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Whereas the evolution of the land cover of the Holocene landscape is rather well documented for the main basin of the Scheldt river (Verbruggen et al , 1996), the vegetation history of Senne valley remains poorly documented Over the last decade, during the systematic archaeological survey conducted by the Direction of Monuments and Sites of the Brussels Capital Region, several exceptionally well preserved meters thick peat deposits have been discovered in the historical centre of Brussels and its surroundings The first results of the palynological, paleofire and geoarchaeological studies reveal a nearly continuous sequence throughout the Holocene The interdisciplinary study of these deposits offer a huge potential to explore the evolution of the paleoenvironment in the river valley and further to contribute to spatial reconstructing the landscape development of the area trough the time As the sites are situated as well in the historical city centre as in the surrounding area it will also allow us to reconstruct the impact of the urbanisation on the natural vegetation and transformation of the peatland ecosystem into urban and cultivated areas in Brussels and its immediate surroundings

The youngest time interval of the Cretaceous is known as the Maastrichtian Age, a reference to the strata exposed in the area surrounding the city of Maastricht, in the Netherlands-Belgium border region (Jagt 2001). The stratigraphic succession at the original type-locality of the Maastrichtian (adjacent to the former ENCI quarry, south of Maastricht) only covers the upper part of the Maastrichtian Stage as defined nowadays. However, recent integrated bio- and chemostratigraphic revision by Vellekoop et al. (2022) has shown that in combination with similar lithological sequences at other quarries in the region (e. g., Hallembaye, Curfs), a substantial part of the Maastrichtian Stage is represented. Over the past centuries, the type-Maastrichtian strata have provided a wealth of paleontological data. Despite its importance to the global geological community, most of the quarries in the region have been closed over the last decades. Instrumental quarries such as that of Curfs have already been out of commission for more than a decade, while others, such as the ENCI quarry, were recently closed. Because the soft limestone rocks weather easily and become overgrown rapidly, access to and study of the Maastrichtian rock succession in its type area is becoming very limited. To preserve the geological heritage of this original type-locality of the Maastrichtian, in 2018 we initiated the ‘Maastrichtian Geoheritage Project’. The goal of this project is to preserve the geological heritage of the Maastrichtian type area by (1) digital imagery, using drone photogrammetry and Differential GPS Base & Rover to generate high-resolution and georeferenced 3D models of the most important quarries in the Maastrichtian type region; and (2) archiving rock samples of these quarries for future research. Over the past years, we collected high-resolution (5 cm spacing) reference sample sets from the Hallembaye (2018) and ENCI (2019) quarries, and generated detailed geo-referenced 3D models for both quarries. For the next few years, several other instrumental quarries will be targeted. The acquired sample sets have already spurred a range of stratigraphic, geochemical and paleontological studies (e.g. Vellekoop et al. 2022), including detailed profiles of carbon isotope data and major and trace element concentrations, and many more to come. Moreover, the Maastrichtian Geoheritage Project sample sets will be made available for collaboration with other researchers in the field. Jagt, J.W.M., 2001. The historical stratotype of the Maastrichtian: A review. In: Odin, G.S. (Ed.), The Campanian-Maastrichtian Boundary, pp. 711–722. Elsevier Science B.V. Vellekoop, J. et al. 2022. A new age model and chemostratigraphic framework for the Maastrichtian type area (southeastern Netherlands, northeastern Belgium). Newsletters on Stratigraphy [accepted]

The Paleogene Period can be considered the cradle of modern marine and terrestrial ecosystems (e.g. Krug et al., 2009; Field et al,. 2018). After global catastrophe at the K-Pg boundary, life recovered and repopulated marine and terrestrial ecosystems (Vellekoop et al., 2017; Lowery et al., 2018; Lowery et al., 2019; Vellekoop et al., 2020), eventually heralding the establishment of the rich and diverse modern marine and terrestrial ecosystems (Krug et al., 2009; Field et al., 2018). It has been suggested the crucial biotic evolution and overturn during the Paleogene was at least partly driven by the climatic evolution across this time interval (e.g. Widlansky et al., 2021). For example, the PETM (56 Ma) likely was key in reshaping the biosphere (Smith et al., 2020). During this hyperthermal, the first representatives of modern mammal orders (e.g., primates, artiodactyls, perissodactyls) suddenly spread over all northern continents, while marine ecosystems are characterized by marked extinctions, radiations and migrations (Gibbs et al., 2012; Speijer et al., 2012). Nevertheless, the evolutionary importance of other warming pulses (e.g., Eocene Thermal Maximum 2 or ETM-2) or the gradual climate trends towards the EECO remains unclear for most fossil groups. For northwestern Europe, terrestrial faunas appear to have been almost consistently in a dynamic state across this time interval, strongly influenced by dispersal events. In contrast to the PETM, the exact timing and paleogeographic conditions remain poorly constrained for post-PETM warming pulses, as only tentative chronological correlation with the Paleogene global temperature curves are established. Therefore, we have initiated a new collaborative project, aimed at creating (1) a better chronostratigraphic framework of Paleogene bioevents among vertebrates, by detailed study of marine and terrestrial strata containing, or interfingering with, vertebrate-rich beds in NW Europe, and (2) generating a better understanding the role of climate change on biotic evolution and overturns during the Early Paleogene, from both a marine and terrestrial perspective.

