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Exhumation and tilting of the late Hercynian continental crust in the Serre Massif (Southern Calabria, Italy)
No full textExhumation and tilting of the late Herchynian continental crust in the Serre Massif (Southern Calabria, Italy)
No full textIn the Serre Massif (Calabria-Peloritani arc) a nearly complete tilted section of the Hercynian continental crust is exposed. The upper levels crop out in the Stilo area (southeastern Serre) and they consist of very low- to low-grade metamorphic phyllites with interbedded marbles and metavolcanic rocks of Ordovician to Carboniferous age. These rocks are intruded by late Hercynian granodiorites. The sedimentary cover is represented, from the bottom upwards, by: Jurassic shallow water limestones; Late Chattian-Burdigalian conglomeratic turbidites (Stilo-Capo d'Orlando Fm.); Serravallian-Tortonian conglomerates and arenites; Zanclean silty clays, argillaceous marls and silts (Trubi Fm.). Jurassic and Cenozoic sediments plunge southeastwards and the dip angle progressively decreases with the younging direction. In the present research an exhumation path for the upper Hercynian crust cropping out in the Stilo zone is traced. Igneous thermobarometry (Al-in-hornblende barometry and hornblende-plagioclase thermometry) was adopted to obtain the depth of the granodiorite at the time of emplacement. Then, sequentially restoring a NW-SE oriented geological section, the exhumation history of the granodiorite was unravelled, from the Present to the Paleozoic. The progressive back-rotations permitted to obtain the depth of the granodiorite at the age of the considered stratigraphic surface and to collect dept-time data useful to trace the exhumation path. The exhumation history of the Stilo granodiorite is characterised by two main episodes separated by a nearly static tectonic phase. The first episode took place from Late Carboniferous to earliest Jurassic and is poorly constrained by stratigraphic records. The second episode, well documented by the stratigraphic records, developed from Oligocene to Present and it is also characterised by episodic subsidence stages. A total amount of 43° southeastward tilting mostly took place from Late Oligocene to Pleistocene. Therefore, a continuous tectonic process from Oligocene to Present is suggested to explain the collected data. The extensional tectonics connected to the eastward migration of the Apenninic Arc played a key role in the tilting of the Serre crustal section
Leucogranite genesis connected with low-pressure high-temperature metamorphism in the Sila basement (Calabria, Italy)
No full textA Late-Hercynian intrusion of two-mica leucogranite from the Sila
(Calabria, Italy) has been examined for petrographic, geochemical, and
radiogenic isotope characteristics. The main objective was to analyse
leucogranite genesis and its relation to partial melting of the Sila
high-grade migmatitic paragneiss, which is affected by low-pressure
metamorphism. The studied leucogranite is strongly peraluminous and is
characterized by the presence of andalusite and sillimanite. It is very
similar in major element composition to experimental melts produced by
muscovite dehydration melting reaction from meta-sedimentary rocks. The
leucogranite has high Rb and low Sr contents, whereas Zr and LREE
concentrations are moderate to low. Variations in Sr, Rb, Zr, and LREE
are inversely correlated to corresponding variations in migmatitic
paragneiss. Maximum Zr and LREE contents in two leucogranite samples
coherently indicate a saturation temperature of ca. 750 degrees C for
both zircon and monazite. The estimate is in good agreement with peak
temperatures of 740-770 degrees C obtained for high-grade rocks
underlying the granite. These observations suggest a melt-restite
connection between leucogranite and migmatitic paragneiss. Sr isotopic
data are in agreement with this hypothesis whereas differences in the Nd
isotopic composition between leucogranite and migmatitic paragneiss are
attributed to disequilibrium retention of monazite in the residue.
Mass-balance calculations, performed combining average major oxides
analyses of leucogranite and migmatitic paragneiss, allow to reconstruct
a composition similar to standard shale, except for the higher Na2O/CaO
ratio
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
Integrated cloverleaf-like paper-based analytical device for quantitative colorimetric sensing of maleic hydrazide
No full textPaper-based analytical devices (PADs) are becoming pivotal tools in the sensing field; however, the integration of molecularly imprinted polymers (MIPs) on them deserves further exploration to obtain all-in-one selective devices. Herein, a cloverleaf-like PAD integrating a MIP for the smartphone-based selective colorimetric determination of maleic hydrazide (MH), a widely used plant growth regulator, is proposed. The device encompasses the complete MH analysis in a 4-leaved format (4L-μMIP/PAD), where the μMIP is housed at the center and each leaf encloses an analytical step (i.e., sample excess removal, washing, analyte elution, and MH colorimetric detection). The μMIP was synthesized with a UV lamp on fiberglass, while the entire paper device was manufactured via laser plotter and wax printer. The μMIP displays an imprinting factor of 17 and was characterized via FTIR, SEM, and elemental mapping, resulting selective toward MH. The colorimetric sensing, integrated on the sensing leaf, was attempted on 13 different paper types. The final 4L-μMIP/PAD allows the selective MH determination in the range 5–60 mg kg−1 (R2 = 0.995; RSD ≤ 11 %, n = 3) with a LOD of 0.7 mg kg−1, meeting the requirements for MH analysis in samples at Maximal Residual Levels admitted by the law. The device ensures the complete MH analysis in 50 min, with 40 μL of sample, resulting stable and ready-for-use, for 1 month (RSD = 9 %). Eventually, the 4L-μMIP/PAD was successfully tested for MH analysis in garlic, onions, and carrots, obtaining recoveries between 89 % and 110 % and reproducible data (RSD ≤ 15 %, n = 3)
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
Strain concentration in marble layers along the Palmi shear zone (Calabria, Southern Italy)
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