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Nuovi contributi alla ricostruzione della stratigrafia vulcanica dell’area di Capo Passero, Sicilia Sud-orientale, nel quadro del vulcanismo del Cretacico superiore nel Plateau Ibleo
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Evolution of the mafic Villa Senni caldera-forming eruption at Colli Albani volcano, Italy, indicated by textural analysis of juvenile fragments
No full textThe Villa Senni Formation (355 ka) represents the youngest mafic caldera-forming eruption of the Colli
Albani Volcano (Central Italy), and one of the best exposed large mafic ignimbrite successions on Earth. The
unusual Si-undersaturated and high-K composition of the magma, and corresponding low magma viscosity,
raise important questions about the conditions of magma ascent, eruption, and fragmentation that led to
such a large explosive eruption. We examined the juvenile clast textures – that is, the abundance, shape, size
and number density of both vesicles and leucite microlites – to reconstruct the fragmentation conditions and
to trace major changes in the ascent rate and vesiculation history of the magma associated with caldera
collapse. The juvenile textures record two major changes in the eruption dynamics through the stratigraphy.
First, the sudden depressurization of the magma chamber and the onset of the first ignimbrite-forming phase
are marked by a dramatic increase in the magma ascent velocity inferred by a decrease in vesicle and leucite
microlite sizes and increase in their number densities. Second, the progressive restoration of pressure within
the magma reservoir as a consequence of caldera collapse is recorded by an inversion of vesicle and leucite
microlite textures, which suggest a strong decrease in magma ascent rate. Complex vent conditions in this
later phase of the caldera collapse are recorded by the diversity of textural features, variation in magma
chemistry and the abrupt changes in the stratigraphic record (including the presence of co-ignimbrite
breccias, spatter clasts and lithics)
Geological and petrographical study of Montecampione Triassic subvolcanic bodies (Southern Alps, Italy). Preliminary geodynamic results
No full textGeological surveying in a metropolitan area: the southern suburbs of Rome
No full textThe southern suburbs of Rome were built up for the most part during the second half of the last century. This contribution illustrates the case study of the Ostiense area, located across the Tiber River valley, where the city’s expansion has mostly not taken into account the geological and hydrogeological characteristic of the land. For this reason, many buildings and infrastructures of the area have been damaged by differential subsidence and flooding. This work proposes a hazard zonation based on the geotechnical, hydrogeological, hydraulic and seismic characteristics of the area, for the purposes of urban development planning and management
Sin-depositional emplacement of the Liguride allochthon in the Miocene foredeep of the Western Romagna Apennines (Italy)
No full textIn Western Romagna, a segment of the “Sillaro Line” has been mapped in detail. The stratigraphic and tectonic analyses of field data have been framed in a regional-scale study of the tectono-sedimentary relationships, the structural styles and the deformation chronology of the Romagna Apennines. The sin-depositional trajectory of the Liguride overthrust has been reconstructed by retro-deformation, and a specific stratigraphic scheme has been elaborated for the Visignano slump-olistostrome. The conclusive interpretations have been summarized in an evolutionary picture of the Liguride overthrust, which correlates the emplacement, the re-mobilization and the tectonic displacement of the main submarine landslides with the allochthon advancement into the middle Miocene Apennine foredeep
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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