Pyrometamorphic Processes at the Magma-Hydrothermal System Interface of Active Volcanoes: Evidence from Buchite Ejecta of Stromboli (Aeolian Islands, Italy)

Moro, Stefano Del; Renzulli, Alberto; Tribaudino, Mario

doi:10.1093/petrology/egq090

Cited by 31 publications

(37 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This hydrated mineral has been observed in volcanic caves and as a product of hydrothermal alteration of volcanic rocks in active volcanoes (Forti, 2005;del Moro et al, 2011). The origin of polyhalite could be attributed to a strong hydrothermal alteration of volcanic rocks by very low pH fluids (del Moro et al, 2011), sublimation from high temperature fumaroles, deposition from aerosols and vapours in low temperature fumaroles, and by alteration of volcanic rocks by oxidation and/or hydration processes (Forti, 2005 12 ] is a product of the reaction between galena and oxidizing pyrite, especially in lead deposits (Anthony et al, 2003). This is consistent with the presence of pyrite, galena and Pb-bearing minerals in fumarolic deposits, like has been reported in diverse active volcanoes (e.g., Africano and Bernard, 2000;Africano et al, 2002;Yudovskaya et al, 2008).…”

Section: Hydrated Sulphatesmentioning

confidence: 98%

Hydrothermal alteration, fumarolic deposits and fluids from Lastarria Volcanic Complex: A multidisciplinary study

Aguilera

Layana

Rodríguez-Díaz

et al. 2016

andgeo

View full text Add to dashboard Cite

ABSTRACT.A multidisciplinary study that includes processing of Landsat ETM+ satellite images, chemistry of gas condensed, mineralogy and chemistry of fumarolic deposits, and fluid inclusion data from native sulphur deposits, has been carried out in the Lastarria Volcanic Complex (LVC) with the objective to determine the distribution and characteristics of hydrothermal alteration zones and to establish the relations between gas chemistry and fumarolic deposits. Satellite image processing shows the presence of four hydrothermal alteration zones, characterized by a mineral assemblage constituted mainly by clay minerals, alunite, iron oxides, and more subordinated ferrous minerals and goethite. Hydrothermal alteration zones present in the Lastarria sensu stricto volcano are directly related to the recent fumarolic activity. Geochemistry of fumarolic gas condensed, obtained from two fumaroles at temperatures between 328 and 320 °C, has allowed detecting 37 diverse elements corresponding to halogens, chalcophiles, siderophiles, alkali metals, alkali earth metals and Rare Earth Elements (REE), with concentrations that vary widely between 5,620 ppm (chlorine) and 0.01 ppm (Mo, Ag, Sn, Pb, Se, Mg and Cr). Logarithm of Enrichment Factor (log EF i ) for each element present values between 6.35 (iodine) and <1 (K, Na, Ca, Fe and Al). Those elements are originated primarily from a magmatic source, whereas at shallow level a hydrothermal source contributes typical rock-related elements, which are leached from the wall rock by a strong interaction with hyperacid fluids. Mostly of elements detected are transported to the surface in the fumarolic emissions as gaseous species, while very few elements (Mg, Ca and Al) are transported in silicate aerosols. A wide spectrum of minerals are present in the fumarolic deposits, which are constituted by sublimates and incrustations, and the main minerals phases are distributed in six mineral families, corresponding to sulphates, hydrated sulphates, sulphides, halides, carbonates, silicates and native element minerals. The sublimate/incrustation minerals are dominated by the presence of sulphate, sulphur, chlorine and diverse rock-related elements, which are formed by processes that include a. oxidation of gaseous phase; b. strong rock-fluid interaction; c. dissolution of silicate minerals and volcanic glass; d. gas-water interaction; e. deposition/precipitation of saline bearing minerals; f. oxidation of sublimates/incrustations to form secondary minerals and g. remobilization of sulphur deposits by meteoric water. Despite that sublimate/ incrustation minerals are dominated by rock-related elements, its chemistry shows high contents of high-volatile elements as As, Sb, Cd, among others. Fluid inclusions studies carried out in thin pseudobanded native sulphur from fumarolic deposits, by use of Raman and infrared spectroscopy combined with microthermometry analyses, provided evidence of H 2 O, CO 2 , H 2 S, SO 4 , COS bearing fluids, homogenization temperatures around 110 °C and salinities v...

show abstract

Section: Hydrated Sulphatesmentioning

confidence: 98%

Hydrothermal alteration, fumarolic deposits and fluids from Lastarria Volcanic Complex: A multidisciplinary study

Aguilera

Layana

Rodríguez-Díaz

et al. 2016

andgeo

View full text Add to dashboard Cite

show abstract

“…Pyrometamorphim at the contact between basic magma and sedimentary or metamorphic rocks (Grapes 1986(Grapes , 2006Graham et al 1988;Preston et al 1999;Renzulli et al 2003;Salvioli-Mariani et al 2005;Harlov et al 2006), as well as hydrothermally altered volcanics (Wood 1994;Wood and Browne 1996;Grapes 2006;Del Moro et al 2011, usually results in partially to completely vesiculated glassy rocks of the sanidinite facies (i.e., buchite; Grapes 2006 and references therein). Partial melting and subsequent crystallization from the anatectic liquid, as well as subsolidus mineral reactions, are the main processes of pyrometamorphism (Grapes 1986;Graham et al 1988;Clark and Peacor 1992;Preston et al 1999;Sokol et al 1998;Grapes 2006;Del Moro et al 2011.…”

