Search results for "PAntelleria"
showing 10 items of 73 documents
Volatiles in pantellerite magmas: A case study of the Green Tuff Plinian eruption (Island of Pantelleria, Italy)
2013
Abstract The Green Tuff (GT) Plinian eruption, the largest in magnitude at Pantelleria, erupted 3 to 7 km3 DRE of pantellerite magma and a small volume of trachyte. Fifty-nine anorthoclase-hosted melt inclusions from the two basal pumice members were analyzed by FT-IR spectroscopy in order to assess the pre-eruptive H2O content in the pantellerite melt. Microanalytical methods were used to determine major element, Cl, F and S contents. Melt inclusions and glassy groundmasses have a nearly homogeneous pantelleritic composition (peralkaline index = 1.9-2.2) and variable water contents ranging from 1.4 to as high as 4.2 wt %, i.e. much higher than the 1.4 wt % of earlier published studies. The…
Evolution of the magma system of Pantelleria (Italy) from 190 ka to present
2022
The eruptive history of Pantelleria has been marked by the eruption of nine peralkaline ignimbrites, with inter-ignimbrite episodes from small, local volcanic centres. New whole-rock geochemical data are presented for seven ignimbrites and used with published data for younger units to track compositional changes with time. From»190 ka, silicicmagmatismwas dominated by comenditic trachyte to comendite compositions, evolving along generally similar liquid lines of descent (LLOD). The final ignimbrite, the Green Tuff (»46 ka), was tapped from a compositionally zoned pantelleritic upper reservoir to a trachytic mush zone. Younger (20–7 ka) silicic magmatism has been relatively small scale, with…
Carbonate precipitation in the alkaline lake Specchio di Venere (Pantelleria Island, Italy) and the possible role of microbial mats
2016
Abstract Alkaline lakes like the hydrothermally affected lake Specchio di Venere (Pantelleria Island, Central Mediterranean) are typical geological settings harbouring calcified microbial mats. The present work is focused on the discrimination between biotic and abiotic processes driving carbonate precipitation in this lake, using hydrochemical, mineralogical and isotopic data. Hydrochemical analyses demonstrate that the lake is nearly 10−fold supersaturated with regard to aragonite and seasonally reaches hydromagnesite supersaturation. Microscopic observations depict organosedimentary laminated structures consisting of microbial communities and aragonitic precipitates, which are rather dis…
Metagenome Assembled Genome of a Novel Verrucomicrobial Methanotroph From Pantelleria Island.
2021
Verrucomicrobial methanotrophs are a group of aerobic bacteria isolated from volcanic environments. They are acidophiles, characterized by the presence of a particulate methane monooxygenase (pMMO) and a XoxF-type methanol dehydrogenase (MDH). Metagenomic analysis of DNA extracted from the soil of Favara Grande, a geothermal area on Pantelleria Island, Italy, revealed the presence of two verrucomicrobial Metagenome Assembled Genomes (MAGs). One of these MAGs did not phylogenetically classify within any existing genus. After extensive analysis of the MAG, we propose the name of “Candidatus Methylacidithermus pantelleriae” PQ17 gen. nov. sp. nov. The MAG consisted of 2,466,655 bp, 71 contigs …
Cooling and crystallization recorded in trachytic enclaves hosted in pantelleritic magmas (Pantelleria, Italy): Implications for pantellerite petroge…
2015
Abstract This study focuses on the comenditic trachyte enclaves hosted in pantelleritic lava and pumices emplaced during one of the most recent eruptive events at Pantelleria (~ 6 ka). Enclaves range from mm-sized fragments to dm-sized blocks with spheroidal to amoeboid shapes and characteristic globular surfaces; they are crystal-rich with ~ 30 vol% large anorthoclase, less abundant Fe-rich olivine, clinopyroxene and Fe–Ti oxides. Vesicles ranging from a few mm to 1–2 cm in size are distributed throughout the enclave and are commonly filled with microlite-free vesicular glass. The groundmass presents spectacular textures, including fine to coarse spherulites and hopper and skeletal microli…
Nutraceutical Value of Pantelleria Capers (Capparis spinosa L.)
