Search

Back‐arc basins (BABs) are associated with plate margins where crustal shortening, seafloor spreading, and volcanism coexist. The Vavilov basin (Tyrrhenian Sea) is a Pliocene BAB associated with the Apennine‐Tyrrhenian Sea subduction system and characterized by mantle exhumation. The NNE‐SSW elongated Vavilov seamount represents the easternmost and younger spreading ridge of the Vavilov basin. Here we present results of a morphological and magnetic study of the Vavilov seamount. Our results show that the seamount represents the last stage of the eastward asymmetric opening of the BAB. Its plumbing system consists of a dike swarm emplaced during the reversed Matuyama epoch and a younger shallow reservoir feeding the central and eastern sectors during the normal Brunhes epoch. This evolution is associated with the progressive loading of the edifice due to lava flow emplacement. The asymmetry of the seamount mirrors the asymmetric opening of the Vavilov back‐arc basin. Plain Language Summary: Stretching of the crust, seafloor spreading, and volcanism occur in the overriding plate above roll‐backing slabs in subduction settings. The Vavilov basin (Tyrrhenian Sea) is a back‐arc associated with the eastward retreating of the Apennine‐Tyrrhenian Sea subduction system. The NNE‐SSW elongated Vavilov submarine volcano represents the easternmost and younger spreading center of this back‐arc basin. Combined morphological and magnetic studies of the Vavilov seamount show that the plumbing system of the seamount consists of an early sheet‐like intrusion system and a younger, central reservoir feeding the magmatism of the central and eastern sectors of the spreading ridge. This evolution is associated with the progressive growth of the edifice due to lava flow emplacement. The morphological and magnetic asymmetry of the seamount is due to the eastward, asymmetric opening of the Vavilov back‐arc basin. Key Points: Magnetic inverse model images the multi‐level plumbing system of the spreading ridge of the Pliocene Vavilov back‐arc basinThe spreading ridge evolves from a fissural to a central‐type activityThe migration of volcanism in spreading ridges mirrors the asymmetric opening of back‐arc basins [ABSTRACT FROM AUTHOR]

Objectives: Deep infiltrating endometriosis (DIE) is associated with chronic pelvic pain, dyspareunia and pelvic floor muscle hypertonia. The primary aim of this study was to evaluate the effect of pelvic floor physiotherapy (PFP) on the area of levator ani hiatus during Valsalva maneuver, assessed using transperineal ultrasound, in women with DIE suffering from superficial dyspareunia.Methods: This was a randomized controlled trial of 34 nulliparous women diagnosed with DIE and associated superficial dyspareunia. After an initial clinical examination, all patients underwent three-dimensional/four-dimensional (3D/4D) transperineal ultrasound to measure the levator hiatal area (LHA) at rest, on maximum pelvic floor muscle contraction and on maximum Valsalva maneuver, and were asked to rate their pain symptoms using a numerical rating scale (NRS). Eligible women were assigned randomly (1:1 ratio) to no intervention (control group, 17 women) or treatment with five individual sessions of PFP (study group, 17 women). Four months after the first examination, all women underwent a second evaluation of pain symptoms and LHA on transperineal ultrasound. The primary outcome measure was the percentage change in LHA on maximum Valsalva maneuver between the baseline and follow-up examinations. The percentage changes in pain symptoms between the two examinations, including superficial and deep dyspareunia, dysmenorrhea, chronic pelvic pain, dysuria and dyschezia, were also evaluated.Results: Thirty women, comprising 17 in the study group and 13 in the control group, completed the study and were included in the analysis. The percentage change in LHA on maximum Valsalva maneuver between the two examinations was higher in the study group than in the control group (20.0 ± 24.8% vs -0.5 ± 3.3%; P = 0.02), indicating better pelvic floor muscle relaxation. After PFP treatment, the NRS score for superficial dyspareunia remained almost unchanged in the control group (median change in NRS (Δ-NRS), 0 (interquartile range (IQR), 0-0)) while a marked reduction was observed in the study group (median Δ-NRS, -3 (IQR, -4 to -2); P < 0.01). Moreover, there was a significant difference between the PFP and control groups with regards to the change in chronic pelvic pain (median Δ-NRS, 0 (IQR, -2 to 0) vs 0 (IQR, 0-1); P = 0.01).Conclusions: In women with DIE, PFP seems to result in increased LHA on Valsalva maneuver, as observed by 3D/4D transperineal ultrasound, leading to improved superficial dyspareunia, chronic pelvic pain and pelvic floor muscle relaxation. © 2020 International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

