Papers by Bernard Mottequin
The Becco locality (Liège province), belongs to the Theux tectonic window and represents a proxim... more The Becco locality (Liège province), belongs to the Theux tectonic window and represents a proximal, probably fluvial, environment corresponding to a channel infill. We present here a preliminary report of the fossil assemblage discovered at the locality. The Becco site has yielded a diverse flora of early seed plants including Moresnetia zalesskyi, Dorinnotheca streeli and Condrusia sp. This assemblage, characteristic of the Belgian Famennian, highlights the diversity of early spermatophytes in the country. Becco has also delivered a rich vertebrate fauna with antiarch, groenlandaspid and phyllolepid placoderms, diplacanthiform acanthodians, as well as actinopterygians and various sarcopterygians. The fossiliferous assemblage of Becco resembles those of several Devonian tetrapod- bearing localities, including that of Strud in Belgium, and could therefore provide a favorable palaeoecological setting in the search for early tetrapods.Peer reviewe
Lower Ordovician brachiopod macrofaunas in Belgium (Avalonia) are seldom collected and studied du... more Lower Ordovician brachiopod macrofaunas in Belgium (Avalonia) are seldom collected and studied due to the poor preservation of material. Here we describe a new fauna of linguliformean brachiopods from the Chevlipont Formation (lower Tremadocian) in the Brabant Massif. The fauna is of low diversity (at least three species belonging to Rosobolus?, Thysanotos, and Broeggeria have been identified) and is dominated by B. cf. salteri (Holl). Low diversity linguliformean brachiopod assemblages in a peri-Gondwanan terrane are characteristic of the lowermost Ordovician. Such assemblages are rooted in the Cambrian indicating that their geographic distribution during the early Ordovician was controlled by the radiation and dispersion of lineages surviving through the latest Cambrian–earliest Tremadocian linguliformean brachiopods taxonomic crisis. In addition we figure for the first time and comment on contemporaneous brachiopod faunas from the Stavelot-Venn Massif in SE Belgium. Finally, we p...
Palaeobiodiversity and Palaeoenvironments, 2020
The Devonian-Carboniferous boundary is associated with a major extinction event of the Phanerozoi... more The Devonian-Carboniferous boundary is associated with a major extinction event of the Phanerozoic. It was also a time marked by a rapid but short-lasting change in deposition called Hangenberg Event. In the Namur-Dinant Basin the uppermost Devonian ('Strunian') deposits recorded a third-order transgression that produced a progressive switch from coastal siliciclastic to proximal mixed deposits with an increase of the carbonate production on the ramp. Hence, the Comblain-au-Pont and lower Hastière formations are considered as the transgressive system tract, whereas the middle member of the Hastière Formation is interpreted as the highstand system tract, capped by an erosion surface corresponding to the third-order sequence boundary. Superimposed on these third-order sequences are well-marked orbitally forced precession cycles (wet-dry climate alternations) of c. 18.6 ka, appearing as irregular c. 30-80-cm-thick couplets of limestone and calcareous shale beds. The Hangenberg Black Shale Event is locally present as dark shales that likely spread over the shelf, marking the maximum flooding surface of the sequence. Before and after this event, carbonate facies rich in benthic macrofauna and microfauna continued to develop. The Hangenberg Sandstone Event, appearing as a sandstone bed in pelagic sections, is variously recorded at the base of the Hastière Formation, either as a sandy siltstone bed in proximal sections or as a horizon with limestone clasts and reworked fossils in more distal settings. The Hangenberg Sandstone Event beds occur sharply in the stratigraphic record and do not correspond to the long sea level fall of a third-order sequence boundary, but most probably to a short out-of-sequence event. The revision of the stratigraphic distribution of major fossil groups pleads for a continuous biostratigraphic succession with no obvious hiatus. The variable development of some micropalaeontological zones at the end of the Devonian is the result of complex ecobiostratigraphic interactions with the environment rather than the reflection of true hiatuses. It is marked by extinctions of Devonian taxa, concomitantly with the end of the reworking produced by the Hangenberg Sandstone Event, most probably immediately below the entry of the conodont Protognathodus kockeli. It is also coincident with the boundary between the foraminiferal zones DFZ7-MFZ1, rugose coral zones RC0-RC1 and between the palynozones LE-VI. After the short-lasting regressive phase of the Hangenberg Sandstone Event, normal depositional settings returned with the deposition of the Hastière Formation. Hence, the end of the Hangenberg Sandstone Event is proposed as the most natural proxy to pinpoint the Devonian-Carboniferous boundary.
