Continental degassing of helium in an active tectonic setting (northern Italy): the role of seismicity

In order to investigate the variability of helium degassing in continental regions, its release from rocks and emission into the atmosphere, here we studied the degassing of volatiles in a seismically active region of northern Italy (MwMAX = 6) at the Nirano-Regnano mud volcanic system. The emitted gases in the study area are CH4–dominated and it is the carrier for helium (He) transfer through the crust. Carbon and He isotopes unequivocally indicate that crustal-derived fluids dominate these systems. An high-resolution 3-dimensional reconstruction of the gas reservoirs feeding the observed gas emissions at the surface permits to estimate the amount of He stored in the natural reservoirs. Our study demonstrated that the in-situ production of 4He in the crust and a long-lasting diffusion through the crust are not the main processes that rule the He degassing in the region. Furthermore, we demonstrated that micro-fracturation due to the field of stress that generates the local seismicity increases the release of He from the rocks and can sustain the excess of He in the natural reservoirs respect to the steady-state diffusive degassing. These results prove that (1) the transport of volatiles through the crust can be episodic as function of rock deformation and seismicity and (2) He can be used to highlight changes in the stress field and related earthquakes

Partially Updated Switching-Method for systems of nonlinear equations

AbstractA hybrid method for solving systems of n nonlinear equations is given. The method does not use derivative information and is especially attractive when good starting points are not available and the given system is expensive to evaluate. It is shown that, after a few steps, each iteration requires (2k + 1) function evaluations where k, 1 ⩽ k ⩽ n, is chosen so as to have an efficient algorithm. Global convergence results are given and superlinear convergence is established. Some numerical results show the numerical performance of the proposed method

Seismically-induced soft-sediment deformation structures in Upper Triassic deepwater carbonates (Central Sicily)

We describe soft-sediment deformation structures into the Upper Triassic cherty limestone outcropping in the Pizzo Lupo section (Central Sicily, Italy), pertaining to the deep-water palaeodomain of the Southern Tethyan margin. In the study section, mainly consisting of thin-bedded mudstone/marl alternations with bedded chert intercalations, some lithofacies have been separated on the basis of the abundance of the calcium carbonate/clay content and the overall textural features. The deformational structures, displaying different deformational styles as folded and faulted beds, disturbed layers, clastic dikes, and slumps occur mainly in the deformed horizons that involve marl-dominated lithofacies. Small-scale water-escape structures involve beds with nodular fabric. Synsedimentary faults affect the mud-limestone dominated lithofacies, which are characterized by fault-rotating blocks producing lateral thinning. These bodies appear to have moved coherently along an overall planar surface. We relate these soft-sediment deformations to slump sheets, associated with down-slope sliding of sedimentary masses. The deformation mechanism and driving force for these soft-sediment deformations are due essentially to gravitational instability and dewatering. Detailing, rotational (slump) and translational (glide) slides and water-escape are the main processes causing the distinguished deformational styles. The synsedimentary extensional tectonics that affected the Upper Triassic pelagic deposits was the triggering process responsible for the instability of the seafloor inducing loss of coherence of the unconsolidated sediments on the sea bottom, developing a large number of gravity-driven slides. The analysis of both of these SSDSs and their relationships with the structural scenario allow us to hypothesise that they are seismically-induced

K022: Effect of combination therapy (ANG II antagonist, valsartan and a calcium channel blocker) in a hypertensive model of diabetic nephropathy

Recently, it has been suggested that in the context of diabetes and hypertension, more aggressive blood pressure targets should be considered. To achieve these levels of blood pressure control, it is likely that combination therapy will need to be used. The present study has explored the role of the addition of either a dihydropyridine or a non-dihydropyridine calcium channel blocker (CCB) to Ang II antagonist based treatment in an experimental model of hypertension and diabetes. The doses chosen for the combination therapy groups were lower than those used with monotherapy in order to achieve similar antihypertensive efficacy. Diabetic (streptozotocin induced) SHR were randomised to no treatment, valsartan (30 mg/kg/day), the non-dihydropyridine CCB verapamil (20 mg/kg/day), the dihydropyridine CCB amlodipine (6 mg/kg/day), a combination of valsartan and amlodipine (20 mg + 4 mg/kg/day respectively) or valsartan and verapamil (20 mg + 15 mg/kg/day respectively). Serial measurements of systolic blood pressure (BP) and albumin excretion rate (AER) were performed monthly (data are shown at week 16 for AER and mean of wk 20-28 for BP). This model was associated with hypertension (control, 217 ± 8, diabetic, 200 ± 5 mmHg) which was reduced by most treatments to a similar degree (valsartan 165 ± 3, amlodipine 164 ± 2, verapamil 182 ± 4, valsartan + amlodipine 151 ± 3 and valsartan + verapamil 169 ± 5 mmHg). Diabetes was associated with a progressive increase in AER (control 1.5 vs diabetic 17 mg/24 hr). Valsartan retarded the increase in AER (11 mg/24 hr). Similar efficacy was observed in the valsartan + amlodipine combination (9 mg/24 hr) but not with amlodipine alone (16 mg/24 hr) despite similar effects on blood pressure. No advantage of verapamil versus amlodipine either as monotherapy or in combination with valsartan was observed. The present study indicates that the combination of an Ang II antagonist and a dihydropyridine CCB is an effective regimen at reducing blood pressure and albuminuria in the context of diabetes and hypertensio

Spatial extent of recent vertical tectonic motions misured in NE Sicily coastal area. Insights from marine geology and coastal geomorphology studies.