Mantle-derived serpentinites have been detected at magma-poor rifted margins and above subduction zones, where they are usually produced by fluids released from the slab to the mantle wedge. Here we show evidence of a new class of serpentinite diapirs within the external subduction system of the Calabrian Arc, derived directly from the lower plate. Mantle serpentinites rise through lithospheric faults caused by incipient rifting and the collapse of the accretionary wedge. Mantle-derived diapirism is not linked directly to subduction processes. The serpentinites, formed probably during Mesozoic Tethyan rifting, were carried below the subduction system by plate convergence; lithospheric faults driving margin segmentation act as windows through which inherited serpentinites rise to the sub-seafloor. The discovery of deep-seated seismogenic features coupled with inherited lower plate serpentinite diapirs, provides constraints on mechanisms exposing altered products of mantle peridotite at the seafloor long time after their formation. [ABSTRACT FROM AUTHOR]

New multichannel seismic reflection profiles were acquired to unravel the structure of a portion of the eastern margin of the Tyrrhenian basin. This extensional feature is part of an Oligocene to Present back-arc basin in the hangingwall of the west directed Apennines subduction system. The basin provides excellent conditions to investigate the early stage processes leading to the development of rifted passive margins and to the emplacement of oceanic crust in an oblique setting. The interpreted post-stack-migrated seismic profiles highlight the geometry and kinematics of the Pontine escarpment that connects the Latium-Campania continental margin to the Vavilov basin. The latter is the main feature of the area, related to the early Pliocene extension of the Tyrrhenian Sea. Several morphological variations are pointed out along strike, mirroring different structural settings of the margin itself: a steeper margin to the north corresponds to high-angle possibly transtensional faults, whereas a smooth slope in the southern portion corresponds to several more distributed listric faults. This work contributes to the understanding of the interplay between extensional and transtensional tectonics along the margins of an oblique back-arc basin. [ABSTRACT FROM AUTHOR]

ABSTRACT The Gulf of Manfredonia and the Tavoliere Plain have experienced intense human colonization since the neolithic times. There is past evidence in the study area of a Roman-age settlement historically known as Salapia, probably located close to the salt-production ponds. In particular, several portions of a partly submerged ancient pier-like structure were found close to Torre Pietra town. This structure has been interpreted as a portion of a dragged-ship channel that connected the town of Salapia to the sea. In this article we discuss the results of a high-resolution geophysical prospecting of the Margherita di Savoia offshore archaeological site (Puglia, Italy). We collected magnetic gradiometric and bathymetric data to map the submerged remains of Salapia harbour. We found evidence of an offshore projection of a Torre Pietra pier-like structure, identifying the direction of the ship channel and possibly the location of the harbour's defensive post. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Inversion of new high-resolution magnetic data from the Marsili seamount and the surrounding basin in the Tyrrhenian Sea reveals NNE–SSW magnetization stripes ranging from the Matuyama chron to the Brunhes chron, including the short positive Jaramillo subchron. The detailed magnetic chronology shows that from the late Matuyama (1.77 Ma), the average half spreading rate was about 1.5 cm yr−1, with a slight decrease between the Jaramillo and the Brunhes events, when the growth of the volcanic edifice overcame lateral spreading. Analysis of spreading rate and volume of erupted lava indicates that at the beginning of the Jaramillo subchron (1.07 Ma), the Marsili basin evolved from pure horizontal spreading to a superinflated seamount as a consequence of tearing of the Ionian slab. Our data give us a snapshot of the geodynamic transition from an active backarc spreading phase to the vertical accretion of the seafloor because of a radical change in the subduction dynamics. [ABSTRACT FROM AUTHOR]

