Seismological study of Larderello — Travale geothermal area

Investigating fossil hydrothermal systems by means of fluid inclusions and stable isotopes in banded travertine: an example from Castelnuovo dell’Abate (southern Tuscany, Italy)

“…Hydrothermal fluid flow is still active in this area as manifested by the travertine deposition from thermal springs at Bagno Vignoni and Bagni San Filippo (Fig. 1a), the occurrence of numerous CO 2 -rich gas emissions (Frondini et al 2009) and the two geothermal fields (Bagnore and Piancastagnaio) exploited for electricity production (Batini et al 2003). All these features can be related to the thermal anomaly generated by a granitoid cooling at about 6-7 km below sea level (Gianelli et al 1988;Bertini et al 1995;Brogi 2008).…”

“…The geothermal systems of southern Tuscany mainly consist of two main reservoirs occurring at shallow crustal levels. The deeper reservoir (T of 300-350 °C, depth 1000-3000 m) is hosted in metamorphic rocks, while the shallower reservoir (T lower than 200 °C, depth 500-1000 m) is hosted mainly in carbonate rocks (Duchi et al 1992;Batini et al 2003). Travertine deposits are the surface manifestation of hydrothermal fluid circulation within the carbonate reservoirs (Brogi et al 2015 and reference therein) and are widely distributed in southern Tuscany and northern Latium (Minissale 2004, Brogi et al 2010aCapezzuoli et al 2011).…”

“…Southern Tuscany is characterized by a broad geothermal anomaly (Della Vedova et al 2001) that is mainly centred in the Larderello-Travale and Monte Amiata geothermal areas (Batini et al 2003) and strictly associated with CO 2 leakage and travertine deposits (Rogie et al 2000;Minissale 2004). The geothermal systems of southern Tuscany mainly consist of two main reservoirs occurring at shallow crustal levels.…”

Convective, intrusive geothermal plays: what about tectonics?

“…Considering Quaternary tectonics, recent studies have suggested an important role of strike-slip faults and step-over zones controlling the magma emplacement in the inner Northern Apennines (Acocella et al, 2006) and in the Mt Amiata area (Brogi and Fabbrini, 2009). Batini et al (1985) presented a seismological study of the Larderello area, showing an intense seismic activity of low magnitude, partially induced, that could be correlated with seismically active structures.…”

Hydrogeochemical processes controlling water and dissolved gas chemistry at the Accesa sinkhole (southern Tuscany, central Italy)

“…The occurrence of ground collapses, basically produced by internal erosion and deformation processes caused by subsurface karstification (Williams, 2003;Sauro, 2003;Waltham et al, 2005), is likely favored by seismic activity (Del Prete et al, 2010) and circulation of CO 2 (H 2 S)-rich fluids (Duchi et al, 1986;Billi et al, 2007;Frondini et al, 2008). An enhanced hydrothermal activity in this area was interpreted as related to a heat flow anomaly (Gianelli et al, 1997;Batini et al, 2003;Bellani et al, 2004) and extensional structures coeval with the emplacement of granitoids at depth in the Late Miocene, exposed or drilled during mining exploitation (Serri et al, 1993;Dini et al, 2005;Benvenuti et al, 1994). Hydrothermal fluid patterns are currently controlled by Early Pliocene-Present high angle normal to strike-slip faults giving rise to local tectonic depressions (Bertini et al, 1991;Carmignani et al, 1994;Jolivet et al, 1998;Rossetti et al, 2011;Brogi et al, 2005;Liotta et al, 2010).…”