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Letters

 

Letter 2 [2010]: Hadrosaur remains in the Late Cretaceous marine sediments of Larcan (Petites Pyrenees, Haute-Garonne, France), by Michel BILOTTE, Yves LAURENT & Dominique TÉODORI.-
Format [HTML] or [PDF 1,166 KB]
Reference: [CG2010_L02]
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 Abstract:  The discovery of two hadrosaur fragments (maxilla and quadrate) in marine sediments of the end of the Cretaceous (uppermost Maastrichtian) is reported. Although this type of taphocoenosis is not exceptional for continental organisms, its situation at approximately 1 m under the iridium zone of the K/T boundary deserves to be emphasized.

Online since May 31, 2010


Letter 1 [2010]: A pterosaur from the Toarcian (Early Jurassic) of the Ardennes (north-eastern France), by Eric BUFFETAUT, Bernard GIBOUT & Danielle DROUIN.-
Format [HTML] or [PDF 735 KB]
Reference: [CG2010_L01]
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 Abstract:  A pterosaur tibia-fibula is described from Toarcian shales ("Marne de Flize") near the city of Charleville-Mézières (Ardennes, northeastern France). The morphology of this element, especially the reduced fibula partially fused to the tibia, suggests that it belongs to the rhamphorhynchid Dorygnathus, which is well represented in the Toarcian Posidonienschiefer of Germany and has also been reported from the Toarcian of Nancy (eastern France).

Online since February 15, 2010


Letter 3 [2009]: An additional hadrosaurid specimen (Dinosauria: Ornithischia) from the marine Maastrichtian deposits of the Maastricht area, by Eric BUFFETAUT.-
Format [HTML] or [PDF 730 KB]
Reference: [CG2009_L03]
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 Abstract:  An isolated dinosaur vertebra from the marine deposits of the Maastrichtian type area, near the city of Maastricht (The Netherlands), collected during the 19th century and kept in the palaeontological collection of the Museum für Naturkunde in Berlin, is described as a caudal vertebra of a hadrosaurid ornithopod. Although it cannot be identified with greater accuracy, this specimen is an addition to the still scanty, but growing, record of non-avian dinosaurs from the Maastrichtian type area. This record is heavily dominated by hadrosaurs, which probably reflects a real abundance of this group of dinosaurs in the late Maastrichtian of Europe.

Online since August 1, 2009


Letter 2 [2009]: Evidence of predation on the vertebra of a hadrosaurid dinosaur from the Upper Cretaceous (Campanian) of Coahuila, Mexico, by Héctor E. RIVERA-SYLVA, Eberhard FREY & José Rubén GUZMÁN-GUTIÉRREZ.-
Format [HTML] or [PDF 1,788 KB]
Reference: [CG2009_L02]
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 Abstract:  In sediments of the Aguja Formation (Late Cretaceous: Campanian) at La Salada in northern part of the state of Coahuila, Mexico, numerous fossils of vertebrates have been discovered including Hadrosauridae. One hadrosaur vertebra provides evidence of predation probably by a giant alligator Deinosuchus riograndensis.

Online since August 1, 2009


Letter 1 [2009]: Serravallian (Miocene) nannofossils in Patagonia, Argentina, by Margarita SIMEONI.-
Format [HTML] or [PDF 689 KB]
Reference: [CG2009_L01]
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 Abstract:  For the first time, nannofossils found in the marine stratigraphic unit named "Patagoniano" which crops out at Cerro Chenque and Cerro Hermitte in southeastern Chubut, Argentina, are documented. They were recovered from pelitic levels in the lower part of coarsening-upward siliciclastic sedimentary sequences. The nannofossils are assigned in part to the Discoaster kugleri Zone NN7 (Martini, 1971) and CN5b (Bukry, 1971, 1973) thus allowing correlation of the productive levels with the Serravallian Stage (upper Middle Miocene).

Nota breve 1 [2009]: Nannofósiles del Serravalliano (Mioceno) en Patagonia, Argentina, de Margarita SIMEONI.-
Formato [HTML] o [PDF 689 KB]
Referencia: [CG2009_L01]
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 Resumen:  Se documenta el primer hallazgo de nannofósiles en el "Patagoniano", unidad estratigráfica marina aflorante en Cerro Chenque y Cerro Hermitte, al sudeste de Chubut, Argentina. Los nannofósiles fueron recuperados en niveles pelíticos inferiores de diferentes ciclos sedimentarios, grano-crecientes hacia la parte superior, formados por rocas siliciclásticas. Los nannofósiles pertenecen, en parte, a la Zona de Discoaster kugleri NN7 (Martini, 1971) and CN5b (Bukry, 1971, 1973) permitiendo la correlación de los niveles fértiles con el Piso Serravalliano (Mioceno Medio superior).

Online since March 31, 2009


Letter 3 [2008]: About the stratigraphic position of the Lower Aptian Roloboceras hambrovi (Ammonoidea) level, by Pierre ROPOLO, Michel MOULLADE, Gabriel CONTE & Guy TRONCHETTI.-
Format [HTML] or [PDF 180 KB]
Reference: [CG2008_L03]
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 Abstract:  In the stratotype of the Lower Aptian substage the position of the assemblage that includes Roloboceras spp. and Megatyloceras spp. has been clearly established as being in the middle part of the upper Bedoulian. Some authors have erected this horizon as a subzone, or even a zone, with R. hambrovi as species-index. In other areas (southern England, eastern Spain, the Ardèche in southeastern France), where taphonomic conditions are not always as favourable as they are in the stratotype, the level at which this assemblage occurs seems to be confined to the upper part of the lower Bedoulian. Various hypotheses are considered in an attempt to explain this divergence.

Online since August 27, 2008


Letter 2 [2008]: Zonation by ammonites and foraminifers of the Vraconnian-Turonian interval: A comparison of the Boreal and Tethyan domains (NW Europe / Central Tunisia), by Francis AMÉDRO & Francis ROBASZYNSKI.-
Format [HTML] or [PDF 144 KB]
Reference: [CG2008_L02]
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 Abstract:  Since the end of the 19th century the interval comprising the uppermost Upper Albian, the Cenomamian, the Turonian and the basal Coniacian has been subdivided, first into ammonite zones, then, beginning in the middle of the 20th century, into zones of planktonic foraminifera. These two groups, one macrofossil, the other microfossil, are particularly effective for bio-chronostratigraphy thanks to their rapid rates of evolution. But differences in the faunal makeup between the Boreal domain (northwestern Europe) and the Tethyan domain (Mediterranean) have for a long time hindered precise correlation of the two domains. Today, in a time interval covering about 16 million years, there are 29 ammonite zones in the Tethyan domain versus 24 in the Boreal one, of which 16 are common to both domains. For the planktonic foraminifera the Tethyan domain has 11 zones, the Boreal domain 10, with 7 in common.

Online since May 17, 2008


Letter 1 [2008]: Characterisation of the organic matter of upper Bedoulian and lower Gargasian strata in the historical stratotypes (Apt and Cassis-la-Bédoule areas, SE France), by François BAUDIN, Michel MOULLADE & Guy TRONCHETTI.-
Format [HTML] or [PDF 180 KB]
Reference: [CG2008_L01]
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 Abstract:  The Total Organic Carbon (TOC) content of the Gargasian strata studied in their historical stratotype area is rather low (0.3% on average). Only a few levels show TOC values approaching 1.2%. This small amount of preserved organic matter, associated with low hydrogen index values (10 to 115 mg hydrocarbons/g TOC), argues for deposition in fully oxic conditions. This organic content is a mixture of land-derived organic particles and deeply oxidized marine organic matter. The organic flux was strongly diluted by the autochthonous carbonate input.

Online since February 4, 2008


Letter 1 [2007]: Parsimony analysis of endemicity of enchodontoid fishes from the Cenomanian, by Hilda Maria Andrade da SILVA & Valéria GALLO.-
Format [HTML] or [PDF 111 KB]
Reference: [CG2007_L01]

 Abstract:  Parsimony analysis of endemicity was applied to analyze the distribution of enchodontoid fishes occurring strictly in the Cenomanian. The analysis was carried out using the computer program PAUP* 4.0b10, based on a data matrix built with 17 taxa and 12 areas. The rooting was made on an hypothetical all-zero outgroup. Applying the exact algorithm branch and bound, 47 trees were obtained with 26 steps, a consistency index of 0.73, and a retention index of 0.50. The topology found with a majority rule consensus was: [(Mexico) + (United States) + (Morocco + Italy) + (Lebanon + Israel) + (Italy-Slovenia) + (Brazil)] + (D.R. Congo) + (Sweden) + (Germany) + (England). The procedure delimited two areas of endemism in the Tethys Ocean. They are Morocco and southern Italy and Lebanon and Israel. The area of endemism formed by Morocco + Italy represents the North African region of the Tethys Ocean, and that formed by Lebanon + Israel is in the mid-Tethyan Ocean. Our results are in partial agreement with the patterns of geographical distribution of certain invertebrate biota.

 Corrigendum:  The fossil locality Lesina referred to in this paper as being in Italy is in fact in Croatia: Lesina is the former  name of  an island (Hvar). This correction does not affect the conclusions of the paper.

Online since April 4, 2007


Letter 2 [2006]: Ankylosaurid (Dinosauria: Thyreophora) osteoderms from the Upper Cretaceous Cerro del Pueblo Formation of Coahuila, Mexico, by Héctor E. RIVERA-SYLVA & Belinda ESPINOSA-CHÁVEZ.-
Format [HTML] or [PDF 617 KB]
Reference: [CG2006_L02]

 Abstract:  Ankylosaurian dinosaur osteoderms have been discovered in the southeastern part of the State of Coahuila, Mexico, in the township of General Cepeda, in the locality known as El Palmar. The osteoderms were collected from rocks that had been correlated to the Cerro del Pueblo Formation (Late Cretaceous: Campanian) of the Difunta Group. The fossil material includes four dermal scutes and three associated fragments that at present cannot be identified. This is the first description of ostoederms and ankylosaurian material from Coahuila.

Online since May 11, 2006


Letter 1 [2006]: The Gargasian (Middle Aptian) of La Tuilière - St-Saturnin-lès-Apt (area of the Aptian historical stratotype, Vaucluse, SE France): geographic setting and outcrop correlation, by Michel MOULLADE, Guy TRONCHETTI, Christine BALME & Georges KOUYOUMONTZAKIS.-
Format [HTML] or [PDF 553 KB]
Reference: [CG2006_L01]

 Abstract:  A stratonomic and micropaleontological analysis of the Aptian marls cropping out in the La Tuilière area near Saint-Saturnin-lès-Apt (Vaucluse, SE France), enabled us to reconstitute a continuous succession almost 120 m thick, that includes the upper terms of the Lower Aptian (Bedoulian) and the lower part of the Middle Aptian (Gargasian). These levels had never before been observed with such continuity in the Gargas region, the Aptian historical stratotype.

Online since January 30, 2006


Letter 1 [2005]: The "sauropod" from the Albian of Mesnil-Saint-Père (Aube, France): a pliosaur, not a dinosaur, by Eric BUFFETAUT, Claude COLLETÉ, Bruno DUBUS & Jean-Louis PETIT.-
Format [HTML] or [PDF 528 KB]
Reference: [CG2005_L01]

 Abstract:  A vertebra from the Albian of Mesnil-Saint-Père (Aube, eastern Paris Basin), previously identified as the first caudal of a sauropod dinosaur, is shown to be a dorsal vertebra of a large pliosaur. The specimen resembles vertebrae from the Albian of England and eastern France that have been referred to the pliosaur Polyptychodon, a taxon in need of revision.

A paper-printed version was published as : "Association Géologique Auboise, Bulletin Annuel, Sainte-Savine, n° 26 (décembre 2005), p. 3-8".

Online since September 13, 2005


Letter 5 [2004]: On a Deinotherium (Proboscidea) finding in the Neogene of Crete, by Athanassios ATHANASSIOU.-
Format [HTML] or [PDF 353 KB]
Reference: [CG2004_L05]

 Abstract:  This paper reports the discovery of an incomplete proboscidean mandible near the village of Maroniá in eastern Crete. The fragment described here includes the first molar (m1) of a deinothere, that because of its large size is identified as Deinotherium giganteum. The specimen was found in shallow-water marine sediments. The presence of Deinotherium on the island, together with other Miocene vertebrate faunas, suggests that during that epoch Crete was connected to the mainland by a wide land bridge.

Online since November 25, 2004


Letter 4 [2004]: New data on the lophophore anatomy of Early Cambrian linguloids from the Chengjiang Lagerstätte, Southwest China, by Zhi-Fei ZHANG, De-Gan SHU, Jian HAN & Jian-Ni LIU.-
Format [HTML] or [PDF 530 KB]
Reference: [CG2004_L04]

 Abstract:  A succession of developmental types in the lophophores of lingulid brachiopods is reported from the Early Cambrian Chengjiang deposits of South China. These types range from trocholophe, schizolophe to simple coiled spirolophe. Of Atdabanian age, this succession of forms is mirrored in the ontogeny of the lophophore of Recent linguloids, thus demonstrating a close similarity in the development of the lophophores of Cambrian and Recent forms. We illustrate also more than 10 extraordinary specimens with aberrant dispositions of the lophophoral arms that extend to unusual lengths either inside or outside the shell.

Online since October 28, 2004


Letter 3 [2004]: Laboratory cultures of calcifying biomicrospheres generate ooids - A contribution to the origin of oolites, by Ulrike BREHM, Katarzyna A. PALINSKA & Wolfgang E. KRUMBEIN.-
Format [HTML] or [PDF 4,929 KB]
Reference: [CG2004_L03]

 Abstract:  The in vitro production of ooid-like structures as possible precursors of oolites has been observed in laboratory cultures of spherical microbial communities isolated from the Wadden Sea (North Sea). The microbial spherulites consist of aggregated benthic diatoms (Navicula perminuta) enveloped by layers of filamentous cyanobacteria of the genus Phormidium and a halo-like biofilm of heterotrophic bacteria. The development of the structures takes several months and these configurations appear to be stable, before they calcify. The precipitation starts on the surface of the spheres as clouds of small scattered crystals, which later increase in size and aggregate to form hollow spheres around the microbial assemblage. Here we report for the first time carbonate precipitation in defined spherical microbial communities.

 Corrigendum:  The authors take this opportunity to rectify a failure to credit Professor-Doctor Heribert CYPIONKA of the Carl von Ossietzky University in Oldenburg, Germany, as the author of the videofile "Cyanobacterial movement inside a biomicrosphere". The videofile in question is one of a number of interesting documents put online by Professor CYPIONKA at: http://www.icbm.de/pmbio/mikrobiologischer-garten/eng/index.php3

Online since June 20, 2004


Letter 2 [2004]: The Gargasian (Middle Aptian) of Cassis-La Bédoule (Lower Aptian historical stratotype, SE France): geographic location and lithostratigraphic correlations, by Michel MOULLADE, Guy TRONCHETTI, Wolfgang KUHNT, Maurice RENARD & Jean-Pierre BELLIER.- (...)
Format [HTML] or [PDF 911 KB]
Reference: [CG2004_L02_MM_etal]

Online since March 21, 2004


Letter 1 [2004]: The Gargasian (Middle Aptian) substage in the Aptian historical stratotypes (SE France): General introduction, by Michel MOULLADE & Guy TRONCHETTI.- (...)
Format [HTML] or [PDF 135 KB]
Reference: [CG2004_L01_MM-GT]

Online since March 15, 2004


Letter 3 [2003]: Note on magnesite formation (Studies on irreversible geochemical reactions Nº 9), by John C. DEELMAN.-
Format [HTML] or [PDF 250 KB]
Reference: [CG2003_L03_JCD]
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 Abstract:  In recent laboratory experiments magnesite (MgC03) has been synthesized at a temperature of 313ºK (= 40ºC). The experiments have demonstrated that irreversible reactions are involved in the low-temperature formation of magnesite. Fundamental to such irreversible reactions is a requirement for fluctuations, i.e., alternations between precipitation and dissolution. But unequivocal evidence for the necessity for fluctuations in order to produce such irreversible geochemical reactions can be demonstrated only by static control experiments. The present note describes several static control experiments on the low-temperature synthesis of magnesite. The first experiment consisted of adding the total amount of ammonia (used in the original experiment in 14 different titration steps) in a single action: only magnesium hydroxide carbonate formed, not magnesite. In the second experiment the possible reaction between magnesium chloride, ammonia and carbon dioxide in solution was studied at 318ºK (= 45ºC): magnesium hydroxide formed, not magnesite. The third static control experiment involved the reaction between magnesium chloride and ammonium carbamate; this time nesquehonite formed, not magnesite. The implications of these static control experiments in relation to the low-temperature formation of magnesite and dolomite in the sedimentary environment are discussed.

Online since December 4, 2003


Letter 2 [2003]: Lower sea levels in the Middle Cenomanian, by Jake M. HANCOCK.-
Format [HTML] or [PDF 280 KB]
Reference: [CG2003_L02_JMH]
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 Abstract:  It has been known since the 1970's that the relatively high sea levels during the Cenomanian in southern England and northern France were interrupted by a strong fall in sea level early in the Middle Cenomanian. This was a eustatic trough whose effects can be found not only in north-west Europe, but also from western Kazakhstan in central Asia to Texas, Colorado and South Dakota in the U.S.A.

Online since July 3, 2003


Letter 1 [2003]: Proof that Lingula (Brachiopoda) is not a living-fossil, and emended diagnoses of the Family Lingulidae, by Christian C. EMIG.-
Format [HTML] or [PDF 1,204 KB]
Reference: [CG2003_L01_CCE]
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 Abstract:  Lingula is often considered a "living-fossil" based on its supposed lengthy morphological conservatism owing to its absence of evolution, and its remarkable survival for more than 550 M.Y. This conclusion is based on the typical apparently unchanged "linguliform" shape of the shell. However the taxa of the family Lingulidae show morphological evolutionary changes despite the fact that the group appears panchronic among the Recent Brachiopoda. Consequently, traditional opinion that Lingula is a "living-fossil" should be rejected. Diagnoses of the Family Lingulidae and of its three genera are herewith emended.

