Native sulfur, sulfates and sulfides from the active Campi Flegrei volcano (southern Italy): Genetic environments and degassing dynamics revealed by mineralogy and isotope geochemistry

Piochi, Monica; Mormone, Angela; Balassone, Giuseppina; Strauß, Harald; Troise, Claudia; Natale, Giuseppe De

doi:10.1016/j.jvolgeores.2015.08.017

Cited by 45 publications

(47 citation statements)

References 53 publications

(164 reference statements)

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“…Comparison between the shallow portion of the resistivity model and independent data. (a) Map of the main caldera structures and faults (redrawn after Isaia et al, ; Piochi et al, ; Vilardo et al, ); red lines represent the faults already reported in Figure ; green, violet, and blue triangles, respectively, represent the BG, BN, and Pisciarelli fumaroles; yellow circle represents the Fangaia mud pool; the yellow star represents the CF23 borehole. (b) CO 2 flux measured along the AMT profile (red shaded boxes highlight the spatial correspondence between geochemical and resistivity data, marking zones of high CO 2 flux and degassing vents).…”

Section: Comparison Of Amt Resistivity Model With Other Geological Anmentioning

confidence: 99%

Reservoir Structure and Hydraulic Properties of the Campi Flegrei Geothermal System Inferred by Audiomagnetotelluric, Geochemical, and Seismicity Study

et al. 2019

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The Campi Flegrei caldera is a large volcanic complex lying in the Campanian Plain, Southern Italy. During its history the caldera experienced episodes of bradyseism and intense swarm seismicity. The mechanism leading to unrest episodes is still debated, and great efforts are ongoing to improve the knowledge of this structure and its evolution due to the high volcanic risk in such a densely populated area. Here we present a resistivity model from a two‐dimensional inversion of audiomagnetotelluric data acquired along an approximately 5.6‐km long profile crosscutting the Solfatara‐Pisciarelli district and the Agnano plain. The resistivity model shows (1) very low resistivity values confined in the first 500 m of depth both in correspondence of the Solfatara‐Pisciarelli districts and the Agnano depression; (2) a resistive plume that extends underneath the Solfatara crater down to 2,000‐ to 3,000‐m depth, and (3) an adjoining relative conductive unit eastward. We discuss the resistivity structures in a multidisciplinary framework integrating inedited geochemical and seismological observations with existing surface geology and subsurface information. The Solfatara‐Pisciarelli district and the Agnano plain, both being expression of intense hydrothermal activity, show different characteristics. Below the Solfatara‐Pisciarelli area, the shallow conductive zone is interpreted as a faulted clay cap that overlies a highly active vapor‐dominated reservoir characterized by a convective mechanism. Conversely, below the Agnano plain, a liquid phase seems to prevail in the reservoir. The spatiotemporal variations of seismicity imply a combined action of preexisting tectonic lineaments and fluid interaction between the gas/steam reservoir and the outflow zone.

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Section: Comparison Of Amt Resistivity Model With Other Geological Anmentioning

confidence: 99%

Reservoir Structure and Hydraulic Properties of the Campi Flegrei Geothermal System Inferred by Audiomagnetotelluric, Geochemical, and Seismicity Study

et al. 2019

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“…Recently, brady seismic crises occurred in 1950–1953, 1970–1972, and 1982–1984, with a total ground uplift of approximately 4 m whereas, at present, Campi Flegrei caldera is in an unrest phase characterized by a consistent ground‐deformation process interpreted, for the 2012–2013 ground uplift, as a magma intrusion at 3 km depth . Below Solfatara crater, deep magmatic fluids reach the hydrothermal system at approximately 2 km depth where they mix with meteoric components before being released at surface through both diffuse degassing and fumaroles, thus generating a high sulfidation system . The two measurement sites (Figure a) are located along the eastern crater wall of Solfatara in a sector characterized by heavily altered deposits, named “encrusted” subsoil domain .…”

Section: Volcanic Site and Sulfurmentioning

confidence: 99%

Field remote Stokes/anti‐Stokes Raman characterization of sulfur in hydrothermal vents

Guimbretière

Duraipandian

Ricci

2018

J Raman Spectroscopy

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To study the dynamics of active volcanic environments, minerals involved in fresh lava flows are a nice probe and Raman spectroscopy is an excellent tool for their characterization. Because of the highly hostile environment linked to volcanic activity, studying lava cooling and weathering needs remote setups and specific procedures dedicated to medium‐high temperature targets. In this paper, we present the remote Raman characterization of sulfur produce by the fumarolic activity at Solfatara crater (Phlegraean Fields, Italy). Two medium temperature sites (280–380 K) were probed with two different Raman setups. For both, β‐sulfur is the prominent type in the entire temperature range and the absolute local temperature of the sulfur was remotely estimated by mean of a Stokes/anti‐Stokes procedure with ±10 K uncertainty. These results represent a good starting point for the development of new setups and protocols aimed to an increase of both measurement distance and temperature range.

