian to Early Barremian age were studied in the Umbria-Marche Apennines, Italy. Lesser magnitude black shale preceding the Faraoni level were identified. They were correlated in two sections using magnetostratigraphy (Fig. 1). Rock-Eval and palynofacies analyses reveal that they are part of a longer-term trend of increased organic matter preservation and burial. In the black shales this is hinted by a progressive increase of total organic carbon (TOC) content, of the hydrogen index (HI), and by increasingly better preserved amorphous organic matter (AOM) towards the Faraoni level (Fig.1). This increase starts in the upper part of the M5n magnetochron. This is coeval with an increase in mercury concentration interpreted to be due to volcanic activity that was measured among others in the Bosso section (Charbonnier et al., 2018). Palaeoenvironmental differences between the Bosso and Frontone sections is shown by differences in palynomorphs and in organic matter preservation, and by the presence of slumps found in Frontone only. Figure 1 : synthetic log of the Bosso and Frontone sections, with magnetostratigraphy and Rock Eval 6 results (TOC and HI) 2. References Baudin, F. & Riquier, L., 2014. The Late Hauterivian Faraoni ‘Oceanic Anoxic Event’: An Update. Bulletin de La Société Géologique de France, 185, 6, 359‑77. Cecca, F., Marini, A., Pallini, G., Baudin, F., & Begouen, V., 1994. A guide level of the uppermost Hauterivian (Lower Cretaceous) in the pelagic succession of Umbria Marches Apennines (Central Italy): the Faraoni level, Rivista Italiana di Paleontologia e Stratigrafia, 99, 4. Sprovieri, M., Coccioni, R., Lirer, F., Pelosi, N. & Lozar F., 2006. Orbital Tuning of a Lower Cretaceous Composite Record (Maiolica Formation, Central Italy). Paleoceanography, 21, 4. Westermann, S., Föllmi, K.B., Adatte, T., Matera, V., Schnyder, J., Fleitmann, D., Fiet, N., Ploch, I. & Duchamp-Alphonse S., 2010. The Valanginian δ13C Excursion May Not Be an Expression of a Global Oceanic Anoxic Event. Earth and Planetary Science Letters, 290, 1‑2, 118‑31. Charbonnier, G., Godet, A., Bodin, S., Adatte, T. & Föllmi, K. B. 2018. Mercury anomalies, volcanic pulses, and drowning episodes along the northern Tethyan margin during the latest Hauterivian-earliest Aptian. Palaeogeography. Palaeoclimatoly. Palaeoecology.

Polar ecosystems support a distinctive, cold-adapted biodiversity that faces significant threats from rapid environmental changes and escalating human impacts. To effectively manage and conserve these living resources, multi-scale data on connectivity and adaptation are essential. Marine protected areas (MPAs) are most effective when designed as interconnected networks that account for both functional diversity and connectivity within and among species. In this study, 607 individuals from ten Trematomus species were analyzed through ddRAD sequencing, yielding thousands of genomic markers to examine patterns of divergence and connectivity on the Southern Ocean shelf, both within and between species. Genomic SNPs showing evidence of selection, identified as "outlier loci," were further analyzed to explore potential local adaptations to varying environmental conditions. Population structure analyses of four species — T. loennbergii, T. eulepidotus, T. scotti, and T. newnesi — indicate extensive dispersal across the Weddell Sea and along the West Antarctic coast, likely facilitated by the Weddell Sea Gyre and the Antarctic Coastal Current. A genetic discontinuity was detected near the Filchner Trough in several species, likely due to the strong outflow from the Filchner-Ronne ice shelf, which may isolate the trough region from the broader Weddell Sea habitat. Additionally, evidence of previously unrecognized cryptic diversity was observed in T. eulepidotus and T. loennbergii. These findings contribute to our understanding of diversity, connectivity, and adaptation on the Southern Ocean shelf, a critical foundation for conservation amid unprecedented global change.

