Building stone employed in the historical monuments of Eastern Sicily (Italy). An example: the ancient city centre of Catania     

Rosalda Punturo  Laura G. Russo  Antonino Lo Giudice  Paolo Mazzoleni  Antonino Pezzino 《Environmental Geology》2006,50(2):156-169

An archaeometric study of the stone materials employed in the Late Baroque historical monuments of the ancient city centre of Catania was carried out. Lithological maps of a selection of monuments, transferred to a digital format, revealed that the stone materials are both magmatic and sedimentary rocks, the colours of which are matched in a peculiar type of bichromy. Particular attention focused on sedimentary rocks, which consist of various types of limestone quarried near the city of Syracuse (Hyblean Plateau, south-eastern Sicily). Carbonate rocks were characterised in terms of mineralogy, petrography and geochemistry, by studying rock samples from both monuments and historical extraction sites. Results showed that, although only one name was historically attributed to the above lithotypes (i.e. “Pietra di Siracusa‘’), they were quarried from many locations and, as they belong to various geological formations, they therefore exhibit great variety. In order to examine the durability of Hyblean limestones employed in works of cultural heritage interest, salt crystallisation tests were carried out according to standard procedure norms (UNI EN 12370 (1999) Determination of resistance to crystallisation of salts, 6p). Results are consistent with the forms of deterioration observed in the monuments, and highlight the close relationship between textural characteristics and damage. Our purpose is to provide a basic tool, which may be useful both for conserving monuments of cultural heritage and for their restoration.  相似文献   

The 1908 Messina Strait earthquake in the regional geostructural framework     

A. Bottari  E. Carapezza  M. Carapezza  P. Carveni  F. Cefali  E. Lo Giudice  C. Pandolfo 《Journal of Geodynamics》1986,5(3-4)

The original historical data from surveys of the damage caused by the great Calabro-Messina earthquake are analyzed in detail. This analysis allows the macroseismic field to be reconstructed in a way more compatible with a modern scientific viewpoint, laying maximum importance on indications supplied by the MSK intensity scale.A geometrical model of the focus has been worked out, adopting in part the schemes proposed by Shebalin. This model, together with the macroseismic field parameters, is correlated with the regional structural parameters. Finally, in their quest for better knowledge of the regional seismotectonic pattern, the authors search for evidence of geodynamic consistency by analyzing a spatio-temporal period in the neighborhood of the event.  相似文献   

On the sun's pole-equator flux differences     

Gaetano Belvedere  Lucio Paternò 《Solar physics》1977,52(1):191-198

We study the possibility that large flux differences between the poles and the equator at the bottom of the solar convective zone are compatible with the small differences observed at the surface. The consequences of increasing the depth of the convective zone due to overshooting are explored.A Boussinesq model is used for the convective zone and we assume that the interaction of the global convection with rotation is modelled through a convective flux coefficient whose perturbed part is proportional to the local Taylor number. The numerical integration of the equations of motion and energy shows that coexistence between large pole-equator flux differences at the bottom and small ones at the surface is possible if the solar convective zone extends to a depth of 0.4R . The angular velocity distribution inside the convective zone is in agreement with the -dynamo theories of the solar cycle.  相似文献   

New clues on the contribution of Earth’s volcanism to the global mercury cycle     

E. Bagnato  A. Aiuppa  F. Parello  P. Allard  H. Shinohara  M. Liuzzo  G. Giudice 《Bulletin of Volcanology》2011,73(5):497-510

