254 research outputs found
Correction to: Nutrition behaviour and compliance with the Mediterranean diet pyramid recommendations: an Italian survey‐based study
No full textThe article “Nutrition behaviour and compliance with the Mediterranean diet pyramid recommendations: an Italian survey‐based study”, written by “Renata Bracale, Concetta M. Vaccaro, Vittoria Coletta, Claudio Cricelli, Francesco Carlo Gamaleri, Fabio Parazzini and Michele Carruba” was originally published electronically on the publisher’s internet portal on 8th November 2019 without open access. With the author(s)’ decision to opt for Open Choice the copyright of the article changed on 23rd December 2019 to © The Author(s) 2019 and the article is forthwith distributed under a Creative Commons Attribution 4.0 International License (https ://creat iveco mmons .org/licen ses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The original article has been corrected
Sustained turbidity currents : evidence from the Pliocene Periadriatic foredeep (Cellino Basin, Central Italy)
No full textThe aim of this work is to investigate the nature of the numerous, very thick deep-water sheet-sandstones that dominate the lower portion of the Cellino Formation (Central Italy).
The studied turbidite system (about 2,500 m thick) represents the Lower Pliocene turbiditic filling of the outer Abruzzo sector of the Periadriatic foredeep. The foredeep was affected by compressional deformation linked to the overall migration of the chain-foredeep system toward the east. Tectonic activity was mostly coeval with the sedimentation and propagated towards the foreland; thrusting became progressively younger from W to E. The Cellino Basin has been intensely explored, being the site of hydrocarbon-bearing sands.
Very thick beds can be distinctively resolved in the well logs and correlated to the measured sedimentary sections on outcrop. Based on well log correlation, tens of individual beds up to 23 m thick have been traced along the axis of the basin over distance of at least 150 km and, perpendicularly to the basin, over distance of 30-40 km (Carruba et al., 2006). Palaeocurrent data taken from basal flute structures indicates southerly-directed flows, parallel to the depocentral axis of the basin. The thickest beds show a basin-wide extension, onlapping the basin margins without significant thickness variation. The Cellino Formation is mostly buried and crops out in a narrow belt a few kilometers west of the Cellino gas field.
The internal organization of the studied megabeds provides evidence for occurrence of long-lived flows and suggests deposition by gradual aggradation from sustained currents (sustained turbidity current, Kneller & Branney, 1995).
Assuming a quasi-steady flow scenario we can explain the nature of the numerous very thick megabeds within the Cellino Fm considering that the determining factors of the thickness of the studied deposits are the confinement of the basin and the rate and the duration of deposition, which may proceed as long as the current maintains a flux of grains towards the site of deposition.
The origin of these large-volume turbidity currents and their high rate of occurrence can be related to an interaction of many factors and external controls, which are typical of the ancient foredeep basins (Mutti et al., 2003).
The depocenter migration of the Periadratic Foredeep caused the accumulation of thick sedimentary bodies, which developed progressively within the depositional axes. Since the collisional margins were convergent, there was longitudinal migration of depocenters. Our data suggest that the studied megabeds could be originated from catastrophic floods and sediment failures during relative falling- and low-stand stage of sea-level forced by dramatic tectonic uplift of basin margins and turbidity systems already deposited in the northern areas
A frequency approach to identifying asteroid families II. Families interacting with nonlinear secular resonances and low-order mean-motion resonances
No full textAims. In an earlier paper we introduced a new method for determining asteroid families where families were identified in the proper frequency domain (n, g, g + s) ( where n is the mean-motion, and g and s are the secular frequencies of the longitude of pericenter and nodes, respectively), rather than in the proper element domain (a, e, sin(i)) (semi-major axis, eccentricity, and inclination). Here we improve our techniques for reliably identifying members of families that interact with nonlinear secular resonances of argument other than g or g + s and for asteroids near or in mean-motion resonant configurations. Methods. We introduce several new distance metrics in the frequency space optimal for determining the diffusion in secular resonances of argument 2g - s, 3g - s, g - s, s, and 2s. We also regularize the dependence of the g frequency as a function of the n frequency (Vesta family) or of the eccentricity e (Hansa family). Results. Our new approaches allow us to recognize as family members objects that were lost with previous methods, while keeping the advantages of the Carruba & Michtchenko (2007, A& A, 475, 1145) approach. More important, an analysis in the frequency domain permits a deeper understanding of the dynamical evolution of asteroid families not always obtainable with an analysis in the proper element domain
Sustained quasi-steady turbidity current : outcrop evidence from the Pliocene peri-Adriatic foredeep (Cellino Fm., Central Italy)
No full textThe aim of this work is to investigate the nature of the numerous, very thick deep-water sheet-sandstones that dominate the lower portion of the Cellino Formation (Central Italy).
