This file was created by the TYPO3 extension publications --- Timezone: CEST Creation date: 2026-04-23 Creation time: 13:57:21 --- Number of references 30 article WOS:000864016300001 The structure of a caldera may influence its activity, making its understanding crucial for hazard assessment. Here, we analysed high-resolution seismic profiles in the Campi Flegrei (southern Italy) offshore sector. We recognised two main fault systems, including those associated with the formation of the caldera and those affecting the resurgent dome. The former system comprises three broadly concentric fault zones (inner, medial and outer ring fault zones) depicting a nested caldera geometry. Considering the relations between faults and seismic units that represent the marine and volcaniclastic successions filling the caldera, all ring faults were formed during the Campanian Ignimbrite eruption (40 ka) and subsequently reactivated during the Neapolitan Yellow Tuff eruption (15 ka). In this last caldera-forming event, the inner and medial fault zones accommodated most of the collapse and were episodically reactivated during the younger volcano-tectonic activity. The second fault system occurs in the apical zone of the resurgent dome and comprises dominantly high-angle normal faults that are mainly related to the volcano -tectonic collapse that followed the Agnano-Monte Spina Plinian eruption (4.55 ka). Finally, we provide a volcano-tectonic evolutionary model of the last 40 kyr, considering the interplay among ring and dome faults activity, volcaniclastic sedimentation, ground deformation and sea-level changes. Article 2022 10.1016/j.jsg.2022.104723 JOURNAL OF STRUCTURAL GEOLOGY 163 PERGAMON-ELSEVIER SCIENCE LTD Jacopo Natale Giovanni Camanni Luigi Ferranti Roberto Isaia Marco Sacchi Volkhard Spiess Lena Steinmann Stefano Vitale article Somma2021 Unconventional geothermal resource development can contribute to increase power generation from renewable energy sources in countries without conventional hydrothermal reservoirs, which are usually associated with magmatic activity and extensional faulting, as well as to expand the generation in those regions where conventional resources are already used. Three recent drilling experiences focused on the characterization of unconventional resources are described and compared: the Campi Flegrei Deep Drilling Project (CFDDP) in Italy, the United Downs Deep Geothermal Power (UDDGP) project in the United Kingdom, and the DEEP Earth Energy Production in Canada. The main aspects of each project are described (geology, drilling, data collection, communication strategies) and compared to discuss challenges encountered at the tree sites considered, including a scientific drilling project (CFDDP) and two industrial ones (UDDGP and DEEP). The first project, at the first stage of pilot hole, although not reaching deep supercritical targets, showed extremely high, very rare thermal gradients even at shallow depths. Although each project has its own history, as well as social and economic context, the lessons learned at each drilling site can be used to further facilitate geothermal energy development. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Article 2021 English 19961073 10.3390/en14113306 Energies 14 MDPI AG 11 Geothermal fields; Geothermal power plants; Renewable energy resources; Resource valuation; Trees (mathematics); Communication strategy; Energy development; Energy productions; Extensional faulting; Geothermal resources; Power generation from renewable; Scientific drilling; Unconventional resources; Infill drilling https://www.scopus.com/inward/record.uri?eid=2-s2.0-85108514269&doi=10.3390%2fen14113306&partnerID=40&md5=37073f9e0e1862f8317209ce37d8db18 Cited by: 6; All Open Access, Gold Open Access, Green Open Access Renato Somma Daniela Blessent Jasmin Raymond Madeline Constance Lucy Cotton Giuseppe De Natale Alessandro Fedele Maria Jose Jurado Kirsten Marcia Mafalda Miranda Claudia Troise Thomas Wiersberg article Sacchi201929 Large calderas are among the Earth's major volcanic features. They are associated with large magma reservoirs and elevated geothermal gradients. Caldera-forming eruptions result from the withdrawal and collapse of the magma chambers and produce large-volume pyroclastic deposits and later-stage deformation related to post-caldera resurgence and volcanism. Unrest episodes are not always followed by an eruption; however, every eruption is preceded by unrest. The Campi Flegrei caldera (CFc), located along the eastern Tyrrhenian coastline in southern Italy, is close to the densely populated area of Naples. It is one of the most dangerous volcanoes on Earth and represents a key example of an active, resurgent caldera. It has been traditionally interpreted as a nested caldera formed by collapses during the 100-200 km3 Campanian Ignimbrite (CI) eruption at ∼ 39 ka and the 40 km3 eruption of the Neapolitan Yellow Tuff (NYT) at ∼ 15 ka. Recent studies have suggested that the CI may instead have been fed by a fissure eruption from the Campanian Plain, north of Campi Flegrei. A MagellanPlus workshop was held in Naples, Italy, on 25-28 February 2017 to explore the potential of the CFc as target for an amphibious drilling project within the International Ocean Discovery Program (IODP) and the International Continental Drilling Program (ICDP). It was agreed that Campi Flegrei is an ideal site to investigate the mechanisms of caldera formation and associated post-caldera dynamics and to analyze the still poorly understood interplay between hydrothermal and magmatic processes. A coordinated onshore-offshore drilling strategy has been developed to reconstruct the structure and evolution of Campi Flegrei and to investigate volcanic precursors by examining (a) the succession of volcanic and hydrothermal products and related processes, (b) the inner structure of the caldera resurgence, (c) the physical, chemical, and biological characteristics of the hydrothermal system and offshore sediments, and (d) the geological expression of the phreatic and hydromagmatic eruptions, hydrothermal degassing, sedimentary structures, and other records of these phenomena. The deployment of a multiparametric in situ monitoring system at depth will enable near-real-time tracking of changes in the magma reservoir and hydrothermal system. © Author(s) 2019. 2019 English 18168957 10.5194/sd-26-29-2019 Scientific Drilling 26 Copernicus GmbH 29-46 Istituto di Scienze Marine (ISMAR), Consiglio Nazionale Delle Ricerche (CNR), Calata Porta di Massa, Naples, 80133, Italy; Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sezione di Napoli, Via Diocleziano, 328, Naples, 80124, Italy; Faculty of Geosciences, University of Bremen, Klagenfurter Str., Bremen, 28359, Germany; Dipartimento di Scienze Geologiche, Università degli Studi Roma Tre, Largo S.L. Murialdo, 1, Rome, 00146, Italy; Dipartimento di Scienze della Terra e Del Mare (DiSTeM), Università degli Studi di Palermo, Via Archirafi, 22, Palermo, 90123, Italy; College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, United States; Dipartimento di Scienze della Terra, dell'Ambiente e Delle Risorse (DiSTAR), Università degli Studi di Napoli Federico II, Via Cinthia, 21, Naples, 80126, Italy; Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 7, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8567, Japan; UCL Hazard Centre, Department of Earth Sciences, University College London, Gower Street, London, WC1E 6BT, United Kingdom; Institut de Ciències de la Terra Jaume Almera, Consejo Superior de Investigaciones Científicas (CSIC), C/Lluís Solé i Sabarís s/n, Barcelona, 08028, Spain; Istituto di Scienze dell'Alimentazione (ISA), Consiglio Nazionale Delle Ricerche (CNR), Via Roma, 64, Avellino, 83100, Italy; GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, Kiel, 24148, Germany; Istituto Nazionale di Geofisica e Vulcanologia (INGV), Via di Vigna Murata, 605, Rome, 00143, Italy Biology; Infill drilling; Offshore oil well production; Sedimentology; Volcanoes, Biological characteristic; Caldera-forming eruption; Campanian Ignimbrite; Geothermal gradients; Hydromagmatic eruptions; Hydrothermal products; Neapolitan yellow tuffs; Sedimentary structure, Offshore drilling https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076110893&doi=10.5194%2fsd-26-29-2019&partnerID=40&md5=d8803c633f6b569ceca00b2cdd727f59 cited By 5 M. Sacchi G. De Natale V. Spiess L. Steinmann V. Acocella M. Corradino S. De Silva A. Fedele L. Fedele N. Geshi C. Kilburn D. Insinga M.