Active volcanoes are thought to be important contributors to the atmospheric mercury (Hg) budget, and this chemical element is one of the most harmful atmospheric pollutants, owing to its high toxicity and long residence time in ecosystems. There is, however, considerable uncertainty over the magnitude of the global volcanic Hg flux, since the existing data on volcanogenic Hg emissions are sparse and often ambiguous. In an attempt to extend the currently limited dataset on volcanogenic Hg emissions, we summarize the results of Hg flux measurements at seven active open-conduit volcanoes; Stromboli, Asama, Miyakejima, Montserrat, Ambrym, Yasur, and Nyiragongo.. Data from the dome-building Soufriere Hills volcano are also reported. Using our determined mercury to SO₂ mass ratios in tandem with the simultaneously-determined SO₂ emission rates, we estimate that the 7 volcanoes have Hg emission rates ranging from 0.2 to 18 t yr^-1 (corresponding to a total Hg flux of ~41 t·yr^-1). Based on our dataset and previous work, we propose that a Hg/SO₂ plume ratio ~10^-5 is best-representative of gas emissions from quiescent degassing volcanoes. Using this ratio, we infer a global volcanic Hg flux from persistent degassing of ~95 t·yr^-1 .  相似文献   

Geomorphology and GIS analysis for mapping gully erosion susceptibility in the Turbolo stream catchment (Northern Calabria, Italy)   总被引：8，自引：0，他引：8  

Massimo Conforti  Pietro P. C. Aucelli  Gaetano Robustelli  Fabio Scarciglia 《Natural Hazards》2011,56(3):881-898

This work summarizes the results of a geomorphological and bivariate statistical approach to gully erosion susceptibility mapping in the Turbolo stream catchment (northern Calabria, Italy). An inventory map of gully erosion landforms of the area has been obtained by detailed field survey and air photograph interpretation. Lithology, land use, slope, aspect, plan curvature, stream power index, topographical wetness index and length-slope factor were assumed as gully erosion predisposing factors. In order to estimate and validate gully erosion susceptibility, the mapped gully areas were divided in two groups using a random partitions strategy. One group (training set) was used to prepare the susceptibility map, using a bivariate statistical analysis (Information Value method) in GIS environment, while the second group (validation set) to validate the susceptibility map, using the success and prediction rate curves. The validation results showed satisfactory agreement between the susceptibility map and the existing data on gully areas locations; therefore, over 88% of the gullies of the validation set are correctly classified falling in high and very high susceptibility areas. The susceptibility map, produced using a methodology that is easy to apply and to update, represents a useful tool for sustainable planning, conservation and protection of land from gully processes. Therefore, this methodology can be used to assess gully erosion susceptibility in other areas of Calabria, as well as in other regions, especially in the Mediterranean area, that have similar morphoclimatic features and sensitivity to concentrated erosion.  相似文献   

Thermodynamic modeling assisted by multivariate statistical image analysis as a tool for unraveling metamorphic P-T-d evolution: an example from ilmenite-garnet-bearing metapelite of the Peloritani Mountains, Southern Italy     

Patrizia Fiannacca  Deborah Lo Pò  Gaetano Ortolano  Rosolino Cirrincione  Antonino Pezzino 《Mineralogy and Petrology》2012,106(3-4):151-171

An ilmenite-garnet-bearing schist from the medium-grade metapelite complex of the Mandanici Unit in the Peloritani Mountains has been investigated to constrain the P-T conditions attained in this sector of the southern European Hercynian chain. Microprobe investigations assisted by statistical handling of X-ray maps via principal component analysis allowed us to better elucidate the porphyroblast-matrix relationships, the geometry of the elemental distribution in garnet porphyroblasts and the average volume percentage of the reactant garnet during retrograde metamorphic evolution. Selected microprobe data were then used to constrain, by means of P-T pseudosections, the main P-T stages of the metamorphic evolution, using the XRF bulk-rock chemistry as the equilibrium chemical composition for the prograde and peak stages and an effective bulk-rock composition for the retrograde one. Peak metamorphic P-T estimates (~530?°C; 0.9?GPa) are consistent with a Hercynian crustal thickening stage at middle-lower crustal conditions, while subsequent evolution, constrained at 420–460?°C; 0.30–0.60?GPa, depicts a retrograde clockwise P-T trajectory linked to exhumation under likely extensional shearing conditions. The results obtained in this paper lead to envisage a new scenario for the crustal evolution of the Peloritani Mountains and stimulate a revision of previous interpretations in the light of the new investigation techniques.  相似文献   

