4 research outputs found
Le ichnocenosi delle unità Eocenico-Mioceniche affioranti tra il Lago Trasimeno e l’Alpe di Poti (Appennino Settentrionale).
No full textTaphonomy and ichnofabric of the trace fossil Avetoichnus luisae Uchman & Rattazzi, 2011 in Paleogene deep-sea fine-grained turbidites: examples from Italy, Poland and Spain.
No full textThe poorly known, helical spiral trace fossil Avetoichnus luisae Uchman & Rattazzi, 2011 has been investigated in fine-grained Paleogene turbidites in Italy, Poland and Spain. It shows a typical stratinomic preservation as endichnia and was developed in turbiditic mud and bioclastic deposits occupying the upper intervals (typically E3-F) of turbidite sequences. Other ichnotaxa occur in deeper levels (e.g., Alcyonidiopsis and Zoophycos in the Trasimeno area), while tree-like forms (e.g., Chondrites intricatus, C. targionii and Cladichnus in the same area), string-like forms (e.g., Planolites or Palaeophycus) and other undetermined burrows are usually found in shallower levels. The distribution of the ichnotaxa indicates an upwards increasing ichnodensity towards the higher intervals in many mud-bioclastic turbidite sequences. Detailed taphonomic analysis of 104 specimens of frequently branched Avetoichnus luisae has shown that a high degree of variation can be observed in their length, general shape, maximum diameter, maximum width of dots, shape of dots, dot distribution, spiral arrangement, central part (axis) and raised edges. These variations suggest that an unknown organism adjusted its activity (agrichnial or fodinichnial) using different strategies in accordance with changes in the turbiditic environment
Avetoichnus luisae ichnocoenosis in Paleogene bottom nepheloid layer deposits, Scaglia Toscana Formation, central Italy
No full textBottom nepheloid layers (BNL) are deep dense waters transporting suspended clay, silt or fine sand with organic matter particles in the central part of basins, with usual suspended sediment concentrations of 1 mg/l and lesser concentrations < 1 mg/l progressively towards the basin plain (Puig et al., 2013). BNL are very common in recent basin margins (e.g. the continental rise of French Mediterranean, North Atlantic), but poorly studied in the geological record. Some authors think that turbulent flow in BNL is more responsible for deposition of mud in flat basin plains than fine-grained turbidites (P. Pilgrim, personal communication 2010). The thickness of BNL deposits depends on bottom current velocity and the balance between gravitational settling of particles, basin plain morphology and turbulence of the current. Burrowing organisms intensively exploit the organic matter deposited in the sea floor by BNL; in Canadian Atlantic basin plain, the upper surface is extremely bioturbated with hundreds of burrow openings per m2 (Hunkins et al., 1969, figs 3, 4). In the Paleogene Scaglia Toscana Formation (central Italy; Trasimeno area, Montanare, M. Solare, M. Maggio, Fig. 1), grey to red mudstones occur in beds which are 40 to 60 cm thick (Fig. 2). They are much thicker than typical mud turbidites of overlying Macigno Formation (Amendola et al. 2015). A typical increasing upward density of trace fossils (Monaco et al., 2012) has been detected. In lower tiers dominate deep endichnia (Zoophycos, Taenidium, Planolites); in middle and shallow tiers dominate very common Avetoichnus luisae, Chondrites targionii, C. intricatus, and Cladichnus. Then, utilizing ichnocoenoses is possible differentiate turbulent flow deposits (see Shanmugam, 2002; turbidites versus BNL deposits), because currents caused variation in food resources and the presence or absence of nutrient-rich fine-grained substrates. Ichnocoenoses of BNL sediments are a new interesting topic of studies in deep-sea depositional systems, as a proxy to elucidate paleoenvironmental and ethological conditions that influenced distribution, concentration, burrow diameter, burrow depth, ichnodiversity and traces fossil assemblages
Los tópicos oracionales en italiano: análisis del Corpus CHROME
No full textThe present study deals with the phonetic description of sentence topics in Italian tourist guides’ speech. Topical coherence characterizes the communicative strategies that human experts adopt when delivering contents to the visitors of cultural sites. Topical progression, which ensures temporal, spatial, and referential continuity, is frequently expressed by sentence topics as well.
The relevant literature generally supports the idea of a topic accent and a rising-falling (or “hat”) contour is described as the most frequent for the unmarked topic in Italian utterance structures, but other realizations are also possible. The hypothesis that we want to test in this work is whether this variability is due to specific factors. Hence, we investigate phonetic realization of sentence topics as a function of syntactic features -structure, function and weight- and textual-pragmatic features -discourse role considering ±aboutness, ±contrastiveness, ±givenness-. Specifically, tonal events, i.e., accents and boundaries, phonetic phrasing, and disfluency phenomena were investigated. Results show that both syntactic and pragmatic factors play a role in the phonetic realization of topics, though they act at different levels. In particular, disfluencies are found to be affected by syntactic weight and givenness, while tonal events seem to depend mainly on the discourse role.El presente estudio se plantea un análisis fonético de los tópicos oracionales en italiano, examinando habla de guías turísticos. La coherencia temática caracteriza las estrategias comunicativas que adoptan los expertos humanos al transmitir contenidos a los visitantes de los sitios culturales. La progresión temática, que garantiza la continuidad temporal, espacial y referencial, se expresa también con frecuencia mediante tópicos oracionales. Por lo tanto, el corpus examinado ofrece la posibilidad de analizar la realización de estas entidades.
La bibliografía pertinente apoya, en general, la idea de un acento de tópico e indica un contorno ascendente-descendente como el más frecuente para el tópico no marcado, aunque resultan posibles otras realizaciones.
La hipótesis que queremos comprobar en este trabajo es si la variabilidad encontrada en la bibliografía se debe a factores sintácticos y pragmáticos específicos. Por lo tanto, investigamos la realización fonética de los tópicos oracionales en función de características sintácticas -estructura, función y “peso”- y de factores textuales y pragmáticos -rol discursivo considerando los siguientes rasgos: ±aboutness, ±contrastiveness, ±givenness-. En concreto, se investigaron los eventos tonales, es decir, los acentos y las fronteras, el fraseo prosódico y los fenómenos de disfluencia. Los resultados muestran que tanto los factores sintácticos como los pragmáticos desempeñan un papel en la realización fonética de los tópicos oracionales, aunque actúan a diferentes niveles. En particular, las disfluencias se ven afectadas por el peso sintáctico y el estatuto informativo, mientras que los eventos tonales parecen depender principalmente del rol discursivo
