Search results for "Volcanic eruptions"
showing 10 items of 27 documents
Chronology of early Archaean granite-greenstone evolution in the Barberton Mountain Land, South Africa, based on precise dating by single zircon evap…
1991
We report precise 207Pb/206Pb single zircon evaporation ages for low-grade felsic metavolcanic rocks within the Onverwacht and Fig Tree Groups of the Barberton Greenstone Belt (BGB), South Africa, and from granitoid plutons bordering the belt. Dacitic tuffs of the Hooggenoeg Formation in the upper part of the Onverwacht Group yield ages between 3445 +/- 3 and 3416 +/- 5 Ma and contain older crustal components represented by a 3504 +/- 4 Ma old zircon xenocryst. Fig Tree dacitic tuffs and agglomerates have euhedral zircons between 3259 +/- 5 and 3225 +/- 3 Ma in age which we interpret to reflect the time of crystallization. A surprisingly complex xenocryst population in one sample documents …
The use of tree-rings and foliage as an archive of volcanogenic cation deposition.
2007
Tree cores (Pinus nigra ssp. laricio) and leaves (Castanea sativa) from the flanks of Mount Etna, Sicily were analysed by ICP-MS to investigate whether volcanogenic cations within plant material provide an archive of a volcano's temporal and spatial depositional influence. There is significant compositional variability both within and between trees, but no systematic dendrochemical correlation with periods of effusive, explosive or increased degassing activity. Dendrochemistry does not provide a record of persistent but fluctuating volcanic activity. Foliar levels of bioaccumulated cations correspond to modelled plume transport patterns, and map short-term volcanic fumigation. Around the fl…
Major and trace elements in Boletus aereus and Clitopilus prunulus growing on volcanic and sedimentary soils of Sicily (Italy)
2017
The aim of this study was to determine and compare the content of 28 elements (Ag, Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb, Sb, Se, Sr, Tl, U, V and Zn) in fruiting bodies of Boletus aereus Bull. and Clitopilus prunulus P. Kumm collected from eleven unpolluted sites of Sicily (Italy) and, also to relate the abundance of chemical elements in soil with their concentration in mushrooms. Median concentrations of the most abundant elements in Boletus aereus ranged from 31,290 μg/g (K) to 107 μg/g (Zn) in caps and from 24,009 μg/g (K) to 57 μg/g (Zn) in stalks with the following abundance order: K > Na > Ca > Mg > Fe > Al > Rb > Zn. The s…
Yttrium and lanthanides in human lung fluids, probing the exposure to atmospheric fallout.
2011
International audience; Inhalation of airborne particles can produce crystallization of phosphatic microcrysts in intraaveolar areas of lungs, sometimes degenerating into pulmonary fibrosis. Results of this study indicate that these pathologies are induced by interactions between lung fluids and inhaled atmospheric dust in people exposed to volcanic dust ejected from Mount Etna in 2001. Here, the lung solid-liquid interaction is evaluated by the distribution of yttrium and lanthanides (YLn) in fluid bronchoalveolar lavages on selected individuals according the classical geochemical approaches. We found that shale-normalised patterns of yttrium and lanthanides have a 'V shaped' feature corre…
Gender as a key factor in trace metal and metalloid content of human scalp hair. A multi-site study
2016
This multi-site study discusses the content of metals and metalloids (MM) in scalp hair of children, living in different environmental contexts, with the purpose of verifying if hair level of some MM is distinctively gender-specific. A total of 943 hair samples (537 females and 406 males) from adolescents were analysed for their content of Al, As, Ba, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, U, V and Zn. Elemental quantification was performed by ICP-MS. The obtained data identified different metal distributions in adolescent girls which exhibited significantly higher hair concentrations of some trace metals, especially Sr, Zn and Ni, than boys. On the base of the median value, hai…
Risk of classic Kaposi sarcoma with residential exposure to volcanic and related soils in Sicily
2009
Purpose Before AIDS, endemic (African) Kaposi sarcoma (KS) was noted to occur in volcanic areas and was postulated to result from dirt chronically embedded in the skin of the lower extremities. The primary cause of all KS types is KS-associated herpesvirus (KSHV) infection, but cofactors contribute to the neoplasia. We investigated whether residential exposure to volcanic or related soils was associated with the risk of classic Kaposi sarcoma (cKS) in Sicily. Methods Risk of incident cKS ( N = 141) compared with population-based KSHV seropositive controls ( N = 123) was estimated for residential exposure to four types of soil, categorized with maps from the European Soil Database and dire…
Speciation of vanadium in urban, industrial and volcanic soils by a modified Tessier method
2016
Vanadium (V) concentrations in industrial, urban and volcanic soils were sequentially extracted using a modified Tessier's method. The voltammetric technique was used to determine V concentrations in solutions obtained from the various extraction steps. At the reference stations, the V concentrations (sum of four individual fractions) in soils ranged from 0.72 to 0.24 g kg(-1) dry weight (d.w.) with a mean value of 0.18 g kg(-1) d.w. V concentrations in soils of the Palermo urban area ranged from 0.34 to 2.1 g kg(-1) d.w., in the Milazzo (industrial) area between 0.26 and 5.4 g kg(-1) d.w. and in the volcanic area near Mt. Etna from 0.91 to 2.9 g kg(-1) d.w. When the V concentrations around…
Increased thyroid cancer incidence in a basaltic volcanic area is associated with non-anthropogenic pollution and biocontamination
2016
The increased thyroid cancer incidence in volcanic areas suggests an environmental effect of volcanic-originated carcinogens. To address this problem, we evaluated environmental pollution and biocontamination in a volcanic area of Sicily with increased thyroid cancer incidence. Thyroid cancer epidemiology was obtained from the Sicilian Regional Registry for Thyroid Cancer. Twenty-seven trace elements were measured by quadrupole mass spectrometry in the drinking water and lichens (to characterize environmental pollution) and in the urine of residents (to identify biocontamination) in the Mt. Etna volcanic area and in adjacent control areas. Thyroid cancer incidence was 18.5 and 9.6/10(5) inh…
Ocean acidification bends the mermaid's wineglass
2015
Ocean acidification lowers the saturation state of calcium carbonate, decreasing net calcification and compromising the skeletons of organisms such as corals, molluscs and algae. These calcified structures can protect organisms from predation and improve access to light, nutrients and dispersive currents. While some species (such as urchins, corals and mussels) survive with decreased calcification, they can suffer from inferior mechanical performance. Here, we used cantilever beam theory to test the hypothesis that decreased calcification would impair the mechanical performance of the green alga Acetabularia acetabulum along a CO 2 gradient created by volcanic seeps off Vulcano, Italy. Cal…
Source and Nature of Inhaled Atmospheric Dust from Trace Element Analyses of Human Bronchial Fluids
2011
International audience; Rapid volcanic eruptions quickly ejecting large amounts of dust provoke the accumulation of heavy metals in people living in surrounding areas. Analyses of bronchoalveolar lavage samples (BAL) collected from people exposed to the paroxysmal 2001 Etna eruption revealed a strong enrichment of many toxic heavy metals. Comparing the BAL to the dust composition of southeastern Sicily, we found that only V, Cr, Mn, Fe, Co, and U enrichment could be related to the volcanic event, whereas Ni, Cu, Cd, and Pb contents come from the dissolution of particles of anthropogenic origin. Furthermore, the nature of these inhaled anthropogenic particles was revealed by anomalous La and…