Search results for "neotectonic"
showing 10 items of 23 documents
VARIABILITY OF DEPOSITIONAL SETTING ALONG THE NORTH-WESTERN SICILY CONTINENTAL SHELF (ITALY) DURING LATE QUATERNARY: EFFECTS OF SEA LEVEL CHANGES AND…
2012
The geological, geomorphological and sedimentological features of the north-western Sicily continental shelf are here illustrated with the aim to propose a geological model able to explain the Neogene-Quaternary evolution of the Sicilian continental margin in the context of the central Mediterranean region. Above the continental shelf and upper slope the sedimentary succession, showing along the different sectors of the margin considerably variable internal geometry and stratigraphic relationships with the underlying units, is interpreted as a IV order depositional sequence (Late Quaternary Depositional Sequence, LQDS) deposited during the last eustatic change (last 125 ky). The lower bound…
Neotectonic uplift and tilting of crustal blocks in Northern Sicily
2009
La Sicilia settentrionale è caratterizzata da un’intensa attività sismica che è espressione di deformazioni attive. In questo settore dell’Isola affiora il nucleo della catena neogenica delle Magrebidi occidentali, che è sottoposto ad intenso sollevamento durante il Plio-Pleistocene. Le deformazioni più recenti sono, in gran parte, rappresentate da sistemi di faglie estensionali e trascorrenti. Il tasso di sollevamento non è uniforme, così come suggerisce la differente elevazione dei depositi di questo periodo. Essi affiorano lungo il settore costiero settentrionale e la loro quota decresce complessivamente dall’estremità nord-est a quella nord-ovest della Sicilia. Le deformazioni più recen…
GENESIS AND GEOMORPHOLOGICAL EVOLUTION OF DEEP-SEATED GRAVITATIONAL SLOPE DEFORMATIONS: AN EXAMPLE OF DATING IN WESTERN SICILY
2010
The study area lies in the westernmost part of the Sicani Mountain range where a superposition of SE-trending, stacked, geological bodies crops out. this structure is the result of transpressive tectonic phases of Miocene and Lower Pliocene age. The neo-autochthon outcrops are made up of clay–marly deposits of the Middle–Upper Pliocene, and of calcarenites of Pleistocene age. The extensional Quaternary tectonic phases later dissected and dismembered the original structure, thus involving the calcarenites that show clear, mainly NE–SW oriented dislocations. Such calcarenites, which have a total thickness of about 80 metres, overlap the Belice marly-arenaceous formation. This determined favou…
Geothermal, hydro-structural and neo-tectonic features of the Sciacca basin
2012
LARGE LANDSLIDES AND NEOTECTONICS: A CASE STUDY IN WESTERN SICILY
2009
The study area is located in the western sector of the Sicanian Mounts where the superimposition, consequence of the Miocene and Lower Pliocene tectonic transpressive phases, of different geologic bodies, having vergence to the southern quadrants, can be observed. In this area, the neo-autochthonous deposits are given by marly-clayey sediments of middle-upper Pliocene, pertaining to the “Marnoso-arenacea” Formation of the Belice Valley, and by Pleistocene calcarenites. The recent extensional tectonic crisis (neotectonics) have further dissected and dismembered the original structural edifice, involving also the Pleistocene calcarenites, which show tectonic displacements mainly NE – SW orien…
STRATIGRAPHIC AND STRUCTURAL ANALYSIS OF A HIGH RESOLUTION SEISMIC SURVEY PERFORMED IN THE BAY OF AUGUSTA (SE SICILY)
2009
The Bay of Augusta is located along the NE margin of the Hyblean Plateau (SE Sicily). In this area a mostly bioclastic and terrigenous Quaternary succession outcrops. This area recorded a constant regional uplift rate of 50 kA. Two main groups of faults, referred to as the northwest and the southwest fault zones, are separated by a central zone where no evident fault planes have been imaged by seismic data. The faults in both groups strike from N30W to N52W and are also inferred to be steeply dipping. The faults pertaining to northwestern cluster show a very little offset, 50 kA. As concern the southeastern fault zone, results coming from radiocarbon age dating don’t have sufficient resolut…
Late Quaternary high uplift rates in northeastern Sicily: evidence from calcareous nannofossils and benthic and planktonic foraminifera
2011
The northeastern part of Sicily is characterized by intense seismic activity. Several systems of faults have been recognized in Pliocene and Pleistocene sediments in the area and, in fact, estimates of uplift rates are among the highest recorded in Sicily and south Italy. We examined calcareous nannofossil and benthic and planktonic foraminifera assemblages from pelitic sediments of the Contrada Zura section (Barcellona Pozzo di Gotto Basin, Furnari village, Messina). The occurrence of Emiliania huxleyi, a coccolithophore species which appeared in the oceanic record about 270,000 years ago, is witness to the uniqueness of this outcrop, while the planktonic/benthic foraminifera ratio indicat…
The Santa Ninfa Cave (Belice Valley): hydrogeochemical features and relationships with neotectonics
2020
The Santa Ninfa Cave (SNC) develops in an outcrop of Messinian gypsum, located in the heart of the zone struck by the 1968 seismic sequence of the Belice valley. It is composed of different levels of sub-horizontal galleries, the lowest of which is characterized by perennial flowing water, running along the water table. From the hydrogeological point of view, it configures as an open circuit, both inflowing and outflowing from/to neighboring aquifers. The geochemical facies of groundwater collected in the SNC is compatible with a meteoric recharge chemically interacting with evaporitic deposits. The most relevant geochemical feature is the mixing between a small tributary of sulfur water wi…
Holocene surface ruptures of the Rurrand Fault, Germany—insights from palaeoseismology, remote sensing and shallow geophysics
2016
The Lower Rhine Embayment in Central Europe hosts a rift system that has very low deformation rates. The faults in this area have slip rates of less than 0.1 mm/yr, which does not allow to investigate ongoing tectonic deformation with geodetic techniques, unless they cover very long time spans. Instrumental seismicity does only cover a small fraction of the very long earthquake recurrence intervals of several thousands of years. Paleoseismological studies are needed to constrain slip rates and the earthquake history of such faults. Destructive earthquakes are rare in the study area, but did occur in historic times. In 1755/56, a series of strong earthquakes caused significant destruction in…