Search publications of the members of the Royal Belgian institute of natural Sciences
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Le sondage d'Havelange : principales données et aspects techniques
- Ce résumé n'est disponible qu'en anglais. Deze samenvatting is alleen beschikbaar in het Engels. Abstract The Famenne seismic campaign (1976-1978), which was carried out in the southern part of Belgium, east of the Meuse Valley, has identified a major subhorizontal reflector, marking an angular unconformity, which was thought to represent the Condroz Overthrust. The outcroup of this thrust fault to the north marks the front of the Variscan Orogeny. The aim of the Havelange weIl was to reach the thrust fault and to determine wether the rockmass underneath was Caledonian or Hercynian, the latter possibility beeing not without economic interest. The well starts within an Upper Devonian formation and then reachs Lower Devonian formations at 1920 m MD. These formations were found till the total depth at 5648 m MD. Palynological data showed the existence of three main faults, respectively at 4850 m MD, 4955 m MD and 5078 m MD. The position of these faults was controlled by different weIl geophysical data. The present paper emphasizes the technical aspects of the drilling work, in connection with the geological formation constitution. The geological and geophysical data achieved are discussed.
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Etude palynostratigraphique du Dévonien inférieur dans l'Ouest de l'Europe
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La minéralisation Ba, (Zn, Pb) de Chaudfontaine (Synclinorium de Verviers, Belgique)
- Deze samenvatting is niet beschikbaar in het Nederlands. Résumé Les gisements à Zn, Pb, (Ba, F) de Belgique se répartissent au sein de trois districts. L'essentiel des productions du passé (environ 1.500.000 t de Zn + Pb) est cependant concentré dans un seul: le Synclinorium de Verviers. Les gisements exploités étaient de type filonien ou paléokarstique. Entre 1964 et 1973, des sondages ont mis en évidence un gisement principalement barytique, et accessoirement plombo-zincifère, à Chaudfontaine. Le contrôle stratigraphique du corps minéralisé de Chaudfontaine, la présence de structures sédimentaires mettant en jeu des cristaux de barite et de sphalérite, la nature métacolloïdale de certaines phases minérales et l'existence d'indices minéralisés situés au même niveau stratigraphique dans d'autres sondages éloignés de Chaudfontaine (Heibaart, Booischot, Bolland, Soumagne) ont permis d'affirmer que la minéralisation de Chaudfontaine était contrôlée par des phénomènes sédimentaires. Ces conclusions ont été confortées par l'étude des inclusions fluides de la barite et des étudesde géochimie isotopique (S, C, O, Sr, Pb). En particulier, les isotopes du Pb soulignent le rôle joué par les sédiments givétiens et frasniens en tant que piège transitoire des métaux introduits par voie sédimentaire. Effectivement, des anomalies lithogéochimiques ont été mises en évidence dans de nombreuses localités des Synclinoria de Verviers et de Namur, aussi bien dans les shales que dans les carbonates méso et néodévoniens. C'est d'ailleurs à cause de la présence d'anomalies zincifères importantes dans les shales de la Formation d'Aisemont (Frasnien supérieur), à Trooz, qu'une étude par diffraction de rayons X des shales frasniens a été entreprise. Elle a révélé la présence de minéraux interstratifiés susceptibles d'adsorber certains métaux. Des recherches diversifiées (géologiques, pétrographiques, paléogéographiques, géochimiques, etc...)conduites sur le gisement de Chaudfontaine et sur les terrains encaissants, dans les Synclinoria de Verviers et de Namur, ont permis de dégager des métallotectes positifs: position stratigraphique, liaison à une formation biostromale, proximité d'un haut-fond et de milieux évaporitiques, nature siliceuse de la roche support, et indices de surface. Le piège du gisement de Chaudfontaine consiste en de petites cuvettes situées au sommet du deuxième biostrome à Phillipsastraea de la Formation d'Aisemont. Elles ont été amenées temporairement à l'émersion et ont évolué vers des conditions évaporitiques (source