Foreword to the special issue: the European project UPStrat-MAFA     

Ragnar Sigbjörnsson  Gaetano Zonno  Carlos Sousa Oliveira 《Bulletin of Earthquake Engineering》2016,14(7):1773-1776

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Defining structural robustness under seismic and simultaneous actions: an application to precast RC buildings     

Domenico Asprone  Raffaele De Risi  Gaetano Manfredi 《Bulletin of Earthquake Engineering》2016,14(2):485-499

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Alluvial terraces on the Ionian coast of northern Calabria, southern Italy: Implications for tectonic and sea level controls     

Gaetano Robustelli  Federica Luc  Fabio Corbi  Teresa Pelle  Francesco Dramis  Giandomenico Fubelli  Fabio Scarciglia  Francesco Muto  Domenico Cugliari 《Geomorphology》2009,106(3-4):165-179

In this paper we present the results of an integrated geomorphological, pedological and stratigraphical study carried out along the Ionian coast of northern Calabria (southern Italy). This area is characterised by the occurrence of five orders of alluvial terraces that are striking features of the landscape, where large and steep catchments debouch from the mountain front to the hilly coastal belt.Field investigations indicate that the deposits of all five terraces are suggestive of shallow gravel-bed braided streams.On the basis of the age of the Pleistocene substratum and morphostratigraphic correlation with marine terraces cropping out in the nearby areas, each order has been associated to specific marine oxygen isotope stages.Consequently, we focused on the interplay of allocyclic factors influencing stream aggradation/degradation. Soil features and other climatic proxies suggest that climate didn't play an important role with respect to tectonic and base-level changes in controlling fluvial dynamics.In particular, we recognised that during the middle Pleistocene the study area experienced a period of subaerial landscape modelling, as suggested by the thick and complex alluvial sequence of the highest terrace (T1). The onset of regional uplift marks a change in the geomorphic scenario, with tectonic and eustatically driven changes in base-level working together in causing switches in fluvial aggradational/erosional phases (T2–T5 terraces). Because of the uplift, river dissection occurred during phases of sea level fall, whereas aggradation phases occurred during periods of climate amelioration (sea level rise) just before highstands were attained.As a consequence, the stepped terraces in the study area reflect the interplay between tectonics (uplift) and sea level changes, in which terraces define episodes of relative sea level fall during the late Quaternary.  相似文献   

Combined statistical and petrological analysis of provenance and diagenetic history of mudrocks: Application to Alpine Tethydes shales (Sicily,Italy)     

Giovanni Barbera  Antonino Lo Giudice  Paolo Mazzoleni  Anna Pappalardo 《Sedimentary Geology》2009,213(1-2):27-40

Mineralogical (X-ray diffraction) and geochemical (X-ray fluorescence) compositional data of Alpine Tethyde mudrocks from Sicily were used to unravel the interplay of provenance and diagenesis by means of multivariate statistical methods (PCA, discriminant function analysis) designed for non-negative constant-sum data. The Sicilian Alpine Tethydes comprise Cretaceous–Eocene scaly shales (Mt. Soro and Upper Scagliose Shales Units), Eocene–Oligocene variegated shales (Troina and Nicosia Units), and Miocene Numidian shales (Nicosia Unit). The use of biplots of clr-transformed variables allows discrimination of two different groups of shales. High CIA values reveal a strongly weathered source area especially for the Numidian shales. The analyses of mixed-layered clay minerals indicate that the behaviour of K2O and geochemical affine elements is controlled by the diagenetic grade, which increases from south-west to north-east in response to tectonic loading. Ratios of selected elements (Zr, Y, La, Nb, Ti, Co, Cr, Ni), considered essentially unchanged with respect to the source rocks, are similar in the scaly and variegated shales, and resemble the Variscan Peloritani metamorphic basement. In contrast, the distinct geochemical signature of the Numidian shales reveals a source similar to the average cratonic sandstone, suggesting derivation from external sources located in the foreland. Multivariate discriminant analysis performed on selected trace elements confirms the previous suggestions.  相似文献