Online since May 1, 2003


Articles

 

Article 6 [2010]: Biostratigraphic distribution of orbitolinids in the ammonite biozones (Urgonian platform of southeastern France). Part 1: Upper Hauterivian-lowermost Barremian, by Bernard CLAVEL, Robert BUSNARDO, Jean CHAROLLAIS, Marc André CONRAD & Bruno GRANIER.-
Format [HTML] or [PDF 34,646 KB]
Reference: [CG2010_A06]
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 Abstract:  The proposed biostratigraphic distribution of orbitolinids from the Upper Hauterivian and the lowermost Barremian of SE France is correlated with the ammonite biozonation. It is based on the detailed study of eight sections which delivered orbitolinids intercalated with or capped by levels with ammonites and, in some cases, echinids and dasycladales. Among the 24 species of orbitolinids present during that period, 3 are restricted to the Late Hauterivian: Praedictyorbitolina busnardoi, Paleodictyoconus beckerae and Valserina primitiva.

Online since August 27, 2010


Article 5 [2010]: Barremian-Aptian Dasycladalean algae, new and revisited, from the Tirgan Formation in the Kopet Dagh, NE Iran, by Morteza TAHERPOUR KHALIL ABAD, Marc André CONRAD, Ali Asghar ARYAEI Aryaei & Ali Reza ASHOURI.-
Format [HTML] or [PDF 6,671 KB]
Reference: [CG2010_A05]
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 Abstract:  Abundant, diversified algal assemblages comprising more than 25 species of Dasycladales are described from Barremian-Aptian limestone deposits of the Tirgan Formation in NE Iran. New species are described: one of them possibly belongs to a new endosporate genus, tentatively assigned the Triploporellaceae; two others, Clypeina ? sp. 1 and Rajkaella ? sp. 1, are left in open nomenclature. The widely distributed, locally abundant Montiella ? elitzae is revisited, because of the presence of a complete, exceptionally well preserved specimen. Yet to be demonstrated, the species is a junior synonym of Turkmenaria adducta Maslov, also originally described from the Kopet Dagh. Other species found in the Arkan section have already been reported from remote locations, primarily in Europe, in areas corresponding to the Northern and/or Southern Tethyan domains. Some of them are known only from the Hauterivian and/or the Barremian, excluding the Aptian, thus dating the lower part of the Arkan section as Barremian, but not excluding the Late Hauterivian.

Online since August 27, 2010


Article 4 [2010]: The Abiod at Ellès (Tunisia): stratigraphies, Campanian-Maastrichtian boundary, correlation, by Francis ROBASZYNSKI & Moncef MZOUGHI.-
Format [HTML] or [PDF 5,972 KB]
Reference: [CG2010_A04]
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 Abstract:  [The Abiod Formation at Ellès (Tunisia): tripartite lithology, biohorizons based on globotruncanids and ammonites, duration, location of Campanian-Maastrichtian boundary, correlation with Kalaat Senan and the Tercis (France) stratotype]
In central Tunisia near the village of Ellès is Wadi Ed Dam. There the Abiod Formation, underlain by the Kef marls and capped by the El Haria marls, crops out in an almost uninterrupted exposure about 286 m thick. In view of its possible use as a regional litho- and bio- stratigraphic reference section for the southern border of the Tunisian trough it is examined in detail here. Fossils studied include foraminifera (115 samples representing 6 micropaleontologic zones, see chart) and ammonites. The biohorizons established are based on the first (FO) or last occurrence (LO) of certain species of planktonic foraminifers in addition to the FO of already established foraminiferal zonal markers. Ammonite markers found include both the FO and LO of some forms, or just one or the other.
The location of the Campanian-Maastrichtian (Cp-Ma) boundary time line at Ellès is established by comparison with that determined at Kalaat-Senan and with that of the international stratotype of Tercis (France), ratified by the International Union of Geological Sciences.
At Kalaat-Senan the Cp-Ma boundary is set at the lower third of the upper indurated limestone bar of the Abiod Formation - the Ncham Member. Its location at Kalaat-Senan is based on the upper limit of occurrence of Nostoceras (Nostoceras) hyatti and Pseudokossmaticeras brandti together with the FO of Nostoceras magdadiae, a Maastrichtian ammonite. At Ellès several of these same markers are present, along with the respective planktonic foraminiferal zones.
The length in years of some lithologic units and paleontologic zones in the Upper Cretaceous succession of wadi Ed Dam was calculated using cyclostratigraphy. The Abiod Formation represents 13.2 Ma, the Radotruncana calcarata Zone 0.79 Ma, and the Nostoceras (Bostrychoceras) polyplocum Zone 0.97 Ma. A proposed subdivision of the Upper Campanian is recommended at the base of the Bostrychoceras Zone.
Li et alii's 1999 proposal for fixing the location of the Cp-Ma boundary at the top of a limestone bed in the El Haria marls is reviewed.

Online since August 27, 2010


Article 3 [2010]: Bucurella, a new genus of the Thyrsoporelleae (fossil Dasycladalean algae), by Bruno GRANIER.-
Format [HTML] or [PDF 2,462 KB]
Reference: [CG2010_A03]
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 Abstract:   A new genus, Bucurella, is described and figured; it is based on Macroporella espichelensis Deloffre et Ramalho, 1971, a taxon known only from the Late Jurassic. It is characterized by the presence of distinctive whorls, each with three thick and broad (fertile) ramifications. The lateral division formula is 1 F: 3 F: (3x2) F: (3x2x2) F = (1: 3: 6: 12); that is the primary ramification divides into three secondaries which in turn branch dichotomously into tertiaries and again into quaternaries. It and its descendant, Zergabriella, are assigned to the Tribe Thyrsoporelleae.

Online since May 31, 2010


Article 2 [2010]: Traces of explosive volcanism in the Pyrenean Campanian around the Campanian-Maastrichtian boundary type section at Tercis (SW France, N Spain). Biostratigraphy with emphasis on the foraminifer Radotruncana calcarata, by Gilles Serge ODIN.-
Format [HTML] or [PDF 6,809 KB]
Reference: [CG2010_A02]
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 Abstract:   Pyroclastic material including idiomorphic crystals of sanidine, biotite, and apatite, first identified in the type section at Tercis are contemporaneous with the Radotruncana calcarata (planktonic foraminifer) total range zone. A search was undertaken to define the palaeogeographical extent and to determine the importance of these remains of a previously unknown Campanian regional alkaline volcanic episode. A preliminary biostratigraphical search was carried out in the Tercis area and in the western Pyrenees followed by detailed micropalaeontological studies in southwestern France and northern Spain. The findings from five upper Campanian platform and flysch facies are reported in detail and deductions from three others are summarized. First, The microfaunal count of the boundary stratotype at Tercis has been increased by the use of acetolytic techniques to disaggregate indurated carbonates. So isolated tests of some key biostratigraphic markers are documented for the first time. The paucity in specimens of Radotruncana calcarata previously seen in thin sections from the type outcrop is not due to a scarcity of this particular taxon but to a general dearth of globotruncanids in the platform facies deposits of the Aturian Basin. The study shows that acetolysis multiplies the power of investigation of indurated limestones. Thus, the abundance and diversity of microproblematica discovered and studied in the stratotype section since 2006 has been confirmed and two new forms of incertae sedis are reported, one of which is called here Velafer ovatus. Today, 70 species of microproblematica are recognized at Tercis. These microproblematica allow a chronologic calibration of the deposits like or even more precise than those obtainable using ammonites or planktonic foraminifers. Sections sampled in the western Pyrenean flysch facies include the stratigraphic interval comprising the total range zone of Rd. calcarata for which we suggest here a duration of 0.80 ±0.05 Ma. No microproblematica were found in these deep detrital facies. 

All sections reaching the Campanian-Maastrichtian boundary contain a Contusotruncana (foraminifer) of which the morphology, illustrated anew from 3 discrete sections, is consistent with that of the specimens identified at this level in the Tercis type-section; they were called C. contusa or C. contusa?/C. patelliformis? These micropalaeontological studies substantiate the choice of Tercis as the best section in the world for location of the stratotype of the Campanian-Maastrichtian stage boundary; they show again its striking regional and global correlative power thanks to the unique diversity of its biological record of the late Cretaceous. In addition, it justifies the choice of a boundary level selected using the near-coincidence of a variety of key events bracketting a guide-event; 12 were clustered around the mid-level 115.2 of the type section where the GSSP of the Campanian-Maastrichtian boundary has been recognized internationally. Consequently, the selected level does not depend on a unique "magic marker" with its inherent uncertainty caused by difficulty in identification and scarcity locally and in other localities and environments. This may well be the case for the guide-ammonite Pachydiscus neubergicus as commonly used as a marker of the Campanian-Maastrichtian boundary.

The biostratigraphical study precisely locates the pyroclastic material observed at Tercis as within the range of Rd. calcarata, immediately above the last occurrence of Tubellus hunzikeri, the first occurrences of Lucernellus aubouini and Aquilegiella varia, 3 microproblematica of which the distribution is well documented at Tercis. Previously reported evidences of volcanism at Tercis: the presence of kaolinite in the clay size fraction and of microcrystals of sanidine, biotite, zircon, apatite are supplemented here by the discovery of slightly calcic and sodic siliceous spherules with traces of magnesium, aluminum and potassium. Kaolinite and sanidine have also been found in contemporaneous levels at Peyrata, in the vicinity of the type section. Farther away in the flysch facies, the contemporaneous deposits contain pyroclastic biotite mica flakes, idiomorphic zircon crystals and, more rarely, apatite crystals of which the morphology is consistent with a volcanic origin. The presence of traces of a volcanic episode in Campanian levels representing about 1 Ma of deposition are thus confirmed but in the Pyrenees no information is available concerning the site of its origin. In fact, the explanations for the presence of the pyroclastic material involves two possibilities: either there was Campanian alkaline volcanic activity in the Pyrenees similar to that associated with subduction (which has not been identified and is not consistent with the accepted geodynamical model of the area) or the pyroclastic material comes from North America, distant some 5000 km. Such long distance transport would involve an west-east eolian conveyance of mm sized volcanic elements for 1 Ma (a hypothesis to our knowledge undocumented).

Online since May 31, 2010


Article 1 [2010]: Problems in the identity of "Crioceras" barremense Kilian, 1895 (Ancyloceratida, Late Barremian), and their proposed resolution, by Didier BERT, Robert BUSNARDO, Gérard DELANOY & Stéphane BERSAC.-
Format [HTML] or [PDF 1,983 KB]
Reference: [CG2010_A01]
Lang.: 

 Abstract:  The study of "Crioceras" barremense Kilian was undertaken as a part of the revision of the Hemihoplitidae. This species was considered "classic" and has been used as the index of an Upper Barremian subzone; this usage raises a number of problems. The type specimen from Tyrol was a fragment described and illustrated by Uhlig as Crioceras sp. ind. aff. roemeri. This specimen could not be retrieved, and a topotype could not be collected. Our study revealed that there is both a biostratigraphic hiatus and important differences between conceptions of this species: (1) that ascribed Uhlig's type specimen (Upper Barremian, Tyrol), (2) Kilian's concept of the specimen he found and named "Crioceras" barremense (probably a Camereiceras from the uppermost levels of the Vandenheckei Subzone or from the basal Sartousiana subzone of the Nauvin site, southeastern France) and (3) current interpretations of authors, who often synonymize the type specimen with Gassendiceras alpinum (d'Orbigny), which occurs in the middle of the Vandenheckei Subzone. So there is a real confusion concerning the synonymy of "Crioceras" barremense. The age of Uhlig's type specimen is too imprecise and its preservation too fragmentary to be reliably identifiable, because the same morphology and ornamentation exist in several species of other genera. Therefore, we recommend the use of the species "Crioceras" barremense Kilian be avoided, in particular as an index, along with that of the genus Barrancyloceras Vermeulen for which "C." barremense is used as reference. Some species formerly assigned to this genus have been referred to the genus Gassendiceras Bert et alii. Consequently, we also recommend the Barremense auctorum Subzone be renamed the Alpinum Subzone (new) [index-species: Gassendiceras alpinum (d'Orbigny)], without changing its limits as currently defined. The lower limit of this subzone is indicated by the first occurrence of Gassendiceras alpinum (a new biohorizon, introduced here), a common, easily identifiable species with a well-defined stratigraphic range.

Online since April 4, 2010


Article 10 [2009]: The Gargasian of Gargas (Vaucluse, SE France): Synthesis of field data and revision of the foraminiferal and ostracodal microfauna, by Michel MOULLADE, Guy TRONCHETTI & Jean-François BABINOT.-
Format [HTML] or [PDF 975 KB]
Reference: [CG2009_A10]
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 Abstract:  Because of urbanization the section at Gargas, historical stratotype of the Aptian stage and of the Gargasian substage, is no longer accessible. However, samples taken there in 1966 by one of us make feasible a reinterpretation of this series in the light of taxonomic and biostratigraphic data from a recent study of Aptian microfaunas from La Tuilière area, some 5 km away.
This new micropaleontologic interpretation shows that the historical section is truncated at its base : the lower (not lowermost) Gargasian is in quasi-direct contact with Urgonian limestones ; the uppermost (marly) Bedoulian, known to be present westward towards Le Chêne as well as at La Tuilière, is absent in the stratotype outcrop. In the samples from the stratotypic succession we have identified (bottom upward):
   • the upper part of the Praehedbergella luterbacheri zone and the Globigerinelloides ferreolensis zone,
   • the G. barri zone,
   • the beginning of the G. algerianus zone,
i.e. these zones comprise the major part of the lower Gargasian, the middle Gargasian and the transition to the upper Gargasian.
The upper part of the G. barri zone and the passage to the G. algerianus zone are in sandy marls of which the upper terms were said to have yielded ammonites of the "Clansayes horizon" (sensu ante). The microfauna does not resolve this apparent discrepancy, for its state of preservation degrades rapidly in the detrital levels, to the point of quasi-disappearance in sands overlying the Clansayesian auct. A comparison with the sector of Banon, only some 10 km away, led us to suggest that these sands cropping out at top of the Gargas Hill might be of Late Albian-Vraconnian age.

Online since December 31, 2009


Article 9 [2009]: Size variations of the vestibula of Krithe gnoma Do Carmo & Sanguinetti, 1999 (Ostracoda): a new procedure for their analysis, by Dermeval Aparecido D0 CARMO, Ricardo Piazza MEIRELES, Paulo Anselmo Ziani SUAREZ & Vinicius Moreira MELLO.-
Format [HTML] or [PDF 895 KB]
Reference: [CG2009_A09]
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 Abstract:  The species Krithe gnoma was described from Holocene sediments on the continental margin of Brazil, where it occurs on both shelf and slope. The shelf distribution of this species is restricted to those areas influenced by the Malvinas current between 32°11' and 22°31'S. K. gnoma was selected due to the excellent resolution of images of the anterior vestibule. So the range in size of the vestibula of this species was used to determine whether or not the dimensions of the anterior vestibule were to some degree related to amount of dissolved oxygen in the water at the sampling site. Female valves of the 7th and 8th instars were measured and their sizes and those of the anterior vestibule were compared. These valves and the reference carapace were collected at six localities in the southern shelf area. The anterior vestibule of right and left valves of the 7th instar and one of the 8th instar from discrete localities were measured. In the reference carapace, the larger left valve also has the larger vestibule. A gerontic 8th instar has valves larger than those of the previous instars, but its vestibula are smaller than those of the 7th instar. The vestibula of the left valves of the 7th instar collected at discrete localities showed consistent differences in size related to the oxygen content of the sampling site. The relationship between vestibule size and oxygen content is inversely proportional.However, the poor correlation factor (R2<<1) of these results are not precise enough to support Peypouquet's hypothesis. But the size of the vestibula of K. gnoma does show some degree of relationship to oxygen content. So it is important to measure the vestibula of species of Krithe using the procedure described here. Rigorous application of this procedure will eliminate the possibility of discrimination based on variations in size due to ontogeny and dimorphism leaving only those related to actual valve size. In any case, variations in the size of vestibula may have a phenotypic origin.

Online since December 31, 2009


Article 8 [2009]: Nummulus brattenburgensis and Crania craniolaris (Brachiopoda, Craniidae), by Christian C. EMIG.-
Format [HTML] or [PDF 1.590 KB]
Reference: [CG2009_A08]
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 Abstract:  The Brattingsborg pennies are mentioned in medieval texts dating from the middle of the first millennium and many popular medieval legends refer to their occurrence on Ivö Island in the Scania region (Sweden) as brattingsborgpenningar or in Latin as Nummulus brattenburgensis. Actually they are valves of the fossil brachiopod Crania craniolaris originally described by Linnaeus (1758) as Anomia craniolaris from the Upper Cretaceous. Later Retzius (1781) created the genus Crania based on these specimens from Ivö Island and on another species he described under Crania (now Isocrania) egnabergensis from Ignaberga in the Scania region. The scientific history of those two species is reviewed along with that of Danocrania tuberculata (Nilsson, 1826), formerly figured as Craniolites brattenburgicus, from the Danian of Scania. Two legends about these "pennies" are included.

Online since October 31, 2009


Article 7 [2009]: Quick look cathodoluminescence analyses and their impact on the interpretation of carbonate reservoirs. Case study of mid-Jurassic oolitic reservoirs in the Paris Basin, by Bruno GRANIER & Christian STAFFELBACH.-
Format [HTML] or [PDF 716 KB]
Reference: [CG2009_A07]
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 Abstract:  Cathodoluminescence analyses on samples from Middle Jurassic oolitic limestones allow us to reconstruct the diagenetic history of these oil and gas reservoirs: a succession of events starting with the early, synsedimentary phases of marine cementation and ending with the addition of hydrocarbons to the reservoir. Constraints on the timing of events are derived from their calibration with the chronology of the well-known regional tectonic calendar. Fracturing, due first to the post-Pyrenean extension and then to the Alpine compression, led respectively in Oligocene times to a recharge of the aquifer and a correlative change in cementation, and in Miocene times to the addition of hydrocarbons into the same flow units, this last event blocking diagenesis, at least in the zone above the oil-water contact. Distributions of cements and residual porosity within sedimentary units without stratigraphic significance, called here "pseudo-parasequences", were for the most part inherited from the original depositional facies.