du S). Les métaux proviennent du dénoyage des sédiments pélitiques d'un bassin subsident. La précipitation de la barite s'est effectuée dans une zone de mélange de deux solutions différentes, l'une apportant le soufre, l'autre les métaux. Finalement, on présente un modèle métallogénique relatif à tous les gîtes à Zn, Pb, (Ba) du Synclinorium de Verviers. Il illustre les notions de permanence et d'héritage. Les métaux de l'ensemble du système proviennent de l'altération continentale. Ils ont été véhiculés notamment par adsorption sur des pélites et ont été introduits dans les sédiments d'un bassin subsident. Ils ont été remobilisés pendant la diagenèse, après l'orogenèse varisque et éventuellement aux diverses périodes d'émersion. Au cours de ces diverses étapes, ils ont précipité à des fronts de dolomitisation, à des fronts d'échange de nappes de natures différentes et dans des pièges sédimentaires, karstiques et tectoniques. L'étude conclut sur les perspectives de prospection dans le Synclinorium de Verviers. Abstract Zn, Pb, (Ba, F) Belgian ore deposits are distributed into three districts. However, in the past, the main productions (around 1.500.000 t of Zn + Pb) were concentrated only into one of the districts, the Verviers Synclinorium. All the mined ore deposits were vein - or paleokarst-type deposits. In 1964, a barite ore deposit, with some sphalerite and galena, was discovered at Chaudfontaine by drillhole. The stratigra- phic control of the Chaudfontaine ore body, the presence of sedimentary structures with barite and sphalerite crystals, the metaco1loidal nature of some mineralogic phases and the presence of other mineralized occurrences in other drillholes, far away from Chaudfontaine (Heibaart, Booischot, Bolland, Soumagne) have led to the conclusion that the Chaudfontaine deposit was of sedimentary origin. This conclusion has been supported by the study of the fluid inclusions of the barite and by isotopic studies (S, C, O, Sr, Pb). In particular, the Pb isotopes emphasize the role of the Givetian and Frasnian sediments as transitory traps for metals introduced during the sedimentation. Effectively, lithogeochemical anomalies have been discovered in many localities of the Verviers and Namur Synclinoria, as well in the Meso and Neodevonian shales as in the carbonates. It is, indeed, because of the discovery of huge zinciferous anomalies at Trooz, in the shales of the Aisemont Formation (Upper Frasnian), that a study by X-ray diffraction has been performed on the Frasnian shales. This has indicated the presence of many interstrati- fied minerals which can have adsorbed metals. Various researches (geological, petrographical, paleontolo- gical, geochemical, etc...) undertaken on the Chaudfontaine deposit and on the country rocks, in the Verviers and Namur Synclinoria, have permitted to define ore guides: stratigraphic position, connection to a biostromal formation, vicinity of a high and evaporites, siliceous nature of the host-rock, and surface mineral occurrences. The trap of the Chaudfontaine ore deposit consists of small depressions on the top of the second Phillipsastraea biostrome of the Aisemont Formation. They have temporary emerged and have evolved to evaporitic conditions (source of S). The metals come from the dewatering of a pelitic subsidizing basin. The precipitation of barite has occurred in a zone of mixing of two different solutions: the first, bringing the sulfur, the second, bringing the metals. Finally, a metallogenic model has been presented for all the Zn, Pb, (Ba) deposits of the Verviers Synclinorium. This illustrates the notions of permanency and inheritance. The metals from this system could come from the continental weathering. These have been carried out, in particular, by adsorption on pelites, and have been introduced into a subsidizing basin. They have been remobilized during the diagenesis, after the variscan orogeny, and eventually, at the periods of emersion. At each successive stage, the metals have precipitated at fronts of dolomitization, at fronts of mixing of various solutions and into sedimentary, karstic and tectonic traps. The study concludes with the chances of success on prospecting in the Verviers Synclinorium.
