32 research outputs found

    Ricostruzione geologica tridimensionale della stratigrafia tardo-quaternaria nel sottosuolo di Ferrara

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    This work is aimed at the reconstruction of the upper Quaternary depositional architecture, below the urban area of Ferrara, in northern Italy. The study area is part of the lower alluvial plain of the Po and Reno rivers and is therefore dominate by fluvial channel sands, levee sands-silts, and interchannel depression mud. The research was focused on the reconstruction of a digital geological model of the sedimentary bodies buried in the first 35 m under the topographic surface. The study units accumulated through Holocene and late Pleistocene times. The research work is based on the analysis of a rich data set, derived from about 2,000 subsurface investigations, consisting of continuous coring, penetration tests (including CPTU and SCPTU), and water wells stratigraphy. The subsurface modelling was achieved through both the conceptual interpretation of surface and subsurface information and the computerized geostatistic interpolation of digitalized data. The digital interpolation overcame the large heterogeneity of the data set into a homogeneous statistical and conceptual framework, through the use of a time and economic efficient work protocol. The research work achieved the reconstruction of the environmental evolution of the area, from the last glacial maximum time up to the present. The large climatic and eustatic fluctuations of the Quaternary largely influenced the environmental evolution and sedimentary dynamics of the area. During the last sea-level lowstand, a large body of synglacial river sands accumulated into the research area, under middle alluvial plain conditions. During phases of the eustatic rising, a thick alluvial plain body aggraded in the southern portion of the study area, fed by Apennines derived rivers, whereas non depositional condition persisted on the northern structural high. The maximum transgression was matched with the widespread sedimentation of fresh water marsh muds. During the highstand times, sands accumulated into both the Po and Reno channels, and mud into the adjacent interfluvial depressions. The research work demonstrated the great role played by the compressive deformation of this portion of the seismic active Apennines Foredeep Basin in the shaping of the depositional architecture. The sedimentary successions accumulated onto the anticline crests are much thinner than those sedimented into the syncline areas. The stratigraphic interpretation of the subsurface data can improve the geotechnical and hydrogeological work and support an improved seismic danger mitigation of an area significantly affected by the May 2012 earthquakes

    Seasonal changes in dry matter yield from Karst pastures as influenced by morphoclimatic features

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    Pastures are strongly affected by local environmental variables in terms of their species richness, plant composition and herbage production. A multi-site monitoring study was conducted over three years to investigate the influence of morphoclimatic factors on the seasonal variations in dry matter (DM) yield from Karst pastures. Seven sites located on the Italian and Slovenian Karst regions were investigated that differed in terms of their geological and geomorphological features, as well as their soil types. At each site, the daily DM yield (kg ha-1 d-1) was determined using Corral-Fenlon method which permits to simulate herbage utilization from grazing herds. The morphoclimatic features were also analysed, with the aim to evaluate the link between seasonal DM yield and geomorphological and environmental factors. Generalized non-linear mixed models were built to study the observed seasonal variations in DM yield, using day of the year (DOY), growing degree days (GDD), and cumulative rainfall. Furthermore, environmental descriptors were included in the model in order to evaluate their effects on DM yield. The seasonal variations in yield showed two growing periods (spring and late summer), which were described by Gaussian curves. For the spring growing period, the model improved when the interaction between soil granulometry and growing degree days corresponding to the curve peak was taken into account. This confirms the influence of soil type and air temperature on pasture yield. For the late summer growing period, the interaction between the sand classes and the number of rainy days from the beginning of the period to the peak of the curve improved the model. The curve parameters of our models are correlated with environmental descriptors depending on the lithology and particle size of soils. The results are essential for the optimization of pasture management and avoiding degradation due to over- or under-grazing

    Liquefaction source layer for sand blows induced by the 2016 megathrust earthquake (Mw 7.8) in Ecuador (Boca de Briceño)

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    Numerous sand boils were generated in the alluvial plain at the mouth of the Rio BriceËœno valley (Ecuador) during the Mw 7.8 earthquake of April 2016. The area is characterized by a series of raised marine terraces formed as a consequence of the rapid tectonic coastal uplift during the Quaternary. Boreholes and geotechnical investigations were carried during post-earthquake surveys and for the purpose of mitigating the liquefaction effects. Five lithological units were identified at a site of embankment, which represented continental-marine and transitional sedimentation since the Last Glacial Maximum. A comprehensive study of texture and petrographic composition of sand boils has been performed and compared with sandy silts and silty sands of the buried sedimentary sequence in order to identify the source levels for liquefaction. The petrographic components, in particular the low content of bioclasts and carbonate fragments of the sand boils, allow to pinpoint a source layer made up of fine-grained silty sands located between 2 and 4.5 m depth (Unit 2) whereas the deeper marine sands, richer in bioclasts, were not involved. The results support the idea that earthquake-induced liquefaction phenomena are not restricted to clean sands and well-sorted deposits, but may affect sand layers with significant amount of nonplastic silt