Online since September 30, 2009


Article 6 [2009]: The Paleocene and earliest Eocene foraminiferal Family Miscellaneidae: neither nummulitids nor rotaliids, by Lukas HOTTINGER.-
Format [HTML] or [PDF 27,417 KB]
Reference: [CG2009_A06]
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 Abstract:  The Miscellaneidae are divided into two groups of species: forms with a single intercameral foramen and forms with two or a row of multiple foramina. Ten taxa ascribed to this family are revised, amply illustrated and discussed considering both micro- and megalospheric generations. The Family Miscellaneidae is assigned to the Superfamily Nonionacea by reason of their planispiral-involute coiling combined with an interiomarginal position of the foramina. Their combined range covers SBZ zones 2-5 and an area comprising the Central and Western Neotethys including the Pyrenean Gulf. They do not reach the western shores of the Atlantic. Miscellanites meandrinus and Bolkarina aksarayi exhibit extreme morphological features, respectively meandrine alar extensions and expanse chambers. These features are of general interest for the comparative anatomy of the shells of the larger foraminifera in order to understand their biological significance.

Online since September 30, 2009


Article 5 [2009]: The ammonite fauna of the 'marls with ferruginous fossils' from the Niort region, France (Lower Oxfordian, Cordatum Zone, Cordatum Subzone), by Philippe QUEREILHAC, Didier MARCHAND, Rémi JARDAT, Alain BONNOT, Dominique FORTWENGLER & Philippe COURVILLE.-
Format [HTML] or [PDF 4,284 KB]
Reference: [CG2009_A05]
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 Abstract:  A new collection of ammonites from the 'marls with ferruginous ammonites' in the Niort region (France), previously studied by Grossouvre (1922), provides a large amount of biostratigraphic, paleoenvironmental and paleogeographic information. The fauna is dated Lower Oxfordian: Cordatum Zone, Cordatum Subzone, probably the lower part of it. In addition, it is unique in western Europe owing to: 1) the species found of which some appear to be known only in this deposit 2) by the extremely atypical domination of the couple Taramelliceras - Creniceras which represent 2/3 of the specimens. Furthermore, the aspect of the fauna strongly suggests that the habitat was a distal platform unknown in other European strata of the same age. A detailed description of the several species is given, sometimes accompanied by a new taxonomic interpretation.

Online since September 15, 2009


Article 4 [2009]: The IMAM case. Additional investigation of a micropaleontological fraud, by Bruno GRANIER, Monique FEIST, Edward HENNESSEY, Ioan BUCUR & Baba SENOWBARI-DARYAN.-
Format [HTML] or [PDF 1,916 KB]
Reference: [CG2009_A04]
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 Abstract:  Starting in 1996 and for almost a decade, M.M. Imam contributed to twelve papers published in international geological journals. These papers dealt with the micropaleontology and biostratigraphy of Cretaceous to Miocene series from Egypt and Libya. They were abundantly illustrated in order to support the author's findings and interpretations. However most photographic illustrations (189 at least) were fabricated with material lifted from the publications of other authors, commonly from localities or stratigraphic intervals other than those indicated by M.M. Imam.

Online since May 18, 2009


Article 3 [2009]: Uppermost Albian biostratigraphy and chronostratigraphy, by Robert W. SCOTT.-
Format [HTML] or [PDF 428 KB]
Reference: [CG2009_A03]
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 Abstract:  The Albian Stage is the highest chronostratigraphic unit of the Lower Cretaceous Series and underlies the Cenomanian Stage of the Upper Cretaceous Series. The Albian is divided into three substages, each of which is composed of two or three zones based on distinctive and phylogenetically related ammonite assemblages. The uppermost zone of the Upper Albian Substage, the Stoliczkaia dispar Zone, is found in many Western European condensed sections. The ammonite assemblage in the thin glauconitic sandstone near La Vraconne, Switzerland, was defined as the 'Vraconnian Stage' in 1868. However this concept has been little used and was abandoned in 1963 as part of the Cretaceous chronostratigraphic scale. A recent proposal to resurrect and redefine this stage is based on a number of criteria and very detailed and reliable stratigraphic data. A quantitative biostratigraphic analysis of the ammonite ranges in the key sections shows that the proposed subzones of the S. dispar Zone have discordant ranges. Furthermore, the utility of a 'Vraconnian Stage' between the Albian and Cenomanian stages is geographically limited and the concept embraces one of many depositional sequence cycles of the Albian. The reinstatement of a 'Vraconnian Stage' is not recommended.

Online since April 22, 2009


Article 2 [2009]: Pseudoshasticrioceras bersaci nov. sp. (Ammonoidea, Gassendiceratinae), and new ammonite biohorizon for the Upper Barremian of southeastern France, by Didier BERT & Gérard DELANOY.-
Format [HTML] or [PDF 1,760 KB]
Reference: [CG2009_A02]
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 Abstract:  Research in the Feraudianus Subzone of the Sartousiana Zone of the Barremian stage led to the discovery of a new species of Pseudoshasticrioceras: P. bersaci nov. sp. Its study provides evidence concerning the developments of the latest Gassendiceratinae Bert et alii, 2006, and the relationship between the genus Pseudoshasticrioceras Delanoy, 1998, and Gassendiceras Bert et alii, 2006. In particular, this new species is derived from Pseudoshasticrioceras magnini (Delanoy, 1992) by a minor revision in the processes of ontogenesis (retardation of ornamentation - neoteny). However, the evolution towards Pseudoshasticrioceras autrani Delanoy, 1998, implies a "failure" in this process that may possibly be related to parallel changes in environmental conditions. On the other hand, the very closely defined stratigraphic position of Pseudoshasticrioceras bersaci nov. sp., and its position in the anagenetic lineage of Pseudoshasticrioceras, demonstrates its interest as a biostratigraphic marker: a new Bersaci Biohorizon is proposed; it is located between the Magnini and the Autrani biohorizons.

Online since April 4, 2009


Article 1 [2009]: Albian-Middle Turonian ostracodes from the Antsiranana region (northern Madagascar): systematics, palaeoecology and palaeobiogeography, by Jean-François BABINOT, Jean-Paul COLIN & Auran RANDRIANASOLO.-
Format [HTML] or [PDF 3,284 KB]
Reference: [CG2009_A01]
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 Abstract:  Ostracode associations from the Antsiranana region, formerly Diego-Suarez, in northern Madagascar have been studied at a taxonomic level. In the Albian-middle Turonian interval, 29 species belonging to 21 genera have been recognized, 10 new species, one new genus (Malagasyella) and a new sub-genus (Hemiglenocythere) have been erected. From a palaeoecological stand point, the succession of ostracode faunas shows a progressive shallowing trend, from basin-slope during Albian times to outer shelf during the Turonian. During these periods, the ostracode faunas of Madagascar show strong affinities with those of India (Rajasthan). This leads to a proposal for the existence of an indo-malagasy ostracode faunal province.

Online since April 4, 2009


Article 9 [2008]: Spirochetes and salt marsh microbial mat geochemistry: Implications for the fossil record, by Elizabeth A. STEPHENS, Olivier BRAISSANT & Pieter T. VISSCHER.-
Format [HTML] or [PDF 315 KB]
Reference: [CG2008_A09]
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 Abstract:  Microbial mats are synergistic microbial consortia through which major elements, including sulfur, are cycled due to microbial and geological processes. Depth profiles of pH, O2, sulfide, exopolymeric substances (EPS), and the rate of sulfate reduction were determined in an Oscillatoria sp. and Microcoleus-dominated marine microbial mat at the Great Sippewissett salt marsh, Massachusetts. In addition, measurements in spirochete enrichments and Spirochaetae litoralis cultures showed sulfide consumption during which polysulfides, thiosulfate, and presumably sulfate formed. These data suggest that spirochetes can play a role in the cycling of sulfur in these mats. The obligate to facultative anaerobic spirochetes may consume sulfide to remove oxygen. Furthermore, spirochetes may enhance preservation of microbial mats within the rock record by degrading EPS and producing low molecular weight organic compounds (LMWOC). Both sulfide oxidation (i.e., oxygen removal) and EPS degradation (i.e., production of LMW organic compounds) stimulate the activity of sulfate-reducing bacteria (SRB), which are responsible for the precipitation of calcium carbonate in most lithifying mats.

Online since December 10, 2008


Article 8 [2008]: On the history of the names Lingula, anatina, and on the confusion of the forms assigned them among the Brachiopoda, by Christian C. EMIG.-
Format [HTML] or [PDF 1,225 KB]
Reference: [CG2008_A08]
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 Abstract:  The The first descriptions of Lingula were made from then extant specimens by three famous French scientists: Bruguière, Cuvier, and Lamarck. The genus Lingula was created in 1791 (not 1797) by Bruguière and in 1801 Lamarck named the first species L. anatina, which was then studied by Cuvier (1802). In 1812 the first fossil lingulids were discovered in the Mesozoic and Palaeozoic strata of the U.K. and were referred to Lingula on the basis of similarity in the form of the shell. In the 1840's other linguliform brachiopods from the Palaeozoic were described. The similarity of the shell form of the extant Lingula and these fossils led Darwin in 1859 to create the description "living fossil" in his book "On the Origin of Species". Thereafter, this Darwinian concept became traditional in that Lingula was considered to lack morphological evolutionary changes. Although denounced as scientifically incorrect for more than two decades, the concept still remains in many books, publications and Web sites, perhaps a witness to palaeontological conservatism.

Online since December 10, 2008


Article 7 [2008]: Holostratigraphy of the Kahmah regional Series in Oman, Qatar, and the United Arab Emirates, by Bruno GRANIER.-
Format [HTML] or [PDF 2,154 KB]
Reference: [CG2008_A07]
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 Abstract:  The stratigraphic framework of the uppermost Jurassic - Lower Cretaceous interval of the Gulf area is revised using both historical and recently acquired paleontological (ammonites, calpionellids, foraminifers, 'calcareous' algae), sedimentological and sequential information. The Kahmah regional Series ranging in age from Late Tithonian to Gargasian (= middle Aptian) times is subdivided into regional stages, named from bottom to top: Rayda (with two substages, Bu Haseer and Belbazem), Salil, Zakum, Lekhwair, Kharaib, Hawar, and Shu'aiba. The Kahmah rests either on strata representing the Habshan regional Stage, which is the last term of the Sahtan regional Series (locally absent due to a stratigraphic hiatus in basinal areas), or on much older strata; it is followed either by the Bab regional Stage (locally absent due to a stratigraphic hiatus on platform areas), or by the Sabsab regional Substage (the lowermost part of the Nahr Umr regional Stage), both of which are assigned the Wasi'a regional Series. The Kahmah succession (as well as those of the Sahtan below and the Wasi'a above) is discontinuous, i.e. punctuated by sedimentary hiatuses due to forced regressions, some of significant importance (in the Zakum or in the Bab, and those bounding the Hawar and the Shu'aiba).

Online since September 28, 2008

Article 7 [2008] - an extra video: Holostratigraphy of the Kahmah regional Series in Oman, Qatar, and the United Arab Emirates, by Bruno GRANIER.-
The video of Fig. 18 revisited


Click on image to play the video file (flv = 5,029 KB)

Online since May 22, 2010


Article 6 [2008]: Middle Jurassic to Lower Cretaceous continental deposits from eastern High Atlas (Morocco): successive paleoenvironments and paleogeographic significance, by Hamid HADDOUMI, André CHARRIÈRE, Bernard ANDREU & Pierre-Olivier MOJON.-
Format [HTML] or [PDF 2,069 KB]
Reference: [CG2008_A06]
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 Abstract:  In the eastern High Atlas (Morocco), continental "Red Beds" overlying the last marine deposits of Jurassic age consist of three main lithostratigraphic units: the Anoual Formation, the Ksar Metlili Formation and the Dekkar Group, bounded by two sharp sedimentary discontinuities. The Anoual Formation is a fluvial dominated deltaic plain deposit. It is followed by a final marine transgression of Early Bathonian age. The Ksar Metlili Formation found only in some subsident areas represents a renewal of fluvio-deltaic environments with a flora of Late Tithonian-Early Berriasian charophytes. The Dekkar Group occupies a larger area of sedimentation, its limits overlap the whole domain. From bottom to top, the succession indicates the existence of three paleoenvironments: alluvial fans deposits locally associated with Barremian?-Aptian lacustrine sediments containing charophytes and ostracods, alluvial plains deposits and finally, marine coastal to brackish plains deposits of the Cenomanian.
After the closure of the Jurassic Atlasic marine trough, the eastern Atlasic "Red Beds" were deposited in response to three main geodynamic events:
   • the filling of the Atlasic trough with very thick deposits in subsiding areas linked to tectonic rifting during the Early Bathonian;
   • the emergence of this area caused a hiatus in sedimentation involving strata ranging in age from Bathonian to Barremian?-Aptian. However, continental sediments are preserved in some onshore geomorphological depressions at the Jurassic/Cretaceous boundary;
   • the opening of new basins, continental during the Barremian?-Aptian, that became marine during the Late Cenomanian as the result of Cenomanian-Turonian transgression.
A comparison of the succession of events recorded in different parts of the Atlasic belts allows reconstruction of the three phases of paleogeographic evolution in these southern Tethyan areas during Middle Jurassic to Late Cretaceous times.

Online since August 1, 2008


Article 5 [2008]: Pseudoperisphinctinae (Ammonitina, Perisphinctidae) from the Leckenbyi horizon (Upper Callovian, Athleta zone) of Montreuil-Bellay (Maine-et-Loire, France) and description of a new species, Choffatia isabellae, by Alain BONNOT, Pierre-Yves BOURSICOT, Patrice FERCHAUD & Didier MARCHAND.-
Format [HTML] or [PDF 2,045 KB]
Reference: [CG2008_A05]
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 Abstract:  Many outcrops exposing the Mid-Callovian/Upper Callovian boundary have been found near Montreuil-Bellay (Maine-et-Loire). The lowermost bed of the Upper Callovian has been dated as the Leckenbyi horizon. It contains an abundant ammonite fauna (3125 specimens), in which Perisphinctidae make up just over half of the specimens. In company with reasonably well-known species such as Pseudopeltoceras leckenbyi (Bean), Orionoides pseudorion (Waagen), Subgrossouvria famulum (Bean) and S. crassa Gérard et Contaut, occurs a species, previously unknown, which is described in this article. Choffatia isabellae n. sp. differs markedly from contemporary Perisphinctidae, for it is distinguished by : 1) a long, smooth juvenile stage, 2) weakly developed ribbing, 3) the absence of parabolic ornamentation and 4) a high frequency of constrictions. As this species is unknown in the fauna of the uppermost Middle Callovian, along with many other species, including Peltoceras marysae Bonnot et alii, it must have colonised the northwestern part of the European platform via the southern margin of the Tethys during the transgressive interval which started at the beginning of the Late Callovian. This new species appears abruptly at the base of the Leckenbyi horizon, reaches its acme in the middle of the horizon, where it probably represents half of the Perisphinctidae, before becoming rare in the upper part of the horizon, then very rare in the Athleta horizon.

Online since April 17, 2008


Article 4 [2008]: Diagenetic rejuvenation of raised coral reefs and precision of dating. The contribution of the Red Sea reefs to the question of reliability of the Uranium-series datings of middle to late Pleistocene key reef-terraces of the world, by Jean-Claude PLAZIAT, Jean-Louis REYSS, Abdelmajid CHOUKRI & Charlotte CAZALA.-
Format [HTML] or [PDF 2,228 KB]
Reference: [CG2008_A04]
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 Abstract:  This paper is a general review of the dating of reefs on the coasts of the Red Sea, including those of Egypt, Jordan, Sudan, Eritrea, Saudi Arabia and Djibouti. New methods of sampling and dating (U/Th) already tested on the reefs and associate deposits of the African coast of Egypt have demonstrated that processes of rejuvenation shown to exist in the best-preserved corals are attributable to the diagenesis of the organic material in their bio-minerals, thus justifying a revision of a great many datings of corals supposedly younger or older than the age assigned to the high-level isotopic substage (δ18O) MIS 5.5 (= 5e). During this late Pleistocene substage, a rapid lowering of sea level, short and limited to about ten meters, was detected and associated with a glacio-eustatic episode of global influence. A comparison of these Middle East reef chronologies with those of New Guinea, Australia and the western Atlantic that are referred only with difficulty to the δ18O global sea-level curves, casts doubt on the reliability of many regional reconstructions. Moreover the most "classic" reef chronologies, more or less out-of-phase with global isotopic records calls for a reexamination of the chronologic basis of the reference curves derived from marine isotopic data.

Online since March 22, 2008


Article 3 [2008]: New biohorizons and proposal for a revision of the ammonite biozonation of the Upper Barremian of southeastern France, by Didier BERT, Gérard DELANOY & Stéphane BERSAC.-
Format [HTML] or [PDF 346 KB]
Reference: [CG2008_A03]
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 Abstract:  New biohorizons and proposal for a revision of the ammonite biozonation of the Upper Barremian of southeastern France.- A new ammonite biozonal scheme is proposed for the Upper Barremian of southeastern France. It takes into account faunal changes, sequence stratigraphy and historical data. Four new biohorizons are proposed. At present, three (formerly six) are accepted for the Upper Barremian: the Vandenheckei, Sartousiana and Giraudi biozones. The first contains three subzones, the Uhligi (current status discussed), the Sayni and the Barremense subzones, and two new biohorizons, the Marchandi and Breistrofferi biohorizons (top of the Barremense Subzone). The Sartousiana Biozone now includes the Limentinus, Provincialis and Feraudianus subzones. This last one lost its status of biozone because of paleontologic and stratigraphic arguments. Six biohorizons are recognized in the Sartousiana Biozone: the Limentinus, Provincialis, Casanovai, Feraudianus, Magnini and Autrani biohorizons. The Giraudi Biozone includes the Giraudi, Sarasini and Waagenoides subzones and the Giraudi, Emerici and Puzosianum biohorizons.