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Benthic foraminiferal and isotopic patterns during the Early Eocene Climatic Optimum (Aktulagay section, Kazakhstan)
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The Knokke well (11E/138) with a description of the Den Haan (22W/276) and Oostduinkerke (35E/142) wells
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Les formations du Dévonien moyen de la Belgique
- Deze samenvatting is niet beschikbaar in het Nederlands. Résumé Les auteurs présentent des propositions pour uniformiser la subdivision en formations du Dévonien Moyen du Synclinorium de Dinant, du Synclinorium de Namur et du Massif de la Vesdre. Dans le Couvinien (sommet de l'Emsien et Eifelien) et le Givetien du bord sud du Synclinorium de Dinant, ils distinguent dix formations formelles et une informelle, qui sont de bas en haut: la Fm de St.-Joseph, la Fm de l'Eau Noire, la Fm de Couvin, la Fm de Jemelle, la Fm de la Lomme, la Formation “X” à Wellin, la Fm d'Hanonet, la Fm de Trois-Fontaines, la Fm des Terres d'Haurs, la Fm du Mont d'Haurs et la Fm de Fromelennes. Le Dévonien Moyen du bord nord du Synclinorium de Dinant et du bord sud du Synclinorium de Namur comprend la Fm de Rivière, la Fm de Névremont et la Fm du Roux. Au bord nord du Synclinorium de Namur, le Dévonien Moyen est représenté par la Fm du Bois de Bordeaux. Dans le Dévonien Moyen du Massif de la Vesdre, les auteurs distinguent la Fm de Vicht, la Fm de Pépinster, la Fm de Névremont et la Fm du Roux. Pour chaque formation, un stratotype et, dans certains cas, une autre coupe de référence sont décrits et figurés. En outre, les variations latérales et l'âge sont discutés. Abstract The authors present proposals to standardize the subdivision into formations of the Middle Devonian strata of the Dinant Synclinorium, the Namur Synclinorium and the Vesdre Massif. They recognize ten formai formations, and one informal, in the Couvinian (uppermost Emsian and Eifelian) and the Givetian strata of the southern flank of the Dinant Synclinorium. These formations are from older to younger : the St.-Joseph Fm, the Eau Noire Fm, the Couvin Fm, the Jemelle Fm, the Lomme Fm, the “X” Formation at Wellin, the Hanonet Fm, the Trois-Fontaines Fm, the Terre d'Haurs Fm, the Mont d'Haurs Fm and the Fromelennes Fm. The Middle Devonian succession of the northern flank of the Dinant Synclinorium and of the southern flank of the Namur Synclinorium comprises the Rivière Fm, the Névremont Fm and the Le Roux Fm. On the northern flank of the Namur Synclinorium, the Middle Devonian is represented by the Bois de Bordeaux Fm.In the Middle Devonian succession of the Vesdre Massif, the authors recognize the Vicht Fm, the Pépinster Fm, the Névremont Fm and the Le Roux Fm. The authors describe and figure a stratotype and, in some cases, an other reference section for each formation. Lateral changes and age of the formations are also discussed.
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Devonian antiarch placoderms from Belgium revisited
- Anatomical, systematic, and paleobiogeographical data on the Devonian antiarchs from Belgium are reviewed, updated and completed thanks to new data from the field and re-examination of paleontological collections. The material of Bothriolepis lohesti Leriche, 1931 is enhanced and the species better described. An undetermined species of Bothriolepis is recorded from the Famennian of Modave (Liège Province), one species of Asterolepis redescribed from the Givetian of Hingeon and another one described from the Givetian of Mazy (Namur Province). Grossilepis rikiki sp. nov. is recorded from the Famennian tetrapod-bearing locality of Strud (Namur Province) and from the Famennian of Moresnet (Liège Province). It is the first occurrence of Grossilepis after the Frasnian and on the central southern coast of the Euramerican continent. Its occurrence in the Famennian of Belgium may be the result of a late arrival from the Moscow Platform and the Baltic Depression, where the genus is known from Frasnian deposits. Remigolepis durnalensis sp. nov. is described from the Famennian of Spontin near Durnal (Namur Province). Except for the doubtful occurrence of Remigolepis sp. in Scotland, this is the first record of this genus in Western Europe. Its occurrence in Belgium reinforces the strong faunal affinities between Belgium and East Greenland and the hypothesis of a hydrographical link between the two areas during the Late Devonian.
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The 2010 archeometric research at Sagalassos
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Sédimentologie, paléoécologie et paléontologie des calcaires crinoidiques au voisinage de la limite Couvinien-Givetien à Wellin: bord sud du synclinorium de Dinant)
- Deze samenvatting is niet beschikbaar in het Nederlands. Résumé L'analyse sédimentologique des couches de transition Eifelien-Givetien dans la région de Wellin montre le passage d'un sytème de rampe mixte siliciclastique et carbonatée à une plate-forme carbonatée de faible pente et sans barrière récifale vraie. L'évolution de la sédimentation est celle d'une mégaséquence d'accrétion littorale au cours de laquelle les corps sédimentaires s'empilent sous forme d'unités progradantes d'épaisseurs décamétriques. L'analyse du contenu de la macrofaune corallienne et de la microflore algaire révèle en premier lieu une très grande diversité et abondance des organismes. Plusieurs assemblages sont reconnus et leur extension verticale est précisée. Ces assemblages reflètent souvent les zonations de faciès au sein de la rampe et ne peuvent donc être utilisés à des fins stratigraphiques qu'avec prudence. La comparaison avec d'autre données du Synclinorium de Dinant montre que le domaine sédimentaire était déjà structuré en "blocs" ou panneaux au sommet de l'Eifelien, préfigurant la situation au Givetien inférieur où plusieurs blocs d'extension plurikilométrique sont connus. Dans ce contexte, la mise en évidence d'une nouvelle formation (dénommée provisoirement Formation X) entre les Formations de Jemelle et d'Hanonet, dans la partie supérieure de l'Eifélien, prend toute son importance: cette formation, épaisse d'environ 120 m et constituée de calcaires crinoïdiques et construits, souligne la présence d'un bloc dans la région de Wellin. Abstract The sedimentology of the Eifelian-Givetian boundary beds in the Wellin area indicates a transition frorn a siliciclastic-carbonate ramp to a gently sloping carbonate platform lacking a true reefal barrier. Prograding decametric sedimentary units form a littoral accretion megasequence. Corallian megafauna and algal microflora are highly diverse and abundant. Several communities are recognized in the ramp but they cannot be used for precise chronostratigraphic correlations. Comparison with other regions of the Dinant Synclinorium shows that the basin was already partitioned into blocks in Late Eifelian time. In Early Givetian several blocks of plurikilornetric extension are identified. In this context, recognition of a new formation, provisionnally called "Formation X", between the Jemelle and Hanonet Formations, is significant. This local unit, some 120 meters thick, is composed of crinoidal and reefal limestones and indicates the existence of a sharply subsiding block in the Wellin area.
