Options
Favara, Rocco
Loading...
Preferred name
Favara, Rocco
Email
rocco.favara@ingv.it
Staff
staff
ORCID
68 results
Now showing 1 - 10 of 68
- PublicationRestrictedEvoluzione tettonica mesozoico-terziaria della Sicilia centrosettentrionale(2009)
; ; ; ; ;Nigro, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Salvaggio, G.; Dipartimento di Geologia e Geodesia, Università di Palermo, Italy - Via Archirafi, 22, 90123, Palermo ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Renda, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; ; ; Sicily owes its complex geological structure to a switch in tectonic regime from the Mesozoic to the Tertiary. A set of tectonic units outcrops in the northern portion of the island that originated during the Tertiary at the expense of paleogeographic domains of the African Mesozoic continental margin. The pre-orogenic successions show different types of deformation (extensional and transcurrent) related to the Jurassic paleotectonic evolution of the southern Neotethys margin. The history of the tectonic inversion of the Neotethys shear zone is recorded in the Cretaceous strata. Extension occurred during late Cretaceous and may be compatible with the tensile stress field related to the Sicilide basin opening. The Neogene deformations are linked to collisional processes and are mostly represented by thrusts and folds. Since the late Miocene onwards, the formation of the Tyrrhenian basin has driven the recent tectonic evolution of Northern Sicily. Its basin formation was realised through extension, followed by transcurrent tectonics along its southern margin.314 52 - PublicationRestrictedPreliminary studies on the geothermal fluids of the island of Ischia: gas geochemistry(1988)
; ; ; ; ; ; ; ; ; ; ; Fumarolic gases and dissolved gases in some thermal waters of Ischia were analyzed.82 6 - PublicationOpen AccessOn-line technique for preparingand measuring stable carbon isotopeof total dissolved inorganic carbonin water samples ( d13CTDIC)(2005)
; ; ; ; ; ;Capasso, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Grassa, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Inguaggiato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Longo, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; ; ; ; A fast and completely automated procedure is proposed for the preparation and determination of d13C of total inorganic carbon dissolved in water ( d13CTDIC). This method is based on the acidification of water samples transforming the whole dissolved inorganic carbon species into CO2. Water samples are directly injected by syringe into 5.9 ml vials with screw caps which have a pierciable rubber septum. An Analytical Precision «Carbonate Prep System» was used both to flush pure helium into the vials and to automatically dispense a fixed amount of H3PO4. Full-equilibrium conditions between produced CO2 and water are reached at a temperature of 70°C (± 0.1°C) in less than 24 h. Carbon isotope ratios (13C/ 12C) were measured on an AP 2003 continuous flow mass spectrometer, connected on-line with the injection system. The precision and reproducibility of the proposed method was tested both on aqueous standard solutions prepared using Na2CO3 with d13C=-10.78 per mil versus PDB (1 s= 0.08, n = 11), and at five different concentrations (2, 3, 4, 5 and 20 mmol/l) and on more than thirty natural samples. Mean d13CTDIC on standard solution samples is –10.89 < per mil versus PDB (1 s= 0.18, n = 50), thus revealing both a good analytical precision and reproducibility. A comparison between average d13CTDIC values on a quadruplicate set of natural samples and those obtained following the chemical and physical stripping method highlights a good agreement between the two analytical methods.240 450 - PublicationOpen AccessDepth influence on the distribution of chemical elements and saturation index of mineral phases in twins maar lakes: The case of the Monticchio lakes (southern Italy)(2016)
; ; ; ; ; ;; In this paper we provide a systematic geochemical study of the Monticchio maar lakes, on the Mt. Vulture volcano, southern Italy, to understand the processes affecting the distribution of chemical elements. A high-resolution conductivity–temperature–depth profile was obtained, and water samples were collected at various depths for analyses of major and trace elements. Although the two lakes are separated by less than 200 m, they exhibit different behaviour. The Ca–Na–HCO3 composition of “Lago Grande” water suggests that low-temperature fluids are leached from the host volcanic rocks. Na–Ca–HCO3 in near-surface “Lago Piccolo” water is derived from the dissolution of local volcanic rocks, while the deepest water samples are bicarbonate alkaline-earth in composition and generally show an enrichment in solutes with respect to the epilimnion layer (except for SO42 − content). The hypolimnion water is principally governed by both the input of saline groundwater from the lake bottom and authigenic processes within bottom sediments. In addition, the occurrence of anoxic conditions and microbial activity is responsible for the transformation of sulphates to hydrogen sulphide, and for the precipitation of Fe sulphide phases. Both processes cause a change in the chemical composition of saline groundwater as it moves upwards. Overall, the water chemistry of the Monticchio lakes is principally affected by: i) the input of CO2-rich volcanic gas; ii) evaporative processes that deplete near-surface water in some elements; and iii) the occurrence of chemical, physical and biological conditions causing the transformation of molecular complexes and consequently promoting mineral precipitation.66 438 - PublicationRestrictedHydrothermal processes governing the geochemistry of the crater fumaroles at Mount Etna volcano (Italy)(2010-11-02)