Online since March 20, 2008


Article 2 [2008]: New micropalaeontological studies on the type section of the Campanian-Maastrichtian at Tercis (SW France): new ostracodes obtained using acetolysis, by Bernard ANDREU & Gilles Serge ODIN.-
Format [HTML] or [PDF 2,490 KB]
Reference: [CG2008_A02]
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 Abstract:  Through the use of acetolysis new micropalaeontological studies on the type section of the Campanian-Maastrichtian boundary at Tercis (SW France) we obtained additional information on ostracodes. Acetolysis on hard carbonates levels of the Tercis quarry found 22 species in addition to those of the studies published in 2001. Today, 75 species are recognized: they represent 34 known genera, and 4 currently unidentified. Small species usually rare of the genera Aversovalva, Bythoceratina and Eucytherura were collected. All of the assemblages (of both genera and species) are characteristic of a Campanian- Maastrichtian open carbonate platform environment.

Online since February 4, 2008


Article 1 [2008]: Planktonic and benthic foraminiferal assemblages and biostratigraphy of the uppermost Bedoulian and lower Gargasian of La Tuilière - St-Saturnin-lès-Apt (area of the Aptian stratotype, Vaucluse, SE France), by Michel MOULLADE, Guy TRONCHETTI & Jean-Pierre BELLIER.-
Format [HTML] or [PDF 7,370 KB]
Reference: [CG2008_A01]
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 Abstract:  Research on the Bedoulian and Gargasian of the Cassis-La Bédoule (Bouches du Rhône, SE France) area is extended, by a study of four overlapping sections in the stratotypic area of the Aptian stage in the hamlet of La Tuilière (commune of Saint-Saturnin-lès-Apt, Vaucluse, SE France). This new information permitted a detailed analysis of upper Bedoulian and lower Gargasian benthic (30 taxa) and planktonic (15 taxa) foraminiferal assemblages. Here we describe, illustrate and give the ranges and distribution of the most significant forms, and call attention to several benthic and planktonic species that may serve as extra-regional markers.
The study of the planktonics in these expanded and continuous sections made it possible to strengthen the zonation which had been established in the Lower Aptian stratotype of Cassis-La Bédoule, i.e. a succession of five zones (cabri, luterbacheri, ferreolensis, barri, algerianus); this zonal scheme is improved by the addition of a horizon with Globigerinelloides ferreolensis heptacameratus nov. subsp., which straddles the boundary between the luterbacheri and ferreolensis zones. We also show the temporal quasi-coincidence of: 1) the top of the Furcata ammonite Zone, 2) the lithological change named "change of color" and 3) a triple micropaleontological datum (FAD of Praehedbergella luterbacheri, LAD of Protocythere bedoulensis and Lenticulina cf. nodosa) of which the importance in the stratotype of Cassis-La Bédoule had already been pointed out. All these data may be valuable in the definition of the Bedoulian-Gargasian boundary.
Within the luterbacheri Zone of the early Gargasian, an episode probably of volcanic origin that we interpret as the equivalent of the Van Gogh Level (initially detected in the Vocontian domain), is marked by a strong crisis in the diversity of epibenthic and planktonic foraminifers, as well as in that of the ostracodes.
From a paleoecological and paleobiogeographical point of view, a comparison of the benthic and planktonic foraminiferal assemblages of La Tuilière with those of neighbouring areas reveals specific features related to paleodepth and shows affinities which appear to be closer with the microfaunas of certain boreal areas (e.g. northern Germany) than with the Tethysian realm.

Online since January 28, 2008


Article 7 [2007]: Facies development during late Early–Middle Cambrian (Tayan Member, Burj Formation) transgression in the Dead Sea Rift valley, Jordan, by Olaf ELICKI.-
Format [HTML] or [PDF 1,120 KB] -  Reference: [CG2007_A07]

 Abstract:  The transgressive Tayan Member of the upper Lower to Middle Cambrian Burj Formation (Jordan) has been investigated in several localities of the Dead Sea Rift valley, Jordan. The lower portion of this member consists of low-energy siliciclastics with indications of temporary, early pedogenetic processes, pointing to some stagnation during transgression. The upper portion of the member was deposited under higher energy conditions. Stromatolites, desiccation cracks, halite-pseudomorphs, laminated dolostones, and tepees, together with ripples, mud-clasts and scours point to a shallow intertidal to supratidal sabkha-related environment in a climate of tropical to subtropical aridity.
The fossil content of the Tayan Member consists exclusively of trace fossils. Simple endobentic, worm-like r-strategists are common in some horizons. For the first time, Treptichnus pedum has been reported from Jordan where it was found near the base of this member. The markedly reduced biodiversity together with sedimentological data led to the interpretation of a strongly stressed, paleoecologically unstable habitat.
Regional comparisons with high-energy transgressive environments laid down at the same time show that the main factors controlling facies development and the migration of facies belts are (1) the topography of the flooded surface and of the hinterland (mainly with only a local effect), (2) the configuration of the coast (local effect), (3) the rate of subsidence and transgression (local to regional effects), and (4) climate (large regional effects). The combination and overlap of these factors controlled facies gradients and may explain special differences between the facies of the Jordanian and those of the near-by Israeli transgressive deposits on the one hand, but, also the obvious general similarity of Lower to Middle Cambrian transgressive successions in the Middle East and the Mediterranean part of Gondwana on the other hand.

Online since November 1, 2007


Article 6 [2007]: Revision of the foraminiferal genus Globoreticulina Rahaghi, 1978 and of its associated fauna of larger foraminifera from the late Middle Eocene of Iran, by Lukas HOTTINGER.-
Format [HTML] or [PDF 7,274 KB]  -  Reference: [CG2007_A06]

 Abstract:  The definition of the type species of the genus Globoreticulina Rahaghi, 1978, G. iranica Rahaghi, 1978, is emended and its age discussed in relation to those of 17 associated taxa of larger foraminifera, all from restricted shallow environments. These taxa represent porcelaneous groups of spiroline habit including Rhabdorites malatyaensis, archaiasines (Archaias operculiniformis and A. diyarbakirensis), agglutinated conicals (Coskinolina and Dictyoconus) and some rotaliids (Medocia and others). These taxa were revised where necessary and their biostratigraphic ranges discussed. In addition to the establishment of a new subfamily of the Alveolinidae, the Malatyninae, the following new Linnaean names are introduced in order to conform with the revisions: Austrotrillina eocaenica n. sp., Neotaberina neaniconica n. gen. n. sp., Neorhipidionina spiralis n. gen. n. sp., Penarchaias n. gen. and Rotaliconus persicus n. gen. n. sp. The species Praerhapydionina huberi Henson is transferred to the genus Haymanella Sirel and the genus Praearchaias Sirel is suppressed. The age of the type level of Globoreticulina iranica is interpreted to be SBZ 18 (Late Bartonian) according to the available local data but the possibility that its stratigraphic position is actually level SBZ 17 or SBZ16 can not be excluded with certainty.

Online since September 25, 2007


Article 5 [2007]: The upper Bedoulian and lower Gargasian Ostracoda of the Aptian stratotype: Taxonomy and biostratigraphic correlation, by Jean-François BABINOT, Michel MOULLADE & Guy TRONCHETTI.-
Format [HTML] or [PDF 4,263 KB] / pages 8-9 in A3 format A3 [PDF 85 KB] -  Reference: [CG2007_A05]

 Abstract:  In the vicinity of Saint-Saturnin-lès-Apt (Vaucluse, SE France), which is included in the area of the historic Aptian stratotype of Apt-Gargas, are four sections in a succession that permits the study in a very detailed and continuous way of the last beds of the upper Bedoulian and those of the lower Gargasian. The Ostracod content of the microfauna is relatively important and in a satisfactory state of preservation. 46 species have been indexed of which three are new: Cytherella circumrugosa nov. sp., Cytherelloidea bedouliana nov. sp. and Parexophthalmocythere (Parexophthalmocythere) sp.
Until the present day, our comprehension of this group of microfossils in this stratigraphic interval was very fragmentary, not just in the Apt region but also in the Bedoulian historic stratotype area (Cassis-la Bédoule). This new study made it possible to determine a good number of species not previously reported in the stratotypes, to refine the generic status of many forms and to place some of them in open nomenclature.
The completion of a chronologic distribution chart collated with a recently published foraminiferal zonation (Cabri, Luterbacheri and Ferreolensis zones) shows very clearly the bipartite distribution of a good part of the Ostracod fauna. Accordingly, two ensembles are recognized, one at the end of the upper Bedoulian (index species Protocythere bedoulensis), the other characterizing the lower Gargasian, identified by the appearance and development of Parataxodonta inornata. The two groups are sharply separated by an episode of impoverished microfaunas at the base of the Gargasian.

Online since July 25, 2007


Article 4 [2007]: Morphological variability of Globorotalia menardii (planktonic foraminifera) in two DSDP cores from the Caribbean Sea and the Eastern Equatorial Pacific, by Michael KNAPPERTSBUCH.-
Format [HTML] or [PDF 1,851 KB] - Reference: [CG2007_A04]

 Abstract:  Variability in the test of Globorotalia menardii during the past 8 million years has been investigated at DSDP Site 502A (Caribbean Sea) and DSDP Site 503A (Eastern Equatorial Pacific). Measurements were made of spire height (∂x), maximum diameter (∂y), the tangent angles of the upper and lower peripheral keels (Φ1, Φ2, respectively), the number of chambers in the final whorl, and the area of the silhouette in keel view. Four morphotypes alpha, beta, gamma, and delta were distinguished. Morphotype alpha was found in strata ranging in age from the Late Miocene through the Holocene. It shows a continuous increase in ∂x and ∂y until the Late Pleistocene. During and after the final closure of the ancient Central American Seaway (between 2.4 Ma and 1.8 Ma) there was a rapid increase in the area of the test in keel view. At the Caribbean Sea site, morphotype beta evolved during the past 0.22 Ma. It is less inflated than alpha and has a more delicate test. In the morphospace of ∂x vs. ∂y, morphotypes alpha and beta can be distinguished by a separation line ∂y = 3.2 * ∂x - 160 (∂x and ∂y in µm). Plots of morphotype alpha are below that line, those of beta are above it. Morphotype alpha is taken to be Globorotalia menardii menardii Parker, Jones & Brady (1865) and includes G. menardii 'A' Bolli (1970). Morphotype beta is identified as G. menardii cultrata (d'Orbigny). Morphotypes gamma and delta are extinct Upper Miocene to Pliocene forms which evolved from morphotype alpha. They have a narrower Φ1 angle and more chambers (≥7) than morphotype alpha commonly with 5 to 6 chambers (7 in transitional forms). In contemporaneous samples morphotype delta can be distinguished from gamma by a smaller value of Φ1 and 8 or more chambers in the final whorl. Morphotype gamma is taken to be G. limbata (Fornasini, 1902) and includes the junior synonym G. menardii 'B' Bolli (1970). Morphotype delta is G. multicamerata Cushman & Jarvis (1930). With the exception of the Late Pleistocene development of G. menardii cultrataonly in the Caribbean the morphological changes of G. menardii at DSDP Sites 502A and 503A are similar. The development from the ancestral G. menardii menardii of the G. limbata - G. multicamerata lineage during the Pliocene and of G. menardii cultrata during the Late Pleistocene suggests responses at the two sites to a changing palaeoceanography during and after the formation of the Isthmus of Panama.

Online since July 2, 2007


Article 3 [2007]: Fluctuations of sea-water chemistry during Gargasian (Middle Aptian) time. Data from trace-element content (Mg, Sr, Mn, Fe) in hemipelagic carbonates from La Marcouline Quarry (Cassis, SE France), by Maurice RENARD, Marc de RAFÉLIS, Laurent EMMANUEL, Catherine BELTRAN, Michel MOULLADE, & Guy TRONCHETTI.-
Format [HTML] or [PDF 1,165 KB] - Reference: [CG2007_A03]

 Abstract:  In the Lower Aptian historical stratotype area (Cassis-La Bédoule, SE France), a geochemical study of the Gargasian (Middle Aptian) marl-limestone alternations of the La Marcouline quarry complements data already obtained from Bedoulian (Early Aptian) sediments there. Nannoconids are the main carbonate producers in both limestones and marls. Although diagenetic minerals, such as ankerite (2.5%) are present in small amounts, the trace-element content of bulk carbonate is very close to that of Nannoconus spp. so geochemical sequences can be defined. The long-term evolution of trace-element content was not affected by diagenetic processes, variations in carbonate mineralogy, or a change of carbonate producers. An increase of around 500 ppm in the strontium content of bulk carbonate occurs between the base of the Cabri zone (late Bedoulian) and the Algerianus zone (late Gargasian). This evolution is linked to fluctuations in seawater Sr/Ca ratios caused by variability in the influx of hydrothermal and river waters, by changes in the ratio of aragonite/calcite production and by shifts in sea level. The eustatic sequence Aptian 4, its parasequences and its key surfaces (sequence boundaries, maximum flooding surface) are clearly reflected in the evolution of the bulk-carbonate contents of manganese.

Online since July 2, 2007


Article 2 [2007]: The Gargasian (Middle Aptian) of La Marcouline section at Cassis-La Bédoule (SE France): Stable isotope record and orbital cyclicity, by Wolfgang KUHNT & Michel MOULLADE.-
Format [HTML] or [PDF 485 KB] - Reference: [CG2007_A02]

 Abstract:  Bulk rock stable isotope analysis of La Marcouline section (Cassis-La Bédoule area, SE France) revealed a general trend of decreasing δ13C and δ18O values from the bottom to the top of the section. The decrease in δ13C values reflects a global trend in Middle Aptian times, namely a return to pre-excursion values of δ13C values following a major, positive excursion in the Early Aptian, which is a reflection of the Oceanic Anoxic Event (OAE) 1a.
Power spectra of the bedding rhythms suggest that precessional and long eccentricity cycles of the Milankovitch band controlled the deposition of marl-limestone bundles. This can be interpreted as the result of a forcing by insolation at low latitudes which resulted in a monsoon-controlled precipitation pattern, that in turn induced the deposition of clay-rich beds. Conversely, limestone beds were formed in periods of dryer climate. Higher sea-surface productivity during wet periods may have been caused by an increase in continental runoff and a consequent enhancement in the delivery of nutrients to epicontinental basins.
An orbital cyclicity in the sedimentary patterns in La Marcouline section provides the opportunity to calibrate the duration of the well-established G. ferreolensis foraminiferal Zone with that of orbital chronology. The G. ferreolensis Zone at Cassis-La Bédoule spans 33 precessional cycles and its duration is thus estimated to be approximately 760  ka. This length of time is significantly shorter than the estimates of published timescales for this zone and thus may be an argument for proposing that the Gargasian substage is significantly shorter than its currently accepted range.

Online since May 24, 2007


Article 1 [2007]: Environmental changes during marl-limestone formation: evidence from the Gargasian (Middle Aptian) of La Marcouline Quarry (Cassis, SE France), by Catherine BELTRAN, Marc de RAFÉLIS, Maurice RENARD, Michel MOULLADE & Guy TRONCHETTI.-
Format [HTML] or [PDF 646 KB]
Reference: [CG2007_A01]

 Abstract:  Limestone-marl alternations are usually interpreted to reflect cyclic paleoenvironmental fluctuations linked to Milankovitch-scale climate variations. However, the impact of diagenesis on lithological differentiation can be overprinted on the primary signal.
In order to evaluate environmental variations during the deposition of the Gargasian hemipelagic limestone-marl alternations from the "La Marcouline" quarry (SE France), we have applied a multi-discipline approach (carbonate geochemistry, micropaleontology and mineralogy). The work uses of a method of granulometric separation of the main carbonate particles which (1) allows the characterization and quantification of the compositions of the carbonate phases of both lithologies and (2) gives access to the geochemical signatures of similar carbonate (bio-) particles in each lithology.
The quantifications show that micarb constitutes a significant portion (around 40 per cent) of the sediments. Their geochemical signatures indicate that most of them were formed by fine fragmentation of nannoconid tests. Based on these interpretations, our results indicate that nannoconids are the major constituents of both the marly limestone and the marl layers and that both lithologies are similar in composition.
The coccolith assemblages (mainly Watznaueria spp.) of the limestone and marl layers are similar and equally well-preserved. Changes in oxygen and carbon isotopic ratios express cyclic fertility and salinity/temperature variations in surface waters. The marls indicate higher fertility and lower salinity (or higher temperature) conditions than those denoted by the marly limestones.
Although diagenesis has not altered these rhythmites no strong evidence has been found for linking classical processes such as dilution or productivity cycles to the composition of the sediments (carbonate constituents and clay mineralogy).
This study demonstrates that La Marcouline succession has retained, as recorded by geochemical proxy, its primary environmental variations. Nevertheless, the homogeneity in both lithotypes of sedimentological parameters (clay mineralogy, sediment composition, ...) seems to indicate that these fluctuations did not affect the ecosystem strongly enough to cause marked differences in the composition of marls and marly-limestones.

Online since February 27, 2007


Article 5 [2006]: New micropalaeontological studies on the stratotype of the Campanian-Maastrichtian boundary at Tercis (SW France): the gilianelles (microproblematica) extracted through acetolysis, by Gilles Serge ODIN & Alexandre LETHIERS.-
Format [HTML] or [PDF 4,212 KB]
Reference: [CG2006_A05]

 Abstract:  The Campanian-Maastrichtian stratotype section at Tercis (SW France) consists mainly of hard calcareous levels. Their treatment using acetolysis left residues among which for the first time well-preserved free microfossils were obtained (These levels had been studied previously only through thin sections). Within these residues, a wealth of calcareous shells of unknown affinity (incertae sedis) occur. These previously undescribed fossils are documented herein with photographs and drawings. Optical observations are synthesised in computer assisted drawings which depict 36 discrete forms. Scanning electron microscopy documented the nannostructures of these tests which led to the recognition of 30 forms with a common organisation and nannostructure. These are the microproblematica group called "gilianelles". The remaining six forms of incertae sedis do not share the same characteristics. According to morphological observations, a planktonic existence is inferred for most of the incertae sedis. The simple organisation and small size of the gilianelles suggest that they may represent a new Order of Rhizopod Protozoans. Their stratigraphical distribution has been established in the stratotype section of the "Grande Carrière" at Tercis (SW France). This distribution shows an extraordinary rate of turn-over with some taxa having a range of less than 1 Ma.

