Jean-Pierre Bellier

Lower cretaceous planktonic foraminiferal biostratigraphy of the Western North Atlantic (ODP Leg 171B), and taxonomic clarification of key index species

Abstract An upper Aptian to Cenomanian sedimentary succession containing unusually well-preserved planktonic foraminifers was documented during ODP Leg 171B, which was devoted to the study of the Blake Plateau off Florida. With the exception of two zones within the Albian, an almost continuous composite section permits detailed investigation of the evolution of the foraminiferal assemblages. Emphasis in this paper is placed on the Aptian/Albian and Albian/Cenomanian transitions. In addition, the excellent preservation of the material enables some taxonomic revision, mainly on the basis of wall microstructural characters, of several planktonic foraminiferal lineages and taxa, such as the Hedbergella praetrocoidea — H. trocoidea — Ticinella eubejaouaensis phylogenetic relationship and the Rotalipora globotruncanoides or Hedbergella rischi species concepts.

Age of the Guatemala breccias around the Cretaceous-Tertiary boundary: relationships with the asteroid impact on the Yucatan

Abstract The upper part of the near K/T boundary limestone breccia deposits which crop out in Guatemala near 16 °N contains impact remains: altered glass spherules (tektites) and elevated concentrations of iridium. This suggests that these deposits could result from the impact of the K/T boundary asteroid on the Yucatan. However, their matrix contains foraminifers of the Eugubina Zone and calcareous nannofossils of the CP1a Zone, an association characterizing Early (but not the earliest) Danian. This unusual assemblage of K/T and Danian components suggests that the upper part of the breccia was reworked several thousands of years after the K/T event.

The Gargasian (Middle Aptian) of Cassis-La Bédoule (Lower Aptian historical stratotype, SE France): geographic location and lithostratigraphic correlations

In the middle of the last century Gargasian strata overlying the historical stratotypic beds of the lower substage of the Aptian (Bedoulian) were still well exposed in a number of quarries that extended in a NNE-SSW trending belt from the village of Roquefort-la Bedoule to the vicinity of the Cassis railway station (...)

Tectonostratigraphic relationships between the North Anatolian Thrust Zone (NATZ), and the Kirsehir Massif to the north of Sivas (Turkey)

In Central Anatolia, to the north of Sivas, the remains of the Northern Neotethyan domain crops out in a system of south verging thrust slices intercalated between the Eurasiatic margin (Tokat Massif), and the Taurus. In these nappes, sedimentary sequences have recorded the last steps of the Neotethyan evolution during the Late Cretaceous and of its closure during Palaeogene times. An ophiolitic melange is dated as Cenomano-Turonian or older and the thrusting of the Neotethyan nappes onto the Taurus belt (which corresponds to the closure of the Neotethys), is pre-Cuisian.

Les nappes tertiaires du Paı̈kon (zone du Vardar, Macédoine, Grèce) : arguments stratigraphiques pour une nouvelle interprétation structurale

Abstract Several interpretations concerning the structures of the Paikon mountains (Greece) have been proposed. Our new results (Upper Jurassic to Lower Cretaceous Radiolaria, Jurassic Gasteropoda...), some of them from metamorphic series (Ellipsactinies and Rudistes in the Lower Unit), give new constraints to build the palaeogeography and the tectonic history. These data permitted to define new series (e.g., the Lakka series) and reconstruct most of the others (e.g., the series of the lower units). Their palaeogeographic similarities are detailed and a new hierarchy of the tectonic contacts is settled (fundamental tectonic contacts or simple disharmonic structures). In that way, it appears that the Gola Tchouka window is the main one in the Paikon massive (Tertiary nappes) under another major unit (Elefterochori unit), which is simply buckled by secondary faults.