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Mormone, Angela
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Mormone, Angela
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- PublicationRestrictedThe Cristal Zn prospect (Amazonas region, Northern Peru). Part II: An example of supergene enrichments in tropical areas(2018)
; ; ; ; ; ; ; ; ; ; ; ; ;; ;The Cristal Zn prospect is located in the northernmost part of a wide mining district corresponding to the “Charlotte Bongará Zinc Project”, which covers an area of approximately 110 km2 in the Amazonas region in northern Peru. The mineralized area consists of many Zn occurrences that contain mixed sulfide and nonsulfide mineralizations. The nonsulfide ores are interpreted to be the product of weathering of primary MVT sulfide bodies. The Zn concentrations of the Cristal prospect are hosted by platform carbonates of the Condorsinga Formation (Early Jurassic), which belongs to the Pucará Group. The prospect extends over an area of approximately 2×1 km, with nearly continuous zones of Zn enrichment that has been detected in soil and rock samples. The nonsulfide mineralization consists mainly of semi-amorphous orange to brown zinc “oxides” that include hemimorphite, smithsonite and Fe-(hydr)oxides. The most important mineralized areas are the Esperanza and Yolanda occurrences, which were also most intensively explored. In both occurrences, the supergene Zn-carbonates and silicates infill solution cavities, or replace the carbonate host rocks and/or the primary sulfides, forming smithsonite- and hemimorphite-rich mineralizations. The analyzed drill core samples have on average 20 wt% Zn and maximum Ge concentrations of 200 ppm. The Bongará area experienced a prolonged phase of weathering from Miocene to Recent under tropical climatic conditions. In these conditions, the weathering processes affected many pre-existing sulfide deposits (e.g. Cristal, Florida Canyon, Mina Grande), where supergene profiles were developed under locally different settings that are defined primarily on the basis of mineralogical and geochemical data. Contrary to the Mina Grande deposit, at Cristal, the development of a karst network was minor due to limited uplift, and supergene alteration did not completely obliterate the roots of the original sulfide orebody. The mineralogy and geochemistry of Bongará nonsulfides is dependent on two main factors at the local scale: (1) uplift rates, and (2) host rock composition. The latter may have favored the development of more (e.g. Mina Grande) or less (e.g. Cristal) alkaline supergene environments. Uplift was controlled by the activity of local faults, which allowed the exposure of sulfide protores at variable elevations in different periods of time and hydrological settings. Such different settings resulted in the precipitation of isotopically different supergene carbonates (e.g. smithsonites and calcites at Mina Grande and Cristal).213 3 - PublicationRestrictedHydrothermal alteration environments and recent dynamics of the Ischia volcanic island (southern Italy): Insights from repeated field, mineralogical and geochemical surveys before and after the 2017 Casamicciola earthquakeThis study presents the results of repeated surveys conducted in hydrothermally altered areas on the active volcanic island of Ischia (in the Gulf of Naples, southern Italy). Data were obtained from field work, in situ temperature measurements, X-ray diffraction, optical and scanning electron microscopy, EDS-SEM micro-analysis, infrared spectroscopy and whole-rock geochemistry analyses on samples collected in October 2016, September 2017,March 2018 and November 2018, both prior to and following the damaging seismic event that occurred in August 2017 at Casamicciola.Mineralogical results point to the evolution of acid sulfate zones along the northern andwestern flanks of a resurgent block located in the central part of the island, in strict relationwith endogenous fluid outgassing indicated in the literature.Mineralogy and whole-rock geochemistry of these acid sulfate zones revealmagmatic-hydrothermal environments in association with major structures that enable fluid circulation. It is interpreted that rare coarser alunites within dominant steam-heated and supergene alteration mineral assemblages are associated with environments that are no longer active, but which are supplied by magmatic vapours. In addition, collected data indicate slowendogenous degassing fromhydrothermal reservoirs. Data fromSeptember 2017 show variations in the sulfate assemblage within the acidic sulfate zone located near the earthquake's epicentre, and acidification and the transitory appearance of alum-(K) is apparent under a nearly unchanged endogenous supply. Meteorological conditions of late summer could, in principle, justify the appearance of alum- (K), but its coexistence with alunogen and soil temperatures refute this possibility. Alum-(K) is interpreted to be the product of alunite decomposition at a local temperature of ca. 100 °C. Assuming a correct space-time relationship between the appearance of alum-(K) and the earthquake, it is thus inferred thatmechanical activation by tectonic stress is the possible cause of alunite decomposition.