-J. Jurado F. Molisso P. Petrosino S. Passaro F. Pepe S. Porfido C. Scarpati H.-U. Schmincke R. Somma M. Sumita S. Tamburrino C. Troise M. Vallefuoco G. Ventura article Somma2019 Monitoring volcanic phenomena is a key question, for both volcanological research and for civil protection purposes. This is particularly true in densely populated volcanic areas, like the Campi Flegrei caldera, which includes part of the large city of Naples (Italy). Borehole monitoring of volcanoes is the most promising way to improve classical methods of surface monitoring, although not commonly applied yet. Fiber optics technology is the most practical and suitable way to operate in such high temperature and aggressive environmental conditions. In this paper, we describe a fiber optics Distributed Temperature Sensing (DTS) sensor, which has been designed to continuously measure temperature all along a 500 m. deep well drilled in the west side of Naples (Bagnoli area), lying in the Campi Flegrei volcanic area. It has then been installed as part of the international ‘Campi Flegrei Deep Drilling Project’, and is continuously operating, giving insight on the time variation of temperature along the whole borehole depth. Such continuous monitoring of temperature can in turn indicate volcanic processes linked to magma dynamics and/or to changes in the hydrothermal system. The developed monitoring system, working at bottom temperatures higher than 100 ◦ C, demonstrates the feasibility and effectiveness of using DTS for borehole volcanic monitoring. © 2019 by the authors. Licensee MDPI, Basel, Switzerland. Article 2019 English 14248220 10.3390/s19051009 Sensors (Switzerland) 19 MDPI AG 5 Boreholes; Boring; Environmental technology; Fiber optics; Fibers; Infill drilling; Temperature sensors; Volcanoes; Well drilling; Campi Flegrei; Continuous monitoring; Distributed temperature sensing; Environmental conditions; Hydrothermal system; Long term monitoring; Temperature calibration; Volcanic monitoring; Monitoring https://www.scopus.com/inward/record.uri?eid=2-s2.0-85062428559&doi=10.3390%2fs19051009&partnerID=40&md5=c306b05e2be37ea1777f67fedcde2433 Cited by: 10; All Open Access, Gold Open Access, Green Open Access Renato Somma Claudia Troise Luigi Zeni Aldo Minardo Alessandro Fedele Maurizio Mirabile Giuseppe De Natale article Torrente20182283 The paper by De Natale et al. (2016, https://doi.org/10.1002/2015GC006183) reported new stratigraphic and geochronological data for a borehole located at Campi Flegrei volcanic area. The authors failed to mention several significant articles on the geological evolution of the region and proposed an interpretation of their data according to the caldera model. Herein, we provide tectonic and stratigraphic data to support a fault model of ignimbrite emission. This comment will also show the inconsistency of the proposed Campi Flegrei caldera. ©2018. American Geophysical Union. All Rights Reserved. Note 2018 English 15252027 10.1029/2017GC007297 Geochemistry, Geophysics, Geosystems 19 Blackwell Publishing Ltd 2283 – 2288 7 Geochronology; Stratigraphy; Caldera; Campi Flegrei; Deep drilling; Fault model; Geological evolution; Southern Italy; Stratigraphic data; Volcanic areas; Faulting https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050753827&doi=10.1029%2f2017GC007297&partnerID=40&md5=8e3f5fa0be69c984877914b395c3abf6 Cited by: 3; All Open Access, Bronze Open Access Maurizio M. Torrente Alfonsa Milia article Iovine2018199 The origin of large variations in stable and radiogenic isotope compositions of magmas erupted from the Neapolitan volcanoes, including Somma-Vesuvius and Campi Flegrei (Southern Italy), has always been contentious. Indeed, the role and relative importance of sediment subduction versus crustal assimilation to explain the chemical and isotopic variations of the erupted magmas remain unclear. Isotopic disequilibrium between minerals and their host indicate that bulk rock analyses are incapable of constraining the isotopic composition of the source. Therefore, we use isotopic (87Sr/86Sr, 18O/16O and 17O/16O) data on separated minerals (feldspar, clinopyroxene and olivine phenocrysts) from pyroclastic successions and lava flows of the Neapolitan volcanic area (Phlegrean Volcanic District and Somma-Vesuvius complex) to better constrain magmatic oxygen and strontium isotope ratios. Magmatic values recalculated from δ18O of olivine and clinopyroxene phenocrysts range from typical mantle values of 5.2‰ to almost 9‰ relative to SMOW. These compositions are very different from those of typical mantle sources. In order to assess the degree of magma evolution from which these minerals formed, the Mg# of clinopyroxene and olivine were converted into host melt Mg#, resulting in the range 44 to 76. Simple assimilation of silicic crustal rocks is difficult to reconcile with the mafic nature of these estimated host magma compositions. This indicates that some mafic, mantle-derived magmas, having unusually heavy oxygen isotope (up to ~9‰) and high Sr isotope compositions (0.7050 to 0.7085), must exist. Crustal assimilation of carbonates can be excluded by the lack of a link between isotopes and major and trace element signatures. Assimilation of either Hercynian-like crust or altered pyroclastic rocks, however, cannot be ruled out completely. However, assimilation of partial melts from a Hercynian-like crust would have to be ~12% and ~21% to explain the heavy oxygen isotope values of Campi Flegrei and Somma-Vesuvius, respectively. Such degrees of assimilation are unlikely since the magmas are either too mafic or too alkaline to be consistent with such high proportion of crustal components. Other, less mafic Campi Flegrei, Somma-Vesuvius and Ischia magmas with more typical mantle oxygen isotopes, have been possibly generated in a mantle source affected by minor contamination by pelagic and carbonate sediments and subsequent assimilation of Hercynian-like crust. Sr-O mixing models indicate that such magmas were derived from a mantle source that was contaminated by up to 10% of a 1:1 mixture of pelagic and carbonate sediments. These findings together demonstrate the highly complex and varied magma sources in the Campania volcanic district. Triple oxygen isotope variations (Δ17O), based on measurements of both 18O/16O and 17O/16O ratios in potential assimilants are in agreement with these conclusions. © 2018 Elsevier B.V. Article 2018 English 00244937 10.1016/j.lithos.2018.07.009 Lithos 316-317 Elsevier B.V. 199 – 211 Campania [Italy]; Campi Flegrei; Italy; Napoli [Campania]; Somma Vesuviana; crustal structure; isotopic composition; magma; mantle structure; oxygen isotope; stable isotope; strontium isotope; volcano https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050411758&doi=10.1016%2fj.lithos.2018.07.009&partnerID=40&md5=0e67c676db2437953c38d6bef5247413 Cited by: 12 Raffaella Silvia Iovine Fabio Carmine Mazzeo Gerhard Wörner Carlo Pelullo Gianluca Cirillo Ilenia Arienzo Andreas Pack Massimo D'Antonio article Carlino2018276 We report combined measurements of petrophysical and geophysical parameters for a 501-m deep borehole located on the eastern side of the active Campi Flegrei caldera (Southern Italy), namely (i) in situ permeability by pumping tests, (ii) laboratory-determined permeability of the drill core, and (iii) thermal gradients by distributed fiber optic and thermocouple sensors. The borehole was drilled during the Campi Flegrei Deep Drilling Project (in the framework of the International Continental Scientific Drilling Program) and gives information on the least explored caldera sector down to pre-caldera deposits. The results allow comparative assessment of permeability obtained from both borehole (at depth between 422 a 501 m) and laboratory tests (on a core sampled at