1,720,963 research outputs found
Thermochronological evidence for Mesozoic-Tertiary tectonic evolution in the eastern Sardinia
No full textApatite fission-track analyses on samples from eastern Sardinia document a complex tectonic history, whose reconstruction is problematic because of the reactivation of faults and structures at different times from Jurassic to Miocene. The oldest ages (150–154 Ma) have been detected on the southern margin of the Gulf of Orosei and are related to the extensional tectonics that characterize the European passive margin during Early and Middle Jurassic times. Thermal modelling of these data allows reconstruction of the burial history of the Mesozoic basin and estimation of a sedimentary thickness of 2000 m. Part of these sediments was eroded during the following uplift, documented by mid-Cretaceous fission-track ages. A further exhumation episode of Eocene age has been revealed by fission-track data on granite samples, and has been inferred to be related to the Alpine orogenic phase. This tectonic episode caused the exhumation of crustal blocks bound by faults that were finally reactivated during the Late Oligocene–Early Miocene
A multi-disciplinary study of deformation of the basaltic cover over fine-grained valley fills: a case study from Eastern Sardinia, Italy
No full textThe Pliocene to Early Pleistocene volcanic activity which generated the basaltic plateau of the Orosei-Dorgali area in Eastern Sardinia led to the disruption of the local hydrographic network by damming some tracts of the fluvial valleys incised in the granite basement. This resulted in the formation of lacustrine basins, whose fine-grained fills were partly interfingered and eventually covered by younger lava flows. In the SW part of the plateau, close to the Galtellì village, a number of unknown depressions, locally named “Paules,” were formed. In order to reconstruct their subsurface structure, two electrical resistivity tomography surveys were carried out across these depressions. The geophysical results, which demonstrate the existence of a disrupted layered system, were used to build a numerical geomechanical model that suggest the depressions originated by local collapses of the basaltic cover due to the compaction of the underlying fine-grained valley fills
COUPLING AMPULLINID GASTROPODS: SEXUAL BEHAVIOUR FROZEN IN PALAEOGENE DEPOSITS OF NORTHERN ITALY
No full textCouples of the ampullinid gastropods Globularia (Eocernina) vulcani (Brogniart, 1823), Amaurellina (Crommium) angustata (Grateloup, 1827) and Amaurellina (Pachycrommium) cf. suessoniensis (d'Orbigny, 1850), composed of dimorphed shells tightly conjoined at the apertures, from the Palaeogene (Eocene and Oligocene) marine successions of northern Italy, are interpreted as buried while mating, specimens being "frozen" while suddenly covered by a mass of sediment. Violent depositional events were responsible for their rapid burial, primarily by volcanoclastics, the formation of which had also involved acidification. The consequent poisoning of sea water and/or overwarming beyond the range in which the gastropods could survive, induced mass mortality. A similar set of conditional circumstances is also discussed for differently sized coupled specimens of Ampullinopsis crassatina (Lamarck, 1804), preserved with their shells slightly apart but with their apertures almost in contact. With reference to the catastrophic eruption of Vesuvius in A.D. 79, when Pompei was buried under tephra, it is thought that volcanic activity caused the death and burial of all these pairing gastropods in a "Pompeian" way
Discussion on «The Sardinia-Corsica microplate and its role in the Northern Apennine Geodynamics: new insights from the Tertiary intraplate strike-slip tectonics of Sardinia» by G. Oggiano, A. Funedda, L. Carmignani & S. Pasci (2009)
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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
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