228 7 - PublicationRestrictedThe volcanic and geothermally active Campi Flegrei caldera: an integrated multidisciplinary image of its buried structure(2014-11)
; ; ; ; ; ; ; ;Piochi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Kilburn, C. R. J.; Department of Earth Sciences, Aon Benfield UCL Hazard Centre, University College London, London, UK ;Di Vito, M. A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Mormone, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Tramelli, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Troise, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;De Natale, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; ; ; ; The Campi Flegrei caldera in southern Italy is one of the greatest geohazard areas on Earth. Evidence of an active magmatic and geothermal system is provided by ongoing ground uplift, with volcano-tectonic and longperiod (LP) seismicity, the persistent degassing of ~1500 tonnes of CO2 per day, the presence of hot fumaroles at temperatures of 90–150 °C, brine-rich aquifers (with total dissolved solids up to 33 g l−1) and high thermal gradients in the crust (with temperatures reaching 420 °C at 3,050 m b.s.l.). Since the 1940s, more than 100 exploratory boreholes have been drilled in the area to depths of 80–3,100 m by the Azienda Geologica Italiana Petroli (AGIP) and the Società Anonima Forze Endogene Napoletane (SAFEN). To date, however, no systematic reanalysis of the drilling data has been carried out, and the buried volcanic structure has not been updated using the most recent scientific results and previous findings. By integrating unpublished data from the AGIP and SAFEN reports with published information from geological, volcanological, petrological, petrophysical and geophysical studies, this paper presents an improved picture of the Campi Flegrei caldera that will be useful for volcanic hazard assessment and mitigation in the Naples area and for future research planning The results suggest that intra-caldera activity has been influenced by how the magmatic system at depths greater than about 4 km has determined the transfer of magma, volatiles, and heat to the overlying geothermal system and, ultimately, to the surface. In particular, intriguing is that the most volcanically active central-eastern sector of the caldera, which is subject to intense bradyseismic ground movement and gas emission, coincides with a structurally delimited subsurface rock volume characterized by an uprising of the 100 °C isotherm, a deep water supply to the shallower aquifer, the early disappearance of secondary calcite, LP seismicity and high seismic S-wave attenuation. In this area, we also document evidence of repeated injection at depths of c. 1.5–3.0 km of isolated and small-volume batches of magma, where occurred their crystallization and degassing. Shallow intrusions and degassing of magma are thus identified as two of the key processes that drive unrest in Campi Flegrei.1208 32 - PublicationOpen AccessGeochemical Characterization of Bauxite Deposits from the Abruzzi Mining District (Italy)The Abruzzi bauxite district includes the deposits located on the Campo Felice plateau and those of the Monti d’Ocre, which had been mined in the first part of the 20th century. Bauxite is of the karst type, with textures ranging between oolitic and oolitic-conglomeratic, the latter suggesting a partial reworking of evolved lateritic soils. The high contents of Al2O3 and Fe2O3 (average values 53.76 and 21.76 wt %, respectively) are associated with the presence of boehmite, hematite, and minor goethite. SiO2 and TiO2 have average values of 7.79 and 2.75 wt %, corresponding to the presence of kaolinite, anatase and rutile. Among the minor so-called “bauxitophile” elements V, Co, Ni, Cr and Zr, the most enriched is Cr, with an average value of 0.07 wt %. Nickel has an average value of 210.83 ppm. Vanadium shows an average value of 266.57 ppm, whereas the average Co concentration is 35.89 ppm. The total rare earth elements (REE) concentration in the sampled bauxite sites is variable between ca. 700 and 550 ppm. Among REEs, the most abundant element is Ce, with Ce anomalies commonly associated with authigenic REE-fluoro-carbonates, probably produced after the REEs remobilization from primary detrital minerals and their precipitation in neo-formed phases during the bauxitization process. Scandium and Ga occur in small amounts (57 and 60 ppm, respectively), but geochemical proxies of their remobilization and uptake in neo-formed minerals (Feand Al-(hydr)oxides, respectively) have been observed. The mean Eu/Eu* and Al2O3/TiO2 ratios and the Ni-Cr contents of the Abruzzi bauxites suggest that the parent rock of these deposits was amaterial of acid affinity, likely corresponding to volcanic tephra or eolic loess-type sands.
