1,721,071 research outputs found
Cosmogenic He exposure dating as a tool to calculate slip rates: example from the Pernicana fault system (Mt. Etna)
No full textConstraining the slip rate of Mt. Etna active faults using cosmogenic 3He exposure dating of basalts
No full textReply to Mazzarini et al. comment on ‘Unveiling ductile deformation during fast exhumation of a granitic pluton in a transfer zone’
No full textIn our reply we demonstrate the inconsistency of the comment we received from Mazzarini et al. Our data,
models and conclusions are solid and framed in the regional evolution of the Northern Apennines, typified by
eastward migration of coeval extensional tectonics and magmatism since late Miocene. We show that understanding
the natural processes recognizable in the Elba Island requires a scientific approach based on reproducible,
reliable and high-quality datasets, independently of the scale of observation
Middle Miocene out-of sequence thrusting and successive exhumation in the Peloritani Mountains, Sicily: Late stage evolution of an orogen unreveled by apatite fission track and (U-Th)/He thermochronometry
No full textApatite fission track (AFT) and (U‐Th)/He (AHe)
thermochronometry are applied to constraint the thermal
history of the basement rock forming the Peloritani
Mountains in northeast Sicily, Italy. AFT ages
range between 29.0 ± 5.5 Ma and 5.5 ± 0.9 Ma while
AHe ages vary from 19.4 Ma to 3.3 Ma. Most AFT
ages are younger than the overlying terrigenous
sequence that, in turn, postdates the main orogenic
phase. Through the coupling of the thermal modeling
with the stratigraphic record, a middle Miocene thermal
event is revealed. This event affected an innerintermediate
portion of the Peloritani Mountains and
is confined by the distribution of the AFT ages <15 Ma. The U‐shaped pattern of AFT ages along N–S transects
across the mountain chain is consistent with burial
below a thrust stack that is a few km thick, created by
an out‐of‐sequence thrusting phase that affected the
inner portion of the belt. The tectonic load was then
removed initially by erosion enhanced by the high
relief at 10–7 Ma. The difference between young
AFT and AHe ages is used to infer a rate of exhumation
of 0.3 mm/yr for this stage. The gap between the
youngest AHe ages and the sedimentary record above
indicate a final exhumation stage with increasing rates
of denudation (1–3 mm/yr) since the Pliocene times
due to extensional tectonics. Citation: Olivetti, V., M. L.
Balestrieri, C. Faccenna, F. M. Stuart, and G. Vignaroli (2010),
Middle Miocene out‐of‐sequence thrusting and successive
exhumation in the Peloritani Mountains, Sicily: Late stage
evolution of an orogen unraveled by apatite fission track and
(U‐Th)/He thermochronometry
Rapid exhumation of young granites in an extensional domain: the example of the Giglio Island pluton (Tuscany)
No full textThe presence of recently intruded granites at Earth’s surface suggests that their exhumation may
have occurred rapidly. The Neogene granites of the Tuscan Magmatic Province (Italy) were
emplaced during a period of extensional tectonics and are ideal for determining and quantifying
the exhumation process. The peraluminous monzogranite of Giglio Island in the northern
Tyrrhenian Sea is characterized by the presence of roof pendants, xenoliths and miarolitic
cavities. The petrologic study of metamorphic xenoliths and new zircon U–Pb ages show that
the granite was emplaced at 6.4–10 km depth at 5.7 ± 0.4 Ma. Exhumation, constrained by
apatite (U–Th)/He ages, was essentially complete in 0.9 Myr at a minimum rate of 6 mm/year.
This requires rapid tectonic unroofing, isostatic rebound and thermal softening activity,
weakening the upper crust and favouring exhumation at a previously undocumented rate
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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