Glacigenic features and Tertiary stratigraphy of the Magellan Strait (Southern Chile)

The seismostratigraphic and structural analysis of the whole length of the Magellan Strait, from the Atlantic to the Pacific entrance is for first time illustrated on the basis of multichannel seismic (MCS) profiles. The Strait crosses a geologically complex region that includes different morphotectonic provinces, and has been subdivided into three distinct segments, eastern (Atlantic), central, and western (Pacific), being each segment characterized by peculiar sedimentary and tectonic architectures. The MCS profiles shed light on the subsurface of the region in particular on the Quaternary and Tertiary features. In the foreland basin province, the MCS profiles imaged an almost undeformed structural and stratigraphic frame with very thick Cretaceous to Tertiary package. Seismic evidence of deformation of the foreland units occurs in the fold-and-thrust belt province. Along the Cordillera province, the Magallanes-Fagnano transform fault exerts an important morpho-tectonic control that strongly conditions its bathymetric profile. The seismic profiles also highlighted a number of depositional features linked to the up to 150 m thick sedimentary record of the glacial cycles. Whereas the eastern segment (outer foreland province) is devoid of significant glacial-related deposits, the central segment (inner foreland and fold-and thrust belt provinces) shows evidence of repeated advances and retreats of the Magellan glacier. An important moraine ridge complex, probably corresponding to the glacial advance "D"of Clapperton et al., has been seismically imaged in the central segment, as well as an older, large bank of ice distal sediments that have been interpreted as proglacial lake deposits, which show evident signs of repeated glacial erosions. Ice-contact features in the form of frontal moraine complexes made up of dipping foreset strata are present in the fjord-like, western segment of the Strait (Cordillera province), along with their related ice-proximal and ice-distal facies. Eventually, the occurrence of preglacial sediments tectonized by the Magallanes-Fagnano transform fault has been reported in the same segment. This fact, which is supported by small outcrops reported in the updated geologic map, if substantiated by further investigations (i.e. advanced seismic reprocessing, sea bottom samplings), would prove the relatively young age (Late Miocene?) of the Magallanes-Fagnano transform fault

Geomorphology and sedimentology of Porto Pino, SW Sardinia, Western Mediterranean

This paper presents a detailed (1:4000) geomorphological, sedimentological and ecological map of a Mediterranean microtidal wave-dominated beach system and adjacent inner shelf. This map is an innovative cartographic product that integrates a range of processes of present and past timeframes. It is part of a larger cartography on the coastal geomorphology of Sardinia (Italy) aiming to facilitate coastal management practices and future scientific research. The study area is located in SW Sardinia (Italy), and focuses on Porto Pino beach, an important tourist destination of semi-pristine nature, facing environmental pressures common to many coastal Mediterranean settings. In this context, the main human impact on coastal dune habitats is described and a full environmental characterization of the beach system is presented

The right to food and food diversity in the Italian Constitution

Il contributo analizza la tutela apprestata dalla Costituzione italiana al diritto al cibo che, pur non essendo espressamente menzionato, viene ricavato attraverso l'analisi di principi ed azioni sottese alla nostra Carta che ne riconoscono il valore: il principio lavorista, la lotta alla povertà, la retribuzione del lavoratore...

Validation of the italian version of the Cluster Headache Impact Questionnaire (CHIQ)

Background: The Cluster Headache Impact Questionnaire (CHIQ) is a specific and easy-to-use questionnaire to assess the current impact of cluster headache (CH). The aim of this study was to validate the Italian version of the CHIQ. Methods: We included patients diagnosed with episodic CH (eCH) or chronic CH (cCH) according to the ICHD-3 criteria and included in the “Italian Headache Registry” (RICe). The questionnaire was administered to patients through an electronic form in two sessions: at first visit for validation, and after 7 days for test-retest reliability. For internal consistency, Cronbach’s alpha was calculated. Convergent validity of the CHIQ with CH features and the results of questionnaires assessing anxiety, depression, stress, and quality of life was evaluated using Spearman’s correlation coefficient. Results: We included 181 patients subdivided in 96 patients with active eCH, 14 with cCH, and 71 with eCH in remission. The 110 patients with either active eCH or cCH were included in the validation cohort; only 24 patients with CH were characterized by a stable attack frequency after 7 days, and were included in the test-retest cohort. Internal consistency of the CHIQ was good with a Cronbach alpha value of 0.891. The CHIQ score showed a significant positive correlation with anxiety, depression, and stress scores, while showing a significant negative correlation with quality-of-life scale scores. Conclusion: Our data show the validity of the Italian version of the CHIQ, which represents a suitable tool for evaluating the social and psychological impact of CH in clinical practice and research

Acoustic facies and seabed features of the mixed carbonate-siliciclastic deposits of the last eustatic cycle in the La Maddalena Archipelago (North Sardinia, Italy)