; ; ; ; ; ; ;Liotta, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Paonita, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Caracausi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Martelli, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Rizzo, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; ; ; ; ; We investigated the geochemistry of the fumaroles at the summit area of Mt. Etna, including sulfur speciation and the content of acidic gases. The carbon-isotope composition of the Etnean plume was also measured in order to compare it to that of fumaroles. Two types of fumaroles were identified: (i) low-temperature fumaroles, which are dominated by CO2 with minor amounts of SO2 and H2S, and negligible chlorine contents, and (ii) high-temperature fumaroles, which are strongly air-contaminated and characterized by appreciable amounts of volcanogenic carbon, sulfur, and chlorine. As recognized by Martelli et al. (2008), both groups of fumaroles are fed by the degassing of an underlying magma; nevertheless, compositional data clearly show that secondary processes affect the composition of the fluids once they leave the magma body. Here a model of cooling and condensation of fluids is proposed to explore such postmagmatic processes. The model, which uses Etnean plume geochemistry as starting composition of fluids exsolved from magma, shows that SO2 and H2S control the redox conditions of the gas mixture during the cooling, until the reactions involving CO/CO2 and H2/H2O ratios are fully quenched at temperatures around 350–450 °C. The dissolution of gases in water, subsequent to condensation, must occur at thermobaric conditions over 50 bar and 260 °C, which allows (a) total removal of HCl, (b) partial removal of sulfur species while preserving the SO2/H2S ratio, and (c) the C/S ratio to increase by almost 10-fold relative to that in the plume. The observed CH4/CO2 ratios are higher than those calculated for the Etnean magmatic gas, and hence they provide evidence of modest contributions from peripheral hydrothermal fluids during the migration of magmatic gases toward the surface in both low- and high-temperature fumaroles. Due to the peculiar thermodynamic conditions, the model predicts that carbon isotopes do not experience any postmagmatic fractionation, and hence the isotopic composition of the fumaroles is representative of magmatic carbon. Measurements of the carbon-isotope composition of the plume corroborate these findings.247 39 - PublicationRestrictedEffect of solid waste landfill organic pollutants on groundwater in three areas of Sicily (Italy) characterized by different vulnerability(2017-06-01)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;; ; ; ;; ; ; ; ; ; ; ; ;The aim of this study was to obtain information on the presence and levels of hazardous organic pollutants in groundwater located close to solid waste landfills. Eighty-two environmental contaminants, including 16 polycyclic aromatic hydrocarbons (PAHs), 20 volatile organic compounds (VOCs), 29 polychlorinated biphenyls (PCBs), 7 dioxins (polychlorinated dibenzo-p-dioxins, PCDDs) and 10 furans (polychlorinated dibenzofurans, PCDFs) were monitored in areas characterised by different geological environments surrounding three municipal solid waste landfills (Palermo, Siculiana and Ragusa) in Sicily (Italy) in three sampling campaigns. The total concentrations of the 16 PAHs were always below the legal threshold. Overall, the Fl/Fl + Py diagnostic ratio revealed that PAHs had a petrogenic origin. VOC levels, except for two notable exceptions near Palermo landfill, were always below the legal limit. As concerns PCB levels, several samples were found positive with levels exceeding the legal limits. It is worth noting that the % PCB distribution differs from that of commercial compositions. In parallel, some samples of groundwater containing PCDDs and PCDFs exceeding the legal threshold were also found. Among the 17 congeners monitored, the most abundant were the highest molecular weight ones.794 9 - PublicationOpen AccessOn-field measurements of CO2 isotope composition of diffuse degassing from soils in volcanic areas: Delta-ray setup for direct measurements in the 0-100% vol. range.(2019-04-10)
; ; ; ; ; ; ; Volcanoes release carbon dioxide in the atmosphere and have been targeted as potential contributors to the global warming. Despite the evidences lay against these conjectures, the accurate estimation of the release of CO2 of volcanic origin in the atmosphere is currently unavailable because both not all the volcanoes of the world are satisfactorily monitored, and the estimations available for monitored volcanoes are often discordant. At the same time, the available estimate for the monitored volcanoes can be different according to the state of activity of the volcano.Multiple sources can be effective in the release of CO2 in volcanic zones as demonstrated by the isotopic fingerprinting of CO2. Better estimates of the amount of carbon dioxide released by different sources represent one means of improving the accuracy of the estimation of the CO2 budget in environmental systems and reducing the knowledge gaps related to the effects of the carbon cycle in the Earth-climate system. The coupled approach of carbon isotope and CO2 flux measurements allows the precise identification of different sources, and enables the evaluation of the mass contribution of each source to the carbon dioxide emissions. From a volcanological perspective, it is well known that the amount of CO2 released by soils before and during periods of unrest increases appreciably, similar to the amount of carbon dioxide released from the craters of the volcanoes. This study focuses on the application of a DeltaRayTM from Thermo Scientific, and reports the development of an innovative