Early Miocene Antarctic glacial history: new insights from heavy mineral analysis from ANDRILL AND-2A drill core sediments     

Francesco Iacoviello  Giovanna Giorgetti  Isabella Turbanti Memmi  Sandra Passchier 《International Journal of Earth Sciences》2015,104(3):853-872

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The influence of petrography,mineralogy and chemistry on burnability and reactivity of quicklime produced in Twin Shaft Regenerative (TSR) kilns from Neoarchean limestone (Transvaal Supergroup,South Africa)     

Vola  Gabriele  Sarandrea  Luca  Della Porta  Giovanna  Cavallo  Alessandro  Jadoul  Flavio  Cruciani  Giuseppe 《Mineralogy and Petrology》2018,112(4):555-576

Mineralogy and Petrology - This study evaluates the influence of chemical, mineralogical and petrographic features of the Neoarchean limestone from the Ouplaas Mine (Griqualand West, South Africa)...  相似文献   

A Cretaceous carbonate delta drift in the Montagna della Maiella,Italy     

Gregor P. Eberli  Daniel Bernoulli  Adam Vecsei  Rizky Sekti  Mark Grasmueck  Thomas Lüdmann  Flavio S. Anselmetti  Maria Mutti  Giovanna Della Porta 《Sedimentology》2019,66(4):1266-1301

The Upper Cretaceous (Campanian–Maastrichtian) bioclastic wedge of the Orfento Formation in the Montagna della Maiella, Italy, is compared to newly discovered contourite drifts in the Maldives. Like the drift deposits in the Maldives, the Orfento Formation fills a channel and builds a Miocene delta‐shaped and mounded sedimentary body in the basin that is similar in size to the approximately 350 km² large coarse‐grained bioclastic Miocene delta drifts in the Maldives. The composition of the bioclastic wedge of the Orfento Formation is also exclusively bioclastic debris sourced from the shallow‐water areas and reworked clasts of the Orfento Formation itself. In the near mud‐free succession, age‐diagnostic fossils are sparse. The depositional textures vary from wackestone to float‐rudstone and breccia/conglomerates, but rocks with grainstone and rudstone textures are the most common facies. In the channel, lensoid convex‐upward breccias, cross‐cutting channelized beds and thick grainstone lobes with abundant scours indicate alternating erosion and deposition from a high‐energy current. In the basin, the mounded sedimentary body contains lobes with a divergent progradational geometry. The lobes are built by decametre thick composite megabeds consisting of sigmoidal clinoforms that typically have a channelized topset, a grainy foreset and a fine‐grained bottomset with abundant irregular angular clasts. Up to 30 m thick channels filled with intraformational breccias and coarse grainstones pinch out downslope between the megabeds. In the distal portion of the wedge, stacked grainstone beds with foresets and reworked intraclasts document continuous sediment reworking and migration. The bioclastic wedge of the Orfento Formation has been variously interpreted as a succession of sea‐level controlled slope deposits, a shoaling shoreface complex, or a carbonate tidal delta. Current‐controlled delta drifts in the Maldives, however, offer a new interpretation because of their similarity in architecture and composition. These similarities include: (i) a feeder channel opening into the basin; (ii) an excavation moat at the exit of the channel; (iii) an overall mounded geometry with an apex that is in shallower water depth than the source channel; (iv) progradation of stacked lobes; (v) channels that pinch out in a basinward direction; and (vi) smaller channelized intervals that are arranged in a radial pattern. As a result, the Upper Cretaceous (Campanian–Maastrichtian) bioclastic wedge of the Orfento Formation in the Montagna della Maiella, Italy, is here interpreted as a carbonate delta drift.  相似文献   

Sea gravity data in the Gulf of Naples. A contribution to delineating the structural pattern of the Phlegraean Volcanic District     

Giovanna Berrino  Gennaro Corrado  Umberto Riccardi 《Journal of Volcanology and Geothermal Research》2008

Bathymetric and gravity surveys were carried out from 1988 to 1994, in the Gulf of Naples (Southern Italy) to offshore extend the already existing Bouguer anomaly map. In order to improve the knowledge of the structural setting beneath the active Neapolitan volcanoes (Vesuvio, Campi Flegrei and Ischia), 862 stations were surveyed within the isobath of 400 m; at the same time, and about 2000 on-land gravity values were also collected. A new Bouguer anomaly map spanning the whole volcanic region was drawn from the final data set. Gravity anomalies were referred to the new absolute gravity station in Naples and computed according to 1980 Geodetic Reference System. Finally, a density value of 2200 kg/m³ was used in the computation of the Bouguer and terrain effects. We carried out the inversion of the gravity anomalies adopting a 2.5-D modelling along selected profiles crossing the investigated area. The interpretative models were constrained to data obtained from deep wells and other geophysical investigations.  相似文献   

