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Inbook Reference Diestiaan ijzerzandsteen: de erfgoedsteen van het Hageland
SAMENVATTING. Een donkerbruine, ijzerhoudende zandsteen tekent het landschap en de karakteristieke archi- tectuur van het Hageland, het oostelijk deel van de provincie Vlaams-Brabant. Deze regio wordt gekenmerkt door een heuvelachtig landschap, waar in Romeinse tijden op de zuidelijk gerichte flanken al wijn werd verbouwd. Op de talrijke heuveltoppen, stille getuigen van versteende zandbanken in de Laat-Miocene zee die het landschap in lang vervlogen tijden overspoelde, komen donkerbruine lagen van ijzerzandsteen voor. Al sinds de vroege Middeleeuwen werd deze steen voor lokaal gebruik ontgonnen, waaruit later de voor de streek typische ‘Demergotiek’ ontstond. De ijzerzandsteen is zeer heterogeen en gevoelig voor verwering. Over het algemeen betreft het een bouwmateriaal met een lage druksterkte, zeker in vergelijking met Gobertange, Lede- of Doornikse steen. De hedendaagse restauratie van deze karakteristieke architectuur wordt geconfronteerd met diverse problemen: natuursteenherstelling is omwille van de donkere kleur minder evident en vaak niet duurzaam, beschikbare reserves zijn zeer beperkt en er zijn geen actieve steengroeves. Een maximale conservering van het authentieke materiaal, geheel in overeenkomst met het Charter van Venetië overigens, dient daarom vaak vooropgesteld. Materiaaltechnisch onderzoek van ijzerzandsteen, gelicht uit gesteentelagen in vijf sites, was noodzakelijk om de wisselende kenmerken van deze natuursteen beter te interpreteren vanuit zijn geologische diversiteit, teneinde de inzetbaarheid als bouwmateriaal te kunnen evalueren. Bovendien werd bestudeerd in hoeverre een mogelijke steen- verstevigende behandeling door middel van ethylsilicaat (TEOS) van ijzerzandsteen tot een verbetering van zijn duur- zaamheid zou kunnen leiden. ABSTRACT. Diest ferruginous sandstone, heritage stone of the Hageland. A dark-brown ferruginous sandstone characterizes the landscape and the typical architecture of the Hageland, the eastern part of the Belgian province Flemish Brabant. The landscape of this region is recognised by an alternation of hills. The southern flanks of these hills are well-suited for cultivating wine, something the Romans already learned some two thousand years ago. On these numerous hill tops, the silent witnesses of petrified shoals from the Diestian sea which overran the landscape long ago, dark-brown layers of ferruginous sandstone occur. Already in the Middle Ages, this stone has been quarried for local use which gradually led to the development of a specific architecture, also known as Demer Gothic. This ferruginous sandstone is however very heterogeneous and sensitive to weathering. In general, it is considered a rather weak building material, especially in comparison with other typical local building materials such as Gobertange, Lede or Tournais stones. However, the restoration of this characteristic architecture is nowadays confronted with various problems: the use of repair mortars is because of the dark color less evident and often not durable, available reserves are restricted and there are actually no active quarries. A maximal conservation of the authentic material, fully in agreement with the Charter of Venice, is hence often required as a premise. Material-technical research of fer- ruginous sandstone, retrieved from sedimentary beds from five locations, was deemed necessary to describe the vary- ing characteristics of this stone within its geological context in order to evaluate the possibility to use the material for restoration purposes. In addition, the effect of a consolidation treatment of the ferruginous sandstone with ethylsilicate (TEOS) to ameliorate its durability was examined.
Located in Library / RBINS Staff Publications
Inbook Reference Différenciation des hématites oolithiques à partir d’observations macroscopiques non destructives : essais de comparaison des matériaux ordoviciens normands et dévoniens belges.
Located in Library / RBINS Staff Publications 2016
Article Reference Differentiation between two salt marsh beetle ecotypes: Evidence for ongoing speciation
The plausibility of trait divergence under divergent natural selection in the presence of gene flow in natural populations is a contentious issue in evolutionary research. Its importance lies in the fact that this process is thought to be one of the key triggers in ecological speciation in which a species splits into ecologically distinct forms when separate niches are occupied. in this study we demonstrate strong genetic divergence at the IDH1 locus between pond- and canal-inhabiting individuals of the salt marsh beetle Pogonus chalceus from the Guerande salt fields. Moreover, wing size, a trait that has a heritable basis in this species, was significantly larger in the pond populations, which is in concordance with the unstable nature of this habitat. The relationship between IDH1 allele frequencies and wing size variation was consistent with patterns seen across western European populations. By means of neutral allozymes and microsatellites we detected a small but significant degree of sexual isolation between ecotypes. We conclude that speciation is ongoing and that divergence reflects a balance between selection and gene flow.