the same depth) for permeability values of ~10−13 m2 (borehole test) and ~10−15 m2 (laboratory test) confirm the scale-dependency of permeability at this site. Additional geochemical and petrophysical determinations (porosity, density, chemistry, mineralogy and texture), together with gas flow measurements, corroborate the hypothesis that discrepancies in the permeability values are likely related to in-situ fracturing. The continuous distributed temperature profile points to a thermal gradient of about 200 °C km−1. Our findings (i) indicate that scale-dependency of permeability has to be carefully considered in modelling of the hydrothermal system at Campi Flegrei, and (ii) improve the understanding of caldera dynamics for monitoring and mitigation of this very high volcanic risk area. © 2018 Elsevier B.V. Article 2018 English 03770273 10.1016/j.jvolgeores.2018.05.003 Journal of Volcanology and Geothermal Research 357 Elsevier B.V. 276 – 286 Istituto Nazionale di Geofisica e Vulcanologia, sezione di Napoli “Osservatorio Vesuviano”, Via Diocleziano 328, Naples, 80124, Italy; Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität, Munich Theresienstrasse 41/III, Munich, 80333, Germany; School of Environment, University of Auckland, 23 Symonds Street, Auckland, 1142, New Zealand Campania [Italy]; Campi Flegrei; Italy; Napoli [Campania]; Boreholes; Core drilling; Drilling; Fiber optic sensors; Flow of gases; Mechanical permeability; Minerals; Risk assessment; Temperature; Thermal gradients; Thermocouples; Volcanoes; Campi Flegrei; Combined measurements; Comparative assessment; Continental scientific drillings; Geophysical parameters; Petrophysics; Temperature profiles; Thermocouple sensors; borehole; caldera; crustal structure; deep drilling; hydrothermal system; permeability; temperature profile; volcano; Boring https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047065989&doi=10.1016%2fj.jvolgeores.2018.05.003&partnerID=40&md5=aae041483ae8954f6d7dbc0615659660 Cited by: 12 Stefano Carlino Monica Piochi Anna Tramelli Angela Mormone Cristian Montanaro Bettina Scheu Mayer Klaus article Carlino201823 The heat flow and distribution of temperatures at depth in the Campania region were analysed and correlated with the volcanism and tectonics of the area. The temperature data, a part of the inventory of the AGIP, SAFEN and ENEL Companies (Inventario delle Risorse Geotermiche Nazionali), were gathered during drilling campaigns that began in 1940. The Campania region is characterised by the presence of two active and high-risk volcanic districts (the Campi Flegrei, Ischia and Vesuvius) emerging at the western boundary of the Campania Plain structural graben, and by the outcropping of the carbonate basement along the borders of the plain. The thermal anomalies have been correlated to different processes: the rising of the upper mantle (at about 20 km depth), the heat flow mass transport due to advection of hot fluids above magma reservoirs and the pure conductive heat transport of deeper crust. Furthermore, the presence of the carbonate basement has possibly buffered the deeper crustal thermal processes. The data also provided an estimation of the brittle-ductile transition zone that has been compared with the seismicity cut-off depth of the area. © 2018 Elsevier B.V. Article 2018 English 03770273 10.1016/j.jvolgeores.2018.10.015 Journal of Volcanology and Geothermal Research 365 Elsevier B.V. 23 – 37 Campania [Italy]; Italy; Calluna vulgaris; Buildings; Heat transfer; Tectonics; Transport properties; Brittle-ductile transition zone; Campania; Distribution of temperature; Geothermal gradients; Magma reservoirs; Thermal anomalies; Volcanic district; Volcanism; geothermal gradient; heat flow; magma chamber; mass transport; tectonic evolution; temperature gradient; thermal convection; volcanism; Geothermal energy https://www.scopus.com/inward/record.uri?eid=2-s2.0-85055128038&doi=10.1016%2fj.jvolgeores.2018.10.015&partnerID=40&md5=fc13f139eee5912ee3282c87eb2cf2fe Cited by: 15 Stefano Carlino article Branscombe201741 Note 2017 English 00963941 10.1029/2017eo067075 Eos (United States) 98 American Geophysical Union 41 4 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029424437&doi=10.1029%2f2017eo067075&partnerID=40&md5=0b1bf70beeff649bd1ccab55c3aa2d43 Cited by: 0; All Open Access, Gold Open Access Alexandra Branscombe article Violante:2017::265 In this study, marine geophysical investigations were utilized to recognize, compare and classify seafloor features related to volcanic activity in the Naples Bay, southern Italy. The dataset includes swath bathymetry, side-scan sonar records, as well as single-channel and multichannel reflection seismics. Ground truth was provided by detailed analysis of gravity cores. By integrating these data, large portions of the seafloor were mapped, providing important information for geohazard assessment. 2017 9780906940570 doi:10.3723/OSIG17.265 Offshore Site Investigation Geotechnics 8th International Conference Proceeding 265-275 https://www.ingentaconnect.com/content/sut/1hzvzd/2017/00000001/00000001/art00014 Crescenzo Violante Marco Sacchi Volkhard Spiess Lena Steinmann article Iovine20171 Geochemical and isotopic (87Sr/86Sr and 18O/16O) data have been acquired on whole rock and separated mineral samples from volcanic products of the 1302 AD Arso eruption, Ischia volcanic island (Gulf of Naples, Southern Italy), to investigate magmatic processes. Our results highlight petrographic and isotopic disequilibria between phenocrysts and their host rocks. Similar disequilibria are observed also for more mafic volcanic rocks from Ischia and in the Phlegraean Volcanic District in general. Moreover, 87Sr/86Sr and 18O/16O values suggest mixing between chemically and isotopically distinct batches of magma, and crystals cargo from an earlier magmatic phase. The radiogenic Sr isotope composition suggests that the mantle source was enriched by subduction-derived sediments. Furthermore, magmas extruded during the Arso eruption were affected by crustal contamination as suggested by high oxygen isotope ratios. Assimilation and fractional crystallization modelling of the Sr-O isotope compositions indicates that not more than ~ 7% of granodioritic rocks from the continental crust have been assimilated by a mantle-derived mafic magma. Hence the recent volcanic activity of Ischia has been fed by distinct batches of magma, variably contaminated by continental crust, that mixed during their ascent towards the surface and remobilized phenocrysts left from earlier magmatic phases. © 2016 Elsevier B.V. Article 2017 English 03770273 10.1016/j.jvolgeores.2016.08.008 Journal of Volcanology and Geothermal Research 331 Elsevier B.V. 1 – 15 Campania [Italy]; Ischia; Italy; Napoli [Campania]; Geochemistry; Isotopes; Minerals; Rock products; Volcanic rocks; Volcanoes; Crustal contamination; Ischia island; Magmatic plumbing system; Mingling/mixing; Stable isotopes; crustal contamination; igneous geochemistry; lava; magmatism; mixing; oxygen isotope; point source; source rock; stable isotope; strontium isotope; volcanic eruption; volcanology; Strontium compounds https://www.scopus.com/inward/record.uri?eid=2-s2.0-84995519396&doi=10.1016%2fj.jvolgeores.2016.08.008&partnerID=40&md5=48c8dbda6417476d005825c07e94c056 Cited by: 13 Raffaella Silvia Iovine Fabio Carmine Mazzeo Ilenia Arienzo Massimo D'Antonio Gerhard Wörner Lucia Civetta Zeudia Pastore Giovanni Orsi article deNatale2017443 The recent investigation carried out on the west bound of the Naples metropolitan area and inside the Campi Flegrei caldera as part of the Campi Flegrei Deep Drilling Project provided new insight in order to reconstruct the volcano-tectonic evolution of this extremely populated area. Campi Flegrei represents the highest risk volcanic areas in the world, although its volcano-tectonic structure, eruptive history and eruptive style of the largest eruptions are intensely debatedby scientists since several decades. We present here a summary of stratigraphic and geochronological dating (40Ar/39Ar) allowing to define the age of intra-caldera deposits belonging to the two highest magnitude