Upper Devonian and Mississippian foraminiferal and rugose coral zonations of Belgium and northern France: a tool for Eurasian correlations

Abstract

The radiation of early Carboniferous foraminifers and rugose corals following the Devonian–Carboniferous crisis offers the best tool for high-resolution correlations in the Mississippian, together with the conodonts in the Tournaisian, notably in the Namur–Dinant Basin. However, some of the guides are facies-controlled and an integrated approach combining biostratigraphy, sedimentology and sequence stratigraphy is critical to identify delayed entries, potential stratigraphic gaps and to avoid diachronous correlations. The main difficulty is in correlating shallow and deeper water facies at any given time. In existing zonations, the Viséan part of the scheme is always more detailed, reflecting the widespread development of shallow-water platforms in the early Viséan which created conditions more suitable for foraminifers and rugose corals over large areas. In contrast, the Tournaisian zones, less well documented, reflect unfavourable environmental conditions in the lower ramp (Dinant Sedimentation Area) and pervasive dolomitization of the inner ramp (Condroz and Namur Sedimentation Areas). Recent progress in understanding the Belgian early Carboniferous sequence stratigraphy and lithostratigraphy, and revision of the biostratigraphy of the key sections, strongly modify former biostratigraphic interpretations. Improvements mainly concern the latest Devonian, the late Tournaisian and the early Viséan. The late Devonian and the Tournaisian are equated with foraminifer zones DFZ1 to DFZ8 and MFZ1 to MFZ8 respectively. The Viséan correlates with zones MFZ9 to MFZ14. Zone MFZ15 straddles the Viséan–Namurian boundary and Zone MFZ16 is the youngest Mississippian zone. The rugose corals allow the recognition of ten zones, RC0 to RC9, covering the Strunian (late Famennian) to Serpukhovian interval. Discrepancies with former zonations are discussed. The Moliniacian Stage is emended to restore the coincidence between its base and that of the Viséan.

New Rugose corals and refinements of the Tournaisian biostratigraphy of the Donets Basin (Ukraine)

“…The distribution of this species includes a narrow stratigraphic interval of the latest Tournaisian: the uppermost Karpivka horizon (C 1 t d 2 subzone) in the Donets Basin, the Kos'va (Lun'evo) horizon of the South Urals, and the uppermost Ivorian (RC4β1) Avins Member of the Longpré Formation of Belgium and in equivalent level in the Bristol area (England, Julien Denayer, written communication, December 2015). This corresponds approximately to the generally accepted correlation of the uppermost Tournaisian units (Hecker, 2001, Menning et al, 2006, Poty et al, 2006, Poletaev et al, 2011.…”

“…In Western Europe, Conilophyllum is a guide taxon for the lowermost Tournaisian (Poty et al, 2006). In Pomerania (Poland, Chwieduk, 2005) and the Rhenish Massif (Germany, Weyer, 1993), the genus appears slightly earlier, before the Devonian-Carboniferous Boundary, whereas in Omolon (E Russia, Poty, 1999), it is known in the late Famennian.…”

Upper and uppermost Famennian (Devonian) brachiopods from north-western France (Avesnois) and southern Belgium

“…com., October 2015), only its base (the equivalent of the bed 159 of the Hastière Formation in the Anseremme section (see Poty et al, 2014)), could be correlated with the Upper praesulcata Zone. Although Poty et al (2006) have assigned the whole Avesnelles Formation to the Upper praesulcata Zone and thus considered it as entirely uppermost Famennian and not Tournaisian in age, we have followed the first opinion here. Nevertheless, the guide species of the standard conodont zonation have never been obtained so far in north-western France and southern Belgium due to unfavourable facies and it is thus not possible to trace the Devonian-Carboniferous boundary on the basis of the first appearance of Siphonodella sulcata, but according to E. Poty (pers.…”

“…Conil et al, 1964Conil et al, , 1986Van Steenwinkel, 1990;Poty, 1999;Poty et al, 2006). Some brachiopods such as Araratella moresnetensis (de Koninck, 1887) and Sphenospira julii (Dehée, 1929) are useful uppermost Famennian guides but, in general, those of the base of the Tournaisian remain poorly known due to their scarcity and the difficulties extracting them from the carbonate matrix.…”

Refinements in biostratigraphy of the foraminiferal zone MFZ11 (late early Viséan, Mississippian) in the Cebeciköy Limestone (Ýstanbul Terrane, NW Turkey) and palaeogeographic implications

“…The V2a, originally defined as a middle Viséan division, is currently connected with the late early Viséan. Our goals in this paper have been: (1) to provide a detailed analysis of the foraminifers and algae of Cebeciköy; (2) to verify that the Cebeciköy Limestone contained the MFZ11 biozone (Poty et al 2006, Hance et al 2011) corresponding roughly to the ancient "V2a"; (3) to revise the eponymous locality of Cebeciköy in order to provide a new detailed analysis of this biozone; (4) to discuss if the subzonation into MFZ11A and MFZ11B existed also locally; (5) to provide some elements of a palaeogeographical analysis of the northern terranes of Turkey.…”