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“…Mixing of these fluids occurs at high temperature (>350°C) at the base of the hydrothermal system (1-1.5 km), whereas a shallow vapor-liquid zone is imaged to be located at depth between 150 and 300 m (2.6-4.5 MPa) where temperature ranges between 190 and 250°C. [Caliro et al, 2007[Caliro et al, , 2014Piochi et al, 2014Piochi et al, , 2015 (Figure 1b). Recent episodes of mud emissions and formation of boiling pools of condensates at Pisciarelli [Chiodini et al, 2011], together with the presence of electrically resistive gas bodies below the fumaroles in Solfatara, overlain by conductive descending bodies of liquid condensates [Bruno et al, 2007;Byrdina et al, 2014;Isaia et al, 2015], support the occurrence of deep processes of condensation within the buried Solfatara gas plume [Chiodini et al, 2015].…”

Section: Geological Setting Of the Case Study: Solfatara And Pisciarellimentioning

confidence: 99%

“…Consistent with the volcanic history of CF [Orsi et al, 1996[Orsi et al, , 2004[Orsi et al, , 2009Di Vito et al, 1999;Isaia et al, 2015], Solfatara and Pisciarelli areas have been assigned the highest probability for the opening of a future vent [Selva et al, 2012;Bevilacqua et al, 2015] and an explosive eruption. A complex fault system, related to the maar-diatreme origin of the Solfatara crater, is believed to be driving the outgassing which in turn leads to a strong alteration of the volcanic products in both areas [Isaia et al, 2015;Piochi et al, 2015;Mayer et al, 2016]. Additionally, recent physical simulations suggest an increased fluid flux within the last two decades, which is deriving from depth and feeding the hydrothermal system [Todesco, 2009].…”

Section: Introductionmentioning

confidence: 99%

Experimental investigations on the explosivity of steam‐driven eruptions: A case study of Solfatara volcano (Campi Flegrei)

et al. 2016

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Steam‐driven eruptions, both phreatic and hydrothermal, expel exclusively fragments of non‐juvenile rocks disintegrated by the expansion of water as liquid or gas phase. As their violence is related to the magnitude of the decompression work that can be performed by fluid expansion, these eruptions may occur with variable degrees of explosivity. In this study we investigate the influence of liquid fraction and rock petrophysical properties on the steam‐driven explosive energy. A series of fine‐grained heterogeneous tuffs from the Campi Flegrei caldera were investigated for their petrophysical properties. The rapid depressurization of various amounts of liquid water within the rock pore space can yield highly variable fragmentation and ejection behaviors for the investigated tuffs. Our results suggest that the pore liquid fraction controls the stored explosive energy with an increasing liquid fraction within the pore space increasing the explosive energy. Overall, the energy released by steam flashing can be estimated to be 1 order of magnitude higher than for simple (Argon) gas expansion and may produce a higher amount of fine material even under partially saturated conditions. The energy surplus in the presence of steam flashing leads to a faster fragmentation with respect to gas expansion and to higher ejection velocities imparted to the fragmented particles. Moreover, weak and low permeability rocks yield a maximum fine fraction. Using experiments to unravel the energetics of steam‐driven eruptions has yielded estimates for several parameters controlling their explosivity. These findings should be considered for both modeling and evaluation of the hazards associated with steam‐driven eruptions.

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Native sulfur, sulfates and sulfides from the active Campi Flegrei volcano (southern Italy): Genetic environments and degassing dynamics revealed by mineralogy and isotope geochemistry

Cited by 45 publications

References 53 publications

Reservoir Structure and Hydraulic Properties of the Campi Flegrei Geothermal System Inferred by Audiomagnetotelluric, Geochemical, and Seismicity Study

Reservoir Structure and Hydraulic Properties of the Campi Flegrei Geothermal System Inferred by Audiomagnetotelluric, Geochemical, and Seismicity Study

Field remote Stokes/anti‐Stokes Raman characterization of sulfur in hydrothermal vents

Experimental investigations on the explosivity of steam‐driven eruptions: A case study of Solfatara volcano (Campi Flegrei)

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