caldera-forming eruptions (i.e. Campania Ignimbrite, 39÷40 ka, and Neapolitan Yellow Tuff, 14.9 ka) and to evaluate the amount of collapse of the eastern sector of the caldera. These results point out: (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 characterised by complex collapse mechanisms and dynamics, whose understanding needs more robust constraints, which can be obtained from scientific drilling. © 2017 WIT Press, Article 2017 English 20419031 10.2495/SAFE-V7-N3-443-448 International Journal of Safety and Security Engineering 7 WITPress 443 – 448 3 Campania [Italy]; Campi Flegrei; Italy; Napoli [Campania]; Deposits; Geochronology; Hazards; Stratigraphy; Tectonics; Volcanoes; Caldera-forming eruption; Campi Flegrei; Collapse mechanism; Neapolitan yellow tuffs; Scientific drilling; Tectonic evolution; Tectonic structure; Volcanic hazards; caldera; collapse; dating method; geochronology; hazard; metropolitan area; project assessment; reconstruction; tectonic evolution; tectonic structure; volcanic eruption; Infill drilling https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054032482&doi=10.2495%2fSAFE-V7-N3-443-448&partnerID=40&md5=e5b018b1f16dcc760b83e72b7b2f6899 Cited by: 0; All Open Access, Bronze Open Access Giuseppe Natale Troise Claudia Somma Renato Giovanni Perillo article Iovine2017 Barium diffusion chronometry applied to sanidine phenocrysts from the trachytic Agnano-Monte Spina eruption (∼4.7 ka) constrains the time between reactivation and eruption of magma batches in the Campi Flegrei caldera. Backscattered electron imaging and quantitative electron microprobe measurements on 50 sanidine phenocrysts from representative pumice samples document core-to-rim compositional zoning. We focus on compositional breaks near the crystal rims that record magma mixing processes just prior to eruption. Diffusion times were modeled at a magmatic temperature of 930 °C using profiles based on quantitative BaO point analyses, X-ray scans, and grayscale swath profiles, yielding times ≤60 years between mixing and eruption. Such short timescales are consistent with volcanological and geochronological data that indicate that at least six eruptions occurred in the Agnano-San Vito area during few centuries before the Agnano-Monte Spina eruption. Thus, the short diffusion timescales are similar to time intervals between eruptions. Therefore, the rejuvenation time of magma residing in a shallow reservoir after influx of a new magma batch that triggered the eruption, and thus pre-eruption warning times, may be as short as years to a few decades at Campi Flegrei caldera. © 2017, Springer-Verlag Berlin Heidelberg. Article 2017 English 02588900 10.1007/s00445-017-1101-4 Bulletin of Volcanology 79 Springer Verlag 2 Campania [Italy]; Campi Flegrei; Italy; Napoli [Campania]; backscatter; caldera; electron probe analysis; geochronology; magmatism; phenocryst; sanidine; timescale; trigger mechanism; volcanic eruption https://www.scopus.com/inward/record.uri?eid=2-s2.0-85010868081&doi=10.1007%2fs00445-017-1101-4&partnerID=40&md5=8e90aa78702502c73f1aaeed7a3bc32c Cited by: 23 Raffaella Silvia Iovine Lorenzo Fedele Fabio Carmine Mazzeo Ilenia Arienzo Andrea Cavallo Gerhard Wörner Giovanni Orsi Lucia Civetta Massimo D’Antonio article DeNatale20172004 Naples and its hinterland in Southern Italy are one of the most urbanized areas in the world under threat from volcanic activity. The region lies within range of three active volcanic centers: Vesuvius, Campi Flegrei, and Ischia. The Campi Flegrei caldera, in particular, has been in unrest for six decades. The unrest followed four centuries of quiescence and has heightened concern about an increased potential for eruption. Innovative modeling and scientific drilling are being used to investigate Campi Flegrei, and the results highlight key directions for better understanding the mechanisms of caldera formation and the roles of magma intrusion and geothermal activity in determining the volcano's behavior. They also provide a framework for evaluating and mitigating the risk from this caldera and other large ones worldwide. © 2017. American Geophysical Union. All Rights Reserved. Note 2017 English 15252027 10.1002/2017GC006972 Geochemistry, Geophysics, Geosystems 18 Blackwell Publishing Ltd 2004 – 2008 5 Volcanoes; Caldera formation; Geothermal activity; Innovative models; Magma intrusion; Scientific drilling; Volcanic activities; Volcanic centers; Volcanic hazards; Hazards https://www.scopus.com/inward/record.uri?eid=2-s2.0-85019073802&doi=10.1002%2f2017GC006972&partnerID=40&md5=f5c68dffd8303bd3d648caa91f167710 Cited by: 13; All Open Access, Green Open Access Giuseppe De Natale Claudia Troise Christopher R. J. Kilburn Renato Somma Roberto Moretti article Costanzo2017278 Shear wave velocities (VS) are defined in the uppermost 1–2 km of the Campi Flegrei caldera through the non-linear inversion of the group velocity dispersion curves of fundamental-mode Rayleigh waves extracted from ambient noise cross-correlations between two receivers. Noise recordings, three months long, at 12 seismic stations are cross-correlated between all couples of stations. The experiment provided successful results along 54 paths (inter-stations distance), of which 27 sampled a depth > 1 km. VS contour lines are drawn from 0.06 km b.s.l. to 1 km depth b.s.l. and show difference between the offshore (gulf of Pozzuoli and coastline) and the onshore areas. At 0.06 km b.s.l., the gulf of Pozzuoli and the coastline are characterized by VS of 0.3–0.5 km/s and of 0.5–0.7 km/s, respectively. Such velocities are typical of Neapolitan pyroclastic soils and fractured or altered tuffs. The inland shows VS in the range 0.7–0.9 km/s, typical of Neapolitan compact tuffs. Velocities increase with depth and, at 1 km depth b.s.l., velocities lower than 1.5 km/s are still present in the gulf and along the coastline while velocities higher than 1.9 km/s characterize the eastern sector (grossly coincident with the Neapolitan Yellow Tuff caldera rim), the S. Vito plain and the area between Solfatara and SW of Astroni. Such features are much more evident along two cross-sections drawn in the offshore and onshore sectors by integrating our VS models with literature data. Our models join previous noise cross-correlation studies at greater scale at depths of 0.7–0.8 km, hence the picture of the Campi Flegrei caldera is shown up to a depth of 15 km. VS of about 1.7 km/s, corresponding to compression velocities (VP) of about 3 km/s (computed by using the VP/VS ratio resulted in the inversion), are found at depths of 1.1 km, in the centre of the gulf of Pozzuoli, and at a depth of about 0.7 km b.s.l. onshore. An increment of VS velocity (~ 1.9–2.0 km/s) is locally observed onshore which might be attributed to a layer of tuffs and tuffites interbedded with thin lava beds, according to the correlation of VS with stratigraphies in the deep drillings of S. Vito. © 2017 Elsevier B.V. Article 2017 English 03770273 10.1016/j.jvolgeores.2017.09.020 Journal of Volcanology and Geothermal Research 347 Elsevier B.V. 278 – 295 Campania [Italy]; Campi Flegrei; Italy; Napoli [Campania]; Acoustic noise; Group velocity dispersion; Landforms; Rayleigh waves; Shear waves; Velocity; Cross correlations; Fundamental modes; Group velocity dispersion curve; Neapolitan yellow tuffs; Non linear inversion; Pyroclastic soils; Seismic station; Shear wave velocity; ambient noise; caldera; correlation; crustal structure; drilling; Rayleigh wave; S-wave; seismic velocity; tuff; Shear flow https://www.scopus.com/inward/record.uri?eid=2-s2.0-85030460928&doi=10.1016%2fj.jvolgeores.2017.09.020&partnerID=40&md5=2f88ee78f2359c64e0ff21c358fb0744 Cited by: 4 M.R. Costanzo C. Nunziata R. Strollo article DeNatale20164836 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 volcano-tectonic 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. © 2016. The Authors. Article 2016 English 15252027 10.1002/2015GC006183 Geochemistry, Geophysics, Geosystems 17 Blackwell Publishing Ltd 4836 – 4847 12 Campania [Italy]; Campi Flegrei; Italy; Naples; Napoli [Campania]; Deposits; Geochronology; Hazards; Stratigraphy; Tectonics; Volcanic