237 60 - PublicationOpen AccessRecycling REEs from the Waste Products of Silius Mine (SE Sardinia, Italy): A Preliminary Study(2021)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;; ; ;The present research represents an approach toward the recycling of extractive waste inspired by circular economy and sustainability that is developed in accordance with Goal 12 of the United Nations 2030 Agenda for Sustainable Development Goals. A new procedure for the recovery of REEs from fluorite–barite–galena ores with calcite gangue from the Silius mine (Sardinia, Italy) is presented. The considered samples are waste materials of Silius mineralization, collected in the old processing plant of Assemini (near Cagliari). In this orebody, REE minerals consist of prevailing synchysite (a REE-bearing fluorocarbonate) and subordinate xenotime-Y (a Y-bearing phosphate). REE fluorocarbonates are extracted using 50% K2CO3 as the leaching solution, at 100 °C. Using a solution (mL)/sample (g) ratio of 25, about 10% of the total REE content of the considered sample is extracted within 1 h. At the laboratory scale, such alkaline leaching of REE from the waste materials allows the recovery of the CO2 produced as K2CO3 from concentrated KOH, in accordance with a circular flow. Further work is ongoing to scale up the process into a pilot plant, to prove that the method developed within this research can be economically feasible, socially suitable, and environmentally respectful.147 20 - PublicationOpen AccessIdentification of a New Heavy-Metal-Resistant Strain of Geobacillus stearothermophilus Isolated from a Hydrothermally Active Volcanic Area in Southern Italy.(2020-04-14)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; Microorganisms thriving in hot springs and hydrothermally active volcanic areas are dynamically involved in heavy-metal biogeochemical cycles; they have developed peculiar resistance systems to cope with such metals which nowadays can be considered among the most permanent and toxic pollutants for humans and the environment. For this reason, their exploitation is functional to unravel mechanisms of toxic-metal detoxification and to address bioremediation of heavy-metal pollution with eco-sustainable approaches. In this work, we isolated a novel strain of the thermophilic bacterium Geobacillus stearothermophilus from the solfataric mud pool in Pisciarelli, a well-known hydrothermally active zone of the Campi Flegrei volcano located near Naples in Italy, and characterized it by ribotyping, 16S rRNA sequencing and mass spectrometry analyses. The minimal inhibitory concentration (MIC) toward several heavy-metal ions indicated that the novel G. stearothermophilus isolate is particularly resistant to some of them. Functional and morphological analyses suggest that it is endowed with metal resistance systems for arsenic and cadmium detoxification.172 27 - PublicationOpen AccessGenomic Insight of Alicyclobacillus mali FL18 Isolated From an Arsenic-Rich Hot Spring(2021)
; ; ; ; ; ; ; ; ; ; ; ;; ; ;; ;Extreme environments are excellent places to find microorganisms capable of tolerating extreme temperature, pH, salinity pressure, and elevated concentration of heavy metals and other toxic compounds. In the last decades, extremophilic microorganisms have been extensively studied since they can be applied in several fields of biotechnology along with their enzymes. In this context, the characterization of heavy metal resistance determinants in thermophilic microorganisms is the starting point for the development of new biosystems and bioprocesses for environmental monitoring and remediation. This work focuses on the isolation and the genomic exploration of a new arsenic-tolerant microorganism, classified as Alicyclobacillus mali FL18. The bacterium was isolated from a hot mud pool of the solfataric terrains in Pisciarelli, a well-known hydrothermally active zone of the Campi Flegrei volcano near Naples in Italy. A. mali FL18 showed a good tolerance to arsenite (MIC value of 41 mM), as well as to other metals such as nickel (MIC 30 mM), cobalt, and mercury (MIC 3 mM and 17 μM, respectively). Signatures of arsenic resistance genes (one arsenate reductase, one arsenite methyltransferase, and several arsenite exporters) were found interspersed in the genome as well as several multidrug resistance efflux transporters that could be involved in the export of drugs and heavy metal ions. Moreover, the strain showed a high resistance to bacitracin and ciprofloxacin, suggesting that the extreme environment has positively selected multiple resistances to different toxic compounds. This work provides, for the first time, insights into the heavy metal tolerance and antibiotic susceptibility of an Alicyclobacillus strain and highlights its putative molecular determinants.155 32 - PublicationOpen AccessThe Campi Flegrei Deep Drilling Project (CFDDP): New insight on caldera structure, evolution and hazard implications for the Naples area (Southern Italy)(2016)
