Effects of CO2 flushing on crystal textures and compositions: experimental evidence from recent K trachybasalts erupted at Mt. Etna

Changes in magmatic assemblages and crystal stability as a response of CO2 flushing in basaltic systems have been never directly addressed experimentally, making the role of CO2 in magma dynamics still controversial and object of scientific debate. We conducted a series of experiments to understand the response of magmas from Etna volcano to CO2 flushing. We performed a first experiment at 300 MPa to synthesize a starting material composed of crystals of some hundreds of m and melt pools. This material is representative of an initial magmatic assemblage composed of plagioclase, clinopyroxene and a water undersaturated melt. In a second step, the initial assemblage was equilibrated at 300 and 100 MPa with fluids having different XCO2fl . Our experiments demonstrate that flushing basaltic systems with fluids may drastically affect crystal textures and phase equilibria depending on the amount of H2O and CO2 in the fluid phase. Since texture and crystal proportions are among the most important parameters governing the rheology of magmas, fluid flushing will also influence magma ascent to the Earths surface. The experimental results open new perspectives to decipher the textural and compositional record of minerals observed in volcanic rocks from Mt. Etna, and at the same time offer the basis for interpreting the information preserved in minerals from other basaltic volcanoes erupting magmas enriched in CO2

The italian quaternary volcanism

The peninsular and insular Italy are punctuated by Quaternary volcanoes and their rocks constitute an important aliquot of the Italian Quaternary sedimentary successions. Also away from volcanoes themselves, volcanic ash layers are a common and frequent feature of the Quaternary records, which provide us with potential relevant stratigraphic and chronological markers at service of a wide array of the Quaternary science issues. In this paper, a broad representation of the Italian volcano logical community has joined to provide an updated comprehensive state of art of the Italian Quaternary volcanism. The eruptive history, style and dynamics and, in some cases, the hazard assessment of about thirty Quaternary volcanoes, from the north ernmost Mt. Amiata, in Tuscany, to the southernmost Pantelleria and Linosa, in Sicily Channel, are here reviewed in the light of the substantial improving of the methodological approaches and the overall knowledge achieved in the last decades in the vol canological field study. We hope that the present review can represent a useful and agile document summarising the knowledege on the Italian volcanism at the service of the Quaternary community operating in central Mediterranean area

Clinical Features, Cardiovascular Risk Profile, and Therapeutic Trajectories of Patients with Type 2 Diabetes Candidate for Oral Semaglutide Therapy in the Italian Specialist Care

Introduction: This study aimed to address therapeutic inertia in the management of type 2 diabetes (T2D) by investigating the potential of early treatment with oral semaglutide. Methods: A cross-sectional survey was conducted between October 2021 and April 2022 among specialists treating individuals with T2D. A scientific committee designed a data collection form covering demographics, cardiovascular risk, glucose control metrics, ongoing therapies, and physician judgments on treatment appropriateness. Participants completed anonymous patient questionnaires reflecting routine clinical encounters. The preferred therapeutic regimen for each patient was also identified. Results: The analysis was conducted on 4449 patients initiating oral semaglutide. The population had a relatively short disease duration (42%  60% of patients, and more often than sitagliptin or empagliflozin. Conclusion: The study supports the potential of early implementation of oral semaglutide as a strategy to overcome therapeutic inertia and enhance T2D management

Valorisation of Biowastes for the Production of Green Materials Using Chemical Methods

With crude oil reserves dwindling, the hunt for a sustainable alternative feedstock for fuels and materials for our society continues to expand. The biorefinery concept has enjoyed both a surge in popularity and also vocal opposition to the idea of diverting food-grade land and crops for this purpose. The idea of using the inevitable wastes arising from biomass processing, particularly farming and food production, is, therefore, gaining more attention as the feedstock for the biorefinery. For the three main components of biomass—carbohydrates, lipids, and proteins—there are long-established processes for using some of these by-products. However, the recent advances in chemical technologies are expanding both the feedstocks available for processing and the products that be obtained. Herein, this review presents some of the more recent developments in processing these molecules for green materials, as well as case studies that bring these technologies and materials together into final products for applied usage