    Ricostruzione geologica tridimensionale della stratigrafia tardo-quaternaria nel sottosuolo di Ferrara

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    This work is aimed at the reconstruction of the upper Quaternary depositional architecture, below the urban area of Ferrara, in northern Italy. The study area is part of the lower alluvial plain of the Po and Reno rivers and is therefore dominate by fluvial channel sands, levee sands-silts, and interchannel depression mud. The research was focused on the reconstruction of a digital geological model of the sedimentary bodies buried in the first 35 m under the topographic surface. The study units accumulated through Holocene and late Pleistocene times. The research work is based on the analysis of a rich data set, derived from about 2,000 subsurface investigations, consisting of continuous coring, penetration tests (including CPTU and SCPTU), and water wells stratigraphy. The subsurface modelling was achieved through both the conceptual interpretation of surface and subsurface information and the computerized geostatistic interpolation of digitalized data. The digital interpolation overcame the large heterogeneity of the data set into a homogeneous statistical and conceptual framework, through the use of a time and economic efficient work protocol. The research work achieved the reconstruction of the environmental evolution of the area, from the last glacial maximum time up to the present. The large climatic and eustatic fluctuations of the Quaternary largely influenced the environmental evolution and sedimentary dynamics of the area. During the last sea-level lowstand, a large body of synglacial river sands accumulated into the research area, under middle alluvial plain conditions. During phases of the eustatic rising, a thick alluvial plain body aggraded in the southern portion of the study area, fed by Apennines derived rivers, whereas non depositional condition persisted on the northern structural high. The maximum transgression was matched with the widespread sedimentation of fresh water marsh muds. During the highstand times, sands accumulated into both the Po and Reno channels, and mud into the adjacent interfluvial depressions. The research work demonstrated the great role played by the compressive deformation of this portion of the seismic active Apennines Foredeep Basin in the shaping of the depositional architecture. The sedimentary successions accumulated onto the anticline crests are much thinner than those sedimented into the syncline areas. The stratigraphic interpretation of the subsurface data can improve the geotechnical and hydrogeological work and support an improved seismic danger mitigation of an area significantly affected by the May 2012 earthquakes

    Ricostruzione geologica tridimensionale della stratigrafia tardo-quaternaria nel sottosuolo di Ferrara

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    Banca dati e Shapefiles ArcGIS delle Mappe della Microzonazione Sismica della totalità del territorio del Comune di Mirabello (Provincia di Ferrara)

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    Banca dati e Shapefiles in ambiente ArcGIS per la Carta Geologica, Carta Geologico-Tecnica, Carta della microzonazione del rischio sismico, potenziale di amplificazione sismica e rischio di liquefazione del territorio del Comune di Mirabello

    Banca Dati ArcGIS e Carte della Microzonazione Sismica del Comune di Sala Bolognese (Provincia di Bologna)

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    Data base e shapefiles Arcgis per la gestione di: Carta Geologica, Carta Geologico-Tecnica, Carta della microzonazione del rischio sismico, potenziale di amplificazione sismica e rischio di liquefazione del territorio del Comune di Sala Bolognese

    Banca dei dati geologici e geotecnici di sottosuolo del terriotrio del Comune di Mirabello

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    Banca dati in ambiente ArgGIS di tutti i dati disponibili al novembre 2014 sul sottosuolo del Comune di Mirabello (Provincia di Ferrara), comprendente sondaggi stratigrafici, prove penetrometriche, indagini geofisiche, informatizzati con criteri congruenti con quelli elaborati dal Serivizio Geologico, Sismico e dei Suoli della Regione Emilia-Romagna. Stato del dato: pubblico

    Report geologico per il sito della stazione sismica IT.SULP – Sulmona (AQ)

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    Istituto Nazionale di Geofisica e Vulcanologia (INGV)Submitted5T. Sismologia, geofisica e geologia per l'ingegneria sismic

    Banca dati geologici di sottosuolo del Comune di Ferrara

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    Banca dati in ambiente ArgGIS di tutti i dati disponibili al novembre 2014 sul sottosuolo del Comune di Ferrara, comprendente sondaggi stratigrafici, prove penetrometriche, indagini geofisiche, informatizzati con criteri congruenti con quelli elaborati dal Serivizio Geologico, Sismico e dei Suoli della Regione Emilia-Romagna. Stato del dato: pubblico
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