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Mechanisms of subduction accretion as implied from the broken formations in the Apennines, Italy
No full textMesoscale structural analysis of the Ligurian broken formations of the Northern Apennines and the regional occurrence of subduction-related structures indicate polyphase folding as the mechanism responsible for progressive disruption. The evidence for direct correlation between regionally extensive noncylindrical folds and tectonic disruption has a strong bearing on determining how the Ligurian accretionary prism evolved. For example, the block-in-matrix structure of the Ligurian tectonic melanges is produced through extension developed along fold limbs in a compressive stress field, as expected from offscraping and intraprism deformation. The model implied by the mesoscale and macroscale analyses of the Ligurian tectonic melanges provides one mechanism of accretion reconciling two deformation styles, i.e., stratal disruption and folding, commonly seen in ancient accretionary prisms. Furthermore, this model could be relevant in active accretionary prisms, especially in the intraprism part, where the seismic and drilling data are sparse
Lateral variability of the erosive plate boundary in the Northern Apennines, Italy
No full textThe early to middle Miocene erosive plate boundary preserved in the Northern Apennines NW of the Sillaro Line is formed by two distinct units - the Sestola-Vidiciatico Tectonic Unit and the Subli - gurian Units. These two units occupy, respectively, the SE and the NW portions of the studied area. Upon closer examination, the features that distinguish these mapped units do not reflect differing plate boundary processes, but rather the incorporation or non-incorporation of forearc-toe mass-wasting deposits into the active subduction channel. In other respects, these two units document similar subduction channel processes, including the contemporaneous activity of multiple sub-parallel slip surfaces. This mode of subduction channel deformation leads to the 'laminar' incorporation of distinct stacked slices within the channel. © 2012 Società Geologica Italiana, Roma
Myths and recent progress regarding the Argille Scagliose, Northern Apennines, Italy
Full text linkArgille scagliose (scaly clay) is a geological term first used in 1840 to describe rocks in the Northern Apennines of Italy. The term was originally created to stress the mesoscopic scaliness of a type of rock that commonly outcrops in this area. The rock is also typified by a chaotic assemblage of blocky components that are embedded within the scaly matrix. Before the advent of plate tectonic concepts, the extreme complexity of these rocks posed an extreme challenge to interpret with then-standard concepts of deposition processes in sedimentary basins. Similar rocks were recognized in many other mountain belts, thus the term became widely used. At the same time, the emphasis of the term changed from a description of the matrix to a term with multiple, intensely debated, genetic associations. Only after the discovery of plate tectonics was it accepted that these rocks are formed at subduction boundaries, and that the multiple types of embedded blocks can have an origin from both slope-instabilities within an accretionary prism, and from tectonic reworking/deformation processes near the base of an active accretionary prism. This paper reconstructs the scientific evolution of thinking about argille scagliose during the years when it was one of the supreme challenges to sedimentary geologists. The often strong debate between competing hypotheses for the origin of these rocks led to many myths that still outcrop in the geological literature. We explore why this happened, the apparent future of modern research on chaotic rocks in the Apennines and other fossil accretionary prisms, and what is and should productively remain from the long geological controversy over argille scagliose
Deformation and Fluid Flow in an Ancient Erosive Subduction Channel: Insight from the Northern Apennines of Italy
No full textGoing 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
Thermal and geological constraints for the timing of the activity the frontal part of an ancient subduction channel, Northern Apennines of Italy
No full text
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
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