Three years (2011–2013) of eruptive activity at Mt. Etna: Working modes and timescales of the modern volcano plumbing system from micro-analytical studies of crystals

Tracking magma dynamics at active volcanoes by using the compositional and textural records of minerals is becoming an important aspect of modern volcanology to solve key issues, such as temporal relationships between magma recharge and eruption, duration of magma storage and final ascent upward to the surface. These issues are relevant at Mt. Etna, where the style of volcanic activity during the last years showed drastic variations in duration and intensity. The paroxysmal activity between 2011 and 2013 at the volcano summit has given the opportunity to investigate the chemical-physical processes driving the activity and to fix their spatial-temporal relationships into the plumbing system. An extensive compositional dataset of plagioclase and olivine crystals from lavas emitted between the 2011 and 2013 at Mt. Etna has been used to constrain modes and timescales of magma storage and transfer to the surface. Plagioclase crystals display either near-equilibrium or disequilibrium textures at the core and rim that indicate complex histories of magma crystallization under variable chemical and physical conditions. Crystals with different textures have been characterized for major (An), minor (Fe and Mg) and trace elements (Sr/Ba). Textural relationships at the plagioclase cores support the idea that crystals undergo variable decompression rates in the deep parts of the plumbing system. Fe and Mg zoning vs. anorthite in correspondence of plagioclase sieve textures at the rim suggest that processes of gas-flushing have a dominant role in triggering paroxysmal eruptions, determining a sudden intensification of the eruptive activity up to the fountaining phase. The Sr/Ba ratio in oscillatory-zoned plagioclase revealed the dominant presence into the plumbing system of high-Sr magma volumes coexisting with low-Sr magma batches that preserve a geochemical signature similar to that of magmas feeding the pre-1971 activity. Through Sr-diffusion modeling in plagioclase the maximum time of magma storage during the considered eruptive period has been evaluated. Timescales of crystal residence in the plumbing system are short (five years to three decades), suggesting limited magma storage and faster transfer dynamics to the surface. Chemical zoning of olivine crystals highlights processes of multi-step magma transfer and residence at different levels of the plumbing system. The upward migration of magmas occurred primarily through multiple episodes of injection and mixing between five compositionally distinct magmatic environments (Mi), whose P-T-ƒO2 characteristics and concentrations in dissolved volatiles were constrained by thermodynamic modeling on the basis of the forsterite contents found at the olivine cores. From a deepest reservoir, located at depth of ~ 600 MPa, the most primitive magma M00 (Fo84) moved along dominant pathways, intercepting the M0 (Fo80–82) at ~ 390 MPa and/or M1a (Fo78; 250 MPa), M1b (Fo75; ~ 140 MPa) and finally the shallow M2 (Fo70–73; ~ 40 MPa) storage zones. For some eruptive episodes, olivine zoning highlights a preferential route of transfer, connecting the M00 and M2 storage zones that facilitated the fast migration of primitive magma at shallow depth. Fe-Mg diffusion modeling on olivine normal and reverse zoning defines the timescales of magma transfer and storage across these magmatic environments, which vary from ~ 1 to 18 months, whereas intrusion and mixing by more basic magma into the shallowest reservoir occurred always within 5 months before the eruption. Relevance of this study mainly relies on the quantification of volcanic processes at depth that may have considerable consequences in development of unusual, high-energy eruptions at basaltic volcanoes, generally acknowledged for their weak to mild explosive activity.Published289-3225V. Dinamica dei processi eruttivi e post-eruttiviJCR Journa

