1,720,995 research outputs found
Stereofotogrammetria satellitare per la ricognizione geoarcheologica dell'area di Cirene (Libia)
No full textNeogene post-collisional evolution of the inner Northern Apennines: inferences from the upper Fiora and Albegna valleys, (Mt. Amiata geothermal area, southern Tuscany)
No full textThe southern Tuscany represents the internal portion of the
Northern Apennines. Its geological setting is particularly complicated
due to two main tectonic phases: a first compressional syn-collisional
phase (Late Cretaceous-Early Miocene) that led to nappe
building and km-scale tectonic features; a later extensional post-collisional
phase (Early Miocene-Pleistocene) led to uplift and unroofing
of the thickened crust is linked to the anticlockwise Apennine rotation
and Tyrrhenian Sea opening.
The upper valleys of the Fiora and Albegna rivers in southern
Tuscany represent a key area to reconstruct the post-collisional tectonic
and sedimentary evolution of this sector of the Apennine
chain. This area is characterized by a tectonic nappe stack built during
the syn-collisional phase, unconformably overlain by Miocene-
Pliocene depositional units, referable to a few sedimentary cycles.
The sedimentary-tectonic evolution for the study area, as recognizable
by field data, is the result of a sequence of different deformative
and depositional events. The compressive event (Early Miocene) led
to crust thickening and emplacement of the Ligurian units onto the
Tuscan Nappe. Later on, a first extensional event (Early-Middle
Miocene) developed low-angle normal faults. This event was responsible
of a strong tectonic elision and crustal thinning, forming the
«serie ridotta», characterized by a megaboudinage tectonic setting
and developing structural-morphological depressions, probably seat
of shallow-marine deposition. A second extensional event (Late
Miocene) developed west-dipping listric normal faults, increasing
the megaboudinage depressions. In the study area, the activity of
west-dipping normal faults caused the deformation of the tectonic
nappe stack with the development of regions with steep east-dipping
attitude of bedding. In these regions east-dipping normal faults
affected the steep dipping bedding, so to form structural depressions
in which tectonic delaminated slices, usually Ligurian units, were
emplaced. Moreover, such structural depressions represented also
the basins of the Late Miocene continental-marine sedimentation. A
third extensional episode (Pliocene) developed with high-angle normal
faults which dissected all the previous structures. During this
extensional event graben and half-graben basins formed, and the
Early Pliocene marine transgression with filling of deep elongated
basins parallel to the chain, developed
Triple folded surface morphology of Neoproterozoic rocks (Jabal Akhdar Dome, Oman Mountains) – Insights into buttressing effects and regional tectonics
No full textNorthern Oman was obducted by allochthonous rocks, including the Semail Ophiolite, during the Cretaceous, which generally hampers field investigations on autochthonous rocks. However, central parts of the Jabal Akhdar Dome provide insights into sub-allochthonous deformation patterns from northern Oman because autochthonous Arabian rocks are exposed. Field survey and satellite image analysis reveal triple-folded autochthonous Neoproterozoic rocks. In the Neoproterozoic succession, carbonates are more resistant to erosion than the under- and overlaying siliciclastics and shape present-day morphology in the superbly exposed surface of the Hat Plateau, where anticlines and synclines coincide with ridges and troughs, respectively.
Previously unrecognized F1 folds are NNE-verging, overturned and tight with amplitudes of 10–100 s of meters, have ESE-oriented fold axes, and display a gently to moderately SSW-dipping penetrative axial-plane cleavage. F1 structures are re-folded by open-tight upright kilometric F2 folds, with NE/NNE-oriented fold axes and a penetrative NE/NNE-striking sub-vertical axial-plane cleavage. A younger ∼WNW-trending broad anticline (F3) exhibits a widely spaced sub-vertical ESE-striking axial-plane cleavage.
The F2 deformation style is heterogeneous. In the West, the NE/ENE-oriented F2 folds are ∼3 km in amplitude and gently plunging. In the East, the NNE-oriented folds are <1 km in amplitude and non-plunging. The change ensues abruptly along a NNE-oriented zone at the western end of the Hat Plateau. The pre-existing NNE-oriented western flank of the Makarem-Mabrouk High/Horst in the subsurface controlled this change, exerting a buttressing effect with less deformation in the East
Physical stratigraphy and facies analysis of an outer carbonate ramp to basinal floor fan turbidite system: the Tertiary "Scaglia Toscana" Fm of the Chianti Mts. (Northern Apennines, Italy)
No full text
Remote Sensing analysis in the florentine plain: investigatin wetland contexts by comparing satellite image and aerial photographs
No full textGli AA. presentano le analisi remote sensing nell'area fiorentina, aplicate all'archeologia del paesaggio e agli insediamenti preistorici dal neoòlitico all'età del Bronzo
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
Geology of the ‘Coltre della Val Marecchia’ (Romagna-Marche Northern Apennines, Italy)
Full text linkA detailed geological map at 1:50,000 scale of the Marecchia Valley and adjoining areas
(Northern Apennines, NA, Italy) is presented here. The Marecchia Valley represents a
geological ‘unicum’ for the NA and it has been the focus of scientific debate for a long time,
due to the occurrence in the area of the ‘Coltre della Val Marecchia (CVM)’, a complex stack
of allochthonous and semi-allochthonous units emplaced in a foredeep basin during the Late
Miocene to Early Pliocene. In order to clarify the geological evolution for this area, the
lithostratigraphic relationships and the tectonic framework have been studied, allowing
better understanding of the complex relationships between tectonics and sedimentation.
The main result has been a new evolutionary framework for this sector of the orogen during
the Late Miocene-Early Pliocene. Several new findings about the geological-structural setting
and stratigraphy, result from the geological map presented here. These are overall supported
by stratigraphic and tectonic evidence, which suggest time and modes of the CVM
allochthonous emplacement within the Messinian-early Pliocene foredeep successions.
Relationships between the allochthonous and autochthonous formations allowed recognition
of two different bodies in the CVM, gravitationally emplaced following different trajectories
and timing
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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