References of "Geologica Belgica"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailLes Monts de Baileux section: detailed sedimentology and magnetic susceptibility of Hanonet, Trois-Fontaines and Terres d'Haurs formations (Eifelian-Givetian boundary and Lower Givetian, SW Belgium)
Mabille, Cédric ULg; Boulvain, Frédéric ULg

in Geologica Belgica (2008), 11

This work details for the first time the sedimentology of Les Monts de Baileux section. This section, located in a quarry between Chimay and Couvin, exposes a remarkable succession of strata from the top ... [more ▼]

This work details for the first time the sedimentology of Les Monts de Baileux section. This section, located in a quarry between Chimay and Couvin, exposes a remarkable succession of strata from the top of the Jemelle Formation to the base of the Mont d’Haurs Formation. It therefore offers the opportunity to investigate the entire Hanonet, Trois- Fontaines and Terres d’Haurs formations, biostratigraphically from Polygnathus ensensis to P. timorensis conodont zones. This large lithostratigraphic thickness of clayley and argillaceous, and also pure limestones encompasses the Eifelian/ Givetian boundary in the lower part of Hanonet Formation, allowing a better understanding of the transition between the Eifelian which corresponds to a mixed siliciclastic-carbonate detrital ramp and the lower Givetian dominated by a carbonate rimmed shelf-related sedimentation. Petrographic study leads to the definition of 21 microfacies integrated into two palaeogeographical models. The first model (13 microfacies) is proposed for the Jemelle, Hanonet and Trois-Fontaines formations, i.e. P. ensensis Zone and almost entire P. hemiansatus Zone. In this platform model, the fore-reef environment is characterized by a high influence of storm events and carbonate input coming from proximal settings. The reef is mainly composed of an accumulation of stromatoporoids, crinoids, tabulate corals and rugose corals with a peloidal matrix. The back-reef area is dominated by agitated environments and calmer lagoons. Locally, less agitated conditions allow growth of massive and laminar organisms. The second model (6 microfacies) concerns the Terres d’Haurs Formation with the end of P. hemianstus Zone and significant part of the P. timorensis Zone. This ramp model is divided into a mid-ramp characterized by open-marine sedimentation interrupted by storm-related events and an inner ramp composed of ooidal shoals, back-shoal sedimentation and storm related deposits. Two other microfacies are fragmentarily defined for the Mont d’Haurs Formation, within the main P. varcus / P. rhenanus intervals. This unit was affected by strong dolomitization processes, where scarcity of well preserved, primary sedimentary fabrics is not favourable for designing of a microfacies-based model at all. The last part of the work concerns stratigraphic variations of magnetic susceptibility (MS). Values of mass MS of rocks were plotted and juxtaposed with semi-quantitative variation curves of microfacies. According to the prevailing magnitudes of MS, the relationships with two controlling parameters are evaluated: terrigenous influence (using the thin-section data on detrital quartz contents as proxies) and wave agitation (based on microfacies interpretation). The transgressive- regressive evolution of microfacies characteristics are compared with the juxtaposed trends in decreasing-increasing MS magnitudes. Approximately two thirds of this section suggests a good matching of the trends on generalized lithological and magnetic data. It is explained by common presence of clayey/silty impurities of slightly to moderately varying compositions which are greatly evidenced by means of thin-section studies and represent a principal and abundant paramagnetic component. The overall MS magnitudes actually show decreasing trends together with vigorous, eustatically driven sealevel rises. However, the remaining third of intervals in this section shows the rather complex than simple, equivocally or negatively arranged sequence/lithologic and MS stratigraphic trends. [less ▲]

Detailed reference viewed: 49 (1 ULg)
Full Text
Peer Reviewed
See detailThe miospores of the Westphalian C / Westphalian D transition in the Campine Basin (Belgium) in the context of the macroflora zonations.
Streel, Maurice ULg; Somers, Y; Dusar, M

in Geologica Belgica (2008), 11(3-4), 243-250

Detailed reference viewed: 16 (2 ULg)
Full Text
Peer Reviewed
See detailSedimentology and magnetic susceptibility of the Couvin Formation (Eifelian, South Western Belgium): Carbonate platform initiation in a hostile world
Mabille, Cédric ULg; Boulvain, Frédéric ULg

in Geologica Belgica (2007), 10(1-2), 47-67

The Eifelian of Belgium is mainly characterised by a mixed siliciclastic-carbonate sedimentation on a ramp profile. In this context, the Couvin Formation is the more important and remarkable exception. It ... [more ▼]