Ultrafast syn-eruptive degassing and ascent trigger high-energy basic eruptions

Lithium gradients in plagioclase are capable of recording extremely short-lived processes associated with gas loss from magmas prior to extrusion at the surface. We present SIMS profiles of the 7Li/30Si ion ratio in plagioclase crystals from products of the paroxysmal sequence that occurred in the period 2011-2013 at Mt. Etna (Italy) in an attempt to constrain the final ascent and degassing processes leading to these powerful eruptions involving basic magma. The observed Li concentrations reflect cycles of Li addition to the melt through gas flushing, and a syn-eruptive stage of magma degassing driven by decompression that finally produce significant Li depletion from the melt. Modeling the decreases in Li concentration in plagioclase by diffusion allowed determination of magma ascent timescales that are on the order of minutes or less. Knowledge of the storage depth beneath the volcano has led to the quantification of a mean magma ascent velocity of ~43 m/s for paroxysmal eruptions at Etna. The importance of these results relies on the application of methods, recently used exclusively for closed-system volcanoes producing violent eruptions, to open-conduit systems that have generally quiet eruptive periods of activity sometimes interrupted by sudden re-awakening and the production of anomalously energetic eruptions.Publishedid 1475V. Processi eruttivi e post-eruttiviJCR Journa

Unraveling Textural and Chemical Features in Volcanic Rocks Through Advanced Image Processing: A Case Study From the 2019 Paroxysmal Eruptions of Stromboli

Abstract The Quantitative X‐Ray Map Analyzer software, a new tool for image processing, has been tested on intertwined pumices and scoriae emitted during the two paroxysmal eruptions of Stromboli of 2019, whose textural and compositional heterogeneities reflect the coexistence of low porphyritic shoshonitic‐basalts and high porphyritic shoshonites. The procedure applied was designed to quantitatively document the complex variations in texture and composition of these products, allowing substantial time reduction of analytical and data processing. The procedure utilizes Principal Components Analysis and supervised Maximum Likelihood Classification for multivariate statistical data handling of an array of X‐ray elemental maps acquired at the millimeter scale in thin‐sections. This technique permits the production of high‐contrast colored images, which allow the classification of rock constituents, extrapolating the associated modal abundances and imaging chemical variations within the glass. Results highlight the close interconnection at the microscale of two types of magma in the erupted products, manifested in each processed image by the presence of contiguous areas preserving textural bulk properties typical of the pumice or scoria. The proportion of the two magmas feeding the eruptions is not simply represented by the proportions of scoria and pumice in individual clasts, as both scoria and pumice contain glass with the composition of shoshonitic‐basalts and shoshonites. This method also allows the recognition of important discordances between the textural and chemical features of the two fractions involved, as well as discernment of the compositions of the two interacting magmas at the microscopic scale, even in those micro‐domains showing evidence of intense interaction processes

Effects of CO2 flushing on crystal textures and compositions: experimental evidence from recent K-trachybasalts erupted at Mt. Etna

Changes in magmatic assemblages and crystal stability as a response of CO2-flushing in basaltic systems have rarely been directly addressed experimentally, making the role of CO2 in magma dynamics still controversial and object of scientific debate. We conducted a series of experiments to understand the response of magmas from Etna volcano to CO2 flushing. We performed a first experiment at 300 MPa to synthesize a starting material composed of crystals of some hundreds of µm and melt pools. This material is representative of an initial magmatic assemblage composed of plagioclase, clinopyroxene and a water-undersaturated melt with 1.6 wt% H2O. In a second step, the initial assemblage was equilibrated at 300 and 100 MPa with fluids having different XCO 2 fl (CO2/(H2O + CO2)). At low XCO 2 fl (< 0.2 to 0.4), plagioclase is completely dissolved and clinopyroxene show dissolution textures. For relatively high XCO 2 fl (0.9 at 300 MPa), the flushing of a CO2-rich fluid phase leads to an increase of the amount of clinopyroxene and a decrease of the abundance of plagioclase at 300 MPa. This decrease of plagioclase proportion is associated with a change in An content. Our experiments demonstrate that flushing basaltic systems with fluids may drastically affect crystal textures and phase equilibria depending on proportions of H2O and CO2 in the fluid phase. Since texture and crystal proportions are among the most important parameters governing the rheology of magmas, fluid flushing will also influence magma ascent to the Earth’s surface. The experimental results open new perspectives to decipher the textural and compositional record of minerals observed in volcanic rocks from Mt. Etna, and at the same time offer the basis for interpreting the information preserved in minerals from other basaltic volcanoes erupting magmas enriched in CO2.Published903V. Proprietà dei magmi e dei prodotti vulcaniciJCR Journa

