Search results for "Cretaceous."
showing 10 items of 166 documents
Cyclostratigraphy and high-frequency carbon isotope fluctuations in Upper Cretaceous shallow-water carbonates, southern Italy
2002
A detailed carbon isotope study has been carried out on a Santonian (Upper Cretaceous) carbonate platform succession that crops out at Monte Sant'Erasmo (southern Italy). Previous centimetre-scale studies on this succession have shown that high-frequency eustatic changes, resulting from the Earth's orbital fluctuations, controlled the hierarchical organization of the depositional and early diagenetic features in elementary cycles, bundles (groups of three to five elementary cycles) and superbundles (groups of three or four bundles). The elementary cycles, which correspond to single beds, suggest a control caused by Earth's precession; the bundles and superbundles record the short ( 100 kyr)…
A Jurassic-Cretaceous intraplatform basin in the Panormide Southern Tethyan margin (NW Sicily, Italy), reaveled by integrating facies and structural …
2016
We illustrate the tectono-sedimentary evolution of a Jurassic-Cretaceous intraplatform basin in a fold and thrust belt present setting (Cala Rossa basin). Detailed stratigraphy and facies analysis of Upper Triassic-Eocene successions outcropping in the Palermo Mts (NW Sicily), integrated with structural analysis, restoration and basin analysis, led to recognize and describe into the intraplatform basin the proximal and distal depositional areas respect to the bordered carbonate platform sectors. Carbonate platform was characterized by a rimmed reef growing with progradational trends towards the basin, as suggested by the several reworked shallow-water materials interlayered into the deep-wa…
Notes on selected Cretaceous echinoids from south-central Sakhalin, Far East Russia
2013
AbstractFrom Albian, Santonian and Campanian strata in south-central Sakhalin, four echinoid taxa are described, illustrated and discussed. In Far East Russia, echinoids are rare constituents amongst mid- and Late Cretaceous macrofaunal assemblages in which inoceramid and non-inoceramid bivalves, plus heteromorph and non-heteromorph ammonites predominate. The sole regular species in the present lot is represented by an incomplete external mould of a primary spine of a rhabdocidarid,Polycidaris(?) sp., from the lower Campanian. Irregular taxa include a fragmentary, specifically indeterminate ‘pygurid’,Echinopygus(?) sp., of late Albian age, as well as two spatangoids. One of these, a toxaste…
Micro- to macro-scale internal structures, diagenesis and petrophysical evolution of injectite networks in the Vocontian Basin (France): implications…
2015
27 pages; International audience; This study discusses the characteristics of two Lower Cretaceous injectite networks in the Vocontian Basin (SE France) using combined structural, sedimentary, diagenetic, and petrophysical analyses. Internal structures, at both the macro- and micro-scale, and diagenetic phases characterising these injectite networks have been described. Simultaneously, precementation porosity values were estimated and parameters controlling the geographical distributions of these values were analysed and statistically tested. All of the data were integrated so as to reconstruct the spatial evolution of the porosity from the time of injection to modern times through five maj…
Support for a Vraconnian Stage between the Albian sensu stricto and the Cenomanian (Cretaceous System)
2008
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…
Description of two new fossil echinoids (Echinodermata: Echinoidea) from the Early Hauterivian (Early Cretaceous) of the Paris Basin (France)
2012
International audience; Deux nouveaux genres et espèces d'échinides, Salvaster roberti gen. et sp. nov. et Pygolampas edita gen. et sp. nov. provenant de la Formation des Calcaires à Spatangues (CSF) sont décrits. La CSF correspond à des sédiments calcaréo-argileux déposés dans le sud-est du bassin de Paris (France) à l'Hauterivien inférieur (Crétacé inférieur). Ces dépôts sont datés de la chronozone à Acanthodiscus radiatus, un intervalle de temps qui a correspondu à un haut niveau marin général en Europe de l'Ouest. La CSF a pourtant livré une riche faune fossile d'environnement marin peu profond, principalement représentée par des invertébrés benthiques. Parmi ceux-ci, 54 espèces d'échin…
First record ofColoborhynchus (Pterosauria) from the Santana Formation (Lower Cretaceous) of the Chapada do Araripe, Brazil
2001
The anterior tips of associated upper and lower jaws of a pterosaur from the Lower Cretaceous of Brazil are described and assigned to the taxonColoborhynchus in the family Ornithocheiridae. It is characterized by the shape and position of the sagittal crest on the upper and lower jaw, the arrangement and length of the teeth and the spoon-like lateral expansion of the anterior parts of the jaws. It closely resemblesColoborhynchus wadleighi from North America andColoborhynchus clavirostris from England. Diagnostic anatomical characteristics permit a revision of the genusTropeognathus, which is shown here to be a junior synonym of other described taxa.Tropeognathus mesembrinus is referred toCr…
Dinosaur bonebed amber from an original swamp forest soil
2021
AbstractDinosaur bonebeds with amber content, yet scarce, offer a superior wealth and quality of data on ancient terrestrial ecosystems. However, the preserved palaeodiversity and/or taphonomic characteristics of these exceptional localities had hitherto limited their palaeobiological potential. Here we describe the amber from the Lower Cretaceous dinosaur bonebed of Ariño (Teruel, Spain) using a multidisciplinary approach. Amber is found in both a root layer with amber strictly in situ and a litter layer namely composed of aerial pieces unusually rich in bioinclusions, encompassing 11 insect orders, arachnids, and a few plant and vertebrate remains, including a feather. Additional palaeont…
Latest Cretaceous storm-generated sea grass accumulations in the Maastrichtian type area, the Netherlands – preliminary observations
2019
Abstract Ever since the first description of fossil material during the mid-nineteenth century, sea grass has been shown to be quite commonly preserved in ‘pockets’ or ‘clumps’ at certain levels within the Gulpen, Maastricht and Kunrade formations in southern Limburg (the Netherlands) and contiguous areas in northeast Belgium. In those places where silicification occurred during early diagenesis, even completely silicified and three-dimensionally preserved stems and roots can be found, mostly of Thalassocharis bosquetii, in association with fully marine molluscs such as dentaliid scaphopods and a range of larger foraminifera, bivalves, gastropods and ammonites. Such occurrences are best kno…
Early Cretaceous termites in amber from northern Spain (Isoptera)
2020
Abstract Two virtually complete termites in Lower Cretaceous amber from the Penacerrada I outcrop, Spain, are described and figured, representing the most well-preserved Isoptera yet discovered from the Albian stage. The material is described as Ithytermes montoyai gen. et sp. nov., and is similar in many details to the slightly younger Krishnatermes yoddha Engel, Barden, and Grimaldi from northern Myanmar amber. Given the presence of distinct soldiers in this grade of Cretaceous termites, it is likely that I. montoyai also exhibited such a tripartite caste system. In addition to the type material of I. montoyai, two fragmentary termites are recorded for the first time in Albian amber from …