A high-resolution Chirp acoustic survey of 250 nautical miles performed in the La Maddalena Archipelago provided a scheme of the acoustic facies of the recentmost sediments and a frame of the large-scale bedforms linked to the last eustatic cycle that characterize its channels. Five main acoustic facies have been recognized and mapped. Due to the good coherence with the sediment texture map of the area, an interpretation of the acoustic facies in sedimentary terms is presented. The archipelago is characterized by a complex system of inlets, promontories, bays and channels ruled by the main tectonic trends of the region. A main, 20 km-long channel (Bucinara Channel) with numerous straits and some shoals divides the northern Sardinia coast from the main islands of Spargi, La Maddalena, Santo Stefano and Caprera. A shorter and larger channel occurs in the northern part of the Archipelago. Two minor sea branches connect these channels. The bathymetry of the area reveals that the channels generally have a flat bottom and steep flanks, with water depth mostly ranging between -35 and -60 m, with the exception of saddles and shoals. The sedimentary regime of the area is controlled by storm-induced currents and by a high carbonate production associated to the widespread presence of the Posidonia Oceanica seagrass, a marine Phanerogama that populates the flanks of the channels of the Archipelago. A multitude of morphologic forms can be attributed to the phases of falling, lowstanding, rising and high-standing of the last Pleistocene-Holocene eustatic cycle. Angular unconformities, gullies and sediment-incised palaeo channels along with abrasion platforms in the granitic basement witness the last sea level fall and low-stand. These forms now lie at water depths ranging between -33 m and -60 m and are covered by a thin veneer of sediments of the Holocene transgression. They have all been formed when the sea-level was about -110 m below the present datum and the Archipelago was a landscape of rocky hills separated by large, flat valleys scoured by torrent-like rivers. The Holocene rise of sea-level (Versilian transgression) caused the flooding of the landscape and the deposition of the thin sedimentary cover imaged by the acoustic profiles. The rising was punctuated by some sea-level still stands evidenced by terraced surfaces lying at depths between -33 m and -47 m which are coherent with the mapped and dated beach-rocks of the Bocche di Bonifacio strait. The decrease of sea level rise at 5000-6000 years B.P. and the following stabilization of sea level have triggered the present sedimentary and hydrodynamic conditions which, in turn, favoured the formation and maintenance of the bedforms. The Archipelago is dominated by an eastward directed sea current, and subordinately by a westward current. In the two main WNW-ESE and W-E trending channels of the Archipelago, the current flows have formed some longitudinal sand ridges up to 3 km long and 5 m high, while in the N-S oriented channels, transversal sand banks up to 10 m thick occur. Sea floor undulations, interpreted as sand waves, are present in some restricted areas close to the Sardinia coast in downflow position with respect to the headlands. Their wavelength (L) ranges between 10 to 40 m and the height (H) is up to 1,5 m, the ratio H/L being 1:20 to 1:30. Those of symmetric shape are due to wave motion during stormy seas. The asymmetric ones, instead, are likely to originate from bottom currents. Their steeper side faces to the East, according to the direction of the dominant current

The sedimentary bedforms in the channels of La Maddalena archipelago (NW Sardinia, Italy): a product of the holocene sea level rising

The use of a Chirp high-resolution acoustic source made it possible the differentiation of acoustic facies in the recentmost sediments of the channels of the La Maddalena Archipelago and the recognition of large scale bedforms linked to the last eustatic cycle. The acoustic facies, distinguished on the basis of their reflectivity characters, show a substantial coherence with the distribution of the sedimentary facies described by previous Authors. In the channels of the archipelago flat bottom sediments with medium to poor reflectivity correspond to sands, gravels and muds mainly of bioclastic composition deriving from the high CaCO3 productivity of the Posidonia Oceanica seagrass that populates the flanks of the channels down to about - 40 m. On the contrary sediments on the flanks, which are mostly non-reflective, are mainly represented by silico-clastic sands resulting from the degradation of the granitic structural highs. Sediments of the most proximal and protected bays are characterized by higher reflectivity and correspond to finer deposits such as silts and sandy silts. The Chirp survey highlighted the occurrence of large scale, low-H/L-ratio bedforms not evidenced on SSS survey because of their too low relief. In the channels roughly oriented W-E sedimentary bodies up to 3 km long and some meter thick occur in axial position. Two larger and thicker transversal bodies are present in two N-S trending channels, where they act as bathymetric thresholds between the adjacent islands. All these acoustically opaque bedforms, classified as sand ridges or sand banks are younger than the underlying sediments. They are mainly composed of bioclastic sands and gravels and represent the product of the present hydrodynamic regime. Seafloor undulations of sand wave type occur in the main channel along the Gallura coast down-flow to the headlands with respect to the dominant, eastward directed current. Symmetric forms may be attributed to stormy wave motion, while the asymmetric ones to the seabed current. Sand ridges and sand waves are significant sedimentary bodies in the archipelago depositional system as they witness the importance of the currents in the hydrodynamic regime. These features are overprinted by smaller sedimentary features such as comet marks, small scale sand waves, sand ribbons and ripple mark fields, which indicate the axes and directions of the sedimentary transport. The large-scale sedimentary bedforms of the channels of La Maddalena archipelago are the result of the hydrodynamic regime set up after the slackening of the sea-level rise, mainly between 6 -5 ky B.P. This event brought to the stabilization of the sea level and the formation and maintenance of the bedforms