Magma storage, ascent and recharge history prior to the 1991 eruption at Avachinsky Volcano, Kamchatka, Russia: Inferences on the plumbing system geometry

Textural and compositional features of plagioclase phenocrysts of the 1991 eruption lavas at Avachinsky Volcano (Kamchatka, Russia) were used to investigate the feeding system processes. Volcanics are porphyritic basaltic andesites and andesites with low-K affinity. A fractionation modeling for both major and trace elements was performed to justify the development of these evolved compositions. The occurrence of other magma chamber processes was verified through high-contrast BSE images and core-to-rim compositional profiles (An and FeO wt.) on plagioclase crystals. Textural types include small and large-scale oscillation patterns, disequilibrium textures at the crystal core (patchy zoning, coarse sieve-textures, dissolved cores), disequilibrium textures at the crystal rim (sieve-textures), melt inclusion alignments at the rim. Disequilibrium textures at the cores may testify episodes of destabilization at various decompression rates under water-undersaturated conditions, which suggests different pathways of magma ascent at depth. At shallower, water-saturated conditions, plagioclase crystallization continues in a system not affected by important chemical-physical perturbations (oscillatory zoning develops). Strongly sieve-textured rims, along with An increase at rather constant FeO, are evidence of mixing before the 1991 eruption between a residing magma and a hotter and volatile-richer one. The textural evidence implies that crystals underwent common histories at shallow levels, supporting the existence of a large magma reservoir whose top is at ~ 5.5 km of depth. Distinct textures at the outer rims in a hand-size sample are evidence that crystals mix mechanically at very shallow levels, probably in a small reservoir at ~ 1.8 km of depth

Violent paroxysmal activity drives self-feeding magma replenishment at Mt. Etna

A new sequence of eruptions occurred at Mt. Etna volcano during the first half of 2017, after almost 8 months of quiescence. These episodes had low-to-mild intensity and markedly differ from the violent paroxysms occurred at the Voragine Crater (VOR) during December 2015 and May 2016. Despite the general weak explosive nature of the eruptions, the activity during 2017 revealed unusually complex dynamics of magma ascent and interaction. Detection and investigation of such dynamics required a multidisciplinary approach in which bulk rock compositions, crystal chemical zoning, diffusion chronometry and ground deformation data have been combined. Bulk rock major and trace elements suggest that the 2017 magmas followed a differentiation path similar to that experienced by magmas erupted at Mt. Etna during the 2015-16 eruptions at VOR. Olivine core compositions and zoning patterns indicate the presence of multiple magmatic environments at depth that strictly interacted each other through some episodes of intrusion and mixing before and during the 2017 eruptive events. Timescales retrieved from diffusion chronometry on olivine normal and reverse zoning correlate well with the ground deformation stages detected through geodetic data and associated models, thus allowing to track the evolution through time of the 2017 volcanic activity. Combination of all petrological and geodetic observations supports the idea that dynamics of magma transfer driving the eruptive episodes of 2017 have been a direct consequence of the violent eruptions occurred at VOR on May 2016, which boosted the ascent of new magma from depth and improved the efficiency of the plumbing system to transfer it upward to the surface. We propose a mechanism of self-feeding replenishment of the volcano plumbing system during 2017, where magma recharge from depth is triggered by sudden unloading of the magma column consequential to the violent paroxysmal activity occurred on May 2016 at VOR.Publishedid 67172V. Struttura e sistema di alimentazione dei vulcaniJCR Journa