Aeromagnetic anomalies reveal hidden tectonic and volcanic structures in the Aeolian Islands, southern Tyrrhenian Sea, Italy

The structures of the Southern Tyrrhenian Sea active volcanoes have been successfully investigated through the use of the magnetic data. Particularly, several high resolution aeromagnetic campaigns have been carried out on the Aeolian Archipelago and its western limit by the Airborne Geophysics Science Team of Istituto Nazionale di Geofisica e Vulcanologia of Roma. The results indicate that the volcanism is controlled by tectonic structures both at local and regional scale. The emplacement of magnetized bodies (e.g. volcanic conduits, dikes swarms, intrusions) is along or strictly correlated with this tectonic framework. The consolidation of highly magnetized material inside the volcanic conduits determines contrast with surrounding less magnetized material producing intense magnetic anomalies. Therefore, modeling of these sources is suggestive of the position and deep extent of eruptive vents, especially in the offshore area, where we do not know where future submarine activity may take place (De Ritis et al., 2005). We present here a case study were the magnetic tool resolved a geological interpretative problem that was not settled earlier. In fact, in the Calabria mainland, widespread, dacitic to rhyolitic pumices with calc-alkaline affinity of Pleistocene age (1-0.7 Ma) are exposed. The tephra falls are related to explosive activity and show thickness decreasing from the Capo Vaticano area southeastward. The lithics indicate a source located not far from Capo Vaticano. The interpretation of the magnetic anomaly field together with the other geological and geophysical data has allowed to discover the presence of a previously unknown volcanic structure (De Ritis et al., 2010), very close to the Calabria Western coast (Capo Vaticano). Aeromagnetic data collected between the Panarea island and the Calabria arc highlight a WNW-ESE elongated positive magnetic anomaly centered on the Capo Vaticano morphological ridge. Forward and inverse modeling show a magnetized body extending from the bathymetric surface to about 3 km of depth. The magnetic properties of such a body are consistent with those of the medium to highly evolved volcanic rocks of the Aeolian Arc, i.e. dacites and rhyolites. The combined interpretation of the magnetic and available geological data reveal that (1) the Capo Vaticano WNW- ESE elongated positive magnetic anomaly is due to the occurrence of a WNW-ESE elongated sill; (2) such a sill represents the remnant of the plumbing system of a Pleistocene volcano that erupted explosively producing the pumice tephra exposed in Calabria; and (3) the volcanism is consistent with the Aeolian products, in terms of age, magnetic signature, and geochemical affinity of the erupted products. The results indicate that such volcanism developed along seismically active faults transversal to the general trend of the Aeolian Arc and Calabria block, in an area where uplift is maximized (4 mm/yr). Such uplift could also be responsible for fragmentation of the upper crust and formation of transversal faults along which seismic activity and volcanism occur

Inverse Modelling of the Reversely Magnetized, Shallow Plumbing System Hosting Oil Reservoirs of the Auca Mahuida Volcano (Payeina retroarc, Neuquén Basin, Argentina)

The Auca Mahuida volcano (2.03–0.88 Ma) located east of the Andean thrust front in the Neuquén basin (Argentina) hosts an oil system of thermogenic origin and is affected by the NW–SE striking-faults. Intrusive bodies and the underlying Jurassic sediments constitute the reservoir rocks. Aeromagnetic data collected in the Auca Mahuida area detected multiple dipolar magnetic anomalies, many of which have reverse polarity. Palaeomagnetic measurements on rock samples collected in the field together with available age determinations indicate that the reversely magnetized sources were mainly emplaced during the Matuyama reverse polarity chron while the normal polarity sources were emplaced during the Olduvai and/or Jaramillo subchrons. The location and geometry of the intrusive bodies is poorly known and the customary magnetic inversion is rendered difficult because of multiple natural remanent magnetization directions. To address these difficulties, a voxel inversion was applied to model the vector residual magnetic intensity (VRMI) transformation of the observed total magnetic intensity data. The modelling showed a 1.5 km deep, subcircular ring-shaped intrusion below the summit of the volcano and a series of NW–SE elongated, fault-controlled intrusive bodies to depths up to 3–4 km. Our results show that magnetic data and VRMI modelling help resolve the geometry of the shallow plumbing system of volcanoes with remanently magnetized sources, and estimate the depth and geometry of potential oil reservoirs in volcanic areas

Inverse modelling of the reversely magnetized, shallow plumbing system hosting oil reservoirs of the Auca Mahuida volcano (Payeina retroarc, Neuquén Basin, Argentina)