rocks; Caldera-forming eruption; Campanian Ignimbrite; Campi Flegrei; Collapse mechanism; Neapolitan yellow tuffs; Scientific drilling; Tectonic structure; Volcanic hazards; argon-argon dating; caldera; deep drilling; geochronology; reconstruction; tectonic evolution; volcanic eruption; Volcanoes https://www.scopus.com/inward/record.uri?eid=2-s2.0-85006489601&doi=10.1002%2f2015GC006183&partnerID=40&md5=2d497bf52ab196d9681f4bf2f4c6a8ff Cited by: 55; All Open Access, Hybrid Gold Open Access Giuseppe De Natale Claudia Troise Darren Mark Angela Mormone Monica Piochi Mauro A. Di Vito Roberto Isaia Stefano Carlino Diana Barra Renato Somma article Preuss2016859 Melt degassing by bubble nucleation and growth is a driving mechanism of magma ascent. Therefore, decompression experiments with hydrous silicate melts were used to investigate the onset and the dynamics of H2O degassing. Nominally H2O undersaturated trachytic Campi Flegrei and phonolitic Vesuvius melts representative for the magma compositions of the Campi Flegrei volcanic system were decompressed at a super-liquidus temperature of 1050°C from 200 MPa to final pressures (Pfinal) of 100, 75, and 60 MPa using continuous decompression rates of 0.024 and 0.17 MPa/s. Experiments started from either massive glass cylinders or glass powder to demonstrate the infl of the starting material on melt degassing. Glass powder can be used to shorten the equilibration time (teq) prior to decompression for dissolution of H2O in the melt. The decompressed samples were quenched and compared in terms of bubble number density (NV), porosity, and residual H2O content in the melt. Decompression of all glass cylinder samples led to homogeneous bubble nucleation with high NV of ∼105 mm-3. The supersaturation pressures for homogeneous bubble nucleation were estimated to be <76 MPa for the trachytic and <70 MPa for the phonolitic melt. In contrast to glass cylinders, the usage of glass powder equilibrated for 24 h before decompression prevented homogeneous bubble nucleation during decompression. We suggest that trapped air in the powder pore space resulted in the formation of tiny H2O-N2 bubbles throughout the samples prior to decompression. Degassing of these glass powder samples was facilitated by diffusive growth of these pre-existing bubbles and thus did not require signifi H2O supersaturation of the melt. This is evidenced by several orders of magnitude lower NV and lower residual H2O contents at correspondingly higher porosities compared to the glass cylinder samples. However, a signifi extension of teq to 96 h in the glass powder experiments led to degassing results comparable to the glass cylinder samples. This effect is probably due to Ostwald ripening, coalescence, and the ascent of the pre-existing bubbles during the extended teq prior to decompression. The NV of the glass cylinder samples were used to test the applicability of the vesiculation model provided by Toramaru (2006). For the applied decompression rates, the experimental NV are up to 5 orders of magnitude higher than the values predicted by the model. This may be mainly attributed to the usage of the macroscopic surface tension and the total H2O diffusivity in the model to describe the molecular process of bubble nucleation. A signifi increase in modeled NV can be achieved by application of a reduced surface tension in combination with the lower diffusivity of network formers as a limiting parameter for the formation of a bubble nucleus. This study demonstrates that the investigation of homogeneous bubble nucleation necessitates an optimized experimental protocol. We strongly recommend performing experiments with massive glass cylinders as starting material. The timescale of decompression is a limiting parameter and must be short enough to minimize the opportunity for a reduction of NV by bubble coalescence. Considering our comparably high NV, the samples of many previous experimental studies that were used to calibrate models for homogeneous bubble nucleation were probably subject to signifi NV reduction. Newly derived data from optimized experiments will require improved models for homogeneous bubble nucleation during magma ascent. © 2016 by Walter de Gruyter Berlin/Boston. Article 2016 English 0003004X 10.2138/am-2016-5480 American Mineralogist 101 Walter de Gruyter GmbH 859 – 875 4 Campania [Italy]; Campi Flegrei; Italy; Napoli [Campania]; Vesuvius; Coalescence; Crystallization; Cylinders (shapes); Degassing; Nucleation; Porosity; Silicates; Supersaturation; Surface tension; Bubble nucleation; Bubble number densities; Campi Flegrei; Decompression experiments; Magma ascents; bubble; decompression; degassing; magma; melt; volcanic glass; Glass https://www.scopus.com/inward/record.uri?eid=2-s2.0-84964938395&doi=10.2138%2fam-2016-5480&partnerID=40&md5=7d42fc264aa1439949dc8aa9f0b8e683 Cited by: 19 Oliver Preuss Holger Marxer Sarah Ulmer Wolf Johannes Marcus Nowak article Steinmann2016361 To date, the origin of the Campi Flegrei caldera is still under debate and may be related to (1) a single caldera collapse associated with the Neapolitan Yellow Tuff (NYT) eruption, (2) two subsequent caldera collapses associated with the NYT and the preceding Campanian Ignimbrite (CI) eruptions forming a nested-caldera complex, or (3) not related to a caldera collapse after all. Here, we study the submerged portion of the caldera, which has favored a marine depositional setting and, thus, represents an ideal location for the reconstruction of its formation history, utilizing multichannel seismic data. Volcanic deposits and edifices were seismically distinguished from sedimentary successions, and the stratigraphy could be refined and extended back to the Campanian Ignimbrite eruption at ~ 39 ka. High-resolution multichannel reflection seismic data revealed the existence of a nested-caldera complex formed during the CI eruption at ~ 39 ka and the more recent NYT eruption at ~ 15 ka. A ring-fault bounding an inner caldera collapse structure was clearly imaged. It appears that this inner ring-fault was initially activated during the CI caldera collapse and later reactivated during the NYT caldera collapse with different amounts of subsidence. The NYT caldera probably formed during an asymmetrical collapse with a maximum subsidence of ~ 75 m in the offshore portion. The vertical displacement related to the CI caldera collapse may be significantly larger. The submerged caldera depression accommodates post-eruption sediments. Within this high-resolution archive, two major unconformities developed at ~ 8.6 ka and 5 ka, when resurgence-related uplift exceeded the rate of sea-level rise concurrent with the emersion of the La Starza terrace. A previously unknown post-collapse submarine volcanic mound located between Nisida Island and Nisida Bank probably formed between 4.8 and 3.7 ka. Also, the Penta Palummo Bank appears to be constructed of at least two monogenetic volcanic edifices, the Penta Palummo volcano formed at ~ 100 ka and a younger mushroom-shaped unit formed between 39 and 15 ka. The main outcome of this study is a conceptual evolutionary model, providing novel insights on the formation of the Campi Flegrei nested caldera in the course of two large-scale eruptions (CI and NYT) with associated caldera collapses along mutual (i.e. reactivated) faults and subsequent caldera resurgence. As both the genesis and subsurface architecture of the Campi Flegrei caldera are still hotly debated topics in literature, our discoveries can be regarded as a substantial advancement in the understanding of the Campi Flegrei volcanic area. © 2016 Elsevier B.V. Article 2016 English 03770273 10.1016/j.jvolgeores.2016.09.001 Journal of Volcanology and Geothermal Research 327 Elsevier B.V. 361 – 374 Campania [Italy]; Campi Flegrei; Italy; Napoli [Campania]; Basidiomycota; Buildings; Seismic response; Seismic waves; Seismology; Stratigraphy; Subsidence; Volcanoes; Caldera formation; Caldera resurgence; Campi Flegrei; Fault system; Nested calderas; Reflection seismics; caldera; Campanian; collapse; formation mechanism; ignimbrite; landform evolution; sea level change; seismic reflection; volcanic