Around 40 million years ago, Antarctica’s geographic isolation led to a dramatic cooling of its marine shelf, causing many lineages to go extinct whilst others adapted and flourished. Among the successful ones is the amphipod family Iphimediidae. Here, we apply advanced phylogenetic, comparative, and morphometric methods to explore the evolutionary processes which generated the exceptional diversity of this clade. To this purpose, three types of data were collected: (1) a novel phylogeny of the family was reconstructed from a multigene molecular dataset, (2) 3D shape data were obtained by applying geometric morphometric methods on micro-CT scans, and (3) stable isotope ratios (δ13C and δ15N) were measured and used as proxy for trophic ecology. First, possible evolutionary correlations between mouthpart shapes and stable isotope ratios were examined. Significant correlations suggest that mouthpart shapes are adapted to the food source. Second, species boundaries were investigated using a combination of DNA-based delimitation methods and detailed morphological/morphometric analyses, revealing that Iphimediidae species diversity is greatly underestimated. Most described species were found to be complexes of multiple, morphologically similar species. Finally, changes in lineage diversification rates were explored alongside the evolution of morphological traits. Late bursts of lineage diversification (appr. 7-3 Mya) combined with a late partitioning of mouthparts’ shape diversity might result from the invasion of novel ecological niches. Plio-Pleistocene glacial cycles, which have been hypothesized to act as a diversity pump, might also have promoted such late diversification events in Antarctic iphimediids. This integrative approach, applied here for the first time in Antarctic invertebrates, enhances our understanding of the evolutionary dynamics shaping Antarctic shelf biodiversity.

Around 40 million years ago, Antarctica’s geographic isolation led to a dramatic cooling of its marine shelf, causing many lineages to go extinct whilst others adapted and flourished. Among the successful ones is the amphipod family Iphimediidae. Here, we apply advanced phylogenetic, comparative, and morphometric methods to explore the evolutionary processes which generated the exceptional diversity of this clade. To this purpose, three types of data were collected: (1) a novel phylogeny of the family was reconstructed from a multigene molecular dataset, (2) 3D shape data were obtained by applying geometric morphometric methods on micro-CT scans, and (3) stable isotope ratios (δ13C and δ15N) were measured and used as proxy for trophic ecology. First, possible evolutionary correlations between mouthpart shapes and stable isotope ratios were examined. Significant correlations suggest that mouthpart shapes are adapted to the food source. Second, species boundaries were investigated using a combination of DNA-based delimitation methods and detailed morphological/morphometric analyses, revealing that Iphimediidae species diversity is greatly underestimated. Most described species were found to be complexes of multiple, morphologically similar species. Finally, changes in lineage diversification rates were explored alongside the evolution of morphological traits. Late bursts of lineage diversification (appr. 7-3 Mya) combined with a late partitioning of mouthparts’ shape diversity might result from the invasion of novel ecological niches. Plio-Pleistocene glacial cycles, which have been hypothesized to act as a diversity pump, might also have promoted such late diversification events in Antarctic iphimediids. This integrative approach, applied here for the first time in Antarctic invertebrates, enhances our understanding of the evolutionary dynamics shaping Antarctic shelf biodiversity.

Polar ecosystems harbour a unique cold-adapted biodiversity that is threatened by rapid environmental change and increasing anthropogenic impact. In this context, collecting data on connectivity between populations is essential for supporting conservation management of living resources and ecosystems. Genetic connectivity is the extent to which populations in different parts of a species' geographical range are linked by the exchange of larvae, juveniles or adults (which are the vectors of genetic material). In the Southern Ocean, several Marine Protected Areas (MPAs) – large areas where human activities are restricted or prohibited to promote conservation – are established or under negotiations. Such MPAs are most effective if implemented as a network that considers genetic diversity and connectivity within and between species. In the present study, 607 individuals of ten Trematomus species were sequenced using reduced representation sequencing techniques. Thousands of genomic variants were used to investigate inter- and intraspecific patterns of divergence and connectivity across the Southern Ocean shelf. Population structure analyses of four different species (T. loennbergii, T. eulepidotus, T. scotti and T. newnesi) suggest long- range dispersal across the Weddell Sea and even along the entire West Antarctic coast that might be facilitated by the Weddell Sea Gyre and Antarctic Coastal current. A genetic break at the level of the Filchner Trough was observed in several species. The strong outflow from the Filchner-Ronne ice shelf may separate the trough area from the remaining Weddell Sea habitat. Finally, results suggest that previously undetected cryptic species may be present within both T. eulepidotus and T. loennbergii. Altogether, the present results contribute to the assessment of diversity and connectivity on the Southern Ocean shelf, which is imperative in view of unprecedented global change.