The Auca Mahuida volcano (2.03–0.88 Ma) located east of the Andean thrust front in the; Neuqu´en basin (Argentina) hosts an oil system of thermogenic origin and is affected by the; NW–SE striking-faults. Intrusive bodies and the underlying Jurassic sediments constitute the; reservoir rocks. Aeromagnetic data collected in the Auca Mahuida area detected multiple; dipolar magnetic anomalies, many of which have reverse polarity. Palaeomagnetic measurements; on rock samples collected in the field together with available age determinations indicate; that the reversely magnetized sources were mainly emplaced during the Matuyama reverse; polarity chron while the normal polarity sources were emplaced during the Olduvai and/or; Jaramillo subchrons. The location and geometry of the intrusive bodies is poorly known and; the customary magnetic inversion is rendered difficult because of multiple natural remanent; magnetization directions. To address these difficulties, a voxel inversion was applied to model; the vector residual magnetic intensity (VRMI) transformation of the observed total magnetic; intensity data. The modelling showed a 1.5 km deep, subcircular ring-shaped intrusion below; the summit of the volcano and a series of NW–SE elongated, fault-controlled intrusive bodies; to depths up to 3–4 km. Our results show that magnetic data and VRMI modelling help resolve; the geometry of the shallow plumbing system of volcanoes with remanently magnetized; sources, and estimate the depth and geometry of potential oil reservoirs in volcanic areas.Facultad de Ciencias Astronómicas y Geofísica

Sprofondamenti in aree urbane: il caso del parco “Ytzhak Rabin” (via Panama, Roma)

In Rome urban area, within the garden dedicated to Ytzhak Rabin (a portion of the Villa Ada park), occurrence of a few collapses has been observed for the first time in September 2012. In the surroundings, presence of underground cavities- mainly catacombs- is conversely well documented by previous studies. Local authorities were immediately informed of sinkholes formation, because collapses occurred very close to a playground located in a highly frequented sector of the garden. Propagation processes of the phenomena, periodically monitored since their first observation, significantly fastened after a period of heavy rainfalls on Rome area in January- February 2014. Thus, multidisciplinary geophysical investigations have been started in agreement with Civil Protection of Rome Municipality, who has taken preliminary safety measures (installation of fences and danger signals). Hitherto, 28 sinkholes have been identified, aligned along a WNW-ESE trending zone, testifying localized collapses of the roof of underground cavities, probably belonging to the palaeocristian catacomb systems dug nearby Via Salaria. Preliminary geophysical prospections have been performed in a small test area, in order to verify methods applicability and thus program a systematic survey of the whole garden. Drillings, and direct exploration of the accessible galleries, will complete the reconstruction of underground geometry and conservation state of vaults and pillars. Once completed the hazard assessment, the planning of urgent works is expected in order to restore the complete use of the garden.Published25 - 422TR. Ricostruzione e modellazione della struttura crostaleN/A or not JC

Indagini geofisiche e geochimiche di un sinkhole in formazione nell’area di Guidonia (Lazio)

The Plio-Quaternary Acque Albule Basin is already known for the occurrence of sinkholes; since the spring 2014, it has been ongoing the study of an active subsidence process, which formed a depressed area near the Guidonia village. During the last year, the phenomenon has become more intense giving rise to two collapses along the eastern rim of the depression. Thus, geophysical and geogeochemical investigation campaigns started in order to understand the genesis and evolution of the phenomenon. Survey results allowed a geological and structural characterization, showing the presence of “travertino” at the depression margins and its absence therein. It has been recognized, by the geophysics, features with NW-SE and NNE-SSW direction ascribable to a possible depression fracturing and consistent with regional structural trends. Thus, it has been possible to plan and perform geognostic investigation consisting in two drillings aimed to define the stratigraphy of the marginal and inner part of the depression.Published7 - 162TR. Ricostruzione e modellazione della struttura crostaleJCR Journa

Gliadin Peptide P31-43 Localises to Endocytic Vesicles and Interferes with Their Maturation

BACKGROUND: Celiac Disease (CD) is both a frequent disease (1:100) and an interesting model of a disease induced by food. It consists in an immunogenic reaction to wheat gluten and glutenins that has been found to arise in a specific genetic background; however, this reaction is still only partially understood. Activation of innate immunity by gliadin peptides is an important component of the early events of the disease. In particular the so-called "toxic" A-gliadin peptide P31-43 induces several pleiotropic effects including Epidermal Growth Factor Receptor (EGFR)-dependent actin remodelling and proliferation in cultured cell lines and in enterocytes from CD patients. These effects are mediated by delayed EGFR degradation and prolonged EGFR activation in endocytic vesicles. In the present study we investigated the effects of gliadin peptides on the trafficking and maturation of endocytic vesicles. METHODS/PRINCIPAL FINDINGS: Both P31-43 and the control P57-68 peptide labelled with fluorochromes were found to enter CaCo-2 cells and interact with the endocytic compartment in pulse and chase, time-lapse, experiments. P31-43 was localised to vesicles carrying early endocytic markers at time points when P57-68-carrying vesicles mature into late endosomes. In time-lapse experiments the trafficking of P31-43-labelled vesicles was delayed, regardless of the cargo they were carrying. Furthermore in celiac enterocytes, from cultured duodenal biopsies, P31-43 trafficking is delayed in early endocytic vesicles. A sequence similarity search revealed that P31-43 is strikingly similar to Hrs, a key molecule regulating endocytic maturation. A-gliadin peptide P31-43 interfered with Hrs correct localisation to early endosomes as revealed by western blot and immunofluorescence microscopy. CONCLUSIONS: P31-43 and P57-68 enter cells by endocytosis. Only P31-43 localises at the endocytic membranes and delays vesicle trafficking by interfering with Hrs-mediated maturation to late endosomes in cells and intestinal biopsies. Consequently, in P31-43-treated cells, Receptor Tyrosine Kinase (RTK) activation is extended. This finding may explain the role played by gliadin peptides in inducing proliferation and other effects in enterocytes from CD biopsies

