Search results for "LCA"
showing 10 items of 1995 documents
Distribution of Lanthanides in Mediterranean Coastal waters
2007
Distribution and behaviour of the whole lanthanide series and yttrium in both seawater column and suspended particulate matter were investigated in coastal water located in the Central Mediterranean Sea. An area characterized by high anthropic pressure, atmospheric fallout and river input due to drainage of little local watersheds was selected. Water masses were discriminated with respect to both surrounding and depth and in relation to the processes occurring at the solid-liquid interface. We found that yttrium and Rare Earth Elements in the labile fraction of the suspended particulates result from the mixing between lithogenic material from the Sicilian basin and detrital material of Saha…
The impact of methanotrophic activity on methane emissions through the soils of geothermal areas
2013
Methane plays an important role in the Earth’s atmospheric chemistry and radiative balance being the most important greenhouse gas after carbon dioxide. It has recently been established that geogenic gases contribute significantly to the natural CH4 flux to the atmosphere (Etiope et al., 2008). Volcanic/geothermal areas contribute to this flux, being the site of widespread diffuse degassing of endogenous gases (Chiodini et al., 2005). In such an environment soils are a source rather than a sink for atmospheric CH4 (Cardellini et al., 2003; Castaldi and Tedesco, 2005; D’Alessandro et al., 2009; 2011; 2013). Due to the fact that methane soil flux measurements are laboratory intensive, very fe…
Geochemistry and mineralogy of sediments and authigenic carbonates from the Malta Plateau, Strait of Sicily (Central Mediterranean): Relationships wi…
2010
Abstract A mud volcano field was recently discovered within the Malta Plateau in the Strait of Sicily (Central Mediterranean Sea). Box-core sediments and associated authigenic carbonates have been collected in water depths of 140–170 m from two distinctive sectors of the area, and analyzed for major, trace and rare earth elements, stable isotopes, and mineralogy. Relative homogeneity in the mineralogy and geochemistry of bulk sediments, and 210Pb activity distributions, argue against an active mud ejection activity. In the Malta Plateau western sector, the sediments show high concentrations of Fe, As, Sb, and Mo, exceeding the background values estimated for the Strait of Sicily. Active flu…
Methanotrophic activity and diversity of methanotrophs in volcanic geothermal soils at Pantelleria (Italy)
2014
Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic or geothermal soils are not only a source of methane, but are also sites of methanotrophic activity. Methanotrophs are able to consume 10–40 Tg of CH4 a−1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria (Italy), Favara Grande, whose total methane emission was previously estimated at about 2.5 Mg a−1 (t a−1). Laboratory incubation experiments with three top-soil samples from …
Gas Geochemistry and Fractionation Processes in Florina Basin, Greece
2019
Florina Basin is located in northern Greece, close to Mount Voras where the volcanic activity of Late Messinian age began. In the area, many CO2-rich gas emissions are present as a bubbling free-phase in groundwater (both springs and wells) and soil gases. Volcanism along with the geological and geodynamic regime of the basin, created the ideal conditions for CO2 accumulation in vertically stacked reservoirs. One of these, industrially exploited by the company Air Liquide Greece, produces 30,000 t/a of CO2. Results show that CO2 concentrations in the gases of Florina can arrive up to 99.8% and are mostly above 90%. Moreover, C-isotope composition (-2.1 to + 0.3 h vs. VPDB) indicates a mixed…
Origin of methane and light hydrocarbons in the gas manifestations of Greece.
2017
The geologic emissions of greenhouse gases (CO2 and CH4) give an important natural contribution to the global carbon budget. However, the contribution of these emissions to the global carbon cycle and their possible role on the climate change remain still poorly quantified (Guliyev and Feizullayev, 1997; Milkov, 2000; Etiope et al., 2015 and references therein). Methane, the most abundant organic compound in Earth's atmosphere, may be created either from existing organic matter or synthesized from inorganic molecules. Accordingly, it can be differentiated in two main classes: a) biotic (either microbial or thermogenic) and b) abiotic. For this study, 115 gas samples of fumarolic, thermal an…
Extreme isotope fractionation of hydrothermal methane due to oxidation processes in hot springs of Central Greece
2017
The Greek territory belongs to the geodynamically active Alpine-Himalayan orogenic belt. As such, it shows intense seismic activity, active volcanic systems and areas of enhanced geothermal fluxes. One of these areas is the Sperchios basin and the northern part of Evia island in central Greece, which present widespread thermal manifestations [1]. Five of them with temperatures from 33 to 80°C present bubbling gases whose dominating species are either CO2 or N2. All gases contain from 27 to 4000 ppm of CH4. The isotopic composition of CH4 in these gases covers a wide range with δ13C values ranging from -21.7 to +16.9‰ and δ2H values ranging from -124 to +301‰. The hottest manifestation displ…
Patch test results with the metalworking fluid series of the German Contact Dermatitis Research Group (DKG).
2004
Based on the information of the interdisciplinary task force on allergy diagnostics in the metal branch, in 2001, the German Contact Dermatitis Research Group (DKG) compiled two metalworking fluid (MWF) test series with currently and previously used components, respectively. After 2 years of patch testing, we present results obtained with these series, based on data of the Information Network of Departments of Dermatology (IVDK). 251 metalworkers who were patch tested because of suspected MWF dermatitis in 2002 and 2003 were included in this retrospective data analysis. Of these, 206 were tested with the current MWF series and 155 with the historical MWF series. Among the current MWF allerg…
Noble gas and CO2 isotopic signatures of the lithospheric mantle underneath Mexico and the Canary Islands: clues from mantle xenoliths and arc lavas
2022
Studying the isotopic composition of fluids trapped in mantle xenoliths opens avenues to understand the origin and cycling of volatiles in the Earth’s upper mantle. In this PhD dissertation, new and in most cases the very first data regarding the isotopic (noble gases and CO2) characterization of the lithospheric mantle portions of three different geodynamic environments are presented: (i) Central and NW Mexico, a continental setting dominated by extension; (ii) the Transmexican Volcanic Belt (TMVB) a subduction setting, and (iii) the Canary Islands, particularly El Hierro and Lanzarote, two oceanic islands formed by mantle plume-derived intraplate volcanism. In total 32 peridotites (includ…
The role of topography and erosion in the development and architecture of shallow-water coral bioherms (Tortonian-Messinian, Cabo de Gata, SE Spain).
2009
23 pages; International audience; During the Miocene, Mediterranean shallow-water carbonates were rich in scleractinian corals, which thrive in various depositional settings. A Tortonian–Messinian bioherm belt developing in a heterozoan-dominated ramp was investigated along a 1.2 km continuous transect located in the Cabo de Gata region. The interval studied displays four depositional environments from mid-to-inner ramp, dominated by swell waves and storm energy, deposited as a single, large-scale depositional sequence during a 3rd to 4th order transgressive–regressive cycle. The bioherms grew in three phases, and were essentially composed of inplace primary frameworks. Three coral genera w…