Shakemaps uncertainties and their effects in the post-seismic actions for the 2012 Emilia (Italy) earthquakes     

Giovanna Cultrera  Licia Faenza  Carlo Meletti  Vera D’Amico  Alberto Michelini  Alessandro Amato 《Bulletin of Earthquake Engineering》2014,12(5):2147-2164

The May 20, 2012, Emilia Ml 5.9 earthquake was followed by some major aftershocks, well recorded by a large number of temporary stations that were installed to monitor the sequence. These additional recordings allowed us a thorough testing of the performance of the ShakeMap—a procedure designed to provide rapid information on the experienced ground motion. We found that the shakemaps for the May 29, 2012, Ml 5.8 earthquake, obtained using the permanent stations only, underestimate significantly the ground motion computed with the highest station density, especially for PSA at long periods (T \(=\) 3.0 s). This low-frequency motion is controlled primarily by the surface waves recorded in the Po plain: the observed site effects are likely not accounted properly by the site correction coefficient based on Vs30 as implemented in the ShakeMap procedure. The shakemaps determined during the seismic sequence have been included in an Italian national law that was passed after the 2012 earthquake. According to this law, the factories safety verifications were bound to the comparison between the shakemaps and the design acceleration required by the current national seismic code. We then decide to appraise the impact of the shakemap accuracy on the law provisions. Following the law recommendations, we have estimated the possible errors resulting from the incomplete evaluation of the ground shaking: our results show that, if the complete dataset were available at the time of the law approval, the number of buildings for which the safety check was required would have been significantly smaller.  相似文献   

Bayesian logistic regression for presence-only data     

Fabio Divino  Natalia Golini  Giovanna Jona Lasinio  Antti Penttinen 《Stochastic Environmental Research and Risk Assessment (SERRA)》2015,29(6):1721-1736

Presence-only data are referred to situations in which a censoring mechanism acts on a binary response which can be partially observed only with respect to one outcome, usually denoting the presence of an attribute of interest. A typical example is the recording of species presence in ecological surveys. In this work a Bayesian approach to the analysis of presence-only data based on a two levels scheme is presented. A probability law and a case-control design are combined to handle the double source of uncertainty: one due to censoring and the other one due to sampling. In the paper, through the use of a stratified sampling design with non-overlapping strata, a new formulation of the logistic model for presence-only data is proposed. In particular, the logistic regression with linear predictor is considered. Estimation is carried out with a new Markov Chain Monte Carlo algorithm with data augmentation, which does not require the a priori knowledge of the population prevalence. The performance of the new algorithm is validated by means of extensive simulation experiments using three scenarios and comparison with optimal benchmarks. An application to data existing in literature is reported in order to discuss the model behaviour in real world situations together with the results of an original study on termites occurrences data.  相似文献   

Joint deconvolution of building and downhole seismic recordings: an application to three test cases     

Bojana Petrovic  Stefano Parolai  Giovanna Pianese  S. Umit Dikmen  Bolot Moldobekov  Sagynbek Orunbaev  Roberto Paolucci 《Bulletin of Earthquake Engineering》2018,16(2):613-641

In this study, the joint deconvolution is applied to recordings of three test cases located in the cities of Bishkek, Kyrgyzstan, Istanbul, Turkey, and Mexico City, Mexico. Each test case consists of a building equipped with sensors and a nearby borehole installation in order to investigate different cases of coupling (impedance contrasts) between the building and the soil by analyzing the wave propagation through the building-soil-layers, and hence resolving the soil–structure-interactions. The three installations considering different dynamic characteristics of buildings and soil, and thus, different building-soil couplings, are investigated. The seismic input (i.e., the part of the wave field containing only the up-going waves after removing all down-going waves) and the part of the wave field that is associated with the waves radiated back from the building are separated by using the constrained deconvolution. The energy being radiated back from the building to the soil has been estimated for the three test cases. The values obtained show that even at great depths (and therefore distances), the amount of wave field radiated back by the building to the soil is significant (e.g., for the Bishkek case, at 145 m depth, 10% of the estimated real input energy is expected to be emitted back from the building; for Istanbul at 50 m depth, the value is also 10–15% of the estimated real input energy while for Mexico City at 45 m depth, it is 25–65% of the estimated real input energy). Such results confirm the active role of buildings in shaping the wave field.  相似文献   

