Search results for "LCA"
showing 10 items of 1995 documents
The contribution of volcanic emissions (Etna, Stromboli and Vulcano) to the atmospheric trace metals budget in the Mediterranean basin
2010
Volcanic emissions represent one of the major natural source for several trace metals (Cd, Cu, As, Pb, Hg and Zn) into the atmosphere both as gaseous and aerosol forms. The Mediterranean Sea can be considered a large geochemical sink for these elements whose source are the huge amounts of aerosols of different origin. The industrialized areas located in the northern part of the basin represent a nearly constant source of the anthropogenic-dominated aerosol. By contrast, the arid and desert regions located at the southern and eastern parts of the Mediterranean, are the sources of frequent dust “pulses” perturbing the “steady-state” conditions of the local atmosphere through the input of seve…
PETROLOGICAL AND EXPERIMENTAL CONSTRAINTS ON THE PRE-ERUPTIVE CONDITIONS OF LA SOMMATA BASALT AND BROWN TUFFS TEPHRA (AEOLIAN ISLANDS)
2011
This work is focused on two key eruptions of Vulcano Island: 1) the most primitive magma of Vulcano erupted by the La Sommata scoria cone, a silica-undersaturated Ca-rich shoshonitic basalt with olivine-hosted primitive melt inclusions having an ultra-calcic character; 2) the most energetic eruptions of the whole Aeolian Archipelago, the Brown Tuffs (BT) eruptions, which produced several pyroclastic deposits, covering an ample age interval, spread out over a large portion of all Aeolian islands up to the northern coast of Sicily (Lucchi et al., 2008). By complementary studies of melt inclusions and experimental petrology, we pursued the following main objectives: (i) to constrain the pressu…
Mafic magma feeds degassing unrest at Vulcano Island, Italy
2022
AbstractThe benign fuming activity of dormant volcanoes is punctuated by phases of escalating degassing activity that, on some occasions, ultimately prelude to eruption. However, understanding the drivers of such unrest is complicated by complex interplay between magmatic and hydrothermal processes. Some of the most comprehensively characterised degassing unrest have recently been observed at La Fossa cone on Vulcano Island, but whether or not these episodes involve new, volatile-rich ascending magma remains debated. Here, we use volcanic gas measurements, in combination with melt inclusion information, to propose that heightened sulphur dioxide flux during the intense fall 2021 La Fossa un…
Seeking the mantle source and storage system of carbonatite magmas: case studies from Fuerteventura (Canary Islands) and Mt. Vulture volcano (souther…
Carbonatite magmatism is mainly associated with intraplate continental tectonic settings, with a temporal distribution from Archean to the present. The growing number of carbonatite occurrences from unconventional tectonic settings, such as oceanic contexts (e.g., Carnevale et al., 2021) or subduction zones (e.g., D’Orazio et al., 2007), received considerable attention during last two decades, given their importance as source of rare elements, and, most importantly, because they provide meaningful information about the geochemical cycle of carbon and mantle metasomatism as well. This work shows how the study of fluids trapped within minerals from carbonatites and carbonatite magmas can prov…
Metallic nanoparticle enrichment at low temperature, shallow CO2 seeps in Southern Italy
2012
We report on metal enrichment along a natural pH gradient owing to increased CO2 degassing at cold, shallow seeps of Vulcano Island in the Mediterranean Sea, off Sicily. We assessed composition of unfiltered and filtered seawater (<100 nm) along acidic zones ranging between ambient and pH 5, and showed that most seep derived elements are present as nanoclusters which then aggregate into larger colloids while mixing with ambient seawater along a pH gradient. Size and elemental composition of such naturally occurring nanoparticles assessed by modern characterisation methods were in good agreement with the results from conventional analytical methods. We provide analytical evidence for the pre…
Groundwater radon measurements in the Mt. Etna area.
2003
Radon levels were measured in 119 groundwater samples collected throughout the active volcanic area of Mt. Etna by means of a portable Lucas-type scintillation chamber. The measured activity values range from 1.8 to 52.7 Bq l(-1). About 40% of the samples exceed the maximum contaminant level of 11 Bq l(-1) proposed by the USEPA in 1991. The highest radon levels are measured in the eastern sector of the volcano, which is the seismically most active zone of the volcano. On the contrary the south-western sector, which is both seismically active and a site of intense magmatic degassing, display lower radon levels. This is probably due to the formation of a free gas phase (oversaturation of CO(2…
Recognition of water masses according to geochemical signatures in the Central Mediterranean sea: Y/Ho ratio and rare earth element behaviour
2007
This study reports the results of geochemical investigations carried out in the Strait of Sicily (Central Mediterranean Sea) during the oceanographic cruise BANSIC 2000, focusing on the area around the Pantelleria Island. We evaluate the interface processes between dissolved phase and suspended particulate matter in the water columns on the basis of Y/Ho ratio and rare earth elements and yttrium distributions that are suitable to trace the occurrence of different water layers in Central Mediterranean Area. The main source of trace elements to the sea water system was recognized in the atmospheric fallout, while different scavenging mechanisms among Y and rare earth elements occur. Cation ex…
HIGH-RESOLUTION PALAEONVIRONMENTAL RECONSTRUCTION OF ODP HOLE 963D (SICILY CHANNEL) DURING THE LAST DEGLACIATION BASED ON CALCAREOUS NANNOFOSSILS
2004
Abstract A palaeoenvironmental reconstruction of Ocean Drilling Program (ODP) Hole 963D (Sicily Channel) has been obtained on the basis of quantitative abundance fluctuations in the calcareous nannofossil assemblages. The studied hole is characterized by a very high sedimentary resolution and covers the last ca. 20 kyr. A new palaeoclimatic curve, based on the Gephyrocapsa muellerae/Upper Photic Zone (UPZ) group ratio, permitted the detection of the rapid climatic fluctuations that characterized the last deglaciation. Cold water masses occupied the Sicily Channel during the glacial period and the Younger Dryas, whereas they were generally warm during the Bolling–Allerod and the Holocene. An…
Integración de restos arqueológicos Almohades en el metropolitano de Granada. La investigación multidisciplinar para el proyecto y desarrollo de infr…
2014
The execution of the Granada Metropolitan’s underground line made possible the discovery of archeological remains of a water tank in Alcázar Genil, a royal muslim residence of the 13th century. The water tank, 419 × 88 ft, was destroyed at its ends due to the growth of the city of Granada during the 20th century and today remains only its center section, under Camino de Ronda, exactly where the future Metropolitan will take place. The location of an underground station will allow the recovery, the integration and the exhibition of the archaeological remains of this water tank. The Alcázar Genil station project brings together the work of several disciplines which put in the same level engin…