; ; ; ; ; ; ; ; ; ; ; ; ;; ; ; ; ; ;The 501 m deep hole of the Campi Flegrei Deep Drilling Project, located west of the Naples metropolitan area and inside the Campi Flegrei caldera, gives new insight to reconstruct the volcanotectonic evolution of this highly populated volcano. It is one of the highest risk volcanic areas in the world, but its tectonic structure, eruptive history, and size of the largest eruptions are intensely debated in the literature. New stratigraphic and 40Ar/39Ar geochronological dating allow us to determine, for the first time, the age of intracaldera deposits belonging to the two highest magnitude caldera-forming eruptions (i.e., Campanian Ignimbrite, CI, 39 ka, and Neapolitan Yellow Tuff, NYT, 14.9 ka) and to estimate the amount of collapse. Tuffs from 439 m of depth yield the first 40Ar/39Ar age of ca. 39 ka within the caldera, consistent with the CI. Volcanic rocks from the NYT were, moreover, detected between 250 and 160 m. Our findings highlight: (i) a reduction of the area affected by caldera collapse, which appears to not include the city of Naples; (ii) a small volume of the infilling caldera deposits, particularly for the CI, and (iii) the need for reassessment of the collapse amounts and mechanisms related to larger eruptions. Our results also imply a revaluation of volcanic risk for the eastern caldera area, including the city of Naples. The results of this study point out that large calderas are characterized by complex collapse mechanisms and dynamics, whose understanding needs more robust constraints, which can be obtained from scientific drilling.538 127 - PublicationRestrictedHigh-silica zeolites in pyroclastic flows from Central Sardinia (Italy): clues on genetic processes and reserves from a mineralogical studyThe island of Sardinia (Italy) presents some of the most interesting zeolite ores in Europe, most of which are associated with old pyroclastic deposits. In particular, the poorly welded ash and pumice pyroclastic flows of the Oligo-Miocene Allai unit were the suspected cause for the widespread zeolitization processes and their subsequent potential economic interest. Fourteen stratigraphic sequences of those Allai flows were sampled and studied, in order to fill the gap existing in the mineralogical database of Sardinian zeolites. A multi-analytical strategy has been used to determine for the first time the nature, the distribution and the textural relationships of the main zeolite types throughout the pyroclastic flows, as well as the geochemical features of the zeolite-bearing rocks. The overall data contribute to depict the main genetic process that involved a hydrothermal environment operative under a dominant closed system, at temperature near to 200 °C and progressively proceeded thanks to cooling and chemical variation of the fluids permeating the matrix. The investigated zeolites mainly consist of Ca-clinoptilolite and/or Na-mordenite, up to 38% in abundance. However, contrarily to the most common clinoptilolite + mordenite paragenesis, mordenite zeolitization is really abundant in the studied ignimbrites in relation to their pristine rhyolitic compositions. The weight percentages and distribution of the industrial minerals throughout the pyroclastic deposits presented by this work can be an important background information for an evaluation of the quality and the reserves of this zeolite mineralization aimed at a possible future exploitation and potential use.
240 2 - PublicationRestrictedFluorophlogopite-bearing and carbonate metamorphosed xenoliths from theCampanian Ignimbrite (Fiano, southern Italy): crystal chemical, geochemical and volcanological insights(2017-10)
; ; ; ; ; ; ; ; ; ; ; ;; ; ;Fluorine-, boron- and magnesium-rich metamorphosed xenoliths occur in the Campanian Ignimbrite deposits at Fiano (southern Italy), at ∼50 km northeast of the sourced volcanic area. These rocks originated from Mesozoic limestones of the Campanian Apennines, embedded in a fluid flow. The Fiano xenoliths studied consist of ten fluorophlogopite-bearing calc-silicate rocks and five carbonate xenoliths, characterized by combining mineralogical analyses with whole-rock and stable isotope data. The micaceous xenoliths are composed of abundant idiomorphic fluorophlogopite, widespread fluorite, F-rich chondrodite, fluoborite, diopside, Fe(Mg)-oxides, calcite, humite, K-bearing fluoro-richterite and grossular. Of the five mica-free xenoliths, two are calcite marbles, containing subordinate fluorite and hematite, and three are weakly metamorphosed carbonates, composed only of calcite. The crystal structure and composition of fluorophlogopite approach that of the end-member. The Fiano xenoliths are enriched in trace elements with respect to the primary limestones. Comparisons between the rare-earth element (REE) patterns of the Fiano xenoliths and those of both Campanian Ignimbrite and Somma-Vesuvius marble and carbonate xenoliths showthat the Fiano pattern overlaps that of Somma-Vesuvius marble and carbonate xenoliths, and reproduces the trend of Campanian Ignimbrite rocks. Values of δ13C and δ18O depict the same trend of depletion in the heavy isotopes observed in the Somma-Vesuvius nodules, and is related to thermometamorphism. Trace-element distribution, paragenesis, stable isotope geochemistry and data modelling point to infiltration of steam enriched in F, B,Mg and As into carbonate rocks at a temperature of ∼300–450°C during the emplacement of the Campanian Ignimbrite.220 1
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