The studied turbidite system (about 2,500 m thick) represents the Lower Pliocene turbiditic filling of the outer Abruzzo sector of the Periadriatic foredeep. The foredeep was affected by compressional deformation linked to the overall migration of the chain-foredeep system toward the east. Tectonic activity was mostly coeval with the sedimentation and propagated towards the foreland; thrusting became progressively younger from W to E. The Cellino Basin has been intensely explored, being the site of hydrocarbon-bearing sands.
The turbidite beds can be distinctively resolved in the well logs and correlated to the measured sedimentary sections on outcrop. Based on well log correlation, tens of individual beds up to 23 m thick have been traced along the axis of the basin over distance in excess of 100 km and, perpendicularly to the basin, over distance of 30-40 km (Carruba et al. in press), with sand volumes on the order of a few 10’s Km3 (10 – 80 Km3). Palaeocurrent data taken from basal flute structures indicates southerly-directed flows, parallel to the depocentral axis of the basin. The thickest beds show a basin-wide extension, onlapping the basin margins without significant thickness variation.
The internal organization of the studied megabeds provides evidence for occurrence of long-lived flows and suggests deposition by gradual aggradation from sustained currents (sustained turbidity current; Kneller and Branney, 1995). The following features have been argued to be characteristic for sustained currents: (i) turbidite beds of extraordinary volume and thickness, (ii) very thick massive basal division (0.5 – 6 m thick), (iii) very frequent alternation of structureless and laminated intervals associated to internal scour surfaces, (iv) thick massive mudstone cap (1-10 m) that terminates the vertical organization of the sedimentary structures, (v) crudely developed grain-size profile that is overall upward fining (normally graded), (vi) abundant organic matter, (vii) extensive water-escape features.
The very thick massive basal division observed in the studied megabeds can be explained with progressive aggradation and absence of traction at the depositional flow boundary. The very frequent alternation of structureless and laminated intervals observed within the studied deposits, and their internal scour surfaces reflect temporal variation in flow velocity and sediment flux within the same current, as indicated by the discontinuity of the scour surface and the constant grain size above and below the surfaces. The graded upper part of the studied megabeds (a thick massive mud cap terminates the vertical organization of the sedimentary structures) represents the deposits of the waning stage of the current.
Assuming a quasi-steady flow scenario we can explain the nature of the numerous very thick megabeds within the Cellino Fm considering that the determining factors of the thickness of the studied deposits are the confinement of the basin and the rate and the duration of deposition, which may proceed as long as the current maintains a flux of grains towards the site of deposition.
The origin of these large-volume turbidity currents and their high rate of occurrence can be related to an interaction of many factors and external controls, which are typical of the ancient foredeep basins (Mutti et al., 2003).
Our data suggest that the studied megabeds could be originated from catastrophic floods and sediment failures during relative falling- and low-stand stage of sealevel forced by dramatic tectonic uplift of basin margins. Where the mountains fronts are close to shoreline, floods would be able to carry the majority of sediment load directly to the sea; the final depositional area of the ancient fluvial system that probably fed the Cellino basin lies in the deep water, far away from river mouths, and it is recorded by basinal turbidite sandstones and megabeds.
Although an understanding of climatic controls is extremely difficult on the basis of available data, high-frequency climatic pulses (that provided the water through which sediments were periodically flushed to the Periadriatic foredeep by flood-related process) could explain the amount of stacked megabeds. In this model, lower-frequency tectonically-forced cycles of uplift/denudation account for sediment availability through time. Consequently, the lower portion of the Cellino Formation could correspond to a stage of a single uplift/denudation cycle. In this stage, the tectonically active Cellino basin reaches its highest instability because the elevation of drainage basins is maximum and its proximity to the shoreline minimum
From seismic to bed : surface–subsurface correlations within the turbiditic Cellino Formation (central Italy)
No full textThe area east of the Gran Sasso Chain in Central Italy has been explored in detail because it holds a hydrocarbon field (Cellino Field), located in the Lower Pliocene foredeep turbidites of the Cellino Formation. Correlation has been made between the hydrocarbon-bearing sedimentary bodies and the same stratigraphic intervals cropping out only few kilometers to the west. The area thus offers a rare example where lithofacies, observed in the field, electrofacies displayed by the electric logs of the wells and seismofacies revealed by seismic survey can be compared.