Section: Pyrometamorphism After Hydrothermal Alterationmentioning

confidence: 99%

“…Partial melting and subsequent crystallization from the anatectic liquid, as well as subsolidus mineral reactions, are the main processes of pyrometamorphism (Grapes 1986;Graham et al 1988;Clark and Peacor 1992;Preston et al 1999;Sokol et al 1998;Grapes 2006;Del Moro et al 2011.…”

Section: Pyrometamorphism After Hydrothermal Alterationmentioning

confidence: 99%

“…The formation of clinopyroxene coronas is common during partial melting at the interface between silica-rich phases or melts and less evolved liquids (Bowen 1928;Searle 1962;Sato 1975;Preston et al 1999;Del Moro et al 2011). Clinopyroxene coronas in the grey xenopumice facies may have formed from thermal decomposition of secondary minerals after calcic amphibole and/or clinopyroxene alteration (possibly chlorite + calcite/anhydrite + smectite + illite).…”

Section: Pyrometamorphism After Hydrothermal Alterationmentioning

confidence: 99%

“…These processes are easily recognizable when dealing directly with hydrothermally altered volcanic samples, but they can be very hard to identify when obliterated by pyrometamorphism (Grapes 2006), i.e., very high-T low-P metamorphism inducing the partial or complete melting of the protolith rock. Hydrothermally altered volcanic rocks subjected to pyrometamorphic processes induced by contact with high-T magmas in active volcanoes (Wood 1994;Grapes 2006;Del Moro et al 2011) usually appear as partly to completely glassy rocks (buchites), characterized by rare minerals and heterogeneous bulk rock composition. Since trachyte rocks are inferred to represent the most likely volcanic equivalents of the xenopumice before hydrothermal alteration and pyrometamorphism, we also describe the petrography and the bulk rock and glass compositions of trachyte pumice (subaerial Holocene trachyte) from a pyroclastic deposit sampled along the El Golfo landslide crown outcropping in the Malpaso area (1500 m a.s.l.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Xenopumice erupted on 15 October 2011 offshore of El Hierro (Canary Islands): a subvolcanic snapshot of magmatic, hydrothermal and pyrometamorphic processes

et al. 2015

Self Cite

View full text Add to dashboard Cite

On 15 October 2011, a submarine eruption offshore of El Hierro Island gave rise to floating volcanic products, known as xenopumices, i.e., pumiceous xenoliths partly mingled and coated with the juvenile basanitic magma. Over the last few years, no consensus in the scientific community in explaining the origin of these products has been reached. In order to better understand the formation of xenopumice, we present a textural, mineralogical, and geochemical study of the possible magmatic, hydrothermal, and pyrometamorphic processes, which usually operate in the plumbing systems of active volcanoes. We carried out a comprehensive SEM investigation and Sr-Nd-Pb isotope analyses on some samples representative of three different xenopumice facies. All the data were compared with previous studies, new data for El Hierro extrusives and a literature dataset of Canary Islands igneous and sedimentary rocks. In the investigated xenopumices, we emphasize the presence of restitic magmatic phases as well as crystallization of minerals (mainly olivine + pyroxene + magnetite aggregates) as pseudomorphs after pre-existing mafic phenocrysts, providing evidence of pyrometamorphism induced by the high-T juvenile basanitic magma. In addition, we identify veins consisting of zircon+REE-oxides+mullite associated with Si-rich glass and hydrothermal quartz, which indicate the fundamental role played by hydrothermal fluid circulation in the xenopumice protolith. The petrological data agree with a pre-syneruptive formation of the xenopumice, when El Hierro basanite magma intruded hydrothermally altered trachyandesite to trachyte rocks and triggered local partial melting. Therefore, the El Hierro xenopumice represents a snapshot of the transient processes at the magma-wall rock interface, which normally occurs in the feeding system of active volcanoes.

show abstract

Geological constraints of a structural model of sector collapse at Stromboli volcano, Italy

Vezzoli

Corazzato

2016

Tectonics

View full text Add to dashboard Cite

This study is focused on the reconstruction of the structure and dynamics of the first lateral collapse that occurred at Stromboli during the Holocene, which represents the structure inherited by all the following collapses that formed the present Sciara del Fuoco depression. The first lateral collapse of Stromboli occurred at the end of the Vancori volcano activity, at about 13 ka ago. The Neostromboli lava cone grew within this collapse amphitheater. Based on a comprehensive geologic and structural analysis of both Vancori and Neostromboli products, we propose an innovative interpretation of the sliding surface. Once considered to be a homogeneous landslide along a deep‐seated sliding surface, we demonstrate that the Upper Vancori failure was accommodated by a more complex deformation regime comprising an upper (proximal) domain of tilted megablocks (toreva) and a lower (distal) domain of fragmental landslide transport and deposition.

show abstract

Pyrometamorphic Processes at the Magma-Hydrothermal System Interface of Active Volcanoes: Evidence from Buchite Ejecta of Stromboli (Aeolian Islands, Italy)

Cited by 31 publications

References 69 publications

Hydrothermal alteration, fumarolic deposits and fluids from Lastarria Volcanic Complex: A multidisciplinary study

Hydrothermal alteration, fumarolic deposits and fluids from Lastarria Volcanic Complex: A multidisciplinary study

Xenopumice erupted on 15 October 2011 offshore of El Hierro (Canary Islands): a subvolcanic snapshot of magmatic, hydrothermal and pyrometamorphic processes

Geological constraints of a structural model of sector collapse at Stromboli volcano, Italy

Contact Info

Product

Resources

About