Search results for "STRATIGRAPHY"
showing 10 items of 904 documents
Deux nouvelles traces de pas de Dinosaures du Trias supérieur de la bordure cévenole (la Grand-Combe, Sud-Est de la France)
2000
Resume Dans une formation sommitale a Argiles bariolees du Trias superieur francais, deux niveaux a traces depas inedites de Dinosaures ont ete decouverts. Elles se rapportent a l'association Otozoum/Grallator qui n'a jamais ete definie precisement en Europe. Sa position stratigraphique precise dans la serie triasique et la comparaison avec les associations ichnologiques des USA et d'Afrique du Sud, confirment l'âge Norien des niveaux a empreintes. Otozoum grandcombensis nov. ichnosp. correspond a des traces de pieds et de mains tetradactyles de meme taille, laissees par un animal bipede occasionnellement quadrupede. Il s'agissait probablement d'un, grand Prosauropode, d'une dizaine de m de…
Integrated stratigraphy of the Oxfordian global stratotype section and point (GSSP) candidate in the Subalpine Basin (SE France).
2014
44 pages; International audience; An integrated biostratigraphic approach, based on ammonites, calcareous nannofossils, dinoflagellates, combined with sedimentology, carbon-isotope and physical stratigraphy, is proposed for the Subalpine Basin (Thuoux and Saint-Pierre d'Argençon sections). Within the expanded marl deposits of the Terres Noires Fm., the Callovian-Oxfordian boundary is particularly well defined by ammonite taxa from different families (i.e. Cardioceratidae, Oppeliidae, Aspidoceratidae and Perisphinctidae), calcareous nannoplankton (first occurrence of large-sized Stephanolithion bigotii) and dinoflagellate cysts (first occurrence of Wanaea fimbriata). This precise biostratigr…
Geophysics and cultural heritage. A living field of research for Italian geophysicists
2015
If one reads the World Heritage List 2002/2003, (http:// whc.unesco.org/archive/WHList02-ENG.pdf), a datum comes out with evidence: 12 countries have 253 World Heritage Sites (WHS) and all the 125 member countries have 586 WHS. Within these 12 countries Italy has 35 WHS corresponding to about 6% of the whole, followed by Spain, 5.8%, France, 4.6%, and the tenth has less than 2% of WHS. Cultural heritage is one of the greatest riches of Italy. Europe, with China, is the land which has the most stratified history in the world, and Italy is likely to still have undiscovered settlements dating from the prehistoric age to the 18th century. Some areas are totally unexplored, others have been only…
Le gallerie VIII e IX: analisi strutturale. Le lucerne. Elementi del corredo personale
2007
The paper reports the results of the archaeological excavations carried out between 2000 and 2007 in the Early Christian cemetery of Villagrazia di Carini. Four periods were recognized in stratigraphy, from late antiquity to the mid-twentieth century. The sepulchral typologies are arcosolia, loculi, "tombe a mensa" and "formae". The cemetery was used by the Christian community of the ancient diocese of Hykkara from the 4th to at least the 7th century A.D.
Catacomba di Villagrazia di Carini. La galleria XII: indagini archeologiche e problemi della conservazione
2017
The archaeological research in the southeastern area of the Early Christian catacombs of Villagrazia di Carini has been ongoing since 2000 to the present, but in 2014 the structural problems occurred during the excavation of the cubicles X13 and X15 have showed that this sector of the cemetery was cut into a tuff stone bench less compact and durable than the rest of the catacomb. Similarly, the excavation in the corridor XII has provided new informations about the serious effects of the physico-chemical changes that occurred here, over the centuries, by the action of the environmental factors and the continued infiltrations of water from the above ground. The risk of a collapse that would m…
Comparative high-resolution chemostratigraphy of the Bonarelli Level from the reference Bottaccione section (Umbria-Marche Apennines) and from an equ…
2006
The Bonarelli Level (BL) from the upper Cenomanian portion of the reference Bottaccione section (central Italy) is characterized by the presence of black shales containing high TOC concentrations (up to 17%) and amounts of CaCO3 near to zero. In the absence of carbonate and, consequently, of relative carbon- and oxygen-isotopic data, the elemental geochemistry revealed to be a very useful tool to obtain information about the palaeoclimatic and palaeoceanographic evolution of the Tethys Ocean during the OAE2. Based on several geochemical proxies (Rb, V, Ni, Cr, Si, Ba), the BL is interpreted as a high-productivity event driven by increasingly warm and humid climatic conditions promoting an a…
Microbial origin for pedogenic micrite associated with a carbonate paleosol (Champagne, France)
1999
Abstract Micro-rods have been observed in indurated carbonate horizons (30 cm thick) that overlie a periglacial chalk formation, in contact with the present-day soil (Champagne, France). They are numerous in the upper part of the hardened layers. Variations in micro-rod morphologies are related to progressive biomineralization of organic matter, transforming purely organic rods into calcite. Mineralized rods undergo diagenesis and their arrangement evolves from a random mesh fabric to recrystallized micritic platelets to microsparite. Two types of organic micro-rods have been observed: bacilliform and thread-like bacteria. Mineralogically, micro-rods are low-magnesian calcite. Crystallograp…
Experimental organic matter maturation at 2kbar: Heat-up effect to low temperatures on vitrinite reflectance
2012
Abstract An experimental study was performed to evaluate the effect of heat-up to various low temperatures on vitrinite reflectance ( VR ) at 2 kbar employing the same previously used heat-up procedures, starting material and apparatus. Heat-up is the isobaric experimental procedure consisting of the increase in temperature of the laboratory vitrinite maturation from room temperature to the desired run temperature T end of heat-up at which the isobaric-isothermal maturation starts. Experiments employed cold-seal pressure vessels with classical heat-up devices and were carried out on wet (water added) xylite of swamp cypress. Confined system maturation experiments were conducted at 2 kbar an…
Formation and significance of black pebbles from the ota limestone (Upper Jurassic, Portugal)
1987
Black pebbles are a characteristic facies element of the Upper Jurassic Ota carbonate bank (Portugal). They occur both scattered or concentrated in two horizons, the upper of which is very widespread and may serve as a lithostratigraphic correlation level.
Mediterranean coccolith ecobiostratigraphy since the penultimate Glacial (the last 145,000years) and ecobioevent traceability
2015
The Mediterranean Sea is a miniature ocean ideal to test the response of marine ecosystems to amplified orbital and suborbital climate changes. Here we present coccolith data from a Sardinia Channel gravity core (Arcose C_33) analysed over the last 145,000 years, with a mean resolution of about 900 years. The study highlights that regional phytoplankton assemblages underwent significant modifications between the penultimate glacial and the last interglacial, as well as between the last glacial and the Holocene. The N ratio palaeoproductivity index suggests reduced productivity levels and the development of a deep nutricline during the last interglacial and the Holocene. Within the last glac…