Search results for "Volatiles"

Fetid odors in Caralluma europaea (Guss.) N.E.Br. (Apocynaceae-Asclepiadoideae): a chemical characterization

2008

Constrains on mantle, slab and crustal contributions to major volatiles and noble gases along the Andean Volcanic Belt

2020

Leachate analyses of volcanic ashes from Stromboli volcano: A proxy for the volcanic gas plume composition?

2011

[1] Many volcanoes show a change in chemical composition of the gas phase prior to periods of eruptive activity. Fine-grained tephra erupted from active vents and transported through volcanic plumes can adsorb, and therefore rapidly scavenge, volatile elements such as sulfur, halogens, and metal species in the form of soluble salts adhering to ash surfaces. Analysis of such water-soluble surface materials is a suitable supplement for remote monitoring of volcanic gases at inaccessible volcanoes. In this work, ash samples of the 2004 to 2009 eruptive activity of Stromboli volcano were sampled, leached, and analyzed for major and trace elements. Data analysis and interpretation was focused on…

Mobility and fluxes of major, minor and trace metals during basalt weathering and groundwater transport at Mt. Etna volcano (Sicily)

2000

Abstract The concentrations and fluxes of major, minor and trace metals were determined in 53 samples of groundwaters from around Mt Etna, in order to evaluate the conditions and extent of alkali basalt weathering by waters enriched in magma-derived CO 2 and the contribution of aqueous transport to the overall metal discharge of the volcano. We show that gaseous input of magmatic volatile metals into the Etnean aquifer is small or negligible, being limited by cooling of the rising fluids. Basalt leaching by weakly acidic, CO 2 -charged water is the overwhelming source of metals and appears to be more extensive in two sectors of the S-SW (Paterno) and E (Zafferana) volcano flanks, where out …

S, Cl and F degassing as an indicator of volcanic dynamics: The 2001 eruption of Mount Etna

2002

[1] The recent eruption of Mount Etna (July 2001) offered the opportunity to analyze magma-derived volatiles emitted during pre- and syn-eruptive phases, and to verify whether their composition is affected by changes in volcanic dynamics. This paper presents the results of analyses of F, Cl and S in the volcanic plume collected by filter-packs, and interprets variations in the composition based on contrasting solubility in magmas. A Rayleigh-type degassing mechanism was used to fit the acquired data and to estimate Henry's solubility constant ratios in Etnean basalt. This model provided insights into the dynamics of the volcano. Abundances of sulfur and halogens in eruptive plumes may help …

Atmospheric sources and sinks of volcanogenic elements in a basaltic volcano (Etna, Italy)

2011

Abstract This study reports on the first quantitative assessment of the geochemical cycling of volcanogenic elements, from their atmospheric release to their deposition back to the ground. Etna’s emissions and atmospheric depositions were characterised for more than 2 years, providing data on major and trace element abundance in both volcanic aerosols and bulk depositions. Volcanic aerosols were collected from 2004 to 2007, at the summit vents by conventional filtration techniques. Precipitation was collected, from 2006 to 2007, in five rain gauges, at various altitudes around the summit craters. Analytical results for volcanic aerosols showed that the dominant anions were S, Cl, and F, and…

Fluid geochemistry in a low-enthalpy geothermal field along a sector of southern Apennines chain (Italy)

2020

Abstract The chemical and isotopic features of the fluids (water and gases) in the Lucane thermal area (southern Italy) have been investigated in order to verify their origin, water temperature in the geothermal reservoir, and to recognize the main natural processes concerning the water composition during ascent towards the surface. The Lucane geothermal system is placed in the southern sector of the Apennines chains, a seismically active area, close to the southern base of the Mt. Alpi carbonate massif. Along the study area, two main sets of high-angle faults form an almost orthogonal fault system that, as suggested by local structural geology, acts as a preferential pathway for uprising d…

Influence of Feeding and Oviposition by Phytophagous Pentatomids on Photosynthesis of Herbaceous Plants

2010

Abstract Feeding by herbivorous insects may change photosynthetic activity of host plants. We studied how feeding and oviposition by herbivorous stink bugs, Murgantia histrionica and Nezara viridula (Heteroptera: Pentatomidae), affect photosynthetic parameters of Brassica oleracea (savoy cabbage) and Phaseolus vulgaris (French bean). First, we measured photosynthetic gas exchange, chlorophyll fluorescence imaging, and emission of induced volatile organic compounds (VOC) immediately after feeding and during a post-feeding period. Photosynthesis decreased rapidly and substantially in B. oleracea and P. vulgaris infested by feeding bugs. Stomatal conductance did not decrease proportionally wit…

Halogen (Cl, F) release during explosive, effusive, and intrusive phases of the 2011 rhyolitic eruption at Cordón Caulle volcano (Chile)

2019

We investigate sulphur, chlorine and fluorine release during explosive, effusive and intrusive phases of the 2011 Cordon Caulle eruption, with a focus on halogen devolatilization. Petrological analysis shows halogen release to have been promoted by isobaric crystallization in slowly-cooled magma that was emplaced in a lava flow and sub-vent intrusion. Fluorine in particular mobilized only after extensive groundmass crystallization and incipient devitrification. By 2017, the gas emitted from vent-proximal fumaroles had hydrothermal compositions, with HCl/HF ratios decreasing with decreasing temperature. We estimate that the eruption could eventually emit up to 0.84 Mt of SO2, 6.3 Mt of HCl, …

Chromatographic fingerprint of the volatile fraction of rare Hedera helix honey and biomarkers identification

2018

Hedera helix (Irish ivy) honey is a very rare food product used in Ireland. The composition of the volatile fraction of this unique honey was studied for the first time using three different extraction procedures (SPE, USE and HS–SPME) and analyzed with gas chromatography and mass spectrometry. As expected, the use of combined techniques resulted in the identification of the detailed composition of honey volatiles. Identified constitutes belongs to the different chemical classes. The presence of 4(1H)-quinolinone, myrtenal and phenylacetonitrile was proposed as biomarkers of the botanical origin of ivy honey. Moreover, they are not widely widespread among honeys of different botanical origi…