Search results for " Vulcano"

Profiling microbial communities in hyperalkaline waters of the Kizildag ophiolite complex (Turkey).

2016

It has recently been hypothesized that life on Earth could have been originated in hyperalkaline waters related to serpentinization of ophiolitic rocks, despite their extreme conditions (high pH and very low levels of nutrients). Five hyperalkaline springs of the Kizildag ophiolite complex (Turkey) were characterized. The dominant gases are either H2, CH4 or N2 . Bacterial diversity, analysed by RISA (Ribosomal Intergenic Spacer Analysis) revealed different profles for each spring. Sequencing of excised DNA bands allowed to identify the presence of Bacillus, Ralstonia, Pseudoalteromonas., Ureibacillus, Alicycliphilus, Anaerococcus. 16S ribosomal DNA sequencing by Illumina is in progress. Th…

New Inferences on Magma Dynamics in Melilitite-Carbonatite Volcanoes: The Case Study of Mt. Vulture (Southern Italy)

2022

This study provides the first micro-thermometric data of fluid inclusions (FIs) in mafic loose (disaggregated) xenocrysts and ultramafic xenoliths in explosive products of the melilitite-carbonatite Mt. Vulture volcano (southern Italy). Pure CO2 late stage FIs hosted in rock-forming minerals of wehrlite xenoliths and clinopyroxene xenocrysts were trapped at the local crust-mantle boundary (32 km). In contrast, trapping pressures within the loose olivine xenocrysts are from 3.2 to 4.5 kbar (8–13 km). Considering the ongoing degassing of mantle-derived CO2 rich gases, together with seismic evidences of the presence of low amount of melts at depth, and the tectonic control of the past volcanic…

Chemical, mineralogical and isotopic observations on hypersaline surficial deposits from Trapani evaporation ponds.

2010

Excess volatiles supplied by mingling of mafic magma at an andesite arc volcano

2010

We present the results of a study of volcanic gases at Soufriere Hills Volcano, Montserrat, which includes the first spectroscopic measurements of the major gas species CO2 and H2S at this volcano using a Multisensor Gas Analyzer System (MultiGAS) sensor. The fluxes of CO2 and H2S were 640.2750 t/d and 84.266 t/d, respectively, during July 2008, during a prolonged eruptive pause. The flux of CO2 is similar to estimates for the entire arc from previous geochemical studies, while the measured H2S flux significantly alters our interpretation of the sulphur budget for this volcano. The fluxes of both sulphur and carbon show considerable excesses over that which can be supplied by degassing of e…

Active biomonitoring (moss-bags) of volcanic emissions on Mt. Etna

2011

Biomonitoring may be defined as the use of organisms and biomaterials (biomonitors) to obtain information on certain characteristics of a particular medium (atmosphere, hydrosphere etc.). In particular, mosses accumulate large amounts of trace metals, making them good bioaccumulators to estimate atmospheric pollution. The moss-bags technique, introduced in the early 1970’, has become very popular. Such active biomonitoring technique is particularly useful in highly polluted areas and has been extensively used in industrial and/or urban areas to examine deposition patterns and to recognize point sources of pollution. The main objective of this study, which represents the first application of…

Volcanic gas and particles monitoring using moss-bags on Vulcano Island, Italy

2013

Non-stationary nature of SO2 degassing at Etna’s North-east crater (Italy).

2012

Investigating Etna’s long-term SO2 flux behaviour has led to important conclusions on the structure of the volcano’s magma feeding system, magma production (and degassing) rates, and causes for the excess degassing behaviour. Nonetheless, our knowledge of the short-term (timescales of seconds to a few hours) behaviour of magmatic volatiles (e.g., bubble coalescence, separate ascent and surface bursting of gas-rich bubbles) in the volcano’s upper feeding conduit system is still fragmentary, and based on indirect evidences (petrologic-textural data, observation of geophysical signals , physical modelling and laboratory experiments). In the past, direct gas flux measurements at Etna have been ta…

Noble gas geochemistry in seismic (Umbria, Italy) and volcanic (Grand Comore Island, Indian Ocean) regions: New methodologies and implications

2020

The noble gases are among the most powerful geochemical tools in different geological settings. For this reason, they represent one of the most valuable tracers of geochemical processes whose variations can be straightforwardly ascribed to magmatic/crustal dynamics. In this dissertation, noble gas (He, Ne, Ar) geochemistry applied in both seismic and volcanic regions are presented. The PhD research has firstly been devoted to the test on the field of an auto-sampler for high-frequency collection of the water samples in order to be analysed for their dissolved noble gases. Then, I developed a lab-based methodology for the in-vacuum extraction of noble gases from waters collected in the coppe…

Effects of reduced pH on shell integrity of a common whelk from a natural undersea CO2 vent community off Vulcano Island, Italy.

2014

Hexaplex trunculus is a widespread Mediterranean gastropod mollusc that plays a crucial role in benthic ecosystem dynamics. Individuals occur in shallow, sublittoral habitats near Vulcano Island, Italy, where an undersea CO2 vent provides a gradient of seawater acidification mimicing future predicted levels of ocean acidification. Individuals were collected from three sites with declining pH [ambient ( pH 8.18), medium (pH 8.05) and low (pH 7.49)]. Dissolution of shells was clearly evident at the medium (smoothing of outer shell ) and low (pitting and holes) pH sites. Scanning electron microcroscopy will provide a qualitative comparative assessment of micro-scale impacts of shell dissolutio…

A regional-scale discontinuity in western Sicily revealed by a multidisciplinary approach: A new piece for understanding the geodynamic puzzle of the…

2015

The results of an integrated stratigraphic, structural, geophysical, and geochemical study reveal the presence of a crustal discontinuity in western Sicily that, at present, runs roughly N-S along a band from San Vito Lo Capo to Sciacca. The boundary between the two zones of this discontinuity is nearly orthogonal to the main thrust propagation of the Sicilian thrust-and-fold belt. The different Permian to Tertiary sedimentary evolution recorded by the two zones appears related to this discontinuity, with thick carbonate platforms in the western sector facing deepwater successions in the eastern one. The presence of Upper Triassic reefs, huge megabreccia bodies, and widespread submarine vol…