The Eifelian of Belgium is mainly characterised by a mixed siliciclastic-carbonate sedimentation on a ramp profile. In this context, the Couvin Formation is the more important and remarkable exception. It represents a carbonate platform initiation in a hostile environment. This work is mainly based on the stratotype, corresponding to two stratigraphic sections located in Couvin, along the southern border of the Dinant Synclinorium. These sections are the Eau Noire and Falaise de l'Abime sections. Unfortunately, they are discontinuous. To allow a better understanding of the sedimentary dynamics, the data are complemented by a shorter but continuous section located in Villers-la-Tour (3.5 km West of Chimay). Petrographic study leads to the definition of 14 microfacies which are integrated in a palaeogeographical model. It corresponds to a platform setting where the reef complex is mainly constituted by an accumulation of crinoids, stromatoporoids and tabulate corals. The microfacies evolution is interpreted in terms of bathymetrical variations. It shows a general shallowing-upward trend encompassing the vertical succession of fore-reef settings, reef development, back-reef and then lagoon environment. This interpretation is supported by trends in mean magnetic susceptibility data, providing a better understanding of the sedimentary dynamics. Moreover, these data show positive correlation with concentrations of detritic minerals, but an inverse relationship with well washed skeletal limestones. The comparison of the three studied sections leads to considerations concerning the lateral variability in the Couvin Formation indicating more agitated conditions in the Abime Member in Villers-le-Tour section. [less ▲]

Detailed reference viewed: 120 (19 ULg)
Full Text
Peer Reviewed
See detailPalynomorph distribution and bathymetry in the Chanxhe section (eastern Belgium), reference for the neritic late to latest Famennian transition (Late Devonian).
Maziane-Serraj, N; Hartkopf-Fröder, C; Streel, Maurice ULg et al

in Geologica Belgica (2007), 10(3-4), 170-175

Detailed reference viewed: 24 (10 ULg)
Full Text
Peer Reviewed
See detailFrasnian
Coen-Aubert, M.; Boulvain, Frédéric ULg

in Geologica Belgica (2006), 9(1-2), 19-25

The name Frasnian, which comes from the locality of Frasnes near Couvin in Belgium, was introduced by Gosselet in 1879 and was formally retained for the lower stage of the Upper Devonian by the ... [more ▼]

The name Frasnian, which comes from the locality of Frasnes near Couvin in Belgium, was introduced by Gosselet in 1879 and was formally retained for the lower stage of the Upper Devonian by the Subcommission on Devonian Stratigraphy in 1981. The modern definition of the Frasnian is based on conodonts and the historical background of the stage is developed in detail herein. Data about the lithostratigraphy, sedimentology, biostratigraphy, chronostratigraphy and absolute age of the Frasnian can also been found in this contribution. [less ▲]

Detailed reference viewed: 54 (3 ULg)
Full Text
Peer Reviewed
See detailDisused Jurassic regional stage from Belgium: Virtonian
Delsate, D.; Boulvain, Frédéric ULg

in Geologica Belgica (2006), 9(1-2), 199-200

An overview of the definition and history of the Virtonian is given with the argumentation for the abandonment of this disused regional stage.

Detailed reference viewed: 23 (0 ULg)
Full Text
Peer Reviewed
See detailDisused Palaeozoic regional stages from Belgium: Devillian, Revinian, Salmian, Gedinnian and Burnotian.
Dejonghe, L.; Herbosch, A.; Steemans, Philippe ULg et al

in Geologica Belgica (2006), 9(1-2), 191-197

Detailed reference viewed: 35 (2 ULg)
Full Text
Peer Reviewed
See detailStrunian
Streel, Maurice ULg; Brice, D; Mistiaen, B

