Search results for "Cretaceou"
showing 10 items of 184 documents
Formation of arcuate orogenic belts in the western Mediterranean region
2004
The Alpine orogen in the western Mediterranean region, consisting of the Rif-Betic belt and the Apennine-Calabrian-Maghrebide belt, is a classic example of an arcuate orogen. It contains fragments of Cretaceous to Oligocene high-pressure/low-temperature (HP/LT) rocks, which were exhumed and dispersed during post-Oligocene extensional deformation and are presently exposed in the soles of metamorphic core complexes. In this paper, we illustrate that the arcuate shape of the orogenic belt was attained during extensional destruction of the earlier HP/LT belt, driven by subduction rollback in a direction oblique or orthogonal to the direction of convergence. Since the Oligocene, sub-duction of M…
Rare earth element contents of Jurassic fish and reptile teeth and their potential relation to seawater composition (Anglo-Paris Basin, France and En…
2002
The rare earth element (REE) chemistry of Jurassic shelf seawater from western Europe (Anglo-Paris Basin) was investigated by analyzing the fish and reptile teeth deposited in shallow to deeper water (<200 m) environments. REE patterns in apatites are controlled by the host sediments. Vertebrate teeth sampled from the siliciclastic sediments (calcareous sandstones and shales) show flat shale-normalized REE patterns that reflect the dominant influence of the continental source from which the REE were derived. Carbonate deposits, protected from the clastic sources, contain fish and reptile teeth whose REE patterns reflect more accurately the REE composition of the overlying water column. The …
Stable isotope composition and rare earth element content of vertebrate remains from the Late Cretaceous of northern Spain (Laño): did the environmen…
2003
Abstract Oxygen and carbon isotope measurements have been performed on phosphatic remains from faunal associations (dinosaurs, crocodiles, turtles and fish) of the Late Cretaceous continental and marine sediments from northern Spain (Basque Country). The environmental meaning of the oxygen isotope record in fossil reptiles is discussed on the basis of known paleoecology, modern fauna analogs, and apatite chemistry (rare earth elements (REE), CO32− and PO43− contents). Fossil remains in sandstones and argillites from two localities (Urria and Cuezva) have low (down to 16‰) and scattered δ18O(PO4,CO3) and δ13C values with REE patterns characterized by strong middle REE enrichments. These geoc…
Mesozoic tectonics and volcanism of Tethyan rifted continental margins in western Sicily
2010
Abstract The paleotectonic and volcanic features of the Jurassic–Cretaceous carbonate successions, outcropping in central-western Sicily, allow us to restore the tectono-sedimentary evolution of a sector of the African continental margin. These successions consist of shallow-to-deep-water Mesozoic deposits that have formed in the carbonate platform-to- pelagic plateau depositional setting of the so-called Trapanese paleogeographic domain. Fieldwork, including structural analyses, has indicated the occurrence of lateral facies changes, resedimented materials, volcanic products (pillow lavas and tuffitic deposits), unconformity surfaces and paleofaults of different trends and age. These data,…
Sedimentary processes in the Carnot Formation (Central African Republic) related to the palaeogeographic framework of Central Africa
1999
Abstract The depositional environment, provenance and processes of emplacement of the detrital material of the Mesozoic Carnot Formation are defined, by bedding and sedimentological analysis of its main facies, and are reconstructed within the palaeogeographic framework of Central Africa. The clastic material was laid down between probably the Albian and the end of the Cretaceous, in a NNW-oriented braided stream fluvial system that drained into the Doba Trough (Chad) and probably also into the Touboro Basin (Cameroon). The material was derived from weathering of the underlying Devonian–Carboniferous Mambere Glacial Formation and of the Precambrian schist–quartzite complex located to the so…
Tetrapod trackways from Southern Egypt and Northern Sudan
1990
Abstract Tetrapod footprints were found in the Cretaceous strata-formerly called “Nuba(n) Sandstone” -of SE-Egypt and NW-Sudan. The trackways are here for the first time described in detail and in connection with their relative depositional environments. As the preservation of these footprints is poor, generic or specific names were not given. The name of the ichnogenus that comes closest to fitting the shape has been noted for each print. With respect to their paleoecological and stratigraphical significance, investigations of tetrapod footprints were necessarily concentrated on the continental strata of Egypt and Sudan. More discoveries will be welcome.
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…