Critical review of Pseudocucurbitidae (Miliolina, Foraminiferea) from the Late Triassic reef environments of the Tethyan area

Abstract. The Late Triassic foraminiferal genera Amphorella, Spiriamphorella, Urnulinella, Pseudocucurbita, Paratintinnina, Costifera and Siculocosta are considered junior synonyms of the genus Cucurbita. Consequently, the number of families of the Milioliporacea (Miliolina) is significantly reduced. The valid species of the genus Cucurbita are considered to be Cucurbita infundibuliforme Jablonský, 1973, C. subsphaerica (Borza & Samuel, 1977a) comb. nov., C. longicollum Senowbari-Daryan, 1983, C. battagliensis (Senowbari-Daryan, 1983) comb. nov., C. cylindrica (Senowbari-Daryan, 1983) comb. nov. and C. floriformis (Altiner et al., 1992) comb. nov.

Cement stratigraphy: image probes of cathodoluminescent facies

Cement stratigraphy of carbonates aims to establish the chronology of processes involved in the rock diagenesis. Regional cement stratigraphy allows correlations and understanding of the petrological heterogeneities in reservoirs and aquifers, but is a long and rigorous approach. This article exposes a methodology of image analysis that facilitates the spatial correlation of diagenetic events in carbonate rocks. Based on the statistical comparison of signals extracted from the red spectrum emission of cathodoluminescence digital images, it gives via crosscorrelation a measure of similarity (values scaled from minimum −1 to maximum 1) between two cathodoluminescence facies. Cementation events and diagenetic chronologies can thus be quickly correlated without the support of a full chronology, the model normally established on cement morphologies, petrological analyses and cathodoluminescence zonation sequences. A case study from two Upper Kimmeridgian Mount Salève outcrops (France) illustrates this methodology. Their diagenetic sequences recorded in cathodoluminescent cements are presented and being compared. The final statistical similarity between the two outcrops reaches an index of R=0.78. This result is sustained by petrological and geochemical analyses such as alizarine-ferricyanure stained thin sections, X microfluorescence mapping of elements, and microthermometry of fluid inclusion

TURRIGLOMINA? ANATOLICA, N. SP. (FORAMINIFERIDA) FROM THE CRETACEOUS OF NORTH-WESTERN ANATOLIA (TURKEY): REMARKS ON THE EVOLUTION OF THE MESOZOIC MEANDROSPIRIDS

A new species of foraminifer, Turriglomina? anatolica n. sp., is erected from the Lower Cretaceous of North-Western Anatolia, Turkey. The species is characterized by a well developed meandrospirid stage followed by a rectilinear, helicoidal stage. The morphology of the new taxon is similar to that of the Triassic genus Turriglomina zaninetti, however, the generic attribution is doubtful as the evolutionary path of meandrospirids is not documented from Triassic to Cretaceous.&nbsp

Microfacies and depositional setting of the Upper Triassic mid-oceanic atoll-type carbonates of the Sambosan Accretionary Complex (southern Kyushu, Japan)

The Upper Triassic shallow-water limestones of the Sambosan Accretionary Complex are reconstructed as a remnant of a mid-oceanic atoll-type build-up upon a seamount in the Panthalassan Ocean. The Sambosan atoll-type carbonates and its pedestal were accreted along with deep-water ribbon-chert and related siliceous rocks to the eastern margin of Asia during the Late Jurassic to Early Cretaceous. Studied limestones crop out in southern Kyushu Island, southwest Japan. Although the prevailing and intense deformation during the accretionary process prevents measurement of sections in stratigraphic successions, and sedimentary structures are poorly preserved, microfacies description and foraminifers analysis allow us to speculate the depositional setting of the Sambosan limestones. Seventeen microfacies are distinguished and several foraminifers of Tethyan affinity are identified. Foraminifers indicate a Late Carnian to Rhaetian age. The Tethyan affinity of the macro- and microfaunas suggests that the Sambosan seamount was located presumably in a low- to middle-latitudinal zone of the southern hemisphere during the Late Triassi