Online since December 14, 2006


Article 4 [2006]: Schmidtites celatus (Obolida, Brachiopoda) from the "Obolus sands" (Upper Cambrian - Lower Ordovician) of Estonia, by Christian C. EMIG.-
Format [HTML] or [PDF 801 KB]
Reference: [CG2006_A04]

 Abstract:  Large collections of the brachiopod obolid Schmidtites celatus have been gathered from Upper Cambrian-Lower Ordovician strata in four northern Estonian localities. The morphological features and the taxonomic characters of the genus and of the single species representing it are re-described and illustrated. New diagnoses are proposed based on characters of the shell and morphological traits that permit Schmidtites celatus to be compared with and distinguished from the other obolid genera occurring in the same samples or areas, i.e. Ungula ingrica, Oepikites, and Obolus apollinis which now includes specimens formerly described as Ungula convexa. Schmidtites celatus differs from them mainly in the arrangement of its musculature.

Online since September 21, 2006


Article 3 [2006]: Are the green algae (phylum Viridiplantae) two billion years old?, by Bernard TEYSSÈDRE.-
Format [HTML] or [PDF 303 KB]
Reference: [CG2006_A03]

 Abstract:  In his book, Life on a young planet, A.H. Knoll states that the first documented fossils of green algae date back 750 Ma. However, according to B. Teyssèdre's book, La vie invisible, they are much older. Using a method which combines paleontology and molecular phylogeny, this paper is an inquiry into the Precambrian fossils of some "acritarchs" and of a primitive clade of green algae, the Pyramimonadales. A paraphyletic group of unicellular green algae, named "Prasinophyceae", is represented at Thule (Greenland) ca. 1200 Ma by several morphotypes of the monophyletic Pyramimonadales, including Tasmanites and Pterospermella that are akin to algae still living today. These two, and others, probably had forerunners going back 1450 / 1550 Ma. Some acritarchs that may represent Pyramimonadales producing "phycomas" which split open for dehiscence were confusingly included in the polyphyletic pseudo-taxon "Leiosphaeridia" and are possibly already present at Chuanlinggou, China, ca. 1730 Ma. Many acritarchs that Timofeev obtained by acid maceration of Russian samples dated between 1800 and 2000 Ma were probably unicellular Chlorophyta which synthesized algaenans or other biopolymers resistant to acetolysis. Living Prasinophyceae are undoubtedly green algae (Viridiplantae). Thus, if Prasinophyceae fossils go back certainly to 1200 Ma, probably to 1500 Ma and possibly to 1730 Ma, then the ancestor of green algae (Chlorophyta and Streptophyta) probably separated from the ancestor of red algae (Rhodophyta) as early as 2000 Ma.

Online since September 19, 2006


Article 2 [2006]: Decastronema kotori gen. nov., comb. nov.: a mat-forming cyanobacterium on Cretaceous carbonate platforms and its modern counterparts, by Stjepko GOLUBIC, Rajka RADOIČIĆ & Lee SEONG-JOO.-
Format [HTML] or [PDF 1,061 KB] - Reference: [CG2006_A02]

 Abstract:  The fossil renamed here was first described in 1959 as Aeolisaccus kotori Radoičić, a new species of a problematic fossil worm, Aeolisaccus Elliott. In 1975 De Castro recognized the true relationships of this microbial fossil: a cyanobacterium related closely to the modern genus Scytonema. The fossil is common in the sediments of the Mesozoic carbonate platforms of southern Europe. This contribution confirmed De Castro's interpretation, determined, using the high resolution of the SEM, the extent to which these fossils have preserved their original architecture, and investigated their presumed modern counterparts among the abundant mat-forming species of Scytonema on the intertidal flats of Andros Island, a part of the Bahama carbonate platform. The systematic affinities of the fossil and the environments it inhabited were reconstructed by comparing the morphology of the fossils to that of their modern counterparts, along with their respective sedimentary contexts. Based on these comparisons, we conclude that the organism lived in a peritidal environment and was buried and fossilized in the shallow waters of an ancient carbonate platform. A formal transfer of the fossil to a new genus of fossil cyanobacteria thereby designated as Decastronema gen. nov. is proposed, honoring the contribution of Prof. Piero De Castro to paleontology.

Online since March 15, 2006


Article 1 [2006]: Microbiofacies analysis of Cambrian offshore carbonates from Sardinia (Italy): environment reconstruction and development of a drowning carbonate platform, by Olaf ELICKI.-
Format [HTML] or [PDF 1,558 KB] or [PDF 1,592 KB - A3-sized pages 10-11]
Reference: [CG2006_A01]

 Abstract:   The Campo Pisano Formation of southwestern Sardinia is represented by an offshore carbonate succession spanning the latest Early to late Middle Cambrian. Paleogeographically, the fauna is characteristic of western Perigondwana, and indicates faunal relations to France, Spain, and Turkey. Microfaunal paleoecology reflects drowning of an isolated carbonate platform at tropical latitudes. Sessile epibenthic filter feeders dominate at the base, succeeded upward by sessile, epibenthic, suspension feeders. Upsection, a shift in the ratio of faunal groups indicates increasing replacement by mobile epibenthos. Autochthonous faunal elements decline near the top where allochthonous taxa become important. In the basal portion of the formation the faunal succession indicates relatively shallow neritic habitats with a moderate influx of suspended sediment, followed by a period of slightly deeper neritic conditions. Probably a shallow bathyal environment was established at the transition to the overlying siliciclastic Cabitza Formation. The bathymetric and ecofacies changes in the Campo Pisano Formation are interpreted as having been caused by a discontinuous rise in eustatic sea-level, probably accompanied by subsidence due to tensional tectonics. The depositional environment was that of a distal open-marine shelf or ramp without strong relief. This interpretation is supported by the lack of significant lateral changes in the fossil assemblages, and an upward deepening of facies. The applied micropaleoecological approach is proven a powerful tool in regional stratigraphy and in the reconstruction of sedimentary realms in the Mediterranean Cambrian, particularly when high-resolution biostratigraphic data and diagnostic sedimentary characteristics are sparse.

Online since February 14, 2006


Article 4 [2005]: Early Aptian δ13C and manganese anomalies from the historical Cassis-La Bédoule stratotype sections (S.E. France): relationship with a methane hydrate dissociation event and stratigraphic implications, by Maurice RENARD, Marc de RAFÉLIS, Laurent EMMANUEL, Michel MOULLADE, Jean-Pierre MASSE, Wolfgang KUHNT, Jim A. BERGEN & Guy TRONCHETTI.-
Format [HTML] or [PDF 868 KB]
Reference: [CG2005_A04]


 Abstract:  Comparison of oxygen and carbon isotope and manganese evolution curves in bulk carbonate from the historical Bedoulian stratotype (Cassis-La Bédoule area, Provence, France) reveals an important geochemical event (negative δ13C and high Mn content) located within the D. deshayesi ammonite Zone and at the base of the R. hambrowi ammonite Subzone. This worldwide event, which can be observed in environments ranging from the fluvial to the pelagic realm (Selli/Goguel level), seems to be related to methane hydrate destabilization. Scenarios for manganese, carbon and oxygen evolutions are proposed for early Bedoulian oxic conditions and for dysoxic/anoxic conditions related to methane hydrate destabilization at the early/late Bedoulian transition. The impacts of this global event on the biosphere (nannoconid crisis) and its stratigraphic implications are considered. Comparison of geochemical and biostratigraphical data from the Cassis-La Bédoule stratotype with that of the Cismon-Apticore reference borehole shows that the La Bedoule sequence records geochemical evolution during the Goguel/Selli Event in more detail than that of any other previously published section.

Online since November 25, 2005


Article 3 [2005]: The distribution of worm borings in brachiopod shells from the Caradoc Oil Shale of Estonia, by Olev VINN.-
Format [HTML] or [PDF 2,396 KB]
Reference: [CG2005_A03]

 Abstract:   Abundant worm borings were found in some brachiopod shells (Clitambonites, Estlandia, Nicolella) from the Ordovician (Caradoc) oil shale in North Estonia. 9 of 21 brachiopod genera (43 %) have been bored. Excluding the size and thickness of valves, no common morphological feature discriminates the brachiopods with borings from those without them. The Trypanites are host-specific, and the frequency of bored valves varies from 6.5 % in Bekkerina to 51 % in Estlandia. The worm larvae preferred hosts with thick lamellose shells, such as those of the clitambonitids, especially Clitambonites schmidti. The boring organisms were size-selective; they preferred large adult specimens. The majority of the borings are oriented, and living hosts were preferred to dead shells. Some clitambonitidine brachiopods, like C. schmidti tolerated a large number of the borer's shafts in their valves. Few bored valves have the blister-like shell-repair structures in their interior.

Online since October 6, 2005


Article 2 [2005]: The Gargasian (Middle Aptian) strata from Cassis-La Bédoule (Lower Aptian historical stratotype, SE France): planktonic and benthic foraminiferal assemblages and biostratigraphy, by Michel MOULLADE, Guy TRONCHETTI & Jean-Pierre BELLIER.-
Format [HTML] or [PDF 3,038 KB]
Reference: [CG2005_A02]

 Abstract:  This paper presents a thorough analysis of foraminiferal assemblages ranging in age from the Bedoulian-Gargasian transition to the middle Gargasian in the Cassis-La Bédoule area (SE France), the historical stratotype of the Lower Aptian substage. This region is particularly suitable for detailed studies of Aptian foraminifera owing to rapid and continuous sediment depositional rates and well-diversified microfaunas. The ranges of benthic forms appear to be fairly stable but some species (Praedorothia praeoxycona, Lenticulina cf. nodosa, Astacolus crepidularis, Globorotalites bartensteini) become extinct at the end of the Bedoulian and thus can be used to separate this substage from the Gargasian. The stratotypic area also offers an opportunity to follow the evolution of planktonic forms step by step at a crucial period of their history, when modalities of speciation and phylogenetic relationships appear to be particularly complex. The important morphologic variability of Aptian planktonic foraminifera does not help finding stable stratigraphic markers; nevertheless, we are able to propose a biozonation comprising five zones (Cabri, Luterbacheri, Ferreolensis, Barri, Algerianus) for the interval under consideration, usually subdivided into three zones. Our study of foraminiferal assemblages and species took into account the range of variability among populations and not just the characteristics of a single specimen, such as the holotype. As a result this paper provides new taxonomic precisions on certain planktonic species hitherto controversial or possibly of doubtful validity.

Online since April 5, 2005


Article 1 [2005]: The modern environments of Molluscs in southern Mesopotamia, Iraq: A guide to paleogeographical reconstructions of Quaternary fluvial, palustrine and marine deposits, by Jean-Claude PLAZIAT & Woujdan R. YOUNIS.-
Format [HTML] or [High Resolution PDF 5,450 KB] or [Low Resolution PDF 3,130 KB]
Reference: [CG2005_A01]

 Abstract:   The Quaternary, mainly freshwater sediments of the Lower Mesopotamian plain include a thin transgressive marine unit which extends inland some 250 km from the present coastline, the Hammar Formation. The identity and respective areal extent of continental and transgressive units are based mainly on their molluscan faunas. Those faunas reflect the several environments of the Middle Eastern biogeographic province: fluviatile, lacustrine, estuarine and lagoonal. The ecological requirements of the more common subfossil and living species of the malacofauna were studied during a month of field reconnaissance.
The freshwater portion comprises only four bivalve species (Corbicula, Unio, Anodonta and Pseudodontopsis). The principal gastropods include Theodoxus (Neritaea), Melanopsis, Melanoides, Bellamya, Gyraulus, Lymnaea (Radix) spp. Corbicula characterizes both fluviatile channels and lacustrine environments; Melanopsis, Melanoides, Theodoxus and the Unionaceae prefer shallow, sparsely vegetated, freshwater lakes. The greatest diversity was seen in the slowly flowing water of the channels draining the marshes; small Planorbids are rarely abundant whereas viviparid and lymnaeids may accumulate near the margins of marshes due to floatation during floods.
The brackish water faunas are characterized by Neritina (Dostia), the potamid Cerithidea (Cerithideopsilla), and Stenothyra. The new combination Theora mesopotamica (Annandale, 1918) is introduced here as the exact equivalent of Abra cadabra Eames et Wilkins, 1957. The abundance of these species is indicative of a restricted, low energy marine environment, confirmed by great numbers of the foraminiferan Ammonia gr. beccarii and the ostracod Cyprideis gr. torosa.
Reworked Hammar Fm marine fossils, first recorded by the Annandale (1918) collection from a lacustrine deposit near Nassiriyah, have been observed in river, marsh and lake sediments too, usually in association with scarce foraminifera. The limited occurrence of these macrofossils (abundant in their life environment) indicates reworking.

Online since January 13, 2005


Article 2 [2004]: Stage boundaries, global stratigraphy, and the time scale: towards a simplification, by Gilles Serge ODIN, Silvia GARDIN, Francis ROBASZYNSKI & Jacques THIERRY.-
Format [HTML] or [PDF 750 KB]
Reference: [CG2004_A02]

 Abstract:  This paper examines four facets of stratigraphic terminology and usage considered faulty and proposes corrective measures. The four perfectible areas are:
(1) The system of dual nomenclature requiring discrete terminologies for the superpositional and temporal aspects of rock units.
(2) The premise that a GSSP establishes the base of a stage as being coincident with the top of the preceding stage rather than simply defining it as the boundary between stages.
(3) The rejection of supplementary (auxiliary) sections that would broaden the knowledge of a GSSP and enlarge the area in which it is easily usable.
(4) The current dual system of nomenclature for Precambrian and Phanerozoic strata is accepted, but a third system is proposed for strata formed in the last 3 to 5 Ma.
In addition, the paper advocates a broader use of a limited number of conventions but warns against their proliferation; units shortened thereby would be more difficult to recognize. It points out the clear distinction between these conventions - a matter of administration and general compliance - and knowledge - a domain where free expression of opinion is indispensable -.

 Errata:  Some errors were encontoured in the above Article. Corrections are listed below. Editors and authors apologize for any inconvenience.

1- Abstract: The sentence "The current dual system of nomenclature for Precambrian and Phanerozoic strata is accepted" should read: "The current different system of subdivision for Precambrian and Phanerozoic strata is accepted". 

2- Figure 2: The words "Lower" and "Upper" in the lower line should obviously read "Early" and "Late" respectively. 

3- Figure 3: The words "Main Hierarchy", lower line of the left column, should read "Sub Hierarchy".

Online since December 3, 2004


Article 1 [2004]: The Mediterranean deep-sea fauna: historical evolution, bathymetric variations and geographical changes, by Christian C. EMIG & Patrick GEISTDOERFER.-
Format [HTML] or [PDF 539 KB]
Reference: [CG2004_A01_CCE-PG]

 Abstract:   The deep-water fauna of the Mediterranean is characterized by an absence of distinctive characteristics and by a relative impoverishment. Both are a result of events after the Messinian salinity crisis (Late Miocene). The three main classes of phenomena involved in producing or recording these effects are analysed and discussed:
- Historical: Sequential faunal changes during the Pliocene and thereafter in particular those during the Quaternary glaciations and still in progress.
- Bathymetric: Changes in the vertical aspects of the Bathyal and Abyssal zones that took place under peculiar conditions, i.e. homothermy, a relative oligotrophy, the barrier of the Gibraltar sill, and water mass movement. The deeper the habitat of a species in the Mediterranean, the more extensive is its distribution elsewhere.
- Geographical: There are strong affinities and relationships between Mediterranean and Atlantic faunas. Endemic species remain a biogeographical problem. Species always become smaller in size eastward where they occupy a progressively deeper habitat.
Thus, the existing deep Mediterranean Sea appears to be younger than any other deep-sea constituent of the World Ocean.

Online since April 12, 2004


Article 7 [2003]: Pristiograptus (Graptoloidea) from the perneri-lundgreni biozones (Silurian) of Lithuania, by Sigitas Radzevičius.-
Format [HTML] or [PDF 1,749 KB]
Reference : [CG2003_A07_SR]

Lang.: 

 Abstract:   Two new forms of Pristiograptus dubius, here designated as varieties "A" and "B", are described and figured. Both were found in core samples representing the perneri through lundgreni biozones of the Wenlock epoch. The cores are from boreholes Šiupyliai-69, Parovėja-9, Likėnai-396, Paežeriai-222 and Sutkai-87 in central and northern Lithuania. The associated graptolites Cyrtograptus perneri Bouček, C. radians Törnquist, C. lundgreni Tullberg, Monograptus flemingii flemingii (Salter), M. testis testis (Barrande), Monoclimacis flumendosae (Gortani) and Pristiograptus pseudodubius (Bouček) (= P. parvus) are all indicative of the perneri, radians and lundgreni biozones of the Wenlock. Two species of Pristiograptus occur in this time-stratigraphic interval: P. dubius and P. lodenicensis. In P. dubius the degree and manner of extension of the thecal apertural lip (thecal hood) onto the succeeding theca distinguish it from otherwise very similar taxa. The thecal morphology of P. lodenicensis differs from that of a typical Pristiograptus in that the apertural lip has a central depression and is rounded into small lobes laterally.

