Giuseppe Zarcone

A regional‐scale discontinuity in western Sicily revealed by a multidisciplinary approach: A new piece for understanding the geodynamic puzzle of the southern Mediterranean

The results of an integrated stratigraphic, structural, geophysical, and geochemical study reveal the presence of a crustal discontinuity in western Sicily that, at present, runs roughly N-S along a band from San Vito Lo Capo to Sciacca (SVCS). The boundary between the two zones of this discontinuity is nearly orthogonal to the main thrust propagation of the Sicilian thrust-and-fold belt. The different Permian to Tertiary sedimentary evolution recorded by the two zones appears related to this discontinuity, with thick carbonate platforms in the western sector facing deep-water successions in the eastern one. The presence of Upper Triassic reefs, huge megabreccias bodies, and widespread submarine volcanisms along the transition zone suggest the presence of a long lasting weakness zone. This zone has been reactivated episodically as transpressional and/or transtensional faults in relation to the different geodynamic stress acting in central Mediterranean area in different epochs. We speculate that this transition zone has represented a segment of the passive margin of the Ionian Tethys. During the Maghrebian convergence a different style of deformation has affected the two sectors floored by different sedimentary multilayers. The orthogonal-to-oblique differential convergence between the two sectors has resulted in right-lateral transpressional motions, leading to oblique thrusting of deep-water-derived thrusts onto platform-derived thrusts associated with clockwise rotations. The oblique convergence is still ongoing as demonstrated by the seismicity of the area, by the geothermal field with high mantle-derived helium fluxes and by the GPS measurements collected by different authors.

A multidisciplinary approach to reveal the Sicily Climate and Environment over the last 20 000 years

We present a thorough review of the knowledge on the climate and environment in Sicily over the last 20 000 years, taking into account results of several studies carried using terrestrial and marine records. We obtain a coherent framework of the most important changes succeeded in the island, even if some points need further investigation.All the reconstructions of surface temperatures of the seas and the air surrounding Sicily point out severe climatic conditions during the last glacial period. The steppe- and semisteppe-like vegetation pattern testifies, together with additional evidence from geochemical data of lacustrine evidence, markedly arid conditions. Fi-nally, significant episodes of sea level drop connected Sicily to the Italian Peninsula and favoured the dispersion of faunal elements from southern Italy.The transition between the last glacial and the Holocene was not characterized by a gradual warming but was punctuated by two abrupt suborbital climatic fluctuations: Bølling-Allerød (warm) and Younger Dryas (cold), as recognized in the sediments recovered close to the northern and southern coast of Sicily. A denser arboreal cover is possibly indicated by the occurrence of dormouse and Arvicola remains.Finally the sensitivity of Sicily to climate perturbations is demonstrated by the occurrence of repeated subtle climatic anomalies during the Holocene, including the Little Ice Age, also known from historical chronicles. Forests, woods and Mediterranean maquis developed in the early-middle Holocene. Thereafter was a general decline of arboreal vegetation, following a general aridification trend that seems to be a common feature in southern Europe and North Africa. Science Greek colonization (7th century before Christ), the landscape was intensively modelled for agriculture and breeding, leading to a significant loss of vegetation cover.

La Piattaforma Carbonatica Panormide: un caso anomalo nell'evoluzione dei bacini della Tetide giurassica

Negli ultimi anni sono state proposte diverse ricostruzioni paleogeografiche dell’area Centro Mediterranea durante il Mesozoico. La Piattaforma Carbonatica Panormide (PCPA) viene collocata tra la Tetide Alpina e la Tetide Ionica, in un’area geodinamicamente molto complessa. Recenti studi hanno documentato la presenza di superfici di discontinuita che caratterizzano l’evoluzione stratigrafica della PCPA rispetto alle adiacenti Piattaforme Carbonatiche Siciliane. La presenza di superfici di discontinuita negli intervalli Retico-Hettangiano e Giurassico Medio-Oxfordiano vengono messe in relazione, attraverso il confronto della storia della subsidenza tra le Piattaforme Carbonatiche, con gli stadi evolutivi della Tetide Alpina

LANDFILL SITE SELECTION FOR MUNICIPAL SOLID WASTE BY USING AHP METHOD IN GIS ENVIRONMENT: WASTE MANAGEMENT DECISION-SUPPORT IN SICILY (ITALY)

The goal of this work was to test a methodology, based on multi-criteria analysis and geographic information systems, aimed at identifying areas potentially suitable to host landfills for Municipal Solid Waste (MSW). Although the above-mentioned methodology was applied to three different areas (Western, South-western and Eastern) of Sicily, in this paper, we present the results of the western sector. The first step consisted of the division of the study area in excluded and potentially suitable sites, on the basis of the Italian current legislation. The suitable sites were subsequently re-evaluated based on additional criteria in order to choose the most suitable ones. This second step consisted of a multi-criteria analysis based on a scores and weights system. The Analytic Hierarchy Process (AHP) was applied to estimate the relative importance weights of the evaluation criteria. The suitability for landfill siting was finally evaluated with the aid of a simple additive weighting method. The resulting land suitability was reported on a scale of 0 to 10, respectively, from the least suitable to the most suitable sites. In order to reveal the most suitable sites, to provide a ranking and, consequently, a quick selection, a spatial clustering process was carried out. In relation to the data obtained, several suitable areas to host sites for MSW landfill in Western Sicily were identified. The application of multi-criteria analysis, together with the use of geographic information systems, provided a powerful tool for the identification of the most suitable site among those identified.