2019
Abstract: Unopened flower buds of Capparis spinosa L. (capers), generally used in the Mediterranean area as food flavoring, are known to be a good source of bioactive compounds. The aim of this work was to evaluate the nutraceutical value of salt-fermented capers collected from different areas of Pantelleria Island (Italy), testing their methylglyoxal and glyoxal trapping capacity and antioxidant activity by 2,2-diphenyl-1-picryl hydrazyl (DPPH), [2,2-azinobis(3-ethylben- zothiazoline-6-sulfonic acid)] diammonium salt (ABTS), and oxygen radical absorbance capacity (ORAC) assays. Hydrophilic extracts were also characterized by high-performance liquid chromatography–electrospray ionization/ma…
A revised stratigraphy of the pre-Green Tuff ignimbrites at Pantelleria (Sicily Channel)
2012
Peralkaline silicic magmas were erupted at Pantelleria in a variety of eruptive typologies and magnitudes: pyroclastic flows, Plinian to strombolian pumice fallout and lava flows. The initial cycle (330- 180 ka) was characterized mainly by effusive activity, and was followed by an intermediate cycle (181 - 85 ka), characterized by a clear drift to explosive activity. This period, onto we focus, is bracketed by six ignimbrite-forming eruptions (older and intermediate of the two caldera collapses at 140 and 50 ka that characterize the volcanological history of the island, which drained silicic and variably peralkaline magma for a cumulative volume close to 6 km3 DRE. These ignimbrites lack of…
MANTLE HETEROGENEITY AND MELTING CONDITIONS IN THE STRAIT OF SICILY RIFT ZONE
2015
The Strait of Sicily Rift Zone (SSRZ) is a northwest-southeast trending transtensional rift system situated on the Pelagian Block, the northern promontory of the African plate that represents the foreland domain of the Sicilian Apenninic-Maghrebian orogeny. The SSRZ consists of three basins: the Pantelleria Trough, the Linosa Trough, and the Malta Trough. Volcanoes are present in or adjacent to all except the Malta Trough, and include two islands (Pantelleria and Linosa) and several seamounts. Volcanism in the SSRZ is dominated by continental OIB-like (C-OIB) Na-alkaline mafic lavas and tuffs. Although petrographically similar, there are significant differences in the major-element, trace-e…
La ceramica comune, le anfore e i laterizi: caratteristiche tecniche ed identificazione delle provenienze.
2009
This paper deals with the analysis of 51 ceramic samples selected from a larger number between the findings coming from the Scauri’s late Roman wreck. The samples, represented by daily use pottery (table ware, cooking ware), transport amphorae, tiles and bricks, were analyzed by means of thin-section petrography. The observations of thin-sections by the polarizing microscope was focused on the paste description as well as on the identification of compositional and/or textural makers to be used for recognizing the area of provenance (production center) of the ceramic objects. Therefore, features such as mineralogy, packing, size distribution and morphology of the aplastic grains were pointed…
Trace elements in Mirror of Venus lake waters (Pantelleria Island, Italy)
2016
Mirror of Venus lake (MV) is a small (1.5 km2) endorheic alkaline lake located in a calderic depression on the northern side of Pantelleria Island (South Italy), a quiescent Pleistocenic stratovolcano located in the NW-SE trending continental rift developed between North Africa and Sicily. The lake, sub-squared in shape (around ca 450 m long and ca 350 m wide and 13 m depth) water input contribution is essentially from the thermal springs situated on its shores (Q = 0.1 l.s-1) and from meteoric waters. A total volume of 580.000 m3 has been estimated in June 2014. CO2 flux measurements made with a floating accumulation chamber in 2014 on the MV surface (both diffusive and bubbling CO2) highl…