Online since November 22, 2003


Reply to Article 6 [2003]: Reply to L.E. Popov and L.E. Holmer (CG2003_A06_LEP-LEH): Obolid taxonomy, by Christian C. EMIG.
Format [HTML] or [PDF 516 KB]
Reference : [CG2003_A06_Reply_CCE]

Lang.: 

Online since October 4, 2003


Article 6 [2003]: Understanding linguloid brachiopods: Obolus and Ungula as examples, by Leonid E. POPOV & Lars E. HOLMER.-
Format [HTML] or [PDF 2,806 KB]
Reference: [CG2003_A06_LEP-LEH]

Lang.: 

 Abstract:  EMIG (2002) re-examined the taxonomy of the genus Obolus EICHWALD from the Middle Cambrian - earliest Ordovician of the East Baltic region as part of a proposal for a wholesale revision of the principles of linguloid systematics. He contended that previous taxonomic studies on Obolus and related forms were carried out erroneously using characters that have no taxonomic value. EMIG's proposed revision is based mainly on the limited morphological diversity between fossil and Recent taxa within a single linguloid Family, the Lingulidae. However, the present study demonstrates the taxonomic validity of the diagnostic characters used for classification within the mostly extinct families of the Superfamily Linguloidea, for they exhibit far more variation in morphology. This study also shows that EMIG has provided no satisfactory basis for his radical changes and revisions to the existing widely accepted taxonomy of the Cambrian to earliest Ordovician Obolidae of the East Baltic. Obolus EICHWALD and Ungula PANDER are shown to constitute distinctive and discrete genera comprising the species Obolus apollinis EICHWALD, O. ruchini KHAZANOVITCH et POPOV, O. transversus (PANDER), Ungula ingrica (EICHWALD), U. inornata (MICKWITZ), and U. convexa PANDER.

Online since September 12, 2003


Article 5 [2003]: New insight on the stratigraphy of the "Upper Thamama" in offshore Abu Dhabi (U.A.E.), by Bruno GRANIER, Ahmed Saqer AL SUWAIDI, Robert BUSNARDO, Sabah Karim AZIZ & Rolf SCHROEDER.-
Format [HTML] or [PDF 7,938 KB]
Reference: [CG2003_A05_BG_etal]
Lang.: 

 Abstract:   An integrated case study of field "A" in offshore Abu Dhabi found that the stratigraphic framework for the uppermost part of the so-called "Thamama Group" required revision. Detailed sedimentological work permitted a subdivision of the succession into lithostratigraphic units (more accurately "allostratigraphic units") and the fossil content permitted their allocation to standard age-related units ranging from Late Barremian through Middle Aptian times. Additional work focused on the so-called "Shu'aiba Formation" and resulted in a new and comprehensive interpretation on a regional scale which differs from published interpretations based on onshore studies in Abu Dhabi, Qatar, and Oman.

Online since July 31, 2003


Article 4 [2003]: A new approach in rock-typing, documented by a case study of layer-cake reservoirs in field "A", offshore Abu Dhabi (U.A.E.), by Bruno GRANIER.-
Format [HTML] or [PDF 436 KB]
Reference: [CG2003_A04_BG]
Lang.: 

 Abstract:  In carbonate reservoirs, the relationship between porosity Ø, a measure of the combined volumes of several kinds of pore space (e.g. interparticle and separate-vug), and permeability K are neither linear nor logarithmic, hence only weakly correlatable. Approaches to an estimation of permeability that employ both petrographical and petrophysical parameters, the so-called rock-typing techniques, have proven to be the most nearly precise. However in many studies simple K/Ø cross-plots are used for each rock-type to provide trendlines from which K values are derived as a function of Ø values; this is common practice even though the coefficient of correlation r2 departs significantly from 1.
This paper describes and provides examples of an improved technique of rock-type classification in which each rock-type is characterized by a discrete and unique Gaussian distribution of log K. It facilitates upscaling for it suggests the use of a single geometric mean value for permeability and a corresponding standard deviation (variance, or coefficient of variation) for each rock-type.
This new technique can be used in uncored wells by extrapolating these determinations into wireline logs as documented below in a case study of layer-cake reservoirs in a field of the Abu Dhabi offshore (U.A.E.).

Online since July 12, 2003


Article 3 [2003]: The Cretaceous of the Elbe valley in Saxony (Germany) - a review, by Karl-Armin TRÖGER.-
Format [HTML] or [PDF 377 KB]
Reference: [CG2003_A03_KAT]
Lang.: 

 Abstract:  In Central Europe one of the most important interchanges between the North Temperate Realm and the Tethyan Realm took place during the Cenomanian along the course of the Elbe Valley Geosuture that separates the Erzgebirge block (part of the Mid European Island during the Cretaceous) from the Lusatian block (West Sudetic Island). Strata of the Lower Cretaceous and the basal portion of Lower Cenomanian are absent in the Elbe Valley Geosuture but a marine transgression in a NW-SE direction occupied a portion of this tract during the late Early Cenomanian and a second incursion from SE to NW occurred during the Late Cenomanian. These transgressions are known to have occurred because of faunal migrations southwards from the North Temperate Realm and northwards from the Tethyan Realm across the Bohemian Basin. Sediments of the first transgression (Lower Cenomanian, dixoni zone) are restricted to the northwestern part of the Elbe Valley Geosuture in the Meissen area for at that time the fluvial Niederschöna Formation occupied the southern part of the Elbe Valley Geosuture and the adjacent Erzgebirge block. Most of the rivers in this system ran eastward but drained toward northern Bohemia. This fluvial environment predominated in the southern part of the Elbe Valley Geosuture and on the adjacent Erzgebirge block.
But the uppermost levels of the fluviatile Niederschöna strata are influenced by marine ingressions. The main transgression from the North Temperate Realm toward the Tethyan Realm took place in the basal Upper Cenomanian (naviculare zone) along the Elbe Valley Geosuture. A small regression followed (plenus event, geslinianum zone): Indications of this regression are visible on the flanks of small islands in the Elbe Valley Geosuture. Four marine sequences are recognized in strata dated Late Cenomanian - earliest Turonian.
These sequences are important for the comparison of Upper Cretaceous formations in Saxony with those of the Upper Cretaceous in northern Bohemia and in the peripheral areas of the NW German-Polish Basin, in the Münsterland, Subhercynian, Eichsfeld regions and in the Anglo-Paris Basin. These sequences are described and their influence on the changes in the paleogeography in the Elbe Valley Geosuture is discussed. Slight variations in sea level as a consequence of local tectonic movements in the Elbe Valley Geosuture cannot be precluded.

Online since April 26, 2003


Article 2 [2003]: Micropaleontological investigations in the modern Mahakam delta, East Kalimantan (Indonesia), by Bernard LAMBERT.-
Format [HTML] or [PDF 4,845 KB]
Reference: [CG2003_A02_BL]
Lang.: 

 Abstract:   The Mahakam delta is a mixed, fluvial and wave dominated delta located in the eastern part of the island of Borneo (the East Kalimantan province of Indonesia). The distribution of benthic fauna in this delta system is influenced by the combined or antagonistic action of three main parameters: fluvial input of fresh water and sediment, tide, and a strong regional north to south drift current. A model of the present-day faunal distribution has been established taking into account the perturbations induced by the tide and by the regional drift current. This model has been extrapolated into the recent past through the study of shallow cores that permit the reconstruction of late Holocene deltaic regression patterns.

Online since March 8, 2003


Article 1 [2003]: The Cenomanian: stage of hindlimbed snakes, by Jean-Claude RAGE & François ESCUILLIÉ.-
Format [HTML] or [PDF 1,578 KB]
Reference: [CG2003_A01_JCR-FE]
Lang.:  

 Abstract:   Three "snakes with legs" are known: Pachyrhachis problematicus, Haasiophis terrasanctus and Eupodophis descouensi. They have short posterior limbs but lack an anterior girdle and forelimbs. Moreover, Pachyophis woodwardi, Mesophis nopcsai and Simoliophis ssp. appear to be closely related to the hindlimbed taxa; consequently, although the presence of posterior limbs has not been demonstrated for these genera, it is presumed that they too were hindlimbed. All these snakes have been recovered only from the Cenomanian. Moreover, these six genera come from a restricted area (western Europe and northwesternmost Africa to the Middle East). This limited geographic range suggests that snakes might have originated in the "Mediterranean" part of the Tethys, but the restricted stratigraphical range remains unexplained.

Online since February 17, 2003


Article 1 [2002]: Tools for linguloid taxonomy: the genus Obolus (Brachiopoda) as an example, by Christian C. EMIG.-
Format [HTML] or [PDF 637 KB]
Reference: [CG2002_A01_CCE]
Lang.: 

 Abstract:   This study points out some basic problems of linguloid systematics and proposes solutions for them. A taxonomic examination of the unique species of the genus Obolus found in the Upper Cambrian of Estonia and Russia, O. apollinis (= O. ruchini, O. transversus, O. rebrovi and Ungula convexa) is used as an example of a methodology employing all of the characters valid for distinguishing species of both extant and fossil Lingulidae. These characters are: - umbonal region; - body musculature; - septa or ridges; - main mantle canals - as established and figured by EMIG (1982, 1983) and BIERNAT and EMIG (1993). All of them have been determined to be taxonomically stable and have been studied and compared to take into account intraspecific variability; they should be used to describe or to redescribe any taxon of the superfamily Linguloidea. Characters of the shell and valves, such as shape, size, and dimensional ratios have no taxonomic value.

Online since November 27, 2002


Memoirs

 

Memoir 3 [2009]: New data on the Middle-Upper Jurassic - Lower Cretaceous Charophytes and Ostracods from the Moroccan Atlas, by Pierre-Olivier MOJON, Hamid HADDOUMI & André CHARRIÈRE.-
Format [HTML] or [PDF 7,487 KB, plates with a coloured background] or [PDF 8,353 KB with black & white plates]
Reference: [CG2009_M03]
Lang.: 

 Abstract:  The Middle Jurassic-Lower Cretaceous continental "Red Beds" of the Moroccan Atlas have provided very interesting new taxa of charophytes and lacustrine ostracods: Aclistochara africana n.sp. (Bathonian), Feistiella atlantis n.sp. (Hauterivian-Lower Barremian), Cypridea suprajurassica n.sp., Cypridea mohandi n.sp. and Cypridea demnatensis n.sp. (Oxfordian ? - Kimmeridgian), Harbinia atlasica n.sp. (Hauterivian ? - Lower Barremian). Micropaleontological data obtained after 2002 contributed the following:
• In the central High-Atlas, discovery of Upper Jurassic charophytes and freshwater ostracods (Dictyoclavator ramalhoi, Porochara kimmeridgensis, Aclistochara bransoni, Cypridea suprajurassica, Cypridea mohandi, Cypridea demnatensis) evince a Barremian ingression, its restricted marine character attested by lagoonal-brackish water ostracods (Harbinia atlasica) and presumed marine ostracods Trachyleberididae (cf. Strigosocythere strigosa, Cythereis ? sp., Protocythere ? sp.) associated with well-developed gypsiferous evaporites.
• In the eastern High-Atlas, charophytes have been found at levels related to the Jurassic/Cretaceous boundary (Upper Tithonian–Berriasian Porochara maxima).
• In the non-marine Lower Cretaceous (Hauterivian ? - Barremian) of the central High-Atlas, mixed Eurasian e and Gondwanian g assemblages of charophytes: Globator (e) and Feistiella (g), and brackish-lacustrine ostracods: (Fabanella-Cetacella (e), Darwinula-Cypridea-Harbinia (e & g) and Salvadoriella-Petrobrasia-Reconcavona-Paracypridea (g), were discovered.
• Complementary data for the Lower Cretaceous charophyte biozonation (Upper Valanginian-Lower Barremian interval) with Globator hemiglobatoroides Mojon n.sp. (Cenozone M7a, NE-Spain) and Globator mutabilis (Cenozone M7b) from NE-Spain and Morocco (central High-Atlas) were obtained.
• In the Moroccan Atlas area several stages in the breaking up of Pangea and the opening of the Atlantic Ocean have been recognized. These dislocations took place mainly during Bathonian times but also involved portions of the Kimmeridgian and Barremian.

Online since October 31, 2009


Memoir 2 [2009]: Subfamily Taramelliceratinae (Ammonitina, Haploceratoidea, Oppeliidae) from Middle and Upper Oxfordian strata (Plicatilis Zone, Vertebrale Subzone - Bimammatum Zone, Berrense Subzone) of N Vienne, France (submediterranean province), by Philippe QUEREILHAC.-
Format [HTML] or [PDF 17,578 KB]
Reference: [CG2009_M02]

 Abstract:  In the area of northern Poitou studied Taramelliceratinae are present at every level except in the Schilli Subzone, itself possibly absent, and the Stenocycloides Subzone in which only Perisphinctidae and Trimarginites sp. occur. Although some species are known and cited in the literature often, they are figured infrequently or not at all: Taramelliceras (Taramelliceras) dentostriatum (Quenstedt), T. (T.) callicerum (Oppel), T. (Proscaphites) anar (Oppel). Here, the ranges of these species in the stratigraphic succession were determined through their association with other faunas in the same collections, using the presence or absence of known precise stratigraphic markers (for example: Neomorphoceras chapuisi (Oppel) = Transversarium Zone, Luciaeformis Subzone; Taramelliceras (? Taramelliceras) colleti (Lee) = Rotoides Subzone; "Epipeltoceras semimammatum" (Quenstedt) = Bimammatum Zone, "Berrense" Subzone, Semimammatum horizon) and/or the disappearance of species with longer ranges (for example: the disappearance of Neoprionoceras lautlingensis (Rollier) which is present in the Parandieri Subzone, but absent in the overlying Luciaeformis Subzone). The ranges of certain species that had been incorrectly located stratigraphically : T. (T.) dentostriatum (Quenstedt), T. (T.) callicerum (Oppel), T. (T.) externnodosum Dorn, have been restored to their true location as determined from their occurrences in the author's collections and in those of other collectors who had noted their stratigraphic relationships to other taxa.
It is recommended that the date of creation of the Luciaeformis Subzone and the Nectobrigensis, Luciaeformis and Subschilli horizons (Middle Oxfordian, Transversarium Zone) should be rectified. Currently, these are indicated as having been created in 1984. However, if the author's name, G. Melendez, is correct the date of their creation cannot have been 1984, the year in which the G. Melendez thesis was defended, for the manuscript was published only in 1989. It is also proposed that the Duongi horizon Melendez, 1989, be renamed as the Duongae horizon Melendez, 1989, because the index form, Perisphinctes (Dichotomoceras) duongi Melendez, 1989, is an ammonite species named to honor of A.N. Duong, a woman.
The study involved more than fifteen hundred individuals, all collected in the zone investigated. Only the most representative are figured here. The poor state of preservation of the ammonites (encrusted, often worn on one face, with the umbilicus not accessible) did not permit measurement (hence no table) except that of the diameter and sometimes the thickness. Previous studies of this subfamily or these species (Oppel, 1863; Quenstedt, 1887; Loriol, 1902; Lee, 1905; Dorn, 1931; Hölder, 1955) are old. References to this subfamily or its representatives in more recent works are only incidental and rarely include descriptions, drawing or photographs. The existence of many ammonites comprising homogeneous groups but without characteristics in common with known species justifies the creation of new species. Some microconchs have been definitely associated with a macroconch species. For others, a lack of material did not permit the establishment of such a direct link so they have been attached to the supposedly related species with the mention, "aff." (for "affinis"). Nevertheless, although described and figured, these forms remain in open nomenclature. There are some "groups" of ammonites with new characteristics that are here associated with a known species because the differences were not sufficient to create new ones; they are distinguished by "var." (for "variety"). There are also some that are referred to a previously known species because they were based only on a fragment (polymorphism?). In addition, in the zone studied the several taxa of this subfamily permit a relatively detailed stratigraphic breakdown because their existence is limited at a maximum to a subzone. However, an exception is the species Taramelliceras (Proscaphites) anar (Oppel, 1863) which ranges from the Antecedens Subzone through the Rotoides Subzone.

Online since September 15, 2009


Memoir 1 [2009]: Mediterranean Neocomian belemnites, part 3: Valanginian-Hauterivian belemnites, by Nico M.M. JANSSEN.-
Format [HTML] or [PDF 2,898 KB]
Reference: [CG2009_M01]

 Abstract:  The classical papers of Raspail (1829, 1830) and Duval-Jouve (1841) described a wide range of belemnite species, mainly from the Lower Cretaceous of the Castellane-Peyroules area (Alpes de Haute-Provence, France). The present work focuses mainly on the biostratigraphy of these previously described belemnite taxa for their stratigraphic relationships had not been determined precisely. Here, biostratigraphy is related to the lithologic successions and faunal associations (ammonites) of various outcrops in the area studied. Complementary data were obtained from the La Lagne, Les Allaves and Pas d'Escale sections (Alpes de Haute-Provence, France). And, in order to attain a better understanding of the stratigraphic distribution of Late Valanginian belemnites in condensed glauconitic deposits, these assemblages are compared with belemnites from deeper water successions in the Angles, Source de l'Asse de Moriez, Cheiron areas and those in the vicinity of La Charce and Vergol that are even deeper.

Online since March 31, 2009


Memoir 4 [2008]: Aptian and Albian Phylloceratids (Ammonoidea) from the Vocontian Basin (SE France), by Bernard JOLY & Michel DELAMETTE.-
Format [HTML] or [PDF 6,688 KB]
Reference: [CG2008_M04]

 Extended English abstract:  More than 2,200 pyritized ammonites of the Superfamily Phylloceratatoidea have been collected in consonance with the scale of the ammonite zonation of the expanded Marnes Bleues Fm in the Vocontian Basin (SE France). This abundant material allows the description and the figuration (specimens and sutures) of 28 taxa of which 4 are new:

  • Phylloceras (Hypophylloceras) moriezense Sayn, 1920 subsp. tenuicostulata nov. Diagnosis: variant of P. (H.) moriezense distinguished by a subrectangular section of the whorl and a flattening of the sides less accentuated than on the typical form, with a very fine costulation that descends almost to the middle of the side (early late Aptian);
  • Phylloceras (Goretophylloceras) vocontium nov. sp. Diagnosis: thick shell, convex sides, rounded and compressed venter, maximum thickness of the whorl near the umbilicus, open umbilicus, constrictions at least at the beginning of the last whorl, oval whorl section, suture line of subgenus Goretophylloceras (mid middle Aptian to earliest Albian);
  • Salfeldiella (Gyrophyllites) falloti nov. sp. Diagnosis: shell with a finely costulate test, smooth internal mold, open umbilicus, nearly flat sides, rounded venter, subquadratic whorl section, proverse constrictions of the internal mold, radial constrictions in small specimens, a ventral sinus in the largest specimens, suture line like that of the genus Gyrophyllites (late Early Aptian to late Aptian);
  • Phyllopachyceras brehereti nov. sp. Diagnosis: thick shell, flat sides, venter flat or slightly convex, whorl quadratic in section, suture lines like those of the genus Phyllopachyceras with tetraphyllic spatulate elongated saddles (early mid-Aptian to early late Aptian).