It is widely known that the subsurface will play a crucial role in the transition towards a carbon-neutral society, with the aid of technologies like geothermal energy, CO2-storage, .... Nevertheless, still a lot of aspects concerning the subsurface, its structure and characteristics remain to be investigated to facilitate the use of underground space in an efficient and safe way. In-depth investigation of the subsurface with conventional techniques such as seismic campaigns or drillings requires high investments, and it is not always straightforward to determine the success-rate upfront. This leads to geodata collections typically displaying a large variety and scatter, both concerning data (type) availability and in spatial distribution. Additionally, incorporating subsurface knowledge from neighboring countries often is challenging, but at the same time indispensable to increase understanding of the own subsurface, not least because some projects may display cross-border influences. It is clear that subsurface exploration benefits from a cross-border and cross-thematic data collection and interpretation approach. One way to organize such data centralization was explored in the framework of the European Horizon2020-project GeoConnect³d, by means of constructing a Structural Framework (SF) and a database of Geomanifestations (GM) for several pilot study areas. The Structural Framework defines geological units by its limits (e.g., faults, terrane boundaries, ...). All known limits and associated parameters are structured in a uniform and inter-connected way. Furthermore, the SF is designed on multiple zoom-levels, hence it can serve as a real backbone to integrate multiple other subsurface models of various scale and resolution together. Geomanifestations are anomalous observations covering a wide range of geo-disciplines, including —but not limited to— temperature, geochemistry, mineralogy and even geophysics data. Such irregularities are too often excluded or ignored in view of the larger cloud of ‘normal’ datapoints. Nevertheless, precisely these anomalies can be of great value for identifying subsurface processes and serve as an excellent pathway for communication to non-experts, and also as guideline for further research. In addition to GIS- and attribute-information, Factsheets summarize the relations between individual geomanifestations, and, if applicable, their connection to the Structural Framework. Especially the latter, the combination of the (independent) elements SF and GM, gives a powerful tool that allows exploring the subsurface in an original and cost-efficient way. The newly gained insights can be directly linked and are extremely relevant to the use of the subsurface, either as storage space or as renewable/green energy-source. But it goes further than that. The overall usability of the SF and GM database is far more fundamental, as it gives innovative clues about characteristics and processes at play in the subsurface, such as fault permeability and connectivity, the presence of advection cells in the upper crust, or gas origin and migration pathways. To quote just one example; in the area of Spa, Belgium, elevated 3He/4He-ratios were analyzed (Griesshaber et al., 1992), a parameter that can highlight mantle gas contribution in gas seeps (White, 2013). This observation was unexpected given the far distance from any volcanic activity, but suggests the presence of deep-seated, transcrustal faults and/or a large-distance connectivity till the Eifel area where mantle-derived magma was involved in recent volcanism. When indirect indications like this are not considered further, such valuable subsurface knowledge is easily overlooked and not at all taken into account for investigating in more detail in the future. Even when limited resources or funding is available, the above-illustrated SF+GM approach can shed new light on properties and processes of the subsurface, given its novel and multidisciplinary approach. An inherent drawback, however, is that such a database is never complete and includes information from a variety of sources. Not only does this demands careful consideration on which data is included (or not), it also has to be taken into account for future database expansion as well as for data interpretation. Simple visualizations on a map without further (geological) background, e.g., combining both surface and at depth data as is the case for Wiesbaden, Germany (Mittelbach & Siebert, 2014), may lead to false conclusions. However, the provided Factsheets and metadata can help in this. Furthermore, at this moment, a large proportion of the entries depends on the availability of literature data, which implies some data source bias is unavoidable. For example, CO2-data typically is measured for springs and streams, while dry CO2-seeps easier remain unnoticed and therefore are reported less consistently. New data collection campaigns, possibly including bio-indicators like plants or ants (e.g., Berberich & Schreiber, 2013), can provide a good starting point for this. The uniform and well-designed structure of the database allows very easy expansion, be it for newly discovered faults, additional geomanifestation types, or parameter updates of either part. In addition, as demonstrated in the GeoConnect³d project, the SF+GM approach is fully transferable to other study areas. This clears the way for a cost-efficient cross-border exploration of the subsurface with wins for both the academic world and common public (geoheritage, education, ...), and significantly contributes to a more data-supported outline for subsurface management. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 731166. References Berberich, G., & Schreiber, U., 2013. GeoBioScience: Red Wood Ants as Bioindicators for Active Tectonic Fault Systems in the West Eifel (Germany). Animals, 3, 475-498. Griesshaber, E., O'Nions, R.K. & Oxburg, E.R., 1992. Helium and carbon isotope systematics in crustal fluids from the Eifel, the Rhine Graben and Black Forest, F.R.G. Chemical Geology, 99, 213-235. Mittelbach, G. & Siebert, S., 2014. Gutachten zur Festsetzung eines Heilquellenschutzgebietes für die Heilquellen (Große und Kleine Adlerquelle, Schützenhofquelle, Kochbrunnen, Salmquelle und Faulbrunnen) von Wiesbaden, Stadt Wiesbaden (WSG-ID 414-005), Wiesbaden, pp. 1-52. White, W.M., 2013. Chapter 12: Noble Gas Isotope Geochemistry, Isotope Geochemistry course notes. Cornell University.