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Evoluzione geomorfologica quaternaria della conca intermontana di Carsoli (Aq)
No full textIn the present work the results of a geological and geomorphological study are presented. The study has been carried out in the
Carsoli intermontane basin (AQ), a wide depression of tectonic origin, located between Abruzzo and Lazio regions, at the boundary of
two different palaeogeographic domains, separated by the “Olevano-Antrodoco” tectonic line.
The Carsoli basin is filled with a continental sedimentary succession of considerable thickness and extent, which has been classified
into several lithostratigraphic units, mainly on the basis of their lithological, morphological and geochronological characteristics.
The oldest continental sediments outcropping within the study area are of lacustrine origin (Bosco di Oricola silts, clays and sands).
These sediments, whose deposition has probably occurred in the Lower – Middle Pleistocene, are characterized by a maximum thickness
of about 200 m. They are widespread in the north-western and central parts of the basin (Bosco di Oricola) and are locally present
on the eastern edge of the basin.
The lacustrine deposits are cut across by an ancient sub-horizontal erosion surface, and at present, only some remnants remain.
The lacustrine sediments are covered, on the north-eastern edge of the basin, by coarse fluvial sediments suspended on the present
plain, originally deposited by the paleo-Turano River (Madonna delle Grazie gravels).
In the central-western and southern part of the study area, a significant sequence of local volcanic deposits, dated around 530 – 540
kyears BP, outcrops. The volcanic sequence abruptly begins from an articulated erosive surface shaped in lacustrine deposits and
Meso-Cenozoic carbonatic bedrock. Three main pyroclastic units are distinguished in the following members: 1) Oricola scalo opening–vent breccias, 2) Oricola Scalo grey tuffs, 3) S. Giovanni red tuffs. Only the last two units widely outcrops in the study area.
The Oricola Scalo opening-vent breccias are relative to the early opening phase of the conduit. They consist of a massive structure
connected to the depositional mechanisms of airfall and/or debris flow, separated by tuff layers related to base surge phenomena.
The Oricola Scalo grey tuffs unit mainly consists of grey ash-lapilli tuffs with surge cross-laminations, and grey lapilli tuffs with a massive
structure of pyroclastic flow. The overlying S. Giovanni red tuffs are characterized, instead, by a thickness and distribution greater
than that of underlying grey tuffs. The unit is mainly composed of red lapilli tuffs, with dune structures or a parallel lamination of surge
and airfall.
After the lacustrine sedimentation and the volcanic episodes, the examined area underwent intense fluvial dynamics. This led to the
sedimentation, in the central-southern and eastern part of the basin, of a sequence of alluvial deposits belonging to different depositional
events. The morpho-litho-stratigraphic analysis of these fluvial deposits, in addition with radiometric ages, allowed for their classification
into four units (Prati gravels, sands and silts, Fioio Stream conglomerates, Immagine gravels, sands and silts, Turano River gravels,
sands and silts) progressively embedded into each other and ranging in age between the late Middle Pleistocene and the Present.
Entrenched in the late Middle Pleistocene alluvial unit, in the southern sector of the basin (Fonte Bosco), a few hundred meters long
and 1.5 meters thick calcareous tufa layer, dated by U-series method at 46,000 ± 6,000 years BP outcrops.
With regard to the most recent depositional phases, great relevance has to be ascribed to the stratigraphic study carried out on the
Fosso Luisa fan (Camerata Nuova) and the radiometric dating of colluvial horizon, there present. This dating, providing a calibrated 14C
age of 3,550-3,400 years BP, has allowed for a temporal definition of some sedimentary and erosive events that marked the upper part
of the fan during the final part of Holocene
Il vulcanismo monogenico medio-pleistocenico della conca di Carsoli (L’Aquila).
No full textThe volcanic field is comprised of several Upper Pleistocene small tuff cones, tuff rings and maars (531 ka), aligned along a NNW-SSE normal fault of regional meaning. Most of the deposits are directly related to vent structures and preserve signs of primary proximal origin consisting of high-energy structures, welded lapilli and ballistic impacts. Characteristic sequences of vent coring eterolithic breccias, dry lapilli-ash surges of high-temperature and wet surges of ash-lapilli tuff are exposed and found in well coring. Juvenile fragments consist of plastically moulded lapilli, essentially composed of diopside, phlogopite, leucite, K-feldspar, apatite and immersed in a turbid micro-cryptocrystalline matrix of Ca-carbonate. Lapilli shape indicates that they agglutinated and quenched when still hot plastic. Silicate glass shards are present and have typical cuspate wedges produced by bubbles expansion and disruption during magmatic activity sustained by juvenile gases. A late phreato-strombolian phase builted several tuff-rings and cones. At Oricola - Carsoli - Rocca di Botte - Camerata Nuova volcanic field, juvenile fragments and tuffs range from phonolitic-foidite to foiditic-carbonatitic to carbonatite s.s. The latter forms small pyroclastic flows and surge deposits. Geological context, age, mineralogy and petrology are germane with the near Grotta del Cervo occurrence and are consistent with the carbonatitic-kamafugitic suite of Italy. This new carbonatitic outcrop, that joins the increasing number of Italian carbonatites, puts Italy in a relevant place for what concerns carbon-rich mantle magmatism occurrences. Actually, the six extrusive carbonatites and the intrusive one so far reported, represent one of the largest concentrations of such a kind of rocks all over the world
U/Th dating of a tufa deposit from the Carsoli intramontane basin (Abruzzo, Italy)
No full textA few km far from the confluence of the Fioi valley into the Carsoli basin, some hundreds m2 wide and ca. 1.5 m thick carbonatic deposit is present, embedded within late Middle Pleistocene alluvial gravel. The deposit formation might be related to sub-aerial deposition of CaCO3 (tufa) from emerging groundwater. A U/Th dating to 46 ± 6 ka BP constrains the deposit within the MIS 3, corresponding to a phase of warming between the MIS 4 and 2
Una nuova segnalazione di carbonatite estrusiva in Italia: il complesso vulcanico di Oricola – Camerata Nuova, Abruzzo.
No full text
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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