eruption; Sea level https://www.scopus.com/inward/record.uri?eid=2-s2.0-84994493618&doi=10.1016%2fj.jvolgeores.2016.09.001&partnerID=40&md5=82ad66c0f6689dc6393785a35dd14f1c Cited by: 20 Lena Steinmann Volkhard Spiess Marco Sacchi article Mormone201539 A 506. m drill-hole has been recently drilled in the framework of the Campi Flegrei Deep Drilling Project (CFDDP) and the International Continental Scientific Drilling Program (ICDP) with the intention of coring the subsurface in the eastern sector of the Campi Flegrei caldera. The borehole, located in the western district of the Neapolitan city (Bagnoli Plain) 3. km to the east of the most active volcanic area and about 5. m above sea level, is now targeted for monitoring purposes.This paper reports the results obtained from the analysis of two short cores collected at depths of -443 and -506m below the ground level. The cores sampled two pre-caldera tuffs. Observations performed by optical and scanning electron microscopy, energy dispersive spectroscopy and powder X-ray diffraction were used to achieve data on the primary lithology, both primary and secondary mineralogical assemblages, and the relationship between texture and secondary mineralization. Sr isotope ratios were determined on selected primary feldspars, whereas δ13C and δ18O analyses were performed on carbonates from veins and filled-voids in tuffs.Our results provide information on the hydrothermal system in the eastern sector of the caldera that was not among the goals in the previous drilling programs. Secondary mineralization suggests a saline hydrothermal environment characterized by fluids that progressively evolved from boiling toward more alkaline and cooler conditions. A paleo-temperature of ca. 160. °C has been inferred from authigenic mineral occurrences and calculated on the basis of equilibria between cored calcites and fluids presently emitted at the surface, by using carbon and oxygen isotope data. The temperature measured at the bottom of the drilling is about 80. °C. © 2014 The Authors. Review 2015 English 03770273 10.1016/j.jvolgeores.2014.12.003 Journal of Volcanology and Geothermal Research 290 Elsevier 39 – 52 Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Vesuviano, Naples, Italy; Dipartimento di Scienze della Terra, Dell'Ambiente e delle Risorse, Università Federico II, Naples, Italy; GeoZentrum Nordbayern, University of Erlangen-Nuremberg, Erlangen, Germany Bagnoli; Campania [Italy]; Campi Flegrei; Italy; Naples; Napoli [Campania]; C (programming language); Core samples; Drills; Energy dispersive spectroscopy; Geothermal fields; Isotopes; Lithology; Mineralogy; Rock drills; Scanning electron microscopy; Sea level; Strontium; Volcanoes; X ray diffraction; Authigenic minerals; Campi Flegrei; Carbon and oxygen isotopes; Continental scientific drillings; Hydrothermal activity; Hydrothermal environment; Pilot holes; Powder X ray diffraction; borehole; caldera; deep drilling; geothermal system; hydrothermal activity; hydrothermal system; isotopic ratio; mineralization; strontium isotope; temperature; tuff; Boreholes https://www.scopus.com/inward/record.uri?eid=2-s2.0-84921314458&doi=10.1016%2fj.jvolgeores.2014.12.003&partnerID=40&md5=4ecc1e886fba62b4eca2de0a6c8efa27 Cited by: 22; All Open Access, Hybrid Gold Open Access A. Mormone C. Troise M. Piochi G. Balassone M. Joachimski G. De Natale article Carlino201523 Article 2015 English 0012821X 10.1016/j.epsl.2015.03.035 Earth and Planetary Science Letters 420 Elsevier 23 – 29 Campania [Italy]; Campi Flegrei; Italy; Napoli [Campania]; Drilling; Risk assessment; Stresses; Borehole measurements; Caldera unrest; Campi Flegrei; Extensional stress; Improved forecast; Leak-off tests; Principal stress; Volcanic eruptions; caldera; deep drilling; geoaccumulation; stress field; structural geology; tectonic evolution; tectonic setting; uplift; volcanic eruption; volcanology; Volcanoes https://www.scopus.com/inward/record.uri?eid=2-s2.0-84961368077&doi=10.1016%2fj.epsl.2015.03.035&partnerID=40&md5=6123fd676f4f0d265033e7b92e6c4653 Cited by: 21; All Open Access, Green Open Access Stefano Carlino Christopher R.J. Kilburn Anna Tramelli Claudia Troise Renato Somma Giuseppe De Natale article Fanara20152284 The solubility of H2O- and CO2-bearing fluids in trachytic and trachybasaltic melts from erupted magmas of the Campi Flegrei Volcanic District has been investigated experimentally at 1100 and 1200 °C, respectively, and at 100, 200, 300, 400, and 500 MPa. The solubility of H2O in the investigated melts varies between 3.48 ± 0.07 wt% at 100 MPa to 10.76 ± 0.12 wt% at 500 MPa in trachytic melts and from 3.49 ± 0.07 wt% at 100 MPa to 9.10 ± 0.11 wt% at 500 MPa in trachybasaltic melts. The content of dissolved CO2 in melts coexisting with the most CO2-rich fluid phase increases from 281 ± 24 ppm at 100 MPa to 2710 ± 99 ppm at 500 MPa in trachyte, and from 727 ± 102 ppm at 100 MPa to 3565 ± 111 ppm at 500 MPa in trachybasalt. Natural samples from the Campanian Ignimbrite eruption (trachyte) and from the Solchiaro eruption (trachybasalt) were collected around the city of Naples and on Procida Island. Deuterium/hydrogen (D/H) ratios were analyzed in natural pumices pre-heated at different temperatures to remove water adsorbed and/or imprinted by glass alteration processes. It has been determined that heating of the glass to 350 °C efficiently removes most of secondary water and the remaining concentrations represent primary magmatic water preserved in the erupted material. Hydrogen isotope composition (with δD values ranging between -70‰ and -110‰) and its correlation with bulk water content in selected pumice samples of the Campanian Ignimbrite eruption are consistent with isotopic fractionation between magmatic fluid and melt during degassing of erupting magma. Hence, the H2O and CO2 contents in natural glasses from pumice samples are considered as minimum estimates on volatile concentrations in the melt just prior to the eruption or at the fragmentation event. The water contents in natural glasses vary from 0.83 ± 0.07 to 3.74 ± 0.06 wt% for trachytes from the Campanian Ignimbrite eruption and from 1.96 ± 0.06 to 3.47 ± 0.07 wt% for trachybasalts from the Solchiaro eruption. The CO2 contents vary from 78 ± 120 ppm CO2 to 1743 ± 274 ppm for trachytes from the Campanian Ignimbrite eruption and from 240 ± 293 to 1213 ± 250 ppm for trachybasalts from the Solchiaro eruption. A combination of natural and experimental data provides minimum pressure estimates for the storage and ascent conditions of magmas. The Campanian Ignimbrite magma could have been stored or ponded during its rising path at two different levels: a deeper one corresponding to depth of about 8 to 15 km and a shallower one at about 1 to 8 km. Trachybasalts from Solchiaro erupted from the deepest level of about 11 km with a storage or ponding level at around 2 to 8 km depth. Although an uncertainty of at least a kilometer has to be considered in estimating storage or ponding depths, these estimates point to significantly deeper magmatic sources for both eruptions as those considered previously. © 2015 by Walter de Gruyter Berlin/Boston. Article 2015 English 0003004X 10.2138/am-2015-5033 American Mineralogist 100 Walter de Gruyter GmbH 2284 – 2297 10 Campania [Italy]; Campi Flegrei; Italy; Napoli [Campania]; Trachytes; Carbon dioxide process; Digital storage; Glass; Isotopes; Ponding; Solubility; Storage (materials); Uncertainty analysis; Volcanoes; Water; Campanian Ignimbrite; Hydrogen isotope; Solchiaro eruption; trachybasalt; trachyte; Volcanic district; Campanian; carbon dioxide; hydrogen isotope; ignimbrite; isotopic fractionation; magma chemistry; solubility; trachyte; volatile substance; volcanic eruption; water content; Carbon dioxide https://www.scopus.com/inward/record.uri?eid=2-s2.0-84943530641&doi=10.2138%2fam-2015-5033&partnerID=40&md5=77161ef51085f932e043c45a959f13c8 Cited by: 27 Sara Fanara Roman E. Botcharnikov Danilo M. Palladino Franziska Adams Julia Buddensieck Andreas Mulch Harald Behrens article Carlino20141 Article 2014 10.1007/s00445-014-0870-2 Bulletin of Volcanology 76 1 – 7 10 