@prefix prodottidellaricerca: . @prefix istituto: . @prefix prodotto: . istituto:CDS043 prodottidellaricerca:prodotto prodotto:ID29062 . @prefix rdf: . prodotto:ID29062 rdf:type prodotto:TIPO1101 . @prefix retescientifica: . prodotto:ID29062 rdf:type retescientifica:ProdottoDellaRicerca . @prefix rdfs: . prodotto:ID29062 rdfs:label "Water-rock interaction in the active geothermal system of Pantelleria, I (Articolo in rivista)"@en . @prefix xsd: . @prefix pubblicazioni: . prodotto:ID29062 pubblicazioni:anno "2001-01-01T00:00:00+01:00"^^xsd:gYear . @prefix skos: . prodotto:ID29062 skos:altLabel "
GIANELLI, G., GRASSI, S. (2001)
Water-rock interaction in the active geothermal system of Pantelleria, I
in Chemical geology
"^^rdf:HTML ; pubblicazioni:autori "GIANELLI, G., GRASSI, S."^^xsd:string ; pubblicazioni:paginaInizio "113"^^xsd:string ; pubblicazioni:paginaFine "130"^^xsd:string ; pubblicazioni:altreInformazioni "This paper, as far as we know, is the only example, so far, of geochemical model by computer simulator applied to a peralkaline geothermal reservoir, reacting with sea water. The feed back of this research can be of interest not only for geothermal exploitation in small islands (and related environmental problems), but also to more general problems of water-rock interaction, such as the prediction of dissolution and precipitation of minerals in natural hydrothermal systems. Chemical Geology is considered one of the best journals in the Earth Science field and presents only peer-reviewed papers with original data on geochemistry, environmental geology and earth resources."^^xsd:string ; pubblicazioni:numeroVolume "181"^^xsd:string . @prefix ns9: . prodotto:ID29062 pubblicazioni:rivista ns9:ID393259 ; pubblicazioni:note "Imapct Factor 2,532"^^xsd:string ; pubblicazioni:descrizioneSinteticaDelProdotto "The geochemical modelling performed with the EQ3/6 code allows us to refine the conceptual model of the geothermal system of Pantelleria. System recharge is predominantly of marine origin, and the intrusion of pure seawater likely occurs throughout the island. The increasing temperatures deplete the fluid of Ca, Mg and SO4 and deposit anhydrite, quartz and clay minerals. The seawater flows through fractures and faults and may attain temperatures of more than 300\u00B0C. Volcanic gases increase the quantities of C and S, decrease the pH and enhance the dissolution of trachyte in the system. Dolomite, calcite and anhydrite should be deposited by the fluid derived from the mixing of gases with marine water. The composition of the reservoir fluid likely derives from the mixing of three end members (seawater, freshwater and volcanic gas, and interactions with a trachytic rock. The minerals present are those found in the reservoir rocks and have been reproduced in the simulations. The model could be improved in future, if more data on the geothermal fluid will be available, and especially as regards the gas composition. Without the input of CO2 to the system trachyte+seawater+freshwater, the total carbonate in the fluid remains too low, and the computed partial pressure of CO2 is much lower than the assumed previously. Values of approximately 0.1-0.2 MPa at reservoir temperature may be more realistic."^^xsd:string ; skos:note "ISI Web of Science (WOS)"^^xsd:string ; pubblicazioni:affiliazioni "Istituto di Geoscienze e Georisorse, Area di Ricerca del CNR, Via Moruzzi 1, 56124, Pisa"^^xsd:string ; pubblicazioni:titolo "Water-rock interaction in the active geothermal system of Pantelleria, I"^^xsd:string ; prodottidellaricerca:abstract "The geothermal fluid sampled in a deep (990 m b.s.l.) well drilled into the peralkaline volcano of Pantelleria consists for the most part of seawater. The fluid is depleted in Ca and Mg and enriched in K, Rb, Cs and F due to interaction with rocks of trachytic composition. A forward geochemical model has been used to simulate the water-rock interaction processes occurring within the geothermal system in the southern part of the island. The simulation assumes different mixtures of seawater with groundwater and volcanic gas. The system model that emerges from the simulation is the following: the seawater flows through fractures and faults, reaching temperatures of over 300\u00B0C in the southern part of the island where an upflow zone of volcanic gas is present. Volcanic gases increase the amount of C and S in the system, lower the pH, and enhance the dissolution of trachyte. After reaction with trachyte the pH increases and the fluid reaches saturation conditions with respect to albite, quartz, saponite, K-feldspar and muscovite, in agreement with the natural hydrothermal mineral assemblages. The model confirms that the reservoir fluid is a mix between seawater and meteoric water, more saline fluids possibly existing in deeper levels. The fluid chemistry and the hydrothermal minerals are similar to those found in the Icelandic geothermal systems of Reykjanes and Svartsengi." ; prodottidellaricerca:prodottoDi istituto:CDS043 . @prefix parolechiave: . prodotto:ID29062 parolechiave:insiemeDiParoleChiave . ns9:ID393259 pubblicazioni:rivistaDi prodotto:ID29062 . parolechiave:insiemeDiParoleChiaveDi prodotto:ID29062 .