The uppermost Famennian (Strunian) is typically a mixed carbonate-siliciclastic unit that deposit... more The uppermost Famennian (Strunian) is typically a mixed carbonate-siliciclastic unit that deposited during the transgressive phase of the first 3 rd order sequence. The Devonian-Carboniferous boundary, recognised at the top of the Hangenberg Sandstone event occured during the transgression. The Hastière Fm represent the first carbonate deposit of the Tournaisian. With the shaly Pont d'Arcole Fm and limestone of the Landelies Fm, its forms the sequence 2. Sequence 3, 4A and 4B are recorded in different units depending on the position on the shelf, notably in the Waulsortian mudmound complex in the southern Dinant sedimentation area and as mostly crinoidal and oolitic limestones in the Condroz sedimentation area. In more proximal areas, these sequences are often dolomitic and only the highstand system tracts are recorded. Sequence 5 filled the inherited depressions around the Waulsortion complex as calci-turbidites forming the 'Black marble' of the Molignée Fm. Sequence 6 finished to smooth the topographic irregularities with the deposition of massive oolithic limestone of the lower Viséan Neffe Formation capped by a pedogenetised cinerite. The middle and upper Viséan formations are monotonous shallow-water deposits, usually stromatolithic and arranged in parasequences with some marine interval such as in the biostromal Chabôfosse facies. In the Visé sedimentation area the late Viséan is represented by a large microbial reef in the stratotypic locality of Visé. Finally, the carbonate shelf has emerged at the end of the Viséan, was karstified and then covered by the Namurian.
Royal Belgian Institute of Natural Sciences, O.D. Earth and History of Life, Vautierstreet 29, B ... more Royal Belgian Institute of Natural Sciences, O.D. Earth and History of Life, Vautierstreet 29, B 1000 Brussels, Belgium. E-mails: roland.dreesen@telenet.be, bmottequin@naturalsciences.be Université de Lille 1, UFR Sciences Terre, UMR CNRS 8198 EvoEcoPaléo, Avenue Paul Langevin, 59655 Villeneuve d’Ascq cedex, France. E-mail: Daniel.Vachard@univ-lille1.fr Evolution & Diversity Dynamics Lab, Université de Liège, Bat. B18, Allée du Six-Août, Sart Tilman, B-4000 Liège, Belgium. E-mail: jmmarion@ulg.ac.be
Geologica Belgica, Aug 29, 2013
The Red Marble of Baelen is a local ornamental stone from the Limbourg area (Vesdre valley, Easte... more The Red Marble of Baelen is a local ornamental stone from the Limbourg area (Vesdre valley, Eastern Belgium), where it has been quarried at least since the 16th century, possibly even from the 9th century. It represents a local Member of the Middle Famennian (late Upper Devonian) Souverain-Pré Formation. It is the only known or at least the only well-documented Mid Famennian red-stained carbonate mudmound complex worldwide. Carbonate microfacies comprise nodular to lenticular algospongal pack/bindstones and massive stromatactis-bearing microbialitic mudstones, both enclosing lenticular crinoidal grain-to rudstones. Silty nodular bioclastic wacke/packstones, strongly affected by pressure solution, mark the transition with underlying and overlying micaceous sandstones and occur as interbeds within the mudmound core. The Red Marble of Baelen displays a few varieties that have been used for a large spectrum of building and decorative purposes, mostly within a short radius of the production sites, in the former Duchy of Limbourg. Its usage was rural and vernacular, although it has been exceptionally employed in prestigious buildings such as the Antwerp town hall.
Geologica Belgica, 2016
Biodiversity hotspots are defined as areas of unusually high biological diversity. This definitio... more Biodiversity hotspots are defined as areas of unusually high biological diversity. This definition is less clear for palaeohotspots but the Royseux locality in Southern Belgium is interpreted as such a site because of the large number of coral species that co-occur within a small area and short time interval. Forty-one species (29 genera) of rugose, tabulate and heterocorallia corals are known within a 6 m-thick 4 th order parasequence (100 kyr). These numbers increase to 50 species in 30 genera if the entire succession is considered. Consequently, Royseux is regarded as the richest site for late Viséan coral diversity on a global scale. Comparison with other sites from Spain, Morocco, the British Isles, and eastern Australia confirms this view. The diversity of brachiopods (at least 18 species within 16 genera) and other invertebrates is also assessed. The great palaeobiodiversity is tentatively explained by the interplay of several global and local causes, including high late Viséan biodiversity at the global scale associated with tectonically and sedimentarydriven micro-environment differentiation. Conversely, the Royseux locality has yielded few endemic taxa.
Cretaceous rocks, unconformably resting on the Palaeozoic basement, are recognised in several reg... more Cretaceous rocks, unconformably resting on the Palaeozoic basement, are recognised in several regions within the southern and northeastern parts of Wallonia (Belgium), mainly in the Mons Basin and the Liege area, respectively. In northeast Wallonia, Upper Cretaceous deposits essentially include sands, chalks and calcarenites. Northwest of Liege, they are generally covered by Cenozoic (Paleogene) and/or thick loess deposits. Campanian and Maastrichtian carbonate rocks (Gulpen and Maastricht formations) are still extensively quarried for the production of Portland cement in the valleys of the Meuse and Geer rivers, north of Liege. They are also excellent reservoir rocks, affected by a double porosity and constitute the Hesbaye aquifer, which is crucial for the water supply of Liege and its suburbs.
