Search results for " geochimica"

Benthic foraminifera as indicators of relative sea-level fluctuations: Paleoenvironmental and paleoclimatic reconstruction of a Holocene marine succe…

2017

This study presents the results of an integrated stratigraphic analysis conducted on a marine gravity core (MSK-12 C4) recovered from the outer continental shelf (82 mwater depth) of western Calabria, ~2.6 km, NE of Capo Vaticano (Eastern Tyrrhenian margin). The gravity core MSK-12 C4 recovered a stratigraphic succession of 4.18 m beneath the seafloor representing the last ~11.1 ka. Sedimentological analysis, micropaleontological quantitative analysis on benthic foraminiferal assemblages, tephrostratigraphy, sequence stratigraphic analysis of high resolution reflection seismic data recorded in the core site area and AMS 14C absolute age determinations allowed reconstructing the marine recor…

UV camera measurement at a dormant volcano

2010

The UV camera is now becoming a new important tool in the armory of volcano geochemists for high rate SO2 flux measurements. The high spatial resolution of the camera is particularly useful for exploring multiple-source SO2 gas emissions, as the large composite fumarolic systems topping most quiescent volcanoes. We report here on the first SO2 flux measurements from individual fumaroles of the fumarolic field of La Fossa crater (Vulcano island, Aeolian island), which we performed using a UV camera in two field campaigns on November 12, 2009 and February 4, 2010. Making advantage of the high temporal and spatial resolution of the UV camera, we derived ~0.5 Hz SO2 flux time-series for the mai…

Vulcamera: a program for measuring volcanic SO2 with UV cameras

2011

UV Cameras for volcanic monitoring

2011

This work, following the field setup of Kantzas et al (2010), with the addition of a single point DOAS telescope, investigated the range of data available utilizing a two camera, dual filter setup and demonstrated its value for future use in the study of degassing volcanic systems.

Redox estimates through trace elements partitioning: application on two Italian volcanoes, model comparison and overview on different geodynamic envi…

2021

Oxygen fugacity of Earth’s mantle is one of the most debated issues of petrology. While is evident that the arc-related magmas are more oxidized than MORB and intraplate magmas, however, is not yet possible to produce a model that can uniquely determine this thermodynamic parameter for the depth of the Earth. Furthermore, there is not a clear cause that create this difference of redox conditions between volcanic products. Recently, several experimental models based on the V partitioning between olivine and mafic melt were published and proposed as tools for investigating the redox state of mantle melts for different geodynamic environments. During this PhD we have applied different oxybarom…

REAL-TIME MEASUREMENT OF VOLCANIC GASES BASED ON INFRARED SPECTROSCOPY

The interpretation of volcanic gas datasets offers key information to build/validate geological models relevant to a variety of volcanic processes and behaviours, including eruptions. Major efforts have therefore been spent in recent years to improve our ability to measure volcanic gas compositions and fluxes. In the last decades, near-infrared room-temperature diode lasers, though in an experimental phase, are finding applications in volcanic gas studies. In this PhD dissertation, I use the GasFinder 2.0, a commercial tunable diode infrared laser transmitter-receiver unit, operating in the 1.3-1.7 m wavelength range, in the attempt to measure CO2 mixing ratios and fluxes in volcanic gas e…

Sea level rise in the Mediterranean Sea: High resolution constraints from vermetid reefs

2009

The Mediterranean Sea (MS), is extremely sensitive to rising sea-levels (SL) as attested by drowned archeological remains from the Roman Period [2]. Due to the absence of coral reefs, evidence for recent and Holocene SL change has so far mainly been restricted to coastal cores [1] archeological remains [2] and submerged speleothem deposits. Vermetid reefs are an extremely sensitive high resolution carbonate archive [3,4] and they are mainly formed in the lower intertidal zone by gregarious and sessile gastropods belonging to the genus Dendropoma (family Vermetidae). Since their interval of growth is restricted to the tidal zone, they can be used as precise SL proxies (about ±0.1 m in low ra…

THE BIOGEOCHEMICAL BEHAVIOUR OF RARE EARTH ELEMENTS AS A CONSEQUENCE OF PROCESSES OCCURING IN THE VITIS VINIFERA L. – SOIL SYSTEM

2014

The geochemical behaviour of lanthanides and yttrium (Rare Earth Elements, REE) has been investigated mainly in geological systems as the REE exploitation in industrial and agricultural practices is progressively growing in the last years, to such an extent to become strategic materials. Extensive researches evidenced that REE capability to investigate processes occurring at the interface between different media such as the in depth investigation of REE behaviour is a matter of fact in many geochemical studies. These capabilities are a consequence of the chemical characters of REE that are exploited to investigate processes occurring during migrations of chemical elements in the soil-to-pla…

Volcanic signature of volatile trace elements on atmospheric deposition at Mt. Etna, Italy

2009

Volcanic volatiles and aerosol emitted into the atmosphere ultimately fall on the Earth’s surface as wet or dry deposition, and they can influence the environment and the ecosystems at local and regional scales. Therefore, atmospheric deposition plays a key-role in the geochemical cycles, redistributing volcanogenic elements to the ground. For this reason, estimating the volcanogenic trace element fluxes from the atmosphere to the surface is necessary for a better knowledge of the environmental impact of the volcanic emissions. Nevertheless, from a literature review, we have recognized the scarcity of investigation on trace element deposition in the surroundings of active volcanoes. Here, w…

THE NATURE AND SOURCE OF MAJOR MAGMATIC VOLATILES: OPEN-VENT DEGASSING VOLCANOES IN THE CENTRAL AMERICAN VOLCANIC ARC

Major volatiles play an important role in subduction zone magmatism, from magma generation in the mantle, to crustal ascent and evolution, until its dramatic expression during a volcanic eruption. In the attempt to add a piece of information on source and behavior of major volatiles in arc volcanism, I here report on the geochemistry of H2O, CO2, S and Cl in two volcanic systems in NW Nicaragua (Central America), San Cristóbal and Telica. The observational approach is based upon combination of some of the most recent techniques in volcanic gas monitoring and petrology. I here explore quiescent and eruptive degassing processes by combining both volcanic gas and melt inclusion approaches. Fie…