Owing to the abundance of the Phylloceratoidea and the variations of specific diversity in 9 fossiliferous levels ranging in age from the late Early Aptian to the end of the Albian it is possible to identify 3 peaks of abundance:

  • peak 1 during the early mid-Aptian (base of the Martini zone),
  • peak 2 near the Aptian and Albian boundary, a few meters below the anoxic Paquier level,
  • peak 3 during the latest Albian (Blancheti zone).

Of these 3 peaks the first is the most important probably because the Vocontian Basin attained its maximum depth during this time. The peaks appear to be correlated with the maximum flooding intervals of depositional sequences. But high sea-levels were not always favourable for the Phylloceratoidea. The very fossiliferous Paquier level, although it took place during a high in sea-level, is characterised by the virtual absence of the deep-water ammonites, e.g. Phylloceratids, Tetragonids and Lytoceratids. This fact is explained by the presence of a deep-water anoxia. Another depletion of Phylloceratoidea in conjonction with a great abundance of Desmoceratid and Mortoniceratid ammonites and benthic fauna (Inoceramids Bivalves) occurred during the early Late Albian. At that time, the Vocontian area appears to have reached a minimal depth resulting from a pause in the rate of subsidence associated with an influx of siliciclastic material that attained the center of the basin.

After a last episode during the Early Cenomanian of the Vocontian Basin when the Phylloceratoidea occurred significant number, this group of ammonites shows a drastic decrease in abundance. This evolution is correlated with the filling of the basin from west to east, thus restricting the Phylloceratoidea and the other deep-water ammonites to a small eastern area (Leiostraca area of Thomel, 1965, 1980).

Online since September 28, 2008


Memoir 3 [2008]: The Douvilleiceratidae (Ammonoidea) of the Lower Aptian historical stratotype area at Cassis-La Bédoule (SE France), by Pierre ROPOLO, Gabriel CONTE, Michel MOULLADE, Guy TRONCHETTI & Roland GONNET.-
Format [HTML] or [PDF 6,688 KB]
Reference: [CG2008_M03]

 Abstract:  Recent biostratigraphic research in the marly limestones of the Cassis-La Bédoule area (SE France) provided a rich macrofauna of Douvilleiceratidae Parona & Bonarelli, 1897. From the uppermost Barremian (Pseudocrioceras waagenoides Subzone) to the middle Aptian (Parahoplites melchioris Zone), specimens of Procheloniceras, Cheloniceras, Roloboceras, Megatyloceras and Epicheloniceras were collected in succession. In this paper we describe the various genera and species from this material and delimit precisely their stratigraphic positions. Our study shows that each genus or subgenus characterizes a discrete stratigraphic interval. In addition, the Cheloniceras meyendorffi (upper Bedoulian), Epicheloniceras debile, Epicheloniceras gracile, and Epicheloniceras buxtorfi (Gargasian = middle Aptian) subzones, originally defined in England by Casey (1961a), are identified for the first time in the Lower Aptian stratotypic area of Cassis-La Bédoule.

 Erratum:  The photo of a specimen of Megatyloceras ricordeanum (d'Orbigny) from the private collection of Cyril Baudouin and coming from the locality of Le Teil (Ardèche) is figured in the memoir of P. Ropolo et alii (2008, Pl. 08, fig. 3 ) instead of and in place of a specimen collected at La Bédoule. The first author (P.R.) tells us that it was because of an error in the labeling of his photographic archives that this unfortunate substitution could occur. He asks not just the owner of the photograph and the ammonite, Cyril Baudouin, but also his co-authors and the editors and readers of Carnets to be good enough to pardon him for this unintentional error.
We remind you that the whole of the material illustrated in this memoir is already deposited or is being deposited, is catalogued or is being catalogued in the Museum of Paleontology of the University of Provence (Aix-Marseilles 1), St. Charles Campus.

Format [HTML] ou [PDF 76 KB]

Online since August 27, 2008


Memoir 2 [2008]: Support for a Vraconnian Stage between the Albian sensu stricto and the Cenomanian (Cretaceous System), by Francis AMÉDRO.-
Format [HTML] or [PDF 8,921 KB]
Reference: [CG2008_M02]

 Abstract:  The geological scale for the middle Cretaceous currently used throughout the world was proposed by Alcide d'Orbigny in the XIXth century between the years 1842 and 1847 and establishes the succession of stages as Albian, Cenomanian and Turonian. In 1868 Renevier proposed that a supplemental chronostratigraphic division be intercalated between the Albian and the Cenomanian: the Vraconnian stage. This term was not generally accepted and after a period when it was referred to by Breistroffer (1936) as a substage constituting the upper part of the Albian, as an equivalent of the Stoliczkaia dispar ammonite Zone, its abandonment was "recommended" by the Conference on the Lower Cretaceous held in Lyon in 1963. The conditions that led to this "decision" will be discussed herein.
Historically, for almost a century the Vraconnian was studied only in the condensed levels of the platform where ammonites are abundant, but the succession is thin and not mappable. The type section of the Vraconnian in the Vaud canton of Switzerland is only 2 meters thick. In France the situation is the same in the northern Alps, in most of central Europe, in Russia, in the Crimea, and as far as the Caspian sea.
The examination of a certain number of sections located in other parts of the world: in the southeastern basin of France (Salazac, Marcoule, Mont-Risou), in the Anglo-Paris basin (Folkestone, Merstham, Grandpré), in the Mons basin (Harchies, Strépy-Thieu), at the southern edge of the Tethys in central Tunisia (Kaalat Senan), in Madagascar (Diégo Suarez) and North America in California (Dry Creek) demonstrates, however, that in a number of regions of the globe the sedimentary record of the Vraconnian is sometimes rather considerable, often much more important than that of the Albian sensu stricto.
In addition, the Vraconnian represents a very important eustatic event between an Albian transgression and the great Cenomanian transgression (third order cycle and the peak of transgression in a second order cycle). It involves a period of rapid ecologic expansion both as regards the macrofauna (ammonites in particular) and microfauna (planktonic foraminifera). These are the main reasons why a rehabilitation of the Vraconnian as a true stage is proposed here.

Online since May 17, 2008


Memoir 1 [2008]: Description and illustration of forty-four gilianelles (microproblematica) and ten other microproblematica of the Cretaceous of the stratotype section at Tercis (Campanian-Maastrichtian boundary), South-West France, by Gilles Serge ODIN.-
Format [HTML] or [PDF 15,672 KB] / pages 45-75 with a coloured background [PDF 3,477 KB]
Reference: [CG2008_M01]

 Abstract:   Following acetolysis, microproblematica were collected from indurated carbonates sampled from the stratotype section of the Campanian-Maastrichtian boundary at Tercis (Landes, France). 44 taxa of the gilianelles group (microproblematica probably pertaining to the Protista, Protozoans, Rhizopods) as well as ten other microproblematica were discriminated. To document the taxa in this paper 281 scanning electronic microscope images and 183 optical microscope images are presented. The gilianelles encompass 36 species, and 8 subspecies referred to 15 genera of which 14 are new. The new genera are: Tercensella, Azymella, Numismella, Aturella, Scutellella, Corniculum, Caccabella, Orculiella, Pennigerella, Corbella, Aquilegiella, Pocillella, Coraliella, Obbella. Among the other microproblematica, nine species and one subspecies are proposed; they are referred to 7 new genera: Globulella, Piperella, Vasculum, Lucernellus, Cimicellus, Tubella, Pilella. This first general view uses normal taxonomic criteria to recognize and define a group of microfossils of which the identity and the consistency of occurrence are herewith established using the morphological characters of the body of the test, the presence and development of the expansions attached to that body, and its ornamentation. The use of these criteria in an ordered manner suggests that a rigorous taxonomic collocation is feasible, needing only a few other observations before becoming a formal classification. The statigraphic distribution of the taxa provides a means for establishment of a remarkable tool for relative dating in the stratotype section and its immediate vicinity ; microproblematica allow the sequence to be subdivided into intervals of deposition on the order of 0.1 Ma, a length of time shorter than the intervals obtained using the many microfossil or macrofossil groups previously employed to calibrate the stratotype. The Campanian-Maastrichtian boundary is within the limits of the genus Aturella lineage in the basal portion of the range of Aturella edentula.

Online since March 22, 2008
(Supplement online since March 27, 2008)


Memoir 2 [2007]: Relations between the northern and southern margins of the Tethys ocean during the Cretaceous period, edited by Luc G. BULOT, Serge FERRY & Danièle GROSHENY.-
Format [HTML] or [PDF 4,951 KB]
Reference: [CG2007_M02]

 Abstract:   The theme of the 2006 meeting of the Groupe Français du Crétacé (GFC) was on a comparison of the northern and southern margins of the Tethyan ocean during the nearly 80 million year span of the Cretaceous period, a time when this large, meander-edged seaway was closed progressively by the movement of two major tectonic plates. Consequently, during this slow closure sedimentary successions near the northern and southern shores of the Tethys provide ideal sites for testing a number of hypotheses. One of these is the degree of correlativity between "events" in tracts far distant from one another. The "events" could be paleontologic (faunal renewal vs. migration), sedimentologic (are depositional sequences and specific lithologies such as black shale or phosphates on either shore coeval?), eustatic vs. tectonic. On November 27-28, 2006, thirty earth scientists met in the École des Mines in Paris to discuss these matters. Thirteen communications were presented, eleven of which as abstracts or extended abstracts comprise this special publication by "Carnets".

1- Robaszynski F., Amédro F., González-Donoso J.M. & Linares D. (2007).- Les bioévénements de la limite Albien (Vraconnien) - Cénomanien aux marges nord et sud de la Téthys (S.E. de la France et Tunisie centrale) [Bioevents at the Albian (Vraconnian) - Cenomanian boundary at the North and South margins of the Tethyan Ocean (SE France and Central Tunisia)].

2- Courville P. (2007).- Échanges et colonisations fauniques (Ammonitina) entre Téthys et Atlantique sud au Crétacé supérieur : voies atlantiques ou sahariennes ? [Late Cretaceous faunal exchange and colonization (Ammonitina) between the Tethys and the South Atlantic: Atlantic or Saharan routes?].

3- Westermann S., Föllmi K.B., Matera V. & Adatte T. (2007).- Phosphorus and trace-metal records during Cretaceous oceanic anoxic events: Example of the Early Aptian OAE in the western Tethys [Évolution de la concentration du phosphore et des métaux-traces durant les événements anoxiques du Crétacé inférieur : exemple de l'événement de l'Aptien inférieur (OAE 1a) dans la Téthys occidentale].

4- Jammes S., Manatschal G. & Ghienne J.-F. (2007).- L'évolution tectono-sédimentaire du système "Golfe de Gascogne/Pyrénées Occidentales" au Crétacé inférieur : un nouveau regard [The tectonic and sedimentary evolution of the Bay of Biscay/Western Pyrenees during the Early Cretaceous : a new point of view].

5- Bardet N., Houssaye A., Pereda Suberbiola X. & Rage J.-C. (2007).- The marine squamates (reptiles) from the Cenomanian-Turonian of the Tethys: a noteworthy radiation [Les squamates (reptiles) marins du Cénomanien-Turonien de la Téthys : une radiation remarquable].

6- Yans J., Masure E., Dejax J., Pons D. & Amédro F. (2007).- Influences boréales dans le bassin de Mons (Belgique) à l'Albien [Boreal influences in the Mons basin (Belgium) during the Albian].

7- Granier B. (2007).- On the track of a major trans-Tethyan discontinuity [Sur la piste d'une discontinuité majeure trans-Téthys].

8- Ferry S., Merran Y., Grosheny D. & Mroueh M. (2007).- The Cretaceous of Lebanon in the Middle East (Levant) context [Le Crétacé du Liban dans le cadre du Moyen-Orient (Levant)].

9- Grosheny D., Chikhi-Aouimeur F., Ferry S., Jati M. , Herkat M., Atrops F., Redjimi W. & Benkerouf F. (2007).- The Cenomanian-Turonian of the Saharan Atlas (Algeria) [Le Cénomanien-Turonien de l'Atlas saharien (Algérie)].

10- Bulot L.G. (2007).- Endémisme et cosmopolitisme des faunes d'ammonites de la plaque arabique au Crétacé moyen (Aptien - Turonien) [Endemism vs. cosmopolitanism of the ammonite faunas from the Arabian plate during mid-Cretaceous times (Aptian – Turonian)].

11- Bulot L.G. & Ferry S. (2007).- La discontinuité albienne à l'échelle globale et ses implications paléobiogéographiques et biostratigraphiques [The Albian unconformity at a global scale and its palaeobiogeographic and biostratigraphic implications].

Online since May 15, 2007


Memoir 1 [2007]: Recent advances in palynology, edited by Philippe STEEMANS & Emmanuelle JAVAUX.-
Format [HTML] or [PDF 5,762 KB]
Reference: [CG2007_M01]

 Abstract:   A set of 11 abstracts and short papers (extended abstracts) of presentations given at a meeting organized by the NFSR Working Group, "Micropaléontologie végétale et Palynologie (MVP)", held on May 24, 2006 at the University of Liège, Belgium. Most contributions are available only in English.

1- Breuer P., Filatoff J. & Steemans P. (2007).- Some considerations on Devonian miospore taxonomy.

2- Breuer P., Dislaire G., Filatoff J., Pirard E. & Steemans P. (2007).- A classification of spores by support vectors based on an analysis of their ornament spatial distribution – An application to Emsian miospores from Saudi Arabia.

3- Dejax J., Dumax É., Damblon F. & Yans J. (2007).- Palynology of Baudour Clays Formation (Mons Basin, Belgium): correlation within the "stratotypic" Wealden.

4- Gerards T., Yans J. & Gerrienne P. (2007).- Quelques implications paléoclimatiques de l'observation de bois fossiles du Wealdien du bassin de Mons (Belgique)
Résultats préliminaires. [FR]

5- Grey K. (2007).- Advances in Ediacaran biostratigraphy in Australia.

6- Javaux E.J. (2007).- Patterns of diversification in early eukaryotes.

7- Prestianni C., Streel M., Thorez J. & Gerrienne P. (2007).- Strud: old quarry, new discoveries. Preliminary report.

8- Steemans P. & Breuer P. (2007).- PalyWeb: A palynomorph database project on the web.

9- Streel M., Renson V. & Vleeschouwer F. de (2007).- Palynological and geochemical data in peat sediments alongside an old (Roman or Merovingian) paved road in the Hautes-Fagnes.

10- Vanmeirhaeghe J. (2007).- Chitinozoans of the lower Llanvirn Huy and the middle Caradoc Sart-Bernard formations (Middle to Upper Ordovician): implications for the stratigraphy of the Condroz Inlier (Belgium).

11- Ville de Goyet F. de, Breuer P., Gerrienne P., Prestianni C., Streel M. &  Steemans P. (2007).- Middle Devonian (Givetian) megaspores from Belgium (Ronquières) and Libya (A1-69 borehole).

Online since March 22, 2007


Memoir 2 [2006]: Illustrated glossary of terms used in foraminiferal research, by Lukas HOTTINGER.-
Format [HTML] or [ PDF Text 739 KB + PDF Figs. 2-27 8,827 KB + PDF Figs. 28-46 7,391 KB + PDF Figs. 47-68 6,805 KB + PDF Figs. 69-83 6,454 KB]
Reference: [CG2006_M02]

 Summary:  An illustrated glossary of terms used in the analysis of the shells of recent and fossil foraminifera supplemented by a rigorous selection of terms that facilitate an understanding of their biology and their use in ecology and biostratigraphy. The glossary includes some 650 entries illustrated by 83 - often composite – figures many of which are stereographs or 3D models. A taxonomic index lists the 140 taxa illustrated.

Online since September 8, 2006


Fig. 83 revisited

Online since August 2, 2007


Memoir 1 [2006]: The Deshayesitidae STOYANOV, 1949 (Ammonoidea) of the Aptian historical stratotype region at Cassis-La Bédoule (SE France), by Pierre ROPOLO, Michel MOULLADE, Roland GONNET, Gabriel CONTE & Guy TRONCHETTI.-
Format [HTML] or [PDF 15,159 KB]
Reference: [CG2006_M01]

 Abstract:   One of the significant results of the multidisciplinary investigations carried out during recent years in the Lower Aptian historical stratotype of the Cassis-La Bédoule region (South-Eastern France) was a proposal to update the local Upper Barremian/Lower Aptian ammonite biozonation in order to be more consistent with the standard Mediterranean zonal subdivisions. So the lower and upper boundaries of the Lower Aptian (= Bedoulian substage of most French authors) as well as the boundaries of four biozones (Paradeshayesites tuarkyricus, P. weissi, Deshayesites deshayesi, Dufrenoyia furcata zones) and two subzones (Roloboceras hambrovi and Paradeshayesites grandis subzones) were identified and formally defined in the stratotype. However, to support this zonal scheme additional descriptions and illustrations of the ammonites collected bed by bed in the several sections studied were still required. In this paper we describe the members of the most significant ammonite family found in the Lower Aptian of Cassis-La Bédoule, i.e. the Deshayesitidae, and delimit precisely their stratigraphic positions. As regards zonation, we have replaced the index ammonite of the earliest Bedoulian Zone, i.e. Paradeshayesites tuarkyricus (BOGDANOVA, 1983), by Paradeshayesites oglanlensis (BOGDANOVA, 1983), and re-established the Pseudocrioceras waagenoides Zone as a subzone.

 Corrigendum:  There is an error in the labeling of Plate 8 in the above Memoir.

Consequently, the above plate caption:
Fig. 2.- Deshayesites evolvens LUPPOV, 1952 (Abm311), Les Fourniers section, bed 115. P. weissi Zone.
Fig. 3.- Deshayesites sp. gr. spathi/normani CASEY, 1964 (ABR340), Les Fourniers section, bed 111. P. weissi Zone.