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Niphargus : a silicon band-gap sensor temperature logger for high-precision environmental monitoring
- A temperature logger, named “Niphargus”, was developed at the Geological Survey of Belgium to monitor temperature of local natural processes. It has a sensitivity of the order of a few hundredths of degrees on temperature variability in open air, caves, soils and river environment. The newly developed instrument uses a state-of-the-art band-gap silicon temperature sensor with integrated digital output. This sensor reduces the risk of drift associated with thermistor-based sensing devices, especially in humid environments. The Niphargus is designed to be highly reliable, low-cost and powered by a single lithium cell with up to several years autonomy, depending on the sampling rate and environmental conditions. A batch of Niphargus loggers was also compared to a precision thermistor to assess absolute temperature accuracy. Further characterization came from two field case studies in Belgium: monitoring of a mineralized water stream near the town of Spa and air temperature monitoring inside Han-sur-Lesse cave.
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Arlon/Autelbas : consommation et modes de vie à l’abbaye de Clairefontaine d’après les restes biologiques des cuisines (13e-16e siècles)
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Radon et gaz rares dans les sciences de la terre et de l'environnement. Actes du Colloque International sur la Géochimie des Gaz (Mons - 3-6 octobre 1990 - Belgique)
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Arlon/Autelbas : Etude des restes organiques des latrines de l’abbaye cistercienne de Clairefontaine (18e siècle)
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Burying Dogs in Ancient Cis-Baikal, Siberia: Temporal Trends and Relationships with Human Diet and Subsistence Practices
- The first objective of this study is to examine temporal patterns in ancient dog burials in the Lake Baikal region of Eastern Siberia. The second objective is to determine if the practice of dog burial here can be correlated with patterns in human subsistence practices, in particular a reliance on terrestrial mammals. Direct radiocarbon dating of a suite of the region’s dog remains indicates that these animals were given burial only during periods in which human burials were common. Dog burials of any kind were most common during the Early Neolithic (,7–8000 B.P.), and rare during all other time periods. Further, only foraging groups seem to have buried canids in this region, as pastoralist habitation sites and cemeteries generally lack dog interments, with the exception of sacrificed animals. Stable carbon and nitrogen isotope data indicate that dogs were only buried where and when human diets were relatively rich in aquatic foods, which here most likely included river and lake fish and Baikal seal (Phoca sibirica). Generally, human and dog diets appear to have been similar across the study subregions, and this is important for interpreting their radiocarbon dates, and comparing them to those obtained on the region’s human remains, both of which likely carry a freshwater old carbon bias. Slight offsets were observed in the isotope values of dogs and humans in our samples, particularly where both have diets rich in aquatic fauna. This may result from dietary differences between people and their dogs, perhaps due to consuming fish of different sizes, or even different tissues from the same aquatic fauna. This paper also provides a first glimpse of the DNA of ancient canids in Northeast Asia.
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Holarctic genetic structure and range dynamics in the woolly mammoth
- Ancient DNA analyses have provided enhanced resolution of population histories in many Pleistocene taxa. However, most studies are spatially restricted, making inference of species-level biogeographic histories difficult. Here, we analyse mitochondrial DNA (mtDNA) variation in the woolly mammoth from across its Holarctic range to reconstruct its history over the last 200 thousand years (kyr).We identify a previously undocumented major mtDNA lineage in Europe, which was replaced by another major mtDNA lineage 32–34 kyr before present (BP). Coalescent simulations provide support for demographic expansions at approximately 121 kyr BP, suggesting that the previous interglacial was an important driver for demography and intraspecific genetic divergence. Furthermore, our results suggest an expansion into Eurasia fromAmerica around 66 kyr BP, coinciding with the first exposure of the Bering Land Bridge during the Late Pleistocene. Bayesian inference indicates Late Pleistocene demographic stability until 20–15 kyr BP, when a severe population size decline occurred.