https://www.scopus.com/inward/record.uri?eid=2-s2.0-84928900065&doi=10.1007%2fs00445-014-0870-2&partnerID=40&md5=72dff8cde8d1e61afa01c0a172ba3ea6 Cited by: 9 Stefano Carlino Anna Tramelli Renato Somma article Popov2014896 We reanalyzed and compared unique data sets, which we obtained in the frame of combined petrophysical and geothermal investigations within scientific drilling projects on four impact structures: the Puchezh-Katunki impact structure (Vorotilovo borehole, Russia), the Ries impact structure (Noerdlingen-73 borehole, Germany), the Chicxulub impact structure (ICDP Yaxcopoil-1 borehole, Mexico), and the Chesapeake impact structure (ICDP-USGS-Eyreville borehole, USA). For a joined interpretation, we used the following previously published data: thermal properties, using the optical scanning technique, and porosities, both measured on densely sampled halfcores of the boreholes. For the two ICDP boreholes, we also used our previously published P-wave velocities measured on a subset of cores. We show that thermal conductivity, thermal anisotropy, porosity, and velocity can be correlated with shock metamorphism (target rocks of the Puchezh-Katunki and Ries impact structures), and confirm the absence of shock metamorphism in the samples taken from megablocks (Chicxulub and Chesapeake impact structure). The physical properties of the lithic impact breccias and suevites are influenced mainly by their impact-related porosity. Physical properties of lower porosity lithic impact breccias and suevites are also influenced by their chemical composition. These data allow for a distinction between different types of breccias due to differences concerning the texture and chemistry and the different amounts of melt and rock clasts. © The Meteoritical Society, 2014. Article 2014 English 10869379 10.1111/maps.12299 Meteoritics and Planetary Science 49 University of Arkansas 896 – 920 5 https://www.scopus.com/inward/record.uri?eid=2-s2.0-84900812435&doi=10.1111%2fmaps.12299&partnerID=40&md5=d9e395827c80b7e60ffcf7484bbd0884 Cited by: 5 Y. Popov S. Mayr R. Romushkevich H. Burkhardt H. Wilhelm article Petrosino2013 In 2012 two seismic surveys were carried out in the area of Bagnolifutura (Campi Flegrei, Naples), with the aim of characterizing the properties of the seismic noise during the drilling activity performed in the framework of the Campi Flegrei Deep Drilling Project (CFDDP; https://sites.google.com/site/ cfddpproject/). During the first survey, which was conducted from 2 to 4 April, before the drilling, seven broadband threecomponent seismometers were installed in two different array configurations. The second survey started on November 26, in concomitance with the drilling operations and fluid injection, and ended on December 5, four days after the end of the drilling, when the maximum depth of 502 m was reached. During this period seven broadband and one short-period three-component sensors were installed. A preliminary spectral analysis was performed on samples of seismic noise; moreover the root mean square of the amplitude of the signals and the polarization parameters were calculated. The preliminary results show similar spectral and polarization features for the data of the two surveys, whereas the amplitude of the seismic noise collected during the second survey is greatly influenced by the bad meteorological conditions. As future development experimental site transfer functions from Nakamura's technique and surface wave dispersion from array techniques will be calculated to obtain the shallow crustal structure. The results corresponding to the different phases of the drilling activity will be compared, with the aim of establishing if significant variations of the medium properties have occurred during the experiment. Moreover the recorded signals will be deeply investigated in order to detect the eventual occurrence of microseismicity induced by fluid injection and to define its features. © 2013 INGV Istituto Nazionale di Geofisica e Vulcanologia. Article 2013 English 15902595 Quaderni di Geofisica 1 https://www.scopus.com/inward/record.uri?eid=2-s2.0-84879623649&partnerID=40&md5=f2e85614dd2549a6f541290a28690461 Cited by: 0 Simona Petrosino Francesca Bianco Antonella Bobbio Mario Castellano Paola Cusano Edoardo Del Pezzo Danilo Galluzzo Mario La Rocca Veronica Maiello article Fanara2013149 Water diffusivity was investigated in phonolitic and trachytic melts containing up to 6wt.% of dissolved water at temperatures between 1373K and 1673K for running time of 108 to 1186s using the diffusion couple technique. The experiments were performed in an internally heated gas pressure vessel (IHPV) at pressures of 0.2 or 0.3GPa and in a piston cylinder apparatus (PCA) at pressures between 0.5 and 2.5GPa. A newly developed rapid heating and rapid quench device was used for short term experiments in the IHPV. Concentration profiles of hydrous species (OH groups and H2O molecules) and total water (bulk water concentration as sum of OH and H2O molecules) were measured along the cylindrical axis of the diffusion sample using IR micro-spectroscopy. The IR spectroscopic technique was calibrated using a set of samples with bulk water contents measured by Karl-Fischer titration. Electron microprobe traverses show no significant change in relative proportions of anhydrous components along H2O profiles, indicating that our data can be treated as effective binary diffusion between H2O and the rest of the silicate melt.Bulk water diffusivity was derived from profiles of total water using a modified Boltzmann-Matano method as well as using fittings assuming a functional relationship between the total water diffusivity (DH2Ot) and the total water concentration (CH2Ot). The fitting of the profiles indicates that for phonolitic melt the water diffusivity is roughly proportional to water content. The following formulation was derived for the prediction of total water diffusivity (m2/s) as a function of T (K) in the T-range of 1373 to 1673K and CH2Ot:logDH2Ot=-7.11-2.07logCH2Ot-4827-4620logCH2OtT.The experimental data are reproduced by this relationship with a standard deviation of 0.07. log units. Water diffusivity in trachytic melts is similar at the same conditions. A pressure effect on water diffusivity could not be resolved in the range 0.2 to 2.5. GPa for phonolitic or trachytic melts. © 2012 Elsevier B.V. Article 2013 English 00092541 10.1016/j.chemgeo.2012.09.030 Chemical Geology 346 149 – 161 Experiments; Infrared spectroscopy; Molecules; Pressure effects; Silicates; Water content; Boltzmann-Matano method; Diffusion couple technique; Functional relationship; Phonolite; Piston-cylinder apparatus; Spectroscopic technique; Trachyte; Water diffusion; concentration (composition); diffusivity; infrared spectroscopy; phonolite; potassium; silicate melt; trachyte; water content; Diffusion in liquids https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876979910&doi=10.1016%2fj.chemgeo.2012.09.030&partnerID=40&md5=8f23882e8aa1952cce384575a25addda Cited by: 25 Sara Fanara Harald Behrens Youxue Zhang article Misiti201150 Viscosities of shoshonitic and latitic melts, relevant to the Campi Flegrei caldera magmas, have been experimentally determined at atmospheric pressure and 0.5GPa, temperatures between 840K and 1870K, and H2O contents from 0.02 to 3.30wt.%.The concentric cylinder technique was employed at atmospheric pressure to determine viscosity of nominally anhydrous melts in the viscosity range of 101.5-103Pas. The micropenetration technique was used to determine the viscosity of hydrous and anhydrous melts at atmospheric pressure in the high viscosity range (1010Pas). Falling sphere experiments were performed at 0.5GPa in the low viscosity range (from 100.35 to 102.79Pas) in order to obtain viscosity data of anhydrous and hydrous melts. The combination of data obtained from the three different techniques adopted permits a general description of viscosity as a function of temperature and water content using the following modified VFT equation:logη=-a+bT-c+dT-e·expg·wTwhere η is the viscosity in Pa·s, T the temperature in K, w the H2O content in wt.