in Geologica Belgica (2006), 9(1/2), 105-109

Detailed reference viewed: 17 (6 ULg)
Full Text
Peer Reviewed
See detailFamennian
Thorez, J; Dreesen, R; Streel, Maurice ULg

in Geologica Belgica (2006), 9(1/2), 27-45

Detailed reference viewed: 27 (2 ULg)
Full Text
Peer Reviewed
See detailAltered rhyolitic rocks in the Visé boreholes: a geochemical approach
Duchesne, Jean-Clair ULg; Goemaere, Eric; Grigolato, Jean-Christophe et al

in Geologica Belgica (2005), 8(3), 71-83

Detailed reference viewed: 42 (7 ULg)
Full Text
Peer Reviewed
See detailFrasnian carbonate buildups of southern Belgium: the Arche and Lion members interpreted as atolls
Boulvain, Frédéric ULg; Demany, B.; Coen-Aubert, M.

in Geologica Belgica (2005), 8(1-2), 69-91

The facies architecture, sedimentary dynamics and paleogeographic evolution were reconstructed for a number of Frasnian buildups developed on a carbonate platform on the south side of the Dinant ... [more ▼]

The facies architecture, sedimentary dynamics and paleogeographic evolution were reconstructed for a number of Frasnian buildups developed on a carbonate platform on the south side of the Dinant Synclinorium (Belgium). Bed-by-bed sampling and detailed petrography were complemented by magnetic susceptibility analysis, allowing for high-precision lateral correlation. Six facies were recognised in the buildups, each characterized by a specific range of textures and assemblage of organisms: grey, pinkish or greenish limestone, with stromatactis, corals and stromatoporoids (facies A3-L3); grey limestone with corals, peloids and dasycladales (facies A4-L4); grey, microbial limestone (facies A5-L5); grey limestone with dendroid stromatoporoids (facies A6-L6); grey, laminar fenestral limestone, (facies A7-L7); grey, bioturbated limestone (facies A8-L8). The time-equivalent off -buildup sediments include a large amount of transported material that originally came from the buildups. Sedimentological evidence suggests that facies A3-L3 developed between the storm wavebase and the fairweather wavebase, in a oligophotic environment. This facies contains lenses of facies A5-L5, with stromatolitic coatings and Renalcis-rich thrombolitic bushes. These lenses were developed in greatest abundance closest to the fairweather wavebase, and they became anastomosing. Facies A6-L6 was developed in an environment with slightly restricted water circulation; there is a steady transition between this facies and the fenestral limestone A7-L7, which were deposited in a moderately protected subtidal to intertidal area. Facies A8-L8 developed at subtidal depths in a quiet, lagoonal environment. The buildups started with the development of facies A3-L3, with microbial lenses and algal facies becoming progressively more abundant upwards. Above about 20m in each buildup, more protected facies are found in the buildup’s central part. This atoll-like geometry suggests the development of restricted sedimentation in this central area, sheltered by bindstone or floatstone facies. The initial development of the lower part of a buildup during a transgression and subsequent highstand would have been followed by reefal growth along the edge of the buildup during the succeeding lowstand; an atoll crown would then have started to develop during the following transgressive stage. The presence of restricted facies can be seen as the consequence of the balance between sea level rise and reef growth. [less ▲]

Detailed reference viewed: 24 (1 ULg)
Full Text
Peer Reviewed
See detailZeolites, prehnite, and pumpellyite from Bertrix, Belgium.
Hatert, Frédéric ULg; Theye, Thomas

in Geologica Belgica (2005), 8(1-2), 33-42

Detailed reference viewed: 18 (3 ULg)
Full Text
Peer Reviewed
See detailA Psammosteid Heterostracan (Vertebrata: Pteraspidomorphi) from the Emsian (Lower Devonian) of the Grand Duchy of Luxembourg
Delsate, D.; Blieck, A.; Steemans, Philippe ULg

in Geologica Belgica (2004), 7(1-2), 21-26

Detailed reference viewed: 28 (0 ULg)
Full Text
Peer Reviewed
See detailJean-Marie Graulich, biographie
Delmer, Andre; Da Silva, Anne-Christine ULg

in Geologica Belgica (2003), 6(3/4), 73-80

Detailed reference viewed: 32 (4 ULg)