FREEWAT,a Free and Open Source,GIS‐Integrated,Hydrological Modeling Platform          下载免费PDF全文

Laura Foglia  Iacopo Borsi  Steffen Mehl  Giovanna De Filippis  Massimiliano Cannata  Enric Vasquez‐Suñe  Rotman Criollo  Rudy Rossetto 《Ground water》2018,56(4):521-523

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Structural development of the Neogene Radicondoli–Volterra and adjoining hinterland basins in Western Tuscany (Northern Apennines,Italy)     

Giovanna Moratti  Marco Bonini 《Geological Journal》1998,33(4):223-241

This paper presents a geological–structural study of some Neogene hinterland basins of the Northern Apennines, located on the Tyrrhenian side of the chain. These basins developed on the already delineated thrust-fold belt from middle–late Tortonian times. Their evolution has been commonly referred to an extensional tectonic regime, related to the opening of the Tyrrhenian Sea. New data have allowed us to hypothesize a different tectonic evolution for the chain, where compressive tectonics plays a major role both in the external and in the hinterland area. In this frame, the hinterland area located west of a major outcropping crustal thrust (Mid-Tuscany Metamorphic Ridge) has been the target of a geological–structural investigation. The field mapping and structural analysis has been focused on the syntectonic sediments of the Radicondoli–Volterra basin as well as on adjoining minor basins. These basins commonly display a synclinal structure and are generally located in between basement culminations, probably corresponding to thrust anticlines. Sediments of the hinterland basins have been affected by compressive deformation and regional unconformities separate stratigraphic units due to the activity of basement thrusts. In the study area, normal faulting either accommodates the thrusting processes or post-dates compressive deformation. A chronology of faulting and a six-stage evolution of this area are presented, providing further insights for the Neogene tectonic evolution of the Northern Apennines. Copyright © 1998 John Wiley & Sons, Ltd.  相似文献   

Evaluation of liquefaction potential in an intermountain Quaternary lacustrine basin (Fucino basin,central Italy)     

Paolo Boncio  Sara Amoroso  Giovanna Vessia  Marco Francescone  Mauro Nardone  Paola Monaco  Daniela Famiani  Deborah Di Naccio  Alessia Mercuri  Maria Rosaria Manuel  Fabrizio Galadini  Giuliano Milana 《Bulletin of Earthquake Engineering》2018,16(1):91-111

In this study, we analyse the susceptibility to liquefaction of the Pozzone site, which is located on the northern side of the Fucino lacustrine basin in central Italy. In 1915, this region was struck by a M 7.0 earthquake, which produced widespread coseismic surface effects that were interpreted to be liquefaction-related. However, the interpretation of these phenomena at the Pozzone site is not straightforward. Furthermore, the site is characterized by an abundance of fine-grained sediments, which are not typically found in liquefiable soils. Therefore, in this study, we perform a number of detailed stratigraphic and geotechnical investigations (including continuous-coring borehole, CPTu, SDMT, SPT, and geotechnical laboratory tests) to better interpret these 1915 phenomena and to evaluate the liquefaction potential of a lacustrine environment dominated by fine-grained sedimentation. The upper 18.5 m of the stratigraphic succession comprises fine-grained sediments, including four strata of coarser sediments formed by interbedded layers of sand, silty sand and sandy silt. These strata, which are interpreted to represent the frontal lobes of an alluvial fan system within a lacustrine succession, are highly susceptible to liquefaction. We also find evidence of paleo-liquefaction, dated between 12.1–10.8 and 9.43–9.13 kyrs ago, occurring at depths of 2.1–2.3 m. These data, along with the aforementioned geotechnical analyses, indicate that this site would indeed be liquefiable in a 1915-like earthquake. Although we found a broad agreement among CPTu, DMT and shear wave velocity “simplified procedures” in detecting the liquefaction potential of the Pozzone soil, our results suggest that the use and comparison of different in situ techniques are highly recommended for reliable estimates of the cyclic liquefaction resistance in lacustrine sites characterized by high content of fine-grained soils. In geologic environments similar to the one analysed in this work, where it is difficult to detect liquefiable layers, one can identify sites that are susceptible to liquefaction only by using detailed stratigraphic reconstructions, in situ characterization, and laboratory analyses. This has implications for basic (Level 1) seismic microzonation mapping, which typically relies on the use of empirical evaluations based on geologic maps and pre-existing sub-surface data (i.e., age and type of deposits, prevailing grain size, with particular attention paid to clean sands, and depth of the water table).  相似文献