Search results for "Jura"

Biotic recovery after the end-Triassic extinction event: Evidence from marine bivalves of the Neuquén Basin, Argentina

2017

We analyze the Late Triassic extinction and Early Jurassic recovery of bivalve faunas within marine environments in the Atuel River area of the Neuquén Basin, Argentina. Data were collected from a hundred samples with invertebrates in a well-exposed uppermost Triassic to lower Jurassic section in the Neuquén Basin (southern Mendoza Province, Argentina) and allow a high-resolution reconstruction of the local diversity dynamics. The nearly continuous presence of marine stenohaline major taxa such as cnidarians, rhynchonelliform brachiopods, echinoderms and cephalopods indicates normal salinity throughout. All bivalve species were identified, and each occurrence was recorded in meters above th…

Deep-rooted “thick skinned” model for the High Atlas Mountains (Morocco). Implications for the structural inheritance of the southern Tethys passive …

2006

A re-interpretation of the deep structure of the High Atlas is presented through integration of geophysical and geological data, highlighting the architectural significance of the southern Tethys palaeomargin. Previous crustal models suggest the occurrence of a flat intra-crustal detachment at a depth of � 20 km, a zone where surface thrusts merge and below which the lower High Atlas crust appears continuous. However, within this study seismic refraction data, electrical resistivity surveys and gravity modelling all appear to detect a jump in crustal thickness between the High Atlas and the northern plains. We interpret these data as penetration by thrusts within the ‘‘South-Atlasic fault’’…

Jurassic architectural model of the southern Tethys Palaeomargin as deduced from Cenozoic geodynamic evolution of the High Atlas Mountains of Morocco.

2006

40 pages; International audience

Middle and Upper Jurassic record in the Western Sicily successions

2015

Middle-Upper Jurassic successions cropping out in western Sicily have been the subject of detailed sedimentological, stratigraphic and palaeontological studies over the last 15 years based on the analysis of ammonite associations. Studies are preferentially focused on the Bathonian-Tithonian chronostratigraphic interval. Some studied successions represent the type-locality of many ammonite species defined by G.G. Gemmellaro, while others have been known only in Sicilian geological literature. The examined sequences were sedimented in different depositional environments (moderately deep external carbonate platform) called Domains, more precisely, the Trapanese and Saccense Domains (TP, Trapa…

Upper Triassic-Jurassic carbonate Platform-Pelagic Plateau Systems From Western Sicily

2009

Triassic/Jurassic carbonates from Western Sicily: their facies and implications for the end-Triassic biotic crisis.

2008

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…

Geological framework of Sicily and the Triassic-Jurassic stratigraphic evolution

2010

Sedimentology and biostratigraphy of a peritidal succession across the Triassic/Jurassic boundary: Monte Sparagio, north western Sicily

2016

A 490 m thick section of shallowing upward peritidal cycles spanning the Triassic-Jurassic boundary is exposed along the northern slope of Mount Sparagio in the San Vito Lo Capo Peninsula (Western Sicily). A detailed microfacies analysis allowed defining the aspects of cyclic sedimentation of this section and especially the stratigraphic occurrence patterns of benthic foraminifera and algae across the T/J boundary. The lower part of cycles commonly shows medium to low energy subtidal facies, typical of the inner lagoon of the carbonate platform. Subtidal facies such as coral bafflestone in some cycles suggest more open lagoonal conditions (patch reefs), while some higher energy layers such …

Correlation between extinction pattern and δ13C fluctuations across the Triassic Jurassic boundary in shallow water settings: a proxy for the present…

2018

With the aim to assess the possible influence of the carbon variations on the benthic communities across the Triassic Jurassic boundary we have carried out sedimentological, biostratigraphic and stable isotope studies on an about 220 m thick peritidal section cropping out in Northwestern Sicily. The subtidal facies of the lower and middle part of this succession show the common occurrence of large and thick megalodontids and a benthic foraminiferal assemblage with Triasina hantkeni and Aulotuortids that supports a Rhaetian age. In the lower part of the succession, a significative biotic perturbation is evidenced by a sudden reduction of the size, shell thickness and abundance of the large m…