Données nouvelles sur les Hétérocoralliaires du Dinantien belge

The material used for this study consists of numerous Heterocorallia from the V2bß, collected at Lives (near Namur, Belgium). The morphology and ontogeny of Heterophyllia ornata M'COY and Hexaphyllia mirabilis DUNCAN are described. The youngest stage observed shows 4 protosepta and 4 interseptal loculi in which the metasepta arise. This pattern of development differs from that usually accepted. The stratigraphie occurence of these species in Belgium is provided

Warnantian

The Warnantian Substage is about 8 to 12 Ma long and was defined as corresponding to the Cf6 Foraminifer Zone by Conil et al., 1977 (= MFZ13 to MFZ15 Zones of Devuyst & Hance (in Poty et al., in press). Its base is taken at the base of the Bonne River Formation (Fm); its top is defined by the base of the Namurian stage, but its upper part is almost completely missing in the Namur-Dinant Basin. The substage is covered by the RC7 and RC8 Coral Zones. It comprises the Bonne River and the Anhée Fms, which are mainly composed of shallowing-upward parasequences which were deposited by aggradation on the shelf, as suggested by their lateral regularity. It corresponds to the HST of the third-order sequence 8 (Thon-Samson Member of the Bonne River Fm) and to the third-order sequences 9 and 10 (Hance et al., 2001; Poty et al., 2002). The lower (MFZ13-MFZ14, RC7) and the upper Warnantian (MFZ15, RC8) can be correlated respectively with the British Asbian and Brigantian Substages

Livian

The Livian Substage is about 3-4 Ma long and was defined as corresponding to the Cf5 Foraminifer Zone by Conil et al., 1977 (= MFZ12 Zone of Devuyst & Hance, in Poty et al., in press). Its base is taken at the base of the "Banc d’or de Bachant"?, a bentonite capping the Moliniacian Neffe Formation (Fm). The top of the substage corresponds to the top of the Bay-Bonnet Member (Mbr) of the Grands-Malades Fm, below the appearance of the first foraminifers marking the base of the Warnantian Substage, at the base of the Thon-Samson Mbr (Bonne River Fm). The substage comprises the Lives Fm, including the Haut-le-Wastia, Corphalies and Awirs Mbrs, and the Grands-Malades Fm including the Seilles-Maizeret and Bay-Bonnet Mbrs. It is mainly composed of shallowing-upward parasequences which were deposited by aggradation on the shelf as suggested by their lateral regularity. The Livian Substage comprises the third-order sequence 7 (from the base of the Lives Fm to the top of the Seilles-Maizeret Mbrs) and the TST of the sequence 8 (Bay-Bonnet Mbr) of Hance et al. (2001). The Livian corresponds to the RC5g Coral Subzone and the RC6 Zone. The Livian can be correlated with the British Holkerian Substage

Hastarian

The Hastarian Substage is the lower subdivision of the Tournaisian. Its base coincides with that of the Carboniferous as defined by the first appearance of the conodont Siphonodella sulcata. Unfortunately, the oldest siphonodellids are absent across the Devonian-Carboniferous boundary in the lower part of the Hastière Formation. The top of the Hastarian is defined by the base of the succeeding Ivorian substage (as emended by Hance et al., this volume) that is recognized by the first appearance of the conodont Polygnathus communis carina. The Hastarian correlates with foraminiferal Zones MFZ1 to MFZ4, rugose coral Zones RC1 and RC2 and the Siphonodella conodont Zone. Hastarian sedimentation occurred within a south-facing ramp setting. Thin-bedded crinoidal wacke- to packstones alternating with argillaceous limestones and thick-bedded crinoidal packtones form the dominant facies

Late Devonian to early Tournaisian Rugose corals

The distribution of Rugose Corals between the end of the Frasnian and the early Tournaisian is reviewed in four selected regions (Belgium and surrounding areas, German cephalopod facies, Poland, Omolon). Four "paleontological events" are distinguished : extinction of most of the Devonian-type Rugose Corals at the end of the Frasnian; development of a new fauna at the beginning of the Upper Famennian; increase and diversification of corals during Strunian; extinction of most of the Strunian corals and replacement by a Tournaisian-type coral fauna at the Devonian-Carboniferous boundary. These seems to be the result of eustatic and probably also climatic fluctuations (variations in sea water temperature)

