1,720,975 research outputs found
The interaction of eustacy and tectonism fromprovenance studies of the Eocene Hecho Group TurbiditeComplex ( South-Centra Plyrenees Spain)
No full textUsing a detailed etrographical procedure conceived for arenites rich in carbonate clasts,the influence of tectonism and eustacy on silicate/carbonate cycles of the Eocene Hecho TurbiditeComplex has been tested,and the palaeogeography of the source/basins ystemo utlined.Both extrabasinal and intrabasinal sources of sediments were active during basin f illing. Forelandt hrusting in the South Central Pyrenees has acted as the major control on the composition and architecture of the Hecho Turbidite Complex. Strong uplift of old silicate andcarbonate source terrains during southward thrust propagation was responsible for erosion, swamping and/or reduction of shelfal areas, and gave rise to siliciclastica nd carbonate basinalsequences
Il Flysch di Solignano nel quadro dei Flysch a Helmintoid (Maastrichtiano inferiore, Appennino settentrionale)
No full textThe Flysch di Solignano was deposited in a basin plain below the CCD close to the western margin of the Ligurian Tethys during Early Maastrichtian.The siliciclastic supply was mainly delivered by a crystalline basement of Sardinian-Corsican affinity. The carbonate supply, made up ofpelagic ooze, derived by oceanic intrabasinal structuralhighs represented by transform prisms uplifted within the compressive field affecting the Ligurian domain during Late Cretaceous. Resedimentation processes were likely triggeredby tsunami waves generated by high-magnitude earthquakes on this confined arm of the Ligurian Thethys.The hypothesis that resedimentation processes not only affected coeval pelagic ooze but also the underlying unconsolidated oceanic sediments of the Cretaceous oceanic coverComplessi di Base) is put forward
THE UPPER CRETACEOUS HELMINTHOID FLYSCH OF THENORTHERN APENNINES: PROVENANCE AND SEDIMENTATION
No full textThe Mt. Cassio, Mt. Caio, Mt. Antola and Solignano successions (Campanian to Maastrichtian) examined in the type localities are made up of three distinct types of turbidite beds: micritic-marly, arenidc-siliciclastic and mixed. The mixed beds exhibit an arenitic-siliciclastic interval sradins upward into a micritic-marly interval.The micritic-marly beds and the micritic-marly intervalsof mixed beds consist chiefly of penecontemporaneous coccolithsplus a clay component indicating resedimentarion ofcoeval pelagic mud and ponions of the underlyingsedimentary successions from structural isolated highs andmarginal shelves. The terrigenous detritus of silióiclasúcbeds and of basal intervals of mixed beds derives mainly fromgranitic and lo\4'- to medium-grade metamorphic rocks of acontinental basement and, in the case of Mt. Caio and Mt.Cassio, from a carbonate sedimentary cover.In the Mt. Cassio siliciclastic beds and intervals of mixedbeds, unlithifred squeezed grains of mudstones with Calpionellidaeand Calcisphamrlidae and argillaceous clasts arepresent, suggesting resedimentation of material from older,still unconsolidated successions. The si-liciclastic beds and intervalsof the Mt. Cassio succession also contain significantamounts of allochems characteristic of the photic àne. indicatingcontributions from Campanian to Màasuichrian-carbonate-pladorm system
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Termocronologia della arenarie di M.te Cervarola (Appennino Settentrionale) attraverso l'analisi delletracce di fissione su apatite e zircone
No full textDottorato di ricerca in scienze della terra. 12. ciclo. A.a. 1998-99. Relatore G. B. Vai. Correlatori G. G. Zuffa e G. A. PiniConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - Piazza Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal
Variations on the Author
Get PDF“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
Get PDFWe 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
HETEROGENEOUS DISTRIBUTION OF CALCITE CEMENT AT THE OUTCROP SCALE IN TERTIARY SANDSTONES, NORTHERN APENNINES, ITALY
No full textCalcite cement derived intraformationally in seven stratigraphic units of marine origin (five submarine-fan deposits and two shelf deposits) is distributed heterogeneously at the outcrop scale. Sandstone beds intercalated with calcareous shale older than Pliocene tend to be completely cemented, whereas stacked sandstone beds that lack shale interbeds have calcite cement in the form of tightly cemented concretions that make up only 10-30% of a bed. The abundance and distribution of concretions, with few exceptions, are irregular and unpredictable. Concretion shapes include spheres (<1 m diameter), oblate and prolate spheroids (<1.5 m), tabular forms (to 8 m long), and irregular forms. Patterns of concretions within beds are remarkably varied and include both random and uniform spacing; preference for either the top, middle, or bottom of beds; preference for faults that cut bedding at a high angle; and localization around shale rip-up clasts. There is no preference of concretions for shell-rich layers. Some formations have cement patterns specific to that formation, whereas other formations have different patterns at different outcrops. Most formations have more than one cement pattern in an outcrop. The lack of strong textural (grain size, graded bedding) or compositional controls on the localization of calcite cement suggests the preeminence of highly localized hydrologic factors in determining the spatial distribution of authigenic pore-filling calcite. Spherical concretions grew by diffusive supply of intraformationally derived components, whereas prolate and elongate concretions grew chiefly under the influence of advective supply. Faults apparently served as fluid conduits and were selectively cemented. In general, only sandstones intercalated with shale are totally cemented. This indicates that shales were a major source of cement components for these sandstones at least
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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