Search results for "CEO"
showing 10 items of 398 documents
A classification of rhizogenic (root-formed) calcretes, with examples from the Upper Jurassic-Lower Cretaceous of Spain and Upper Cretaceous of south…
1997
Characterisation of Mesozoic–Cenozoic deformations and palaeostress fields in the Central Constantinois, northeast Algeria
1998
Abstract Tectonic analysis in conjunction with the microtectonic study of Mesozoic–Cenozoic series of the Central Constantinois of Algeria are used to reconstruct the sequence of tectonic phases since Cretaceous times. The retrotectonic method used to marshal the microtectonic data makes it possible to distinguish deformations related to Mesozoic tectonic phases from those associated with Cenozoic pre- and post-thrust sheet phases. A N120°E extensional and a N180°E compressional phase are highlighted in Albian–Cenomanian and latest Maastrichtian times, respectively. The Cenozoic era is marked by a series of three compressional phases oriented N90°–120°E in the Late Eocene, and N20°–30°E and…
Arctic mosasaurs (Squamata, Mosasauridae) from the Upper Cretaceous of Russia
2020
Abstract From the northern part of Chukotka Region (Russian Far East) and Nether-Polar Urals, one of the oldest and one of the most northerly occurrences of mosasaur remains in the world are recorded. The appearance of mosasaurs at high latitudes could be explained by the expansion of their habitat and an unusual balance of insolation. Polar day conditions could have been useful for marine predators such as mosasaurs because they could have hunted for prey at any time. During the Cretaceous, almost two months of complete darkness can be reconstructed for the territory of present-day Chukotka, and more than one month of twilight. It is highly unlikely that these large-sized animals with a hi…
High-pressure metamorphism in the Aegean, eastern Mediterranean: Underplating and exhumation from the Late Cretaceous until the Miocene to Recent abo…
2003
[1] We report 40Ar/39Ar ages from various tectonic units in the Aegean and westernmost Turkey. On the basis of published geochronologic data and our 40Ar/39Ar ages we propose that the Aegean is made up of several high-pressure units, which were successively underplated from the Late Cretaceous until the Miocene. Ages for high-pressure metamorphism range from 80–83 Ma in parts of the Vardar-Izmir-Ankara suture zone in the north to 21–24 Ma for the Basal unit in the Cyclades and the external high-pressure belt on Crete in the south. Published seismic data suggest that high-pressure metamorphism is currently occurring underneath Crete. Younging of high-pressure metamorphism in a southerly dire…
A new breath of life for anoxia.
2008
The middle of the Cretaceous (120–80 Ma) was one of the warmest periods of the past 300 m.y., with tropical sea-surface temperatures well over 30 °C ([Puceat et al., 2007][1]; [Forster et al., 2007a][2]) and atmospheric CO2 levels much higher than today. Therefore this period can give us crucial
Palaeohistology and palaeopathology of an Aeolosaurini (Sauropoda: Titanosauria) from Morro do Cambambe (Upper Cretaceous, Brazil)
2021
A recent publication of fossil bones of titanosaurs assigned to Aeolosaurini from the Morro do Cambambe site (Mato Grosso state, Brazil, Upper Cretaceous) reported anomalous growth in some of them. Here, we present osteohistological sections of elements to understand not only the microstructure and growth of such bones, but also the nature of those anomalies. Among them, we selected one cervical and one mediumposterior dorsal rib, and a haemal arch. The primary bone of all specimens consisted of a variation of the fibrolamellar complex, with the inner cortex being rich in woven bone with dispersed longitudinal canals, while the outer cortex was parallel-fibred with rows of longitudinal cana…
First record of early Aptian Oceanic Anoxic Event 1a from the Paris Basin (France) - Climate signals on a terrigenous shelf
2021
Abstract In 2013, Andra (French National Radioactive Waste Management Agency) drilled boreholes to the south-east of the Paris Basin, to characterise Aptian and Albian clayey formations, including the ‘Argiles a Plicatules’ Formation dated as early Aptian. One of these boreholes intersected this formation with an excellent recovery allowing detailed biostratigraphy (ammonites), sedimentology, clay mineralogy, isotope geochemistry (δ13Corg) and Rock-Eval analyses to be performed. The base of the formation corresponds to transgressive dark-grey silty clays with iron oolites and plant debris indicating a coastal environment evolving up-section to upper offshore environments. Higher in the succ…
Age determination of the Arcillas de Morella Formation (Maestrazgo Basin, Spain)
2014
New palynological analysis of the Arcillas de Morella Formation provides data for determinations of age of the Lower Cretaceous strata in the Ermita Sant Antoni de la Vespa section located in the d...
Dematiaceous Hyphomycetes from Pantelleria Mediterranean maquis litter. Third contribution
2010
In the third contribution to the study of Pantelleria meditteranean maquis litter, thirteen species of Dematiaceous Hyphomycetes are found and described. Three of them are proposed as new species: Anungitea pseudoramosa, A. sibaensis and Subulispora insularis.
An unusual conchorhynch from the upper Maastrichtian of the southeast Netherlands and the distinction between nautiloid and ammonoid conchorhynchs (M…
2022
Abstract A single, atypical conchorhynch (calcitic tip of a cephalopod lower jaw), recovered from the uppermost Meerssen Member (Maastricht Formation, upper Maastrichtian) at the former ENCI-HeidelbergCement Group quarry, south of Maastricht, is described as a new parataxon, Conchorhynchus illustris sp. nov. The specimen can be differentiated from all previous conchorhynch records on account of its large size, elongated shape and, in particular, of the structure of its apical part which is smooth and forwardly elongated. During the Late Cretaceous, conchorhynchs formed part of the jaw apparatus of nautilids and of two ammonoid suborders, Phylloceratina and Lytoceratina. Since conchorhynchs …