Vertical position of sea-level, pointed out by related deposits and morphologies, provide useful markers to estimate tectonic uplift rates. For the Holocene very high uplift rates are misured in the northeast Sicily coast (Antonioli et al., 2009). This study compare vertical tectonic movements and marine geology data in the coastal sector between Capo d\u2019Orlando and Brolo (NE Sicily); tectonic lineaments show different trends both onland (Nigro & Sulli, 1995) and offshore (Nicolich et al.,1982) and also the morphological response follow closely this difference. The geomorphologic survey provided data on Holocene uplift rates. We studied an archaeological ancient quarry of grinding wheels for oil that has been found in the Capo d\u2019Orlando inshore (Scicchitano et al., 2011). They present semi submerged circular holes in Stilo-Capo d\u2019Orlando deposits (Carbone et al., 1998). The tectonic uplift was evaluated as the difference between the observed local paleo-sea level position and the predicted sea-level curve for the same locality (Lambeck et al., 2011). The resulting uplift rates is 0.36 mm/yr (Scicchitano et al., 2011). In this area we studied also the Brolo stack. It is a metamorphic rocks emerging at 450 m from the coastline. The study led to discovery a fossils-bearing conglomerate in protected trays at 3.5 m a.s.l.. Radiocarbon analysis on a gastropod, gave us an age of 4965 years +-70 cal BP. If we compare this data with the predicted local sea level curves (Lambeck et al., 2011), we obtain an uplift rate about 1.5 mm/yr (Lo Presti et al., 2010), which is higher than that calculated in the study of archaeological rest. A detailed study of Brolo sector show us different morphological coastline position of Brolo plain. A picture of the year 1847 shows the coastline about 200 m landward. In Brolo coastal plain we have also found a Spondylus at -6 m b.s.l. We wait for the radiocarbon dating which allows us to have a new uplift rate data. The analysis of marine geology data (Multibeam) evidenced structures connected to different faults systems, such as the submarine canyons that are the continuation of river beds. Multibeam data evidenced also tilted NE-ward submerged surfaces, indicating existing structural movements, interesting only restricted areas. So, very different uplift rates in the Holocene in very close areas distant only about 10 kilometers: both 0.36 mm/yr (Scicchitano et al. 2011) and 1.5 mm/yr (Lo Presti et al. 2010), and morphobathymetric data (tilted surfaces), evidence the important role of active tectonic lineaments. Seismic reflection profiles support this assumption, showing the metamorphic basement strongly dissected by high-angle faults, which at place determines the occurrence of emergent rock bodies (e.g. the Brolo stack). All this suggesting the occurrence of \u201crestricted regions\u201d in the coastal-marine sector with different geological behavior as response to prominent tectonic releasing bands, determining their horizontal and vertical movements

Geo-hazards of the San Vito peninsula offshore (southwestern Tyrrhenian Sea)

In this paper we present geomorphological hazard mapping of the San Vito Peninsula offshore (Sicilian margin of Tyrrhenian Sea), characterised by a very narrow continental shelf and a very dipping, tectonically active continental slope, no far from a seismogenic belt. The data set consists of morpho-bathymetric models achieved by means of multibeam survey and scattered high resolution seismic profiles. The morpho-bathymetric study highlighted some potential sites of geomorphological hazards, the most representative of which are: (i) two canyons developing from the upper slope off San Vito Cape down to the Erice basin; (ii) a dense network of small incisions across the upper slope; (iii) a very active landslide, developed onland and extending in the continental shelf close to the Scopello village. The geomorphological features that can generate submarine hazard are represented by: unstable sediment packages into canyon heads or along the upper slope; submarine canyons with regressive erosion; coastal landslides

Late 6th – early 4th century BCE western Greek amphorae produced in Selinunte (western Sicily): Ceramic paste characterisation by an integrated archaeometric approach

This paper aims at an interdisciplinary, archaeological and archaeometric characterisation of the western Greek amphorae series produced in late Archaic and Classical-period at Selinunte (southwestern Sicily). Furthermore, it seeks for archaeometric parameters useful for its distinction from the morphologically very similar production of nearby Agrigento. The research is based on a macroscopic examination, according to the standardised methods of Fabrics of the Central Mediterranean (FACEM), combined with petrographic analyses of 25 amphorae samples and eight coarse ware samples of presumed local fabric found mostly in Selinunte, in the artisanal quarter, in the western town, and in the major sanctuary on the acropolis. Furthermore, a small selection of three amphorae has been unearthed in the western necropolis of Himera and at Cossyra/Pantelleria. Chemical analyses have been undertaken on a group of ten amphorae and four coarse ware samples. As a result, our study confirms the local manufacture of the entire selection of 33 samples and the more than acceptable petrographic and chemical homogeneity of the ceramic pastes produced with locally sourced clays. Some slight but significant compositional, textural and micro-paleontological differences between Selinuntine and Agrigento productions were pointed out. The identification of a production of western Greek wine-carrying (?) amphorae in Selinunte dating from the late 6th-earlier 4th century BCE supports earlier archaeometric analyses and breaks ground for a better understanding of the colony's economic development during the late Archaic and Classical periods. The present research will help to clarify the distribution of the class especially in Selinunte's territory, while its supra-regional circulation seems to have been quite limited