OSTRACODS FROM THE LATE TRIASSIC (NORIAN) OF YUKON, CANADA: NEW TAXONOMIC AND PALAEOBIOGEOGRAPHIC INSIGHTS

The present work investigates the significance of Late Triassic ostracods from the Yukon Territory, Canada, and adds to the scientific knowledge of the taxonomy of these organisms during the Norian, which remain poorly documented and understood. Fifteen limestone samples representing distinct marine palaeoenvironments cropping out at Lime Peak, Stikinia terrane, provided 90 species, including 9 newly described: Alatobairdia? sohni n. sp., Bairdia aksala n. sp., B. taan n. sp., B. yukonensis n. sp., Cornutobairdia yukonella n. sp., Lobobairdia whitella n. sp., Mirabairdia canadia n. sp., Hungarella limella n. sp., Leviella riedeli n. sp. Most assemblages point to neritic conditions in the photic zone. A similarity analysis demonstrates the distinct composition of reef-related and algae-related ostracod assemblages. The ostracod-algae associations in Lime Peak reveal that the affinity of Bairdiidae for algae (Dasycladaleans in the case of Lime Peak) was already established in the Norian. A faunal link is identified during the Norian between eastern and western Panthalassa and Japan, in line with studies on other taxa. The flux of species between eastern Panthalassa and Tethyan areas appears very unbalanced in the Late Triassic with most migrations originating from the Tethys. Further data from other Middle and Upper Triassic Panthalassan localities and stages (i.e. Ladinian and Carnian) are needed to confirm whether this apparent trend is due to sampling bias or reflects real dispersal fluxes

UN ASPECT DE LA PLATE-FORME CARBONATEE TRIASIQUE DANS LES HELLENIDES INTERNES: LE CHAINON D'OREOKASTRO

Au N de Tessalonique, entre la route Tessalonique-Langhadas et la valleé du Gallikos, le petit chainon d'Oréokastro s'allonge sur environ 12 km suivant une direction NW-SE. Sa dorsale est constituée par des calcaires triasiques qui font l'objet de cette étude. L'analyse micropaléontologique, stratigraphique et sédi­mentologique a permis de distinguer deux séries stratigraphiques, l'une caractérisée par des associations de Fora­minifères du Trias inférieur, l'autre par des microfaunes attribuables au Trias moyen (Anisien)

PAULBRONNIMANNINAE RETTORI & ZANINETTI, 1993 (FORAMINIFERIDA, AMMODISCIDAE) AND OTHER ANISIAN FORAMINIFERS FROM THE PIZ DA PERES SECTION (VALDAORA-OLANG, PUSTERIA VALLEY, DOLOMITES, NE ITALY)

The anisian  succession exposed in the Piz da Peres area, studied by De Zanche et al. (1992) using sequence  stratigraphy, is here examined from a micropaleontological  point of view. The Recoaro Limestone, deposited during highstand  time, contains the most diversified microfauna of the stratigraphic succession; it is Pelsonian in age, with the rypical association Meandrospira dinarica-Pilammina densa; the coeval Pelsonian foraminifers Paulbronnimannia  judicariensis  (Premoli Silva, 1971) and Paulbronnimannia  whittakeri Rettori gen. n., sp. n,, are also  present

Depositional environment and biofacies characterisation of the Triassic (Carnian to Rhaetian) carbonate succession of Punta Bassano (Marettimo Island, Sicily)

The aims of this study are to reconstruct the geological setting of the Punta Bassano series (Marettimo Island, Egadi Archipelago, western Sicily) and its palaeogeographic evolution. The reference section for the Upper Triassic of Marettimo shows an alternation of marl and limestone beds together with brecciated levels. The limestones are both homogeneous mudstones with evaporite pseudomorphs and laminated with fenestrae. Foraminiferal, palynomorph, and ostracod associations constrain the Punta Bassano sequence to the Carnian-Rhaetian interval. The Punta Bassano succession represents a shallow inner ramp, ranging from open-marine environment with good water circulation to lagoonal and peritidal protected environments. Freshwater input from rivers or groundwater on the carbonate ramp is indicated by the ostracod microfauna. The comparison of facies and microfauna with those from other sequences of the Mediterranean Upper Triassic (Pyrenees, Corsica, Sardinia, and Tunisia) allows us to confine the Punta Bassano sedimentation to the northern margin of the Tethys, between the Corsican and the Pyrenean depositional setting. These new results indicate that Marettimo Island, which is considered a single structural element being formed by four tectonic units, is a piece of the southern margin of the European Plate, displaced over a longer distance to become part of the other Egadi Islands, when the Corso-Sarde block made its rotation and successive collision with the North African Margi

CARACTÉRISATION MICROPALEONTOLOGIQUE DU "RHÉTIEN" DANS L'AXE NORD-SUD (TUNISIE CENTRALE); COMPARAISON AVEC LE RHÉTIEN DE LA DORSALE ET DE LA PLATE-FORME SAHARIENNE

The  micropaleontologic study of the oolitic dolomites from the Fkirine Formation, outcropping along the North-South Axis, allows to characterize the Upper Triassic (Norian?-Rhaetian) in Central Tunisia based on the discovery of Agathammines (Hoyenella inconstans and Agathammina austroalpina) and Aulotortus. This "Rhaetian" benthic foraminiferal assemblage, well known in the Peritethyan areas and locally associated with Gandinella falsofriedli, partially occurs in the type-locality of the Fkirine Formation ("Dorsale Tunisienne") and within the Zerzour Formation  from the Saharian Shelf (Jeffara)