%, and a, b, c, d, e, and g are the VFT parameters. This model reproduces the experimental data (95 measurements) with a 1σ standard deviation of 0.19 and 0.22 log units for shoshonite and latite, respectively. The proposed model has been applied also to a more evolved composition (trachyte) from the same area in order to create a general model applicable to the whole compositional range of Campi Flegrei products.Moreover, speed data have been used to constrain the ascent velocity of latitic, shoshonitic, and trachytic melts within dikes. Using petrological data and volcanological information (geometrical parameters of the eruptive fissure and depth of magma storage), we estimate a time scale for the ascent of melt from 9. km to 4. km depth (where deep and shallow reservoirs, respectively, are located) in the order of few minutes. Such a rapid ascent should be taken into account for the hazard assessment in the Campi Flegrei area. © 2011 Elsevier B.V. Article 2011 English 00092541 10.1016/j.chemgeo.2011.08.010 Chemical Geology 290 50 – 59 1-2 Campania [Italy]; Campi Flegrei; Italy; Napoli [Campania]; Atmospheric pressure; Atmospheric temperature; Atmospherics; Cylinders (shapes); Reservoirs (water); Spheres; Thermal logging; Viscometers; Water content; Campi Flegrei; Concentric cylinders; Falling sphere; Latites; Micropenetration; Shoshonites; air temperature; atmospheric pressure; caldera; experimental study; hazard assessment; magmatic differentiation; P-T conditions; petrology; shoshonite; viscosity; volcanology; Viscosity https://www.scopus.com/inward/record.uri?eid=2-s2.0-80054917604&doi=10.1016%2fj.chemgeo.2011.08.010&partnerID=40&md5=8d421390754c57472ae170d86667b7d9 Cited by: 24 V. Misiti F. Vetere C. Freda P. Scarlato H. Behrens A. Mangiacapra D.B. Dingwell article Behrens201186 Erratum 2011 English 00092541 10.1016/j.chemgeo.2010.02.008 Chemical Geology 288 86 1-2 https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051671584&doi=10.1016%2fj.chemgeo.2010.02.008&partnerID=40&md5=b134bbe0e6327fe66ff22c7b4e307c1c Cited by: 0; All Open Access, Bronze Open Access Harald Behrens article Mormone2011385 The distribution of the alteration assemblages and the related physico-chemical changes induced in the rocks with depth, may provide useful information on the state of the system. Drillholes are the only way to define hydrothermal alteration depth-profiles in variable geological contexts. Deep drillings exploiting programs were conducted since the 1970's by the Agip-Enel Joint Venture in the Quaternary Campi Flegrei caldera (southern Italy), where a geothermal system has been active since at least historical times. New macroscopic and microscopic investigations were performed on selected samples made available by Agip in order to: 1) define the precursor lithology, 2) describe the relationships among texture, mineralogy and depth of the studied core samples and 3) examine the character of the secondary minerals and their distribution with depth and temperature. The new data are integrated with physical properties and elastic parameters of cored rocks, as well as structural information and field data, all available from the physical, seismological, geodetical and volcanological literature. The depth-related multi-parameters profiles provide evidence on the different behavior of the buried rocks beneath the Licola 1, Mofete and San Vito 1 areas, sited in three structurally different sectors of the caldera. The features of the hydrothermally altered rocks are a key to interpret the heterogeneities of the Campi Flegrei substratum, as deduced by velocity, attenuation and scattering P- and S- waves tomography. The time and space distribution of both the eruptive vents and the extruded magma volumes are consistent with the results of our analysis. Therefore, we interpret the observed Campi Flegrei geothermal system as a response to the distribution of volcanic activity in two structurally distinct sectors of the caldera. The central-eastern sector, where the San Vito 1 well was drilled, represents the preferential pathways for both gas escape and magma ascent at least since 8 kyrs, in contrast with the other sites of the caldera where eruptions occurred with minor frequency and magnitude. 2011 English 03698963 10.2451/2011PM0027 Periodico di Mineralogia 80 Sapienza Universita Editrice 385-406 Istituto Nazionale di Geofisica e Vulcanologia, Sezione Osservatorio Vesuviano, Napoli, Italy; Dipartimento di Scienze della Terra, Università Degli Studi di Napoli Federico II, Via Mezzocannone 8, 80134 Napoli, Italy 3 https://www.scopus.com/inward/record.uri?eid=2-s2.0-84855852091&doi=10.2451%2f2011PM0027&partnerID=40&md5=83189c0c483030eb78489a94ad6d4e97 cited By 16 A. Mormone A. Tramelli M.A. Di Vito M. Piochi C. Troise G.D. Natale article Vetere2011251 The solubility of H2O-CO2-bearing fluids in shoshonitic melts relevant to magmas of the Vulcanello peninsula and to mafic melts from magmas erupted at Campi Flegrei (Italy) was experimentally determined at pressures from 50 to 400MPa and at temperature of 1250°C. No quench crystals and less than 1vol.% bubles were observed in the rapid quenched glasses. H2O and CO2 contents in the experimental glasses were determined via Karl-Fischer Titration (KFT) and FTIR spectroscopy. For the quantification of volatile concentrations by IR spectroscopy we have calibrated the absorption coefficients of water-related and carbon-related IR bands for the shoshonitic composition. The determined absorption coefficients are 0.80±0.06L mol-1 cm-1 for the band at ~4500cm-1 (OH groups) and 1.02±0.03L mol-1 cm-1 for the band at ~5200cm-1 (H2O molecules). CO2 is bound in the shoshonitic glass as CO32- exclusively; its concentration was quantified by the peak height of the low wavenumber band of the doublet near 1430cm-1 using the calibrated absorption coefficient of 356±18L mol-1 cm-1.The H2O solubility in the shoshonitic melts is in the same range as observed for other natural aluminosilicate melts, i.e. 5.12±0.07wt.% at 200MPa and 7.92±0.07wt.% H2O at 400MPa. A non-linear variation of the H2O and CO2 solubility in the melts with increasing mole fraction of H2O (and thus decreasing mole fraction of CO2) in the fluid was observed at each investigated pressure. At 1250°C, the concentration of dissolved carbonate (expressed as CO2 component) in melts coexisting with nearly pure CO2 fluid increases from 307 to 2932ppm (±10% relative) as the pressure increases from 50 to 400MPa. The comparison of the dataset with available models predicting the H2O and CO2 concentrations in silicate melts coexisting with H2O-CO2-bearing fluids shows that the effect of melt composition is not calibrated appropriately in the models.The experimental data are used to re-evaluate the typical pressures of glass inclusions entrapment in phenocrysts from Minopoli2 eruption and the results indicate that the main magma chamber may have been located at a depth of ~ 4000 m. © 2011 Elsevier B.V. Article 2011 English 03770273 10.1016/j.jvolgeores.2011.03.002 Journal of Volcanology and Geothermal Research 202 251 – 261 3-4 Campania [Italy]; Campi Flegrei; Italy; Lipari Islands; Messina [Sicily]; Napoli [Campania]; Sicily; Vulcano; Aluminosilicates; Bearings (structural); Crystals; Fluids; Fourier transform infrared spectroscopy; Glass; Solubility; Water absorption; Campi Flegrei; ; O; Shoshonitic magmas; Vulcanello; absorption coefficient; carbon dioxide; FTIR spectroscopy; mafic rock; magma; magma chamber; magmatism; phenocryst; shoshonite; silicate melt; solubility; volcanic eruption; volcanic glass; Absorption spectroscopy https://www.scopus.com/inward/record.uri?eid=2-s2.0-79955038579&doi=10.1016%2fj.jvolgeores.2011.03.002&partnerID=40&md5=c3a4f0e0f1b9a1e444d90128c3188d77 Cited by: 42 Francesco Vetere Roman E. Botcharnikov François Holtz Harald Behrens Rosanna De Rosa article DeNatale200748 Conference paper 2007 English 18163459 10.2204/iodp.sd.4.15.2007 Scientific Drilling 48 – 50 4 https://www.scopus.com/inward/record.uri?eid=2-s2.0-78651563043&doi=10.2204%2fiodp.sd.4.15.2007&partnerID=40&md5=5b6e15e7ecd821c9efaff1c021efb48d Cited by: 3; All Open Access, Gold Open Access, Green Open Access Giuseppe De Natale Claudia Troise Marco Sacchii