The Belgian Frasnian was investigated for a long time and displays well dated and correlatable se... more The Belgian Frasnian was investigated for a long time and displays well dated and correlatable sections. They allow to document the evolution of the carbonate platform and buildups, and their decease relating to the Frasnian crises. The sequence stratigraphy of the Middle and Upper Frasnian was revised here and has allowed to establish that the development of the buildups was well correlated with the third-order sequences. During the Middle Frasian, the onset and vertical growth of the three levels of reefs (" Arche " , " Boverie " and " Lion ") correspond to the transgressive system tract (TST) of the sequences. During the high-stand (HST) and the falling-stage system tracts (FSST), their vertical growth decreased, and they evolved to progradant carbonate platforms, 1 – 3 km wide and un to140 m high (including the biohermal core), in which bounstone are replaced by packstone – grainstone, then by shallow-water and intertidal mudstone (FSST). There is n...
The Hun Member of the Yvoir Formation represents the uppermost part of the Hastarian Substage (Lo... more The Hun Member of the Yvoir Formation represents the uppermost part of the Hastarian Substage (Lower Tournaisian, Lower Carboniferous) in the southern part of the Condroz sedimentation area of the Namur-Dinant Basin (S Belgium). This 12 m-thick member is composed of sandy bioclastic limestone alternating with shale layers and cherts; it is interpreted as the lowstand system tract of the third order sequence #3 of Hance et al. (2001). In the Chansin quarry (Bocq valley), this member has yielded an abundant association of silicified fauna showing an exquisite preservation. The association is dominated by rugose and tabulate corals along with brachiopods whereas bryozoans, gastropods and trilobites are only minor components. The rugose corals fauna is composed of solitary trochoid, ceratoid or cylindroid forms belonging to Amplexus coralloides, cf. Amplexizaphrentis sp., Bradyphyllum sp., Caninia cornucopiae, C. aff. cornucopiae, Caninophyllum patulum, " Lophophyllum " koninc...
Bulletin of Geosciences, 2015
A diverse assemblage of minute brachiopods is reported from the Viséan (late Asbian) Meenymore Fo... more A diverse assemblage of minute brachiopods is reported from the Viséan (late Asbian) Meenymore Formation exposed in the Gleniff outlier, County Sligo, northwest Ireland. The assemblage includes 14 micromorph species and juveniles of larger species, in which spire-bearers (Athyridida, Spiriferida and Spiriferinida) are the most diverse. Most of the species are left in open nomenclature as only few specimens show internal features. However, a new species of the uncommon orthotetide Drahanorhynchus (D. gleniffensis sp. nov.), previously known from the Mississippian of the Czech Republic, Spain and Germany, is described. In addition, the lectotype of the athyridide Hustedia multiplicata (de Koninck, 1887), from the Tournaisian of Tournai (Belgium) is selected and illustrated photographically for the first time. The brachiopods from Gleniff are associated with other small-sized benthic organisms particularly echinoderms and molluscs (gastropods, rostroconchs). The environmental factors, which lead to the small size, are not clearly understood although they probably included a combination of biological (e.g. food supply) and physicochemical (e.g. water oxygenation) parameters. Salinity is probably not implicated because brachiopods and echinoderms are generally stenohaline.
ABSTRACT This field trip is dedicated to the Devonian and Lower Carboniferous siliciclastics and ... more ABSTRACT This field trip is dedicated to the Devonian and Lower Carboniferous siliciclastics and carbonates from the northern and eastern borders of the Dinant Synclinorium. The sections that will be visited are the following: 1) Tihange, 2) Ombret-Rawsa, 3) Petit Avin quarry, 4) Bois d’Anthisnes quarry, and 5) Belle-Roche quarry.
Development and preservation of the geological heritage in the Liège province (Belgium): the Amps... more Development and preservation of the geological heritage in the Liège province (Belgium): the Ampsin and Tchafornis (Engis) geosites par Bernard MOTTEQUIN (*), Laurent BARCHY (**), Emmanuel CHEVALIER (**), Jean-Marc MARION (*) & Edouard POTY (*) Résumé.-Plusieurs initiatives destinées à mettre en valeur le patrimoine géologique ont été récemment développées en province de Liège (Belgique). Parmi celles-ci figurent les géosites d'Ampsin et des Tchafornis (Engis). Le géosite d'Ampsin illustre le passage brusque des faciès carbonatés peu profonds du Viséen moyen aux faciès détritiques terrigènes du Namurien. Celui des Tchafornis offre l'opportunité d'observer un magnifique exemple de biostrome à grands rugueux coloniaux de la base du Frasnien supérieur (Dévonien supérieur). Tous deux sont situés dans d'anciennes carrières et mettent également en évidence l'industrie extractive de la région. Abstract.-Several initiatives intended to highlight the geological heritage have been recently developed in the Liège province (Belgium). The Ampsin and Tchafornis (Engis) geosites rank among them. The Ampsin geosite shows the clearcut passage between the shallow carbonate facies of the Middle Viséan and the terrigenous detrital facies of the Namurian. The Tchafornis geosite gives the opportunity to observe a superb example of biostrome with large colonial rugose corals of the base of the Upper Frasnian (Upper Devonian). Both are located in disused quarries and also give prominence to the regional extractive industry.
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Papers by Bernard Mottequin