Should read as follows:
Fig. 2.- Deshayesites sp. gr. spathi/normani CASEY, 1964 (ABR340), Les Fourniers section, bed 111. P. weissi Zone.
Fig. 3.- Deshayesites evolvens LUPPOV, 1952 (Abm311), Les Fourniers section, bed 115. P. weissi Zone.

Online since May 11, 2006


Memoir 2 [2005]: Pre-Cambrian to Palaeozoic Palaeopalynology and Palaeobotany, edited by Philippe STEEMANS & Emmanuelle JAVAUX.-
Format [HTML] or [PDF 142 KB]
Reference: [CG2005_M02]

 Abstract:   A set of 14 abstracts and short papers (extended abstracts) of presentations given at a meeting organized by the NFSR Working Group, "Micropaléontologie végétale et Palynologie (MVP)", held on May 11, 2005 at the University of Liège, Belgium. These contributions are available only in English.

1- Breuer P., Al-Ghazi A., Filatoff J., Higgs K.T., Steemans P. & Wellman C.H. [2005].- Stratigraphic palynology of Devonian boreholes from northern Saudi Arabia.

2- François L., Grard A. & Goddéris Y. [2005].- Modelling atmospheric CO2 changes at geological time scales.

3- Gerrienne P., Meyer-Berthaud B. & Fairon-Demaret M. [2005].- The significance of Runcaria (Middle Devonian, Belgium) in the evolution of seed plants.

4- Golubkova E. & Raevskaya E. [2005].- Main changes in microfossil communities during the Upper Proterozoic of Russia.

5- Javaux E.J. & Marshall C.P. [2005].- Tracking the record of early life.

6- Prestianni C. [2005].- Early diversification of seeds and seed-like structures.

7- Raevskaya E. [2005].- Diversity and distribution of Cambrian acritarchs from the Siberian and East-European platforms - a generalized scheme.

8- Ribecai C., Bagnoli G., Mazzarini F. & Musumeci G. [2005].- Paleontological evidence for Late Cambrian in the Arburese area, SW Sardinia.

9- Rubinstein C.V. [2005].- Ordovician to Lower Silurian palynomorphs from the Sierras subandinas (Subandean ranges), northwestern Argentina: a preliminary report.

10- Streel M. & Hartkopf-Fröder C. [2005].- Late Famennian correlation by miospores between the Refrath 1 borehole (Bergisch Gladbach-Paffrath Syncline, Germany) and the reference section of Chanxhe (Dinant Syncline, Belgium).

11- Vanguestaine M. & Brück P.M. [2005].- A Middle Cambrian age for the Ediacara fauna from the Booley Bay Formation, County Wexford, Ireland: new acritarch data and its implications.

12- Vanmeirhaeghe J., Yans J., Préat A., Grassineau N. & Verniers J. [2005].- New evidence for the Hirnantian (Upper Ordovician) in Belgium? An integrated isotopical, biostratigraphical and sedimentological approach.

13- Vecoli M., Lehnert O. & Servais T. [2005].- The role of marine microphytoplankton in the Ordovician biodiversification event.

14- Wauthoz B. [2005].- Correlation and biostratigraphy of the Kortrijk (Sint-Antonius) and Kortrijk (Lust) boreholes (early Silurian, Belgium).

Online since December 31, 2005


Memoir 1 [2005]: Discoaster zonation of the Miocene of the Kutei Basin, East Kalimantan, Indonesia (Mahakam Delta Offshore), by Bernard LAMBERT & Cécile LAPORTE-GALAA.-
Format [HTML] or [PDF 9,897 KB]
Reference: [CG2005_M01]

 Abstract:  Thirteen time-stratigraphic associations of the nannofossil Discoaster have been defined and used in the Miocene Kutei Basin of eastern Borneo to establish a regional stratigraphic framework. The methodology used is discussed and the fossils employed are figured and annotated. Their aid in resolving the timing, stages and details of delta construction is presented graphically.

Online since May 26, 2005


Memoir 1 [2002]: Diatom based transfer function for estimating the chemical composition of fossil water. Calibration based on salt lakes of the Lipez area in the southwestern Bolivian Altiplano, by Simone SERVANT-VILDARY, François RISACHER & Maurice ROUX.-
Format [HTML]
Reference: [CG2002_M01_SSV-FR-MR]
Lang.:  

 Abstract:   Diatom assemblages and water chemistry were studied in 13 shallow salt lakes in the southern part of the Bolivian Altiplano. At each locality bottom sediment and water samples were collected simultaneously. Relationships between the composition of the diatom assemblages and variations in water chemistry were collated in order to permit the estimation of ancient water chemistries based on changes in the make up of fossil diatom associations in older sediments. Weighted Averages treated by Partial Least Squares regression (WA and WA-PLS methods) allowed an estimation of optima and the relative tolerances of 61 species to variations in salinity and to the relative quantities of the 15 chemical elements studied, among them boron and lithium.

Online since October 14, 2002

2nd edition: On January 30, 2006 we edited the pdf file of the first memoir either published in Carnets.
Format [PDF 885 KB]
Reference: [CG2002_M01]
Lang.:  

Online since January 30, 2006


Special Publications

 

Book 1 [2010]: An atlas of calcareous algae. Carboniferous algae of the Arctic Alaska, by Bernard MAMET & Alain PRÉAT.-
Format [HTML] or [PDF 6,048 KB]
Reference: [CG2010_SP01] or [CG2010_BOOK_01]
Lang. : 

Dépôt légal: 
ISBN13: 978-2-916733-08-1

 Abstract:  An atlas illustrating 54 genera of marine algae and some microproblematica. They are observed in the field and in boreholes of the Lisburne Group throughout the Alaskan Arctic Cordillera (Brooks Range).

Online since July 1, 2010


Special Publication 1 [2009]: Cenozoic Dasycladales. A photo-atlas of Lutetian species from French Cenozoic basins, by Patrick GÉNOT.-
Format [HTML] or [PDF 68.244 KB]
Reference: [CG2009_SP01]

Dépôt légal: 
ISBN13: 978-2-916733-03-6

 Introduction:  Dasycladales are unicellular green algae in existence since the Paleozoic era. Dasycladales discovered in the Cenozoic strata of the French sedimentary basins are noteworthy for the exceptional quality of their preservation. Although most fossil Dasycladales are known only in thin sections, the coatings of the Dasycladales in these basins, particularly of those in Lutetian beds, are easy to extract from sandy sediments and then are examined under the electron microscope. This method of investigation facilitates greatly the identification of the external and internal features of each species.

Online since January 20, 2009


e-Books

 

Book 2 [2010] : Short Treatise on Foraminiferology (Essential on modern and fossil Foraminifera), by Jean-Pierre BELLIER, Robert MATHIEU & Bruno GRANIER.-
Format [HTML] ou [PDF 7,724 KB]
Reference : [CG2010_BOOK_02]
Lang.:  

Dépôt légal:
ISBN13: 978-2-916733-07-4

 Foreword:  After some forty years in the academic world and before abandoning a position as an employee of the State educational system to enter the new world of "pensioners", it seemed worthwhile to the first author (J.-P.B.) of this brief discussion to compile a short document that presents a synopsis of the knowledge acquired, taught and put to use for more than four decades. This fascicle reviews only the foraminifers, which, along with calcareous nannofossils, are the fundamental tools of modern biostratigraphy, used for worldwide oceanographic studies and for the correlation of oil wells. It deals essentially with the small foraminifers, that is those of modest size without a complex internal architecture. These include the planktonic foraminifers of which the rapid evolution and great dispersion permit the establishment of reliable biochronologic scales of reference.
This short course is intended for students preparing for the CAPES (Certificat d'aptitude au professorat de l'enseignement du second degré = Certificate of Aptitude for a Professorship of Instruction in the Second Grade), for students working toward the Aggregation in Natural Sciences in pursuit of a scientific career in the universities or in the CNRS (Centre National de la Recherche Scientifique = National Centre for Scientific Research), and for students who hope to work in the oil industry where a specialization in the field of micropaleontology is considered useful and is still valued. It will also interest amateur naturalists and that portion of the general public attracted by the beauties of the microscopic world, now living, or extinct and represented only by fossils.

Online since July 1, 2010


Book 3 [2009]: PaleoParks - The protection and conservation of fossil sites worldwide, by Jere H. LIPPS & Bruno R.C. GRANIER (special editors).- Reference: [CG2009_BOOK_03]

Dépôt légal: 
ISBN13: 978-2-916733-06-7

 List of Contents:  

   • Cover page
Format [HTML] or [PDF 422 KB]
   • Chapter 1. PaleoParks: Our paleontological heritage protected and conserved in the field worldwide, by Jere H. Lipps 
Format [HTML] or [PDF 1,013 KB]
   • Chapter 2. The Triassic Guanling fossil Group - A key GeoPark from Barren Mountain, Guizhou Province, China, by Xiaofeng Wang, Xiaohong Chen, Chuanshang Wang & Long Cheng
Format [HTML] or [PDF 5,376 KB]
   • Chapter 3. The GeoPark of Haute-Provence, France - Geology and palaeontology protected for sustainable development, by Jean-Simon Pagès
[HTML] or [PDF 2,478 KB]
   • Chapter 4. The protection and use of the geological and paleontological heritage in Baja California Sur, Mexico, by Javier Gaitán Morán & Alejandro Álvarez Arellano
[HTML] or [PDF 391 KB]
   • Capítulo 4. El resguardo y aprovechamiento del patrimonio geológico y paleontológico en Baja California Sur, México, por Javier Gaitán Morán & Alejandro Álvarez Arellano
[HTML] o [PDF 391 KB]
   • Chapter 5. Protecting fossil sites in New Zealand, by Bruce W. Hayward
[HTML] or [PDF 548 KB]
   • Chapter 6. The Salt Range: Pakistan's unique field museum of geology and paleontology, by Shahid Jamil Sameeni
[HTML] or [PDF 1,454 KB]
   •  Chapter 7. Paleontological parks and museums and prominent fossil sites in Thailand and their importance in the conservation of fossils, by Nareerat Boonchai, Paul J. Grote & Pratueng Jintasakul
[HTML] or [PDF 7,448 KB]
   • Chapter 8. Managing fossil resources at the Falls of the Ohio, Indiana and Kentucky, USA: A fossil park in an urban setting, by Alan Goldstein
[HTML] or [PDF 259 KB]
   • Chapter 9. Paleo-piracy endangers Vendian (Ediacaran) fossils in the White Sea - Arkhangelsk region of Russia, by Mikhail A. Fedonkin, Andrey Yu. Ivantsov, Maxim V. Leonov, Jere H. Lipps, Ekaterina A. Serezhnikova, Eugeniy I. Malyutin & Yuriy V. Khan
[HTML] or [PDF 2,686 KB]
   • Chapter 10. Copper Canyon track locality (Pliocene) conservation strategies, Death Valley National Park, USA, by Torrey Nyborg
[HTML] or [PDF 2,220 KB]
   • Chapter 11. A possible Late Miocene fossil forest PaleoPark in Hungary, by Géza Császár, Miklós Kázmér, Boglárka Erdei & Imre Magyar
[HTML] or [PDF 3,862 KB]

Online since September 17, 2009


Book 1 [2008]: Guidebook for the post-congress fieldtrip in the Vocontian Basin, SE France (September 11-13, 2008), by Emanuela MATTIOLI (special editor), Silvia GARDIN, Fabienne GIRAUD, Davide OLIVERO, Bernard PITTET & Stéphane REBOULET.-
Format [HTML] or [PDF 1,910 KB]
Reference: [CG2008_BOOK_01]

Dépôt légal: 
ISBN13: 978-2-916733-02-9

 List of Contents:  

   • Chapter 1. The Aalenian-Bajocian (Middle Jurassic) of the Digne area
   • Chapter 2. The Global Boundary Stratotype Sections and Points (GSSP) of the Hauterivian: La Charce section (Drôme, France, Vocontian Basin)
   • Chapter 3. The nannofossil succession of la Charce across the Valanginian-Hauterivian boundary
   • Chapter 4. The OAE 1d (Oceanic Anoxic Event, latest Albian)
   • Chapter 5. The GSSP (Global boundary Stratotype Section and Point) for the base of the Cenomanian stage (Kennedy et alii, 2004)
   • Chapter 6. The Cenozoic of the Barrême syncline.

Online since September 7, 2008


Book 2 [2006]: Photo-Atlas of living Dasycladales, by Sigrid BERGER.-
Format [HTML] or [PDF Cover 112 KB + PDF p. 1-50 2,261 KB + PDF p. 51-100 7,036 KB + PDF p. 101-150 5,519 KB + PDF p. 151-200 6,181 KB + PDF p. 201-250 4,363 KB + PDF p. 251-300 3,012 KB + PDF p. 301-348 3,978 KB]
Reference: [CG2006_BOOK_02]

Dépôt légal: DLF-20070216-197
ISBN10: 2-916733-01-9

 Foreword:  (by Filippo BARATTOLO) "Dasycladales, from whichever point of view they are observed, biological or paleontological, never lack in surprises for their elegant structural simplicity is associated with an extraordinary morphological plasticity. This is why their study is so exciting and compelling for those who have a regard for these algae.
During 540 million years of evolution, periods of crisis or stagnation followed others of sudden diversification at both generic and specific levels. Their persistence in the paleontological record as autotrophic marine organisms linked to well-defined ecological conditions make Dasycladales a potentially valuable tool for the recognition of global changes on Earth during the whole of the Phanerozoic. On the other hand, the preservation and occurrence of dasycladaleans as fossils depend strictly on the presence of a calcified envelope which varies in occurrence or degree of development from species to species as well as from one growth stage to another. It is a common experience for the paleophycologist that parts of the fossil alga cannot be observed because they have not been calcified. As a consequence the systematics of fossil Dasycladales leaves open to interpretation (the function of laterals, vestibules, etc.). It is only through a continuous comparison to living counterparts that cannot be disregarded, and becomes more and more delicate on moving from the Cenozoic to Paleozoic, that can provide a measure by which the reliability of an interpretation can be judged. This is why the Sigrid Berger’s Photo-Atlas of living Dasycladales is most welcome. This contribution not only adds useability to the previous elegant Berger & Kaever’s (1992) volume, but integrates that work with new spectacular photos and details as well as an updated systematic scheme and a selected bibliography. The Photo-Atlas of living Dasycladales is a helpful, easy-to-use tool to introduce biologists and paleontologists to the Dasyclad-world and to stimulate their interest in it. Moreover the electronic format will surely allow a broader public to become familiar with the extant dasycladaleans or to update their databases.
I think that I express the sentiments of all phycologists and paleophycologists in thanking sincerely the Author for having made available to the scientific community her rich photographic documentation and Bruno Granier for his precious, steadfast efforts to promote the knowledge of Dasycladales through his employment of the web."

Online since September 4, 2006


Book 1 [2006]: Les algues vertes (phylum Viridiplantae), sont-elles vieilles de deux milliards d'années ?, by Bernard TEYSSÈDRE [available in a French version only!].-
Format [ HTML] or [PDF 1,089 KB]
Reference: [CG2006_BOOK_01]

Dépôt légal: DLF-20070216-196
ISBN10: 2-916733-00-0

 Foreword:  (by Françoise DEBRENNE) "Bernard TEYSSÈDRE is an emeritus professor, formerly director of a unit of the CNRS/University of Paris Department of Human and Social Sciences. He directed the Institute of the Esthetics of Comtemporary Arts as well as a doctoral program in the Arts and Science of Art. A Doctor of History and Philosophy, his basic objective is the search for origins, either those based on our imagination as shown by his books:
- "Naissance du diable. De Babylone aux grottes de la Mer Morte" (Birth of the Devil, from Babylon to the grottos of the Dead Sea ),
- "Le diable et l'enfer au temps de Jésus" (The Devil and Hell at the time of Jesus),
- "Anges, astres et cieux" (Angels, Stars and Heavens),
or those concerning the beginnings of any form of life. Was he already thinking about the investigation that he was to carry out concerning the time when life was hidden, "La Vie Invisible" when he wrote the surprising politico-romanesque fiction around COURBET’s sulfurous "Origine du Monde" (Origin of the World) and then transferred his interests from the archeology of our beliefs to a scientific search for our origins? Always passionately interested in the sciences concerning evolution, he has a quasi-encyclopedic knowledge regarding fossils and their descendants that specialists may well envy. The study of the first three billion years of the history of life is still in its early stages and is in full evolution. Ninety per cent of Precambrian fossils have been discovered in less than the last twenty years. In "La Vie Invisible" Bernard TEYSSÈDRE has integrated the findings of paleontology, biochemistry and molecular phylogeny. It is the first synthesis of what is now called Integrative Geology. We learn to appreciate a writing style, to which we are now unaccustomed, which only Anglo-Saxon authors seem capable of presenting.
The work offered here is based on a disagreement between the author and Andrew KNOLL, the latter author dating the appearance of green algae at about 750Ma. Bernard TEYSSÈDRE analyses this problem using the methods that he recommended in "La Vie Invisible" that combine traditional descriptive paleontology with ultrastructural and biochemical analyses and compares these results with those of molecular phylogeny. Used with discrimination and competence, this tool does not permit the establishment of a precise taxonomy, but avoids erroneous taxonomies based on convergence and allows the establishment of a succession of nodal points in the evolution of a lineage. This work has led him to the conclusion that the Pyramimonadales appeared before 1500 Ma, and that the divergence of green and red algae took place around 2000 Ma. The date in question, 750 Ma, is really far off … the mark.
The author promises us a palaeontology of the Precambrian times to the light of molecular phylogeny. This well-aimed work lets us hope for a forthcoming synthesis of new data on the evolution of life since its origins."

Online since September 26, 2006


Novel

 

Les chiens aboient..., by Herbert WILD.-
Format [HTML]
Référence : [CG2009_ROMAN]

Dépôt légal: 
ISBN13: 978-2-916733-05-0

 Contents : 

  • Préface (Michel DURAND DELGA)
  • Première partie : La joie de créer
  • Deuxième partie : La poursuite sauvage
  • Troisième partie : ... la caravane passe
  • Commentaires (Michel DURAND DELGA)

Electronic edition by Jean-Marie OLLIVIER & Bruno GRANIER (photo © R. OLLIVIER)

Online since May 18, 2009






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