We investigated the geochemistry of the fumaroles at the summit area of Mt. Etna, including sulfu... more 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
Geochemical investigations carried out over a wide area of western Sicily covering the Castellamm... more Geochemical investigations carried out over a wide area of western Sicily covering the Castellammare-Alcamo, Montevago and Sciacca hydrothermal basins, highlighted variable contributions of mantle-derived helium as showed by the concentrations and the helium isotopic ratios measured in both dissolved and free gases. The ^3He/^4He values reveal a progressive decrease from the Sicily Channel (2.8Ra at Sciacca area) to the Tyrrhenian sea (0.7Ra at the Alcamo-Castellammare area). The flux of mantle-derived helium computed by the relations of O'Nions and Oxburgh (1988), results higher than the typical diffusive flux in continental crust (up to about 3 orders of magnitude in the Sciacca basin), suggesting that the helium contribution probably is not fully diffusive. On the basis of the relationships between the production of radiogenic helium and the related heat, the content of radiogenic helium can account for the emission temperature of the thermal waters only at the Sciacca basin ...
Since 1987, periodic soil CO2 flux measurements on the south-western sector and on the eastern fl... more Since 1987, periodic soil CO2 flux measurements on the south-western sector and on the eastern flank of Mt Etna have been performed to monitor volcanic activity. Many studies have demonstrated that soil CO2 flux is closely related to the magma dynamics of Mt Etna. To further confirm this relationship and better understand the influence of rising magma on soil CO2 emission, we periodically measured the 13C values as well as the soil CO2 flux at several points in both areas of Mt Etna. The comparison between 13C values and soil CO2 flux revealed two groups of data with different behaviours: (i) data arranged along mixing lines between organic and deep origins of CO2; (ii) data with high soil CO2 fluxes and 13C values with organic marker. The variations in 13C in (i) are temporally well correlated with the total amount of the soil CO2 emitted in the areas. This result strongly corroborates the primary role played by magma dynamics in the control of soil CO2 flux in the analysed are...
The geochemical study of lakes needs the use of specific instruments and sampling techniques that... more The geochemical study of lakes needs the use of specific instruments and sampling techniques that make possible the study of physico-chemical parameters, even in deep portion of lakes (underwater conditions, high pressure, low/high temperature and sometimes acidic waters). Since 2007 we studied Monticchio lakes (Lago Piccolo and Lago Grande, Southern Italy) focusing on chemistry of dissolved gases and on major and trace elements of lake waters. Special attention was given to the choice and optimization of instruments and sampling techniques. An update of bathymetry of the lakes was performed by means of a Garmin 250C Fishfinder coupled with a Garmin V GPS, allowing us to estimate partial and total water volumes, particularly useful in water balance and dissolved gas budget. The bathymetric map was also used for the localization of germane sampling points. By means of high resolution multiparametric probe (im71 – Ageotec), temperature, pH and electrical conductivity data were acquire...
A simple method for determining the δ13C of TDIC (Total Dissolved Inorganic Carbon) in natural wa... more A simple method for determining the δ13C 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 car...