This surface-subsurface integrated study of the Cellino Formation has revealed the presence of different turbiditic facies associations, their related electrical expressions and the possibility of a seismostratigraphic subdivision of the unit. These correlations exemplify the different resolution of these three complementary methods of investigation
Sedimentary evolution in a migrating foredeep basin : geometry and facies analysis of the massive sandy bodies of the Cellino Formation (Lower Pliocene Periadriatic foredeep, Central Italy)
No full textThe sedimentary evolution of the Lower Pliocene Periadriatic Foredeep in Central Italy is described on the basis of integrated facies analysis of the numerous turbidite massive sandy bodies (megabeds) and correlations of well log-field data, which give new perspectives on the effects of the basin migration.
The basin evolution shows four major morphological changes during the Lower Pliocene. In a first phase, the basin was fed From the south, as testified by coarse clastic, turbiditic sediments coming from the Maiella Massif. Subsequently (second stage) its Southern feeding system was switched off by the uplift of a structural high (Cigno structural high) and the basin received turbidite fill from northern source areas. Basin-wide, very thick (2 to 22 m) megabeds are the result of aggradation of high efficiency, large-volume turbidites that can be interpreted as deposited from sustained (long-lived) currents flowing in a confined basin.
The foredeep migration towards the south-east, common in the entire Periadriatic foredeep, caused, in the third phase, a reactivation of the sedimentation with megabeds thinning southward in the northern uplifting area, followed by megabeds prograding and aggrading into a new depocenter located to the south. In the final stage, the increasing uplift of the northern part of the basin, due to thrusts active in the north-western area, gave rise to its deep erosion, above a relevant unconformity, development of channels filled by sands in the inner fan and progradation of the outer fan southward. It is hoped that this study can be applied to other migrating basins of the Periadriatic Foredeep
Sedimentary evolution in a migrating foredeep basin: Geometry and facies analysis of the massive sandy bodies of the Cellino Formation, Lower Pliocene Periadriatic Foredeep (Central Apennines, Italy)
No full textThe sedimentary evolution of the Lower Pliocene Periadriatic Foredeep in Central Italy is described on the basis of integrated facies analysis of the numerous turbidite massive sandy bodies (megabeds) and correlations of well log-field data, which give new perspectives on the effects of the basin migration. The basin evolution shows four major morphological changes during the Lower Pliocene. In a first phase, the basin was fed from the south, as testified by coarse clastic, turbiditic sediments coming from the Maiella Massif. Subsequently (second stage) its southern feeding system was switched off by the uplift of a structural high (Cigno structural high) and the basin received turbidite fill from northern source areas. Basin-wide, very thick (2 to 22 m) megabeds are the result of aggradation of high efficiency, large-volume turbidites that can be interpreted as deposited from sustained (long-lived) currents flowing in a confined basin. The foredeep migration towards the south-east, common in the entire Periadriatic foredeep, caused, in the third phase, a reactivation of the sedimentation with megabeds thinning southward in the northern uplifting area, followed by megabeds prograding and aggrading into a new depocenter located to the south. In the final stage, the increasing uplift of the northern part of the basin, due to thrusts active in the north-western area, gave rise to its deep erosion, above a relevant unconformity, development of channels filled by sands in the inner fan and progradation of the outer fan southward. It is hoped that this study can be applied to other migrating basins of the Periadriatic Foredeep
Mitochondrial biogenesis as a cellular signaling framework
No full textThe identification, more than 50 years ago, of mitochondria as the site of oxidative energy metabolism has prompted studies that have unraveled the complexity of the numerous biosynthetic and degradative reactions, fundamental to cell function, carried out by these organelles. These activities depend on a distinctive mitochondrial structure, with different enzymes and reactions localized in discrete membranes and aqueous compartments. The characteristic mitochondrial structural organization is the product of both synthesis of macromolecules within the mitochondria and the import of proteins and lipids synthesized outside the organelle. Synthesis and import of mitochondrial components are required for mitochondrial proliferation, but rather than producing new organelles, these processes may facilitate the growth of pre-existing mitochondria. Recent evidence indicates that these events are regulated in a complex way by several agonists and environmental conditions, through activation of specific transcription factors and signaling pathways. Some of these are now being elucidated. Generation of nitric oxide (NO) appears to be a novel player in this scenario, possibly acting as a unifying molecular switch to trigger the whole mitochondriogenic process
Age and structural evolution of salt diapirism in the Iranian sector of the Persian Gulf
No full text- …
