Search results for " Geologia"
showing 10 items of 570 documents
Gis-analysis to assess landslide susceptibility in a fluvial basin of NW Sicily (Italy).
2008
Abstract Landslide hazard assessment, effected by means of geostatistical methods, is based on the analysis of the relationships between landslides and the spatial distributions of some instability factors. Frequently such analyses are based on landslide inventories in which each record represents the entire unstable area and is managed as a single instability landform. In this research, landslide susceptibility is evaluated through the study of a variety of instability landforms: landslides, scarps and areas uphill from crown . The instability factors selected were: bedrock lithology, steepness, topographic wetness index and stream power index. The instability landform densities computed f…
New biostratigraphic data from the Ladinian pelagic limestones of Pizzo di Sant’Otiero - Madonie Mountains, Sicily
2014
New biostratigraphic data, based on conodont investigations, were collected from the Ladinian limestones recently described at Sant’Otiero, a locality near the Village of Petralia Sottana in the Madonie Mountains (Central-Northern Sicily). At this locality a new calcareous succession lying at the base of a major tectonic unit of the Maghrebian chain is described. This succession consists of a lower massive part formed by a carbonate megabreccia, the elements of which are shallow water extraclasts with dasycladalean algae (Diplopora annulatissima Pia), benthic foraminifers, “Tubiphytes” and problematic organisms commonly described from Anisian carbonate platforms. Upward a well-bedded succes…
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…
Benthic foraminifera as indicators of relative sea-level fluctuations: Paleoenvironmental and paleoclimatic reconstruction of a Holocene marine succe…
2017
This study presents the results of an integrated stratigraphic analysis conducted on a marine gravity core (MSK-12 C4) recovered from the outer continental shelf (82 mwater depth) of western Calabria, ~2.6 km, NE of Capo Vaticano (Eastern Tyrrhenian margin). The gravity core MSK-12 C4 recovered a stratigraphic succession of 4.18 m beneath the seafloor representing the last ~11.1 ka. Sedimentological analysis, micropaleontological quantitative analysis on benthic foraminiferal assemblages, tephrostratigraphy, sequence stratigraphic analysis of high resolution reflection seismic data recorded in the core site area and AMS 14C absolute age determinations allowed reconstructing the marine recor…
Sea-level changes during the last 41,000 years in the outer shelf of the southern Tyrrhenian Sea: Evidence from benthic foraminifera and seismostrati…
2011
Abstract An integrated high resolution study based both on a seismostratigraphic approach and on a sedimentary core (VIB 10), collected in the outer shelf (127 m depth) from the southern Tyrrhenian Sea (Gulf of Termini, Sicily), provides new data about climatic, eustatic and paleoenvironmental changes during the last ∼41,000 years. The results based on the interpretation of a seismic profile, on benthic foraminifera assemblages and on δ18O records, allowed recognition of two drastic sea-level falls during the Last Glacial Maximum (LGM) and the Younger Dryas (YD). The short deglacial event, between LGM and YD, known as Bolling/Allerod, played an important role in the sea-level rise that prod…
Growth and geomorphic evolution of the Ustica volcanic complex at the Africa-Europe plate margin (Tyrrhenian Sea)
2021
18 pages, 13 figures, 1 table
Magmatism Along Lateral Slab Edges: Insights From the Diamante-Enotrio-Ovidio Volcanic-Intrusive Complex (Southern Tyrrhenian Sea)
2019
Volcanic‐intrusive complexes often formed along lateral slab edges as a consequence of subduction‐induced mantle flow. We investigate this process in the southern Tyrrhenian Sea by integrating multibeam bathymetry, seismic‐reflection data, regional magnetic anomalies data, and seismological data. The interpretation of the data highlights the presence of magmatic intrusions that locally reach the seafloor forming volcanic edifices. Chimneys, lava flows, and laccoliths are observed beneath and surrounding the volcanoes. The emplacement and cooling of the magma occurred during the Brunhes Chron. The volcanoes are not active even if the hydrothermal activity occurs. The volcanic‐intrusive compl…
The southern Tyrrhenian Sea margin an example of lithospheric scale strike-slip duplex
2010
The southern Tyrrhenian Sea margin is dominated by deformations whose kinematics are relatively poorly constrained, and different models have been proposed to account for its recent evolution. Analysis of new structural and space geodesy data, combined with available geophysical information, reveal a deformation field characterised by subhorizontal NW-SE directed shortening and SW-NE directed extension. The main recognised regional-scale structure comprises E-W trending fault zones, namely the Ustica-Eolie Line and the Mt. Kumeta-Alcantara Line, connected by the NW-SE trending Marettimo, Trapani, San Vito, Palermo, Gratteri-Mt. Mufara and Eolie faults. This fault network displays a remarkab…