Located in Library / RBINS Staff Publications
Conference Reference Digital Animal Sound Archive: a collaborative repository for bio-acoustics
The use of animal sounds is widespread but yields extensive and scattered individual collections. Making this data FAIR will lead to deeper knowledge. The overall objective of DASA is to set-up a robust data model and a user-friendly website enabling Belgian bio-acoustic workers to collect, archive and explore biological acoustic data. The starting point is bats, but the data model is kept open for any biological or mechanical sounds. We will build a digital archive that adds to RBINS' collections, serves as a reference collection of species and call types, offers a validated dataset for classifiers and will be a resource for meta-analyses.
Located in Library / RBINS Staff Publications 2024
Article Reference Discovery of a new inland population of Amara strenua Zimmerman, 1832 at Heverlee, central Belgium (Coleoptera: Carabidae)
Located in Library / RBINS Staff Publications 2022
Article Reference Dispersal model alert on the risks of alien species introduction by ballast waters in protected areas from the Western Antarctic Peninsula
Aim The Western Antarctic Peninsula is challenged by climate change and increasing maritime traffic that together facilitate the introduction of marine non-native species from warmer regions neighbouring the Southern Ocean. Ballast water exchange has been frequently reported as an introduction vector. This study uses a Lagrangian approach to model the passive drift of virtual propagules departing from Ballast water hypothetic exchange zones, at contrasting distances from the coasts. Location Western Antarctic Peninsula. Methods Virtual propagules were released over the 2008–2016 period and at three distances from the nearest coasts: 200 (convention for the management of Ballast Water, 2004), 50 or 11 nautical miles (NM). Results Results show that exchanging Ballast water at 200 NM considerably reduces the arrival of propagules in proposed marine protected areas of the western side of the Antarctic Peninsula. On the eastern side, propagules can reach north-eastern marine protected areas within a few days due to strong currents for all tested scenarios. Seasonal and yearly variations indicate that exceptional climate events could influence the trajectory of particles in the region. Ballast water should be exchanged at least 200 NM offshore on the western side of the Antarctic Peninsula and avoided on the eastern side to limit particle arrival in proposed marine protected areas. Focusing on Deception Island, our results suggested that the Patagonian crab (Halicarcinus planatus) observed in 2010 could have been introduced in case of Ballast water exchange at 50 NM or less from the coast. Main conclusions This study highlights the importance of respecting Ballast water exchange convention to limit the risk of non-native species introduction. Ballast water exchange should be operated at least at 200 NM from the coasts, which further limits particle arrival in shallow water areas. This is especially important in the context of a more visited and warmer Southern Ocean.
Located in Library / RBINS Staff Publications 2022
Article Reference Dispersal of continental vertebrates during the Paleogene: Preface
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Located in Library / RBINS Staff Publications
Article Reference Dispersals of placental carnivorous mammals (Carnivoramorpha, Oxyaenodonta & Hyaenodontida) near the Paleocene-Eocene boundary: a climatic and almost worldwide story
During the Late Paleocene and around the Paleocene-Eocene boundary, there were important mammalian dispersals in Laurasia involving earliest modern mammals such as rodents, primates, perissodactyls, and artiodactyls. The placental carnivorous mammals (Viverravidae, “Miacidae”, Hyaenodontida, Oxyaenodonta) importantly took part in these dispersals. The present article shows that these latter mammals allow reconstructing faunal dispersal scenarios during the early Paleogene. Indeed, they evidenced several dispersal ways among Laurasia, but also with Africa and possibly India. The dispersal phases discussed in the present paper concern the Early Paleocene, Late Paleocene, latest Paleocene (Clarkforkian NALMA), and Paleocene-Eocene transition.
Located in Library / RBINS Staff Publications
Article Reference Disrupted continental environments around the Devonian-Carboniferous Boundary: introduction of the tener event
Recent refinements of the palynological stratigraphic scheme around the Devonian-Carboniferous Boundary in southern Belgium result in new questions on the effect of the Hangenberg Biocrisis on spores and on the validity of some ‘biozones’. Verrucosisporites nitidus, the guide taxa of the last Devonian palynozone (LN zone) is lacking in many sections and its presence is only acknowledged in proximal settings. Hence the LN zone is considered as an ecozone rather than a biozone. Moreover, investigation of the uppermost part of the uppermost Famennian shows that the palynological assemblages is dominated by abnormal forms of Retispora lepidophyta, notably by R. lepidophyta var. tener which seems to be characteristic of this interval in Western Europe. It is thus proposed to introduce the global tener event as a potential marker of the Hangenberg Biocrisis on land and in proximal marine settings. This profusion of abnormal spores is thought to be related to climatic variation possibly in link with global cooling below the Devonian-Carboniferous Boundary.
Located in Library / RBINS Staff Publications 2016
Book Reference Distribution stratigraphique des mégaspores dans quelques sondages de la région nord-est de la Campine
Located in Library / RBINS Staff Publications