Descripción
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The Mt. Amiata is the biggest and youngest (200,000 years old) volcano in Tuscany and hosts the second largest geothermal field of Italy. Its south-westernmost and east-northernmost borders are characterized by the presence of several gas discharges, having high CO2 concentrations (>95% by vol.). In the eastern part of Mt. Amiata area and particularly close to Abbadia San Salvatore an intense Hg mining activity had taken place up to the end of the seventies. During these investigations in two drillings (namely, Acqua Passante and Ermeta, respectively) a CO2-rich gas fertile horizon was intercepted. These wells discharge a CO2-rich gas in the atmosphere since 1938 and 1959, respectively. In this work the results of a geochemical and isotopic survey carried out on these gas discharges are presented. The CO2 flux from both the two vents and the soil in their surrounding areas was also measured using hot-wire anemometer and accumulation chamber methods, respectively. The two chimneys are emitting up to 15,000 tons year?1 of CO2 and can be regarded as a natural subsurface CO2 accumulation in the case they will be shut down. The accumulation chamber method applied to determine the CO2 output in the area between the two drillings has allowed to calculate that presently 11.81 tons of CO2 (ca. 4,311 ton year?1) are released from about 653,500 m2, i.e. more than 3 times less than the CO2 discharged by two chimneys. The direct survey of CO2 soil flux has indicated the presence of possible fractures/faults from where higher amounts of CO2 can be released. | |
Internacional
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Si |
Nombre congreso
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34th International Geological Congress |
Tipo de participación
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960 |
Lugar del congreso
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Brisbane (Australia) |
Revisores
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Si |
ISBN o ISSN
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978-0-646-57800-2 |
DOI
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Fecha inicio congreso
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05/08/2012 |
Fecha fin congreso
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10/08/2012 |
Desde la página
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1251 |
Hasta la página
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1251 |
Título de las actas
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Proceedings of the 34th International Geological Congress 2012 |