method for directly determining in the field the isotope composition of carbon dioxide discharged by soils at concentrations from atmospheric to 100 vol %. To settle the DeltaRayTM to the determination of the isotope composition of soil gases, a sampling method has been designed to analyse the isotope composition of the CO2 in a gas sample of unknown CO2 concentration, reduce the measurement operation time without loss of accuracy, and measure the isotope composition of the CO2 without changing the instrument configuration. The results of the first application on Vulcano (Aeolian Islands) are reported in order to evaluate the amount of hydrothermal CO2 discharged by soils. The amount of hydrothermal CO2 released by soils is not negligible because of the specific extent of the degassing surface. For the first time, the budget of the CO2 of hydrothermal origin discharged by soils on Vulcano was computed separately from the contribution of the biogenic source, and the data indicate a degassing area that is wider than that previously reported in the literature. Furthermore, the synchronous and extensive investigation of both the spatial distribution of the carbon isotope composition of CO2 and the CO2 flux provides a better assessment of the amount of CO2 of deep origin. Monitoring of this type of CO2 represents a step forward in the evaluation of the volcanic hazard.35 6 - PublicationRestrictedA simple method to determine the δ13C content of total dissolved inorganic carbon(2002)
; ; ; ; ; ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Grassa, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Inguaggiato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Pecoraino, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Capasso, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; ; ; ; A simple method for determining the d13C of TDIC (Total Dissolved Inorganic Carbon) in natural waters was developed and tested. The proposed method is based on chemical and physical stripping of CO2 from water samples. The sampling apparatus consists of a glass bottle (ca 100 ml) totally filled with water sample in the field and sealed by gas-tight rubber/teflon plug. In the laboratory, we introduce 10 ml of pure Ar as host gas into the bottles and draw out an equal volume of water. About 0.5 ml of 37% extra-pure HCl is then injected into the bottle. Water pH decreases to values close to 1 and, therefore, the only carbon species present is CO2 both as dissolved and gaseous phase. Then the bottle is connected to a vacuum line to extract CO2 gas and to purify it by means of standard techniques for CO2 purification. In order to test this method, several sea water samples were prepared and analysed, as well as a series of standard solutions of Na2CO3 at known isotopic composition of carbon. The accuracy of these measurements was ± 0.2 %° vs V-PDB and their reproducibility was better than 0.2 %° vs V-PDB.177 26 - PublicationRestrictedActive geodynamics of the central Mediterranean Sea: Tensional tectonic evidences in western Sicily from mantle-derived helium(2005)
; ; ; ; ; ; ;Caracausi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Italiano, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Nuccio, P. M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Paonita, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Rizzo, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; ; ; ; ; We report results on the measured high 3He/4He isotope ratio in western Sicily, interpreted together with the heat data. The study of this sector of the Europe-Africa interaction is crucial to a better understanding of the tectonics and the geodynamical evolution of the central Mediterranean area. The estimated mantle-derived helium fluxes in the investigated areas are up to 2–3 orders of magnitude greater than those of a stable continental area. The highest flux, found in the southernmost area near the Sicily Channel, where recent eruptions of the Ferdinandea Island occurred 20 miles out to sea off Sciacca, has been associated with a clear excess of heat flow. Our results indicate that there is an accumulation of magma below the continental crust of western Sicily that is possibly intruding and out-gassing through roughly N-S trending deep fault systems linked to the mantle, that have an extensional component. Although the identification of these faults is not sufficiently constrained by our data, they could possibly be linked to the pre-existing faults that originated during the Mesozoic extensional-transtensional tectonic phases.447 133 - PublicationOpen AccessA landscape approach in the isotopic modeling of natural precipitations: two cases in Mediterranean mountain areas(2004)
; ; ; ; ; ;Madonia, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Meli, G.; C.F.T.A., Università di Palermo, Via Archirafi 36, 90123 Palermo, Italia ;Parello, F.; C.F.T.A., Università di Palermo, Via Archirafi 36, 90123 Palermo, Italia ;Valenza, M.; C.F.T.A., Università di Palermo, Via Archirafi 36, 90123 Palermo, Italia; ; ; ;The present paper proposes a method to simplify the very complex isotopic fractionation processes occurring during the water cycle. The method is constrained by a relatively small number of variables, with the precision needed in hydrological applications. After a theoretical introduction on the adopted interpolation criteria, two cases in the Mediterranean are presented. In both cases the evaluation of the “geometric complexity” of the systems appears to be the best tool to produce reliable isotopic models. If the complexity is low, it is apparently easier to fit different models; on the contrary the higher the complexity is, more difficult it is to find a reliable model but, at the same time, more difficult it is to find effective alternative models.153 149