Proceedings of the XIth International Symposium on Fossil Cnidaria and Porifera, Liege, Belgium, August 19-29, 2011: Preface

peer reviewe

Tournaisian

The main elements that prompted the international community to use the Tournaisian as a name for the oldest stage of the Mississippian Subsystem are the same as those for the Viséan, i. e., the quality of exposures in southern Belgium, the diversity of facies, the pioneering palaeontological work that started in the mid 19th century and development of foraminiferal, conodont and rugose corals zonations in the last decades. The numerous Tournaisian sections in southern Belgium document a progressive change in environmental setting, from a ramp during the early Tournaisian to a shelf during the late Tournaisian. The spectacular late Tournaisian Waulsortian buildups that occurred within 2 third-order sequences had a strong impact on subsequent Viséan sedimentation. Recent advances in understanding the sequence stratigraphy has led to new insights on correlation between the central Dinant Sedimentation Area and more proximal areas

Moliniacian

The Moliniacian is the basal division of the Viséan in Belgium (regional Substage). Its base is identified by the entry of the foraminifer Eoparastaffella simplex in the Salet road section and correlates with the base of the Viséan Stage. Its top is defined by the base of the Livian Substage and coincides with a major bentonite, the ‘Banc d’or de Bachant’. It correlates with the late Chadian to Arundian of the British Isles and it provides a record of the final stage of the evolution of the Namur-Dinant Basin from a homoclinal ramp (in the Tournaisian) to a broad shelf of regional extend (end of the Moliniacian). It is characterized by varied facies reflecting different sedimentary environments across the basin and rich foraminifer and coral faunas that allow good biostratigraphic correlation. It is known from numerous sections in Belgium and Northern France

Fasciculate kleopatrinid corals from the Bashkirian (Late Carboniferous) of Sardar Formation (Ozbak-Kuh mountains, East-central Iran)

In the East-Central Iran, the Sardar Formation (upper Visean–Moscovian) consists of shallow-water limestone with intercalations of shale containing rugose corals, tabulate corals and brachiopods. Ten sections were sampled in the Ozbak-kuh Mountains, from north to south. Among the rugose corals, an assemblage of fasciculate Kleopatrinidae has been collected. The latter contains the species: Paraheritschioides antoni antoni, P. antoni minor, P. gracilis and two new species for the genera Fomichevella and Heintzella. Heintzella is described from Iran for the first time. However, its age, as determined by conodonts and foraminifers, is early to middle Bashkirian (early late Carboniferous). The most similar, time-equivalent faunal associations are that of the Ellesmere Island, Sverdrup Basin in Arctic Canada, Alexander terrane and Brooks Range in southeastern Alaska and eastern Klamath terrane in northern California, where similar tropical warm water conditions have been identified during the Bashkirian in the northern hemisphere. During these times central Iran block and Northern provinces, characterized by a dominant carbonate facies and more diversified colonial coral faunas

Late Viséan to Early Serpukhovian Rugose Corals from the Yashui Section, Guizhou, South China

Abundant rugose corals are recorded in the Yashui Section in Huishui County of Central Guizhou, South China. The section is mainly composed of light-coloured bioclastic limestone with intercalations of some beds of dolomitized limestone and punctuated by a certain number of unconformities. Totally 20 species belonging to 13 genera are recognized. The composition of the fauna shows resemblance to the Western European faunas of latest Viséan to early Serpukhovian age. Many well-known European taxa such as Dibunophyllum bipartitum, Palaeosmilia murchisoni, Lithostrotion decipiens, Siphonodendron pauciradiale and Aulina rotiformis appear in Yashui, but with different stratigraphic ranges. There are also some endemic taxa such as Arachnolasma sinense, Yuanophyllum kansuense, Kueichouphyllum sinense and Stylostrotion petalaxoidae which can be used for correlations throughout South China. The coral diversity of the Yashui section shows: (1) a diversity decrease in the uppermost part of the Viséan, and (2) a poorly renewed fauna in the Serpukhovian, which is the similar pattern recorded in Palaeotethys. Therefore, a coral based biostratigraphic succession to separate the early Serpukhovian from latest Viséan is difficult to establish. Among the 20 species, 18 are described and illustrated, including 2 in open nomenclature. Two species are omitted from the description due to their bad preservation