Search results for " mineralogia."
showing 10 items of 43 documents
Ab-initio investigation of the thermodynamic stability of the magnesio-wüstite solid solution under Earth’s lower mantle conditions
2014
Secondary Minerals From Italian Sulfuric Acid Caves
2017
Italy is a country hosting a large number of hypogenic sulfuric acid (SAS) speleogenesis caves, mostly located along the Apennine chain, but also in Campania (along the coastline of Capo Palinuro), Apulia (along the coastline of Santa Cesarea Terme) and Sicily. Besides the typical morphologies related to their special geochemical origin (cupolas, replacement pockets, bubble trails, etc), these caves often host abundant secondary mineral deposits, mainly gypsum, being the result of the interaction between the sulfuric acid and the carbonate host rock. Native sulfur deposits are also well visible on the ceiling and roof, and peculiar sulfuric acid minerals such as jarosite, alunite, and other…
The use of moss-bags technique for volcanic aerosols investigation on Mt. Etna (Italy)
2014
Explosive eruptions and volcanic passive degassing inject large quantities of gas and particles into the atmosphere that are ultimately deposited at the Earth’s surface through wet or dry deposition processes, affecting the atmosphere, the hydrosphere and the biosphere. Mount Etna (Italy) is one of the most prodigious and persistent sources of gases and particles to the troposphere. Volcanic emissions were studied at Etna volcano by using moss-bags technique. Mosses (Sphagnum species) were exposed around the volcano at different distances from the active vents to evaluate the impact of its emissions into the atmosphere and in the local surrounding. The results confirmed the huge amount of s…
Caratterizzazione mineralogico-petrografica delle malte in opera nel Castello di Calatamauro a Contessa Entellina (Sicilia occidentale)
2008
Analisi di argille siciliane per una valutazione preliminare dell’attitudine all’impiego nel settore dell’architettura in “terra cruda”
2008
Le "argille ceramiche" della Sicilia occidentale e centrale
2011
L’argilla è senza dubbio uno dei primi materiali naturali o “geomateriali” che l’uomo abbia mai usato, ed anche oggi, in molteplici temi applicativi della geologia, la conoscenza approfondita delle formazioni argillose diventa spesso un aspetto di primaria importanza. Le peculiari proprietà di acquisire un’eccellente plasticità una volta mescolata con acqua in proporzioni opportune e quindi di essere facilmente modellata, di acquistare rigidità in seguito ad asciugamento, di diventare solida in modo permanente dopo cottura, unitamente alla pressoché ubiquitaria disponibilità, hanno fatto sì che l’argilla sia stata sempre ricercata e lavorata con ottimi risultati per foggiare vasellame di us…
Fe-periclase reactivity at Earth's lower mantle conditions: Ab-initio geochemical modelling
2017
Intrinsic and extrinsic stability of the (Mg, Fe) O solid mixture in the Fe-Mg-Si-O system at high P, T conditions relevant to the Earth's mantle is investigated by the combination of quantum mechanical calculations (Hartree-26 Fock/DFT hybrid scheme), cluster expansion techniques and statistical thermodynamics. Iron in the (Mg, Fe) O binary mixture is assumed to be either in the low spin (LS) or in the high spin (HS) state. Un-mixing at solid state is observed only for the LS condition in the 23-42 GPa pressure range, whereas HS does not give rise to un-mixing. LS (Mg, Fe) O un-mixings are shown to be able to incorporate iron by subsolidus reactions with a reservoir of a virtual bridgmanit…