Aeromagnetic anomalies reveal hidden tectonic and volcanic structures in the Aeolian Islands, southern Tyrrhenian Sea, Italy

The structures of the Southern Tyrrhenian Sea active volcanoes have been successfully investigated through the use of the magnetic data. Particularly, several high resolution aeromagnetic campaigns have been carried out on the Aeolian Archipelago and its western limit by the Airborne Geophysics Science Team of Istituto Nazionale di Geofisica e Vulcanologia of Roma. The results indicate that the volcanism is controlled by tectonic structures both at local and regional scale. The emplacement of magnetized bodies (e.g. volcanic conduits, dikes swarms, intrusions) is along or strictly correlated with this tectonic framework. The consolidation of highly magnetized material inside the volcanic conduits determines contrast with surrounding less magnetized material producing intense magnetic anomalies. Therefore, modeling of these sources is suggestive of the position and deep extent of eruptive vents, especially in the offshore area, where we do not know where future submarine activity may take place (De Ritis et al., 2005). We present here a case study were the magnetic tool resolved a geological interpretative problem that was not settled earlier. In fact, in the Calabria mainland, widespread, dacitic to rhyolitic pumices with calc-alkaline affinity of Pleistocene age (1-0.7 Ma) are exposed. The tephra falls are related to explosive activity and show thickness decreasing from the Capo Vaticano area southeastward. The lithics indicate a source located not far from Capo Vaticano. The interpretation of the magnetic anomaly field together with the other geological and geophysical data has allowed to discover the presence of a previously unknown volcanic structure (De Ritis et al., 2010), very close to the Calabria Western coast (Capo Vaticano). Aeromagnetic data collected between the Panarea island and the Calabria arc highlight a WNW-ESE elongated positive magnetic anomaly centered on the Capo Vaticano morphological ridge. Forward and inverse modeling show a magnetized body extending from the bathymetric surface to about 3 km of depth. The magnetic properties of such a body are consistent with those of the medium to highly evolved volcanic rocks of the Aeolian Arc, i.e. dacites and rhyolites. The combined interpretation of the magnetic and available geological data reveal that (1) the Capo Vaticano WNW- ESE elongated positive magnetic anomaly is due to the occurrence of a WNW-ESE elongated sill; (2) such a sill represents the remnant of the plumbing system of a Pleistocene volcano that erupted explosively producing the pumice tephra exposed in Calabria; and (3) the volcanism is consistent with the Aeolian products, in terms of age, magnetic signature, and geochemical affinity of the erupted products. The results indicate that such volcanism developed along seismically active faults transversal to the general trend of the Aeolian Arc and Calabria block, in an area where uplift is maximized (4 mm/yr). Such uplift could also be responsible for fragmentation of the upper crust and formation of transversal faults along which seismic activity and volcanism occur.UnpublishedWien1V. Storia e struttura dei sistemi vulcanici4V. Vulcani e ambiente7A. Geofisica di esplorazioneope

Editorial for Special Issue “Present and Past Submarine Volcanic Activity (1)”

Over 1 million volcanoes on the Earth surface occur in marine and submarine environments in different geodynamic contexts [...

Analysis of the Aeromagnetic Anomalies of the Auca Mahuida Volcano, Patagonia, Argentina

We present the analysis of the subsurface structure of the Auca Mahuida volcano based on high-resolution aeromagnetic data integrated with the available geological information. Most of the detected magnetic anomalies have a dipolar structure opposite to that of the present geomagnetic field. According to the available geochronological data and paleomagnetic measurements, the source bodies of Auca Mahuida mainly emplaced in the Matuyama reverse polarity chron. The Reduction-to-the-Pole map confirms that the magnetization direction is mainly reverse with only few anomalies normally magnetized. Two opposite, coexisting polarities do not allow to fully remove the dipolar character of the field in the Reduction-to-the-Pole transformation. Therefore, we model the measured anomaly field by applying analytical techniques that are independent of the magnetization direction. The obtained anomaly strikes and source geometries indicate an emplacement of intrusive bodies controlled by the regional faults affecting the Auca Mahuida basement and the sedimentary successions of the Neuquén basin. Magma upraised along these faults and fractures feeding the volcanic activity and subsequently crystallized. The averaged power spectrum and Euler Deconvolution indicate source depths consistent with those of the intrusions recognized in wells. Borehole data highlight the widespread presence of intrusive bodies below the Auca Mahuida central crater and the peripheral sectors at depth of 2 km below sea level. These bodies have played a major role in the thermal maturation of hydrocarbons and in the subsequent accumulation of oil below the volcano. The obtained results shed light on the Auca Mahuida feeding system and on the intrusions geometry, also pointing out the effectiveness of the magnetic prospecting in the oil industry even in presence of strong remanent magnetization.Published3273–32902TR. Ricostruzione e modellazione della struttura crostaleJCR Journa