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Complete Mitochondrial Genomes of Ancient Canids Suggest a European Origin of Domestic Dogs
- The geographic and temporal origins of the domestic dog remain controversial, as genetic data suggest a domestication process in East Asia beginning 15,000 years ago, whereas the oldest doglike fossils are found in Europe and Siberia and date to >30,000 years ago. We analyzed the mitochondrial genomes of 18 prehistoric canids from Eurasia and the New World, along with a comprehensive panel of modern dogs and wolves. Themitochondrial genomes of all modern dogs are phylogeneticallymost closely related to either ancient or modern canids of Europe. Molecular dating suggests an onset of domestication there 18,800 to 32,100 years ago. These findings imply that domestic dogs are the culmination of a process that initiated with European hunter-gatherers and the canids with whom they interacted.
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Mitochondrial DNA diversity and evolution of the Pleistocene cave bear complex
- Cave bears are among the most well known extinct Pleistocene mammals. Their biogeography and taxonomy, along with the factors that led to their extinction, have been subject to long-standing controversy. Here, we reconstruct the phylogeography as well as the temporal and spatial population dynamics of cave bears across their range using mitochondrial DNA control region sequences from 77 published as well as 65 new cave bear samples, Our analyses reveal a dramatic loss of genetic diversity in cave bear populations after 30,000 years before present and provide evidence for a range decline from east to west towards the onset of the last glacial maximum. Our results also suggest that the three major haplogroups within cave bears, which may correspond to distinct species, were previously more widespread, with relict populations in remote and alpine areas still harbouring haplotypes that have disappeared from most of their previous range. Applying a phylogenetic dating approach, we estimated the age of the oldest of our samples, originating from the Yana River region in north-eastern Siberia, to be around 178,000 years, which confirms a previous estimate of a Middle Pleistocene age based on its stratigraphic position. Our results extend our knowledge about the evolutionary history of cave bears, but they also show that to unravel the complexities of cave bear evolution future ancient DNA studies on this Pleistocene species will need to go beyond short mitochondrial DNA fragments, including full mitochondrial genomes as well as nuclear DNA sequences.
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Atlas des gisements plombo-zincifères du Synclinorium de Verviers (Est de la Belgique)
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The First Upper Paleolithic Human Remains from Belgium: Aurignacian, Gravettian, and Magdalenian Fossils at the “Troisième caverne” of Goyet
- There is ample evidence of human occupation across Northern Europe throughout various periods of the Upper Paleolithic. However, the biological characteristics of the Northern European Upper Paleolithic humans and their mortuary practices remain largely unknown because of a dearth of human fossils. In Belgium, although the presence of humans has been verified at multiple archeological sites, no Upper Paleolithic fossil has yet been identified. In this context, the recent discovery of Upper Paleolithic human remains at Goyet (Belgium) fills in an important chronological gap. The “Troisième caverne” of Goyet, excavated at the end of the 19th and early 20th century, yielded a rich archeological sequence ranging from the Middle and Upper Paleolithic to historical times. In 2008, we began documenting the Paleolithic occupations of the “Troisième caverne” by reassessing the collections from the site which heretofore had only been partially studied. The updated inventory of human remains was accomplished by conducting a detailed sorting of the paleontological collections in order to identify human remains that may have been overlooked thus far. As a result, the collections from the “Troisième caverne” now include nearly 200 human bones/bone fragments and isolated teeth that correspond to various materials from different periods. The morphometric study of the human specimens from Goyet, completed by direct radiocarbon dating and stable isotope analysis, shows that they represent two main samples—a series of Late Neandertal remains (Rougier et al. 2012) and a set of modern human specimens from three periods of the Upper Paleolithic, namely the Aurignacian, Gravettian, and Magdalenian. The latter include fragmentary elements from the cranial and infracranial skeleton. Interestingly, those from the Gravettian and Magdalenian present anthropogenic traces and ochre traces. We will discuss the importance of these new fossils in the context of the human population of Northern Europe during the Upper Paleolithic.
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Onder de Euregio - de verbinding tussen landschap en geologie in de Euregio Maas-Rijn