Copyright of PSN is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We have used free-air gravity satellite data from GEOSAT and ERS-1 missions to compile a Bouguer gravity map of the Mediterranean Sea. The complete Bouguer correction has been applied by using the method of Parker, that acts in the Fourier domain and permits the exact evaluation of the gravity contribution from an highly sampled topographic model of the land. The density used for the Bouguer reduction has been obtained from the gravity data set itself, by using two different optimization methods that have given the same optimal result of 2400 kg m−3. We have studied the radial power spectrum of the data, choosing the optimal Bouguer density from its slope, as the one which minimizes the fractal dimension of the resulting gravity map. The second approach consists of studying the correlation between topography and Bouguer anomaly by spatial cross-plots for a significant subset of the data. Both these approaches are aimed at reducing the short-wavelength effects of topography in the gravity map, but in the past they have been traditionally used alternatively since they gave different optimization values, especially the second method that seems to ignore large-wavelength isostatic effects. Actually, we have revisited both the methodologies, proposing slight modifications to make their efforts compatible. Their coincident results confirm their validity of application and give reliability to the recovered value of the Bouguer optimal density. Moreover, modifying the second approach allows us to compile a sort of normalized correlation map, which we propose in this paper, defining the 2-D isostatic setting of the investigated region without introducing any further lithospheric model. The final result is a revised Bouguer map compiled using a grid with a resolution of 2 min, that is useful for large-scale geological studies and gives important information about the compensation mechanism of the Mediterranean Sea: in a direct way we have found that the overall region seems to be in a complete isostatic equilibrium apart from the young basins of Tyrrhenian Sea and Aegean Sea, confirming previous similar results. [ABSTRACT FROM AUTHOR]

This paper shows the results of a detailed reprocessing of aeromagnetic data, obtained by the downward projection to the seabed. The area of interest is centered over the Tyrrhenian Basin, whose bathymetric–topographic lay-out is characterized by a somewhat irregular trend. The origin of the intense depth variations depends on the Tyrrhenian structural setting, that is associated with the presence of several tectonic lineaments, seamounts or volcanic islands. The data were characterized by good quality and dense sampling, but they have been reprocessed in order either to solve some problems in the original compilation, and to reduce the distortion of the geomagnetic anomaly field caused by the difference of distance between the survey level and the magnetic source. The reprocessed magnetic map is proposed as an effective analysis tool for the Tyrrhenian area that is characterized by high susceptibility lithotypes. Downward projection of the aeromagnetic data by BTM algorithm increases the definition of the anomalous magnetic signal without distortions in the geometric pattern of the field, thus showing a more stable and effective association between the magnetic anomalies and their geological sources. This effect is particularly true for high frequency anomalies that are directly comparable after the topographic projection because the depth filtering effect is attenuated. Moreover, the BTM method has been applied for the first time to a regional scale survey that shows substantial advantages because no fictitious anomalies in the high frequency sector of the spectrum were generated. This has been a typical effect of the traditional downward projection methods widely used before. The final result is a BTM anomaly map that is able to show the structural connections between the geological magnetic sources of the Tyrrhenian Sea area. [ABSTRACT FROM AUTHOR]

3 Mabrouk M, Del Forno S, Spezzano A, Raimondo D, Arena A, Zanello M, Leonardi D, Paradisi R, Seracchioli R. Painful Love: Superficial Dyspareunia and Three Dimensional Transperineal Ultrasound Evaluation of Pelvic Floor Muscle in Women with Endometriosis. In particular, we assessed endometriosis-associated pain symptoms (chronic pelvic pain, dysmenorrhea, dysuria, dyschezia and dyspareunia) with special focus on the most troublesome symptom, superficial dyspareunia, which seems to be widespread in women with endometriosis and, in the majority of cases, is concomitant with deep dyspareunia3. We thank Dr Hirsch and his colleagues for their interest in our study1 and their constructive comments. [Extracted from the article]

High-resolution seismic reflection, magnetic and gravity data, acquired offshore of Etna volcano, provide a new insight to understanding the relationship between tectonics and spatial-temporal evolution of volcanism. The Timpe Plateau, a structural high pertaining to the Hyblean foreland domain, located offshore of southeastern Mt. Etna, is speckled by volcanics and strongly affected by strike-slip tectonics. Transpressive deformation produced a push-up and a remarkable shortening along WNW-ESE to NW-SE trending lineaments. Fault segments, bounding basinal areas, show evidence of positive tectonic inversion, suggesting a former transtensive phase. Transtensive tectonics favoured the emplacement of deep magmatic intrusive bodies and Plio-Quaternary scattered volcanics through releasing zones. The continuing of wrench tectonics along different shear zones led to the migration of transtensive regions in the Etna area and the positive inversion of the former ones, where new magma ascent was hampered. This process caused the shifting of volcanism firstly along the main WNW-ESE trending "Southern Etna Shear Zone", then towards the Valle del Bove and finally up to the present-day stratovolcano. [ABSTRACT FROM AUTHOR]