Search results for "Jura"

Paleokarstic overprint on the Panormide Carbonate Platform (Sicily)around the T/J boundary

2011

Schiavitù mediterranea. Corsari, rinnegati e santi di età moderna

2009

Durante l'età moderna l'area mediterranea è segnata dalla guerra da corsa e dalla pirateria, su cui prosperano intere città, cristiane e musulmane. Quanti cadono in mano corsara, ridotti in schiavitù, attendono di essere riscattati o scambiati e, in cattività danno origine a una intricata storia di abiure e conversioni -dall'islam al cristianesimo e viceversa. Il libro, basato su ricche e talvolta inesplorate fonti documentarie,mostra il forte coinvolgimento delle istituzioni laiche ed ecclesiastiche in questa nuova dimensione della contesa politica internazionale. L'efficacia nella evangelizzazione dei captivi e degli schiavi ha come risultato eclatante la canonizzazione di santi neri (com…

Sicilian Jurassic Phisiography and Geologic Realms

2004

Two tectono-sedimentary domains, which were deformed during the Neogene and evolved into two large structural sectors, characterize the Sicilian Jurassic: the Maghrebides and Peloritani. Africa margin sediments, passing downward to Triassic successions and perhaps originally to Paleozoic deposits, characterize the former. The latter belongs to the European "Calabrian Arc", where the Jurassic transgressively rests on a continental substrate (i.e. the crystalline Variscan basement). These domains are characterized by four sedimentary facies: shallow platform-derived limestones; condensed seamount-type red limestones; nodular limestones with ammonites; deep radiolarites and shales. These facie…

Phylogeny and origin of Jurassic irregular echinoids (Echinodermata: Echinoidea).

2006

27 pages; International audience; A phylogenetic analysis of Jurassic irregular echinoids is realized to explore the origin and early evolution of this important subset of echinoids. The phylogeny is based on 39 characters and considers data from apical system architecture, the corona including tuberculation and spines, Aristotle's lantern, and general test shape. Results corroborate the monophyly of Irregularia, and clarify the phylogenetic interrelationships existing between the main groups of irregular echinoids. Specializations of the Aristotle's lantern, spines, tubercles and phyllodes constitute the apomorphies for different taxa, as for the whole of Irregularia. The phylogenetic sign…

Synsedimentary-tectonic, soft-sediment deformation and volcanism in the rifted Tethyan margin from the Upper Triassic–Middle Jurassic deep-water carb…

2014

Abstract The Pizzo Lupo section (Sicanian Mts, central Sicily) is an Upper Triassic–Lower Jurassic condensed deep-water succession, where the relationships among synsedimentary tectonic, soft-sediment deformations, volcanism and lithological changes reflect the evolution of a rift-basin. The morphostructural setting of the studied basin appears as a gently dipping slope where a fault-delimited area (graben to halfgraben) was developed. The instability of the sea floor, related to the seismic shocks, was the cause of the gravity-driven deformational sedimentary structures (slumping, breccia channelized bodies). The partly stratified basaltic rocks, with disorganized and chaotic stratificatio…

Continental weathering and climatic changes inferred from clay mineralogy and paired carbon isotopes across the early to middle Toarcian in the Paris…

2014

Abstract Lower Toarcian strata (Lower Jurassic) have been extensively studied with a view to understanding the oceanographic, climatic and biological processes that drove the Earth's system into an Oceanic Anoxic Event (OAE). For this time period, the evolution of the European marine seaways is now relatively well constrained owing to multiple geochemical studies, but investigations regarding climatic trends in the continental realm remain sparse. In the present study, we test the clay mineralogy as a continental climate-sensitive proxy in the well-documented Sancerre core (southern Paris Basin). We compare variations in the kaolinite content with p CO 2 fluctuations (derived from paired ca…

Record of the end-Triassic crisis in south-western Sicily: palaeoenvironmental changes reflected by the carbonate facies architecture.

2009

Acidification processes in a peritidal carbonate succession across the Triassic/Jurassic boundary (Sicily)

2017

For the first time, a correlation between biostratigraphic events and δ13C curve was attempted along an UpperTriassic-Lower Jurassic peritidal limestone succession cropping out in westernmost Sicily. The peritidal carbonates are organized in shallowing upward cycles characterized by subtidal skeletal mudstone to grainstone, intertidal microbial mats and supratidal paleosoils. About 300 meters of this succession covering the Triassic-Jurassic interval were studied in details. On the base of the macro- and microfossil assemblages from the subtidal facies, four informal units have been recognized along the studied section. Unit R1 (at the base, 111 m thick) is dominated by large megalodonts, r…

Triassic/Jurassic boundary in peritidal carbonates from western Tethys

2016

A carbonate platform from the western margin of the Ionian Tethys has been investigated for biotic and geochemical variations across the Triassic/Jurassic boundary (TJB). The section of Mount Sparagio (north-western Sicily) exposes a peritidal succession of Rhaetian-Hettangian age with a thickness of about 400 m. The peritidal sediments are organized in metre-scale shallowing upward cycles formed by subtidal, intertidal and supratidal facies. Along the section, the subtidal facies vary from bioturbated mud/wackestones with rare mollusc shells, to Megalodont-rich wacke/packstones to, more rarely, coral bafflestones, most likely as response to variations of the accommodation space and water e…

Les ammonites de l'Hettangien, du Sinémurien et du Pliensbachien inférieur de la Dorsale de Grande Kabylie (Algérie).

2008

Dommergues, Jean-Louis, Cattaneo, Gérard, Aïte, Ramdane, Gélard, Jean-Pierre (2008): Les ammonites de l'Hettangien, du Sinémurien et du Pliensbachien inférieur de la Dorsale de Grande Kabylie (Algérie). Geodiversitas 30 (3): 539-576, DOI: http://doi.org/10.5281/zenodo.5378393