Oxygen isotope measurements were carried out on monthly average samples of rain water collected i... more Oxygen isotope measurements were carried out on monthly average samples of rain water collected in Sicily at Palermo (sea level), Scillato (400 m. a.s.l.) and Piano Battaglia (1600 m. a.s.l.) during different periods between 1976 and 1979. The purpose of these measurements was to obtain information about the vertical isotopic gradients in precipitation in Sicily, to use these data for research work on hydrology. -from English summary
The "Macalube di Aragona" area is located in Central Sicily (Italy) within a thick accr... more The "Macalube di Aragona" area is located in Central Sicily (Italy) within a thick accretionary wedge (up to 6 km), developing along the frontal part (Southern margin) of the Sicilian thrust belt. Mud volcanoes are among the most important natural emissions of waters, oil and gaseous hydrocarbons from buried sediments. We have periodically collected gases from one mud volcano and
We investigated the geochemistry of the fumaroles at the summit area of Mt. Etna, including sulfu... more 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
Geochemical investigations carried out over a wide area of western Sicily covering the Castellamm... more Geochemical investigations carried out over a wide area of western Sicily covering the Castellammare-Alcamo, Montevago and Sciacca hydrothermal basins, highlighted variable contributions of mantle-derived helium as showed by the concentrations and the helium isotopic ratios measured in both dissolved and free gases. The ^3He/^4He values reveal a progressive decrease from the Sicily Channel (2.8Ra at Sciacca area) to the Tyrrhenian sea (0.7Ra at the Alcamo-Castellammare area). The flux of mantle-derived helium computed by the relations of O'Nions and Oxburgh (1988), results higher than the typical diffusive flux in continental crust (up to about 3 orders of magnitude in the Sciacca basin), suggesting that the helium contribution probably is not fully diffusive. On the basis of the relationships between the production of radiogenic helium and the related heat, the content of radiogenic helium can account for the emission temperature of the thermal waters only at the Sciacca basin ...
Since 1987, periodic soil CO2 flux measurements on the south-western sector and on the eastern fl... more Since 1987, periodic soil CO2 flux measurements on the south-western sector and on the eastern flank of Mt Etna have been performed to monitor volcanic activity. Many studies have demonstrated that soil CO2 flux is closely related to the magma dynamics of Mt Etna. To further confirm this relationship and better understand the influence of rising magma on soil CO2 emission, we periodically measured the 13C values as well as the soil CO2 flux at several points in both areas of Mt Etna. The comparison between 13C values and soil CO2 flux revealed two groups of data with different behaviours: (i) data arranged along mixing lines between organic and deep origins of CO2; (ii) data with high soil CO2 fluxes and 13C values with organic marker. The variations in 13C in (i) are temporally well correlated with the total amount of the soil CO2 emitted in the areas. This result strongly corroborates the primary role played by magma dynamics in the control of soil CO2 flux in the analysed are...
The geochemical study of lakes needs the use of specific instruments and sampling techniques that... more The geochemical study of lakes needs the use of specific instruments and sampling techniques that make possible the study of physico-chemical parameters, even in deep portion of lakes (underwater conditions, high pressure, low/high temperature and sometimes acidic waters). Since 2007 we studied Monticchio lakes (Lago Piccolo and Lago Grande, Southern Italy) focusing on chemistry of dissolved gases and on major and trace elements of lake waters. Special attention was given to the choice and optimization of instruments and sampling techniques. An update of bathymetry of the lakes was performed by means of a Garmin 250C Fishfinder coupled with a Garmin V GPS, allowing us to estimate partial and total water volumes, particularly useful in water balance and dissolved gas budget. The bathymetric map was also used for the localization of germane sampling points. By means of high resolution multiparametric probe (im71 – Ageotec), temperature, pH and electrical conductivity data were acquire...
A simple method for determining the δ13C of TDIC (Total Dissolved Inorganic Carbon) in natural wa... more A simple method for determining the δ13C 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 car...
Oxygen isotope measurements were carried out on monthly average samples of rain water collected i... more Oxygen isotope measurements were carried out on monthly average samples of rain water collected in Sicily at Palermo (sea level), Scillato (400 m. a.s.l.) and Piano Battaglia (1600 m. a.s.l.) during different periods between 1976 and 1979. The purpose of these measurements was to obtain information about the vertical isotopic gradients in precipitation in Sicily, to use these data for research work on hydrology. -from English summary
The "Macalube di Aragona" area is located in Central Sicily (Italy) within a thick accr... more The "Macalube di Aragona" area is located in Central Sicily (Italy) within a thick accretionary wedge (up to 6 km), developing along the frontal part (Southern margin) of the Sicilian thrust belt. Mud volcanoes are among the most important natural emissions of waters, oil and gaseous hydrocarbons from buried sediments. We have periodically collected gases from one mud volcano and
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