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Hidden Terranes in the northern Apennines, Italy: a record of Late Cretaceous-Oligocene transpressional tectonics
Full text linkWe propose that a very oblique or transpressional tectonic regime was dominant during the early (pre‐collisional) orogenic evolution of the Northern Apennines (Late Cretaceous to Early Oligocene). This hypothesis resolves many inconsistencies in the previous reconstructions of this orogenic belt, which were based on a classic model of orthogonal convergence between the European and Adriatic plates. The crucial lines of evidence that point to a major role of oblique tectonics in the structuring of the Northern Apennines are: (1) the plate tectonics framework, that indicates left‐lateral oblique convergence along the Europe/Adria plate margin; (2) the lack of a magmatic arc during the entire pre‐collisional convergent history of the chain (a time span >45 m.y., from Late Cretaceous to Early Oligocene); (3) the long (20 m.y.) residence time of turbidite sequences in the trench (the “dormant” trench); (4) the multiple source areas of turbidites from both sides of the basin, and the associated coarse gravity deposits; (5) the opposite vergence of deformations in some oceanic units; (6) the unmatching stratigraphic features, distinct deformation and metamorphic histories between adjacent overthrust oceanic units (Ligurids), here interpreted as tectonostratigraphic terranes. Specific aspects of Apennine stratigraphy and tectonics and the geometry and structure of the contacts between the Ligurid Units suggest the existence of a number of terranes juxtaposed by transpression during the early (Late Cretaceous to Early Oligocene) orogenic evolution of the chain
Cretaceous flysch deposits of the Northern Apennines, Italy: age of inception of orogenesis-controlled sedimentation
No full textCretaceous flysch deposits of the Northern Apennines, Italy: age of inception of orogenesis-controlled sedimentation
No full textCalcareous nannofossils have proved to be very effective in determining the age of Cretaceous flysch sequences of the Northern Apennines. Here, we focus on the beginning of flysch sedimentation, which replaced previous pelagic deposition during the Late Cretaceous convergence stage. In all the examined sequences an early to late Campanian age has been determined for the bases of the flysch formations, implying an essentially synchronous start of orogenesis-controlled sedimentation within the Ligurian Apenninic (Ligurian) Ocean Basin. Data obtained from the siliciclastic turbidite sequence (Vat Lavagna/Mt. Gottero Sandstones) overlying Jurassic ophiolites and sedimentary cover, indicate continuous sedimentation from earliest Campanian to early Paleocene. Thus, either a forearc or 'dormant trench' tectonic setting seems to be required for this sequence. Regarding the calcareous Helminthoid Flysch, a minor diachrony in the basal ages suggest a general younging from south to north. The onset ages of flysch sedimentation range from early Campanian (Southern Tuscany Flysch), to early-middle Campanian (Mt. Caio/Ottone Flysch), to latest Campanian (S. Remo, Mt. Antola, Mt. Cassio, Mt. Caio/Orocco Flysch). This diachrony could be the consequence of Late Cretaceous-early Tertiary transcurrent tectonics in the Apenninic Basin and/or of multiple source areas (from both the European/Iberian and Adriatic margins). These tectonic implications are in agreement with the kinematic evidence of a transpressional regime along the Iberian/Adriatic plate boundary (Apenninic sector) during the Late Cretaceous
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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