http://hdl.handle.net/2122/266 Search the Channel search http://www.earth-prints.org/simple-search http://hdl.handle.net/2122/4831 Title: Volcanological and structural evolution of the Ischia resurgent caldera (Italy) over the past 10 ka. <br/> <br/>Authors: De Vita, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Sansivero, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Orsi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Marotta, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Piochi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia <br/> <br/>Abstract: Volcanic activity on the island of Ischia included both effusive and explosive eruptions, mainly occurred in the eastern sector of the island. Vent location, eruption dynamics, transport mechanisms and depositional processes, have been reconstructed for each recognized unit. In the past 10 ka, periods of quiescence alternated with periods of very intense volcanism, which was mainly concentrated at about 5.5 and over the past 2.9 ka. Volcanism was not continuous and strongly influenced by the mechanism of a resurgence phenomenon, which affects the island since about 33 ka. Therefore, it has been hypothesized that magma intrusion and uplift events occurred intermittently. In the past 5.5 ka, volcanic activity has been invariably accompanied by the emplacement of slope instability-related deposits testifying that also slope instability was induced by reactivation of vertical movements, likely related to resurgence. http://hdl.handle.net/2122/4827 Title: The Campanian Ignimbrite and Codola tephra layers: Two temporal/stratigraphic markers for the Early Upper Palaeolithic in southern Italy and eastern Europe <br/> <br/>Authors: Giaccio, B.; Istituto di Geologia ambientale e Geoingegneria, CNR, Via Bolognola 7, 00138 Rome, Italy; Isaia, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Fedele, F. G.; Laboratorio di Antropologia, Dipartimento delle Scienze biologiche, Università di Napoli “Federico II”, Naples, Italy; Di Canzio, E.; Dipartimento di Scienze della Terra, Università di Roma “La Sapienza”, Rome, Italy; Hoffecker, J.; Institute of Arctic and Alpine Research, University of Colorado, Boulder, USA; Ronchitelli, A.; Dipartimento di Archeologia e Storia delle Arti, Università di Pisa, Pisa, Italy; Sinitsyn, A. A.; Institute of the History of Material Culture, Russian Academy of Sciences, Petersburg, Russia; Anikovich, M.; Institute of the History of Material Culture, Russian Academy of Sciences, Petersburg, Russia; Lisitsyn, S.; Institute of the History of Material Culture, Russian Academy of Sciences, Petersburg, Russia; Popov, V. V. <br/> <br/>Abstract: Tephra layers from archaeological sites in southern Italy and eastern Europe stratigraphically associated with cultural levels containing Early Upper Palaeolithic industry were analysed. The results confirm the occurrence of the Campanian Ignimbrite tephra (CI; ca. 40 cal ka BP) at Castelcivita Cave (southern Italy), Temnata Cave (Bulgaria) and in the Kostenki–Borshchevo area of the Russian Plain. This tephra, originated from the largest eruption of the Phlegrean Field caldera, represents the widest volcanic deposit and one of the most important temporal/stratigraphic markers of western Eurasia. At Paglicci Cave and lesser sites in the Apulia region we recognise a chemically and texturally different tephra, which lithologically, chronologically and chemically matches the physical and chemical characteristics of the Plinian eruption of Codola; a poorly known Late Pleistocene explosive event from the Neapolitan volcanoes, likely Somma–Vesuvius. For this latter, we propose a preliminary age estimate of ca. 33 cal ka BP and a correlation to the widespread C-10 marine tephra of the central Mediterranean. The stratigraphic position of both CI and Codola tephra layers at Castelcivita and Paglicci help date the first and the last documented appearance of Early Upper Palaeolithic industries of southern Italy to ca. 41–40 and 33 cal ka BP, respectively, or between two interstadial oscillations of the Monticchio pollen record – to which the CI and Codola tephras are physically correlated – corresponding to the Greenland interstadials 10–9 and 5. In eastern Europe, the stratigraphic and chronometric data seem to indicate an earlier appearance of the Early Upper Palaeolithic industries, which would predate of two millennia at least the overlying CI tephra. The tephrostratigraphic correlation indicates that in both regions the innovations connected with the so-called Early Upper Palaeolithic – encompassing subsistence strategy and stone tool technology – appeared and evolved during one of the most unstable climatic phases of the Last Glacial period. On this basis, the marked environmental unpredictability characterising this time-span is seen as a potential ecological factor involved in the cultural changes observed. http://hdl.handle.net/2122/4644 Title: The paroxysmal event and its deposits <br/> <br/>Authors: Pistolesi, M.; Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italia; Rosi, M.; Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italia; Pioli, L.; University of Oregon, Eugene, OR, USA; Renzulli, A.; Istituto di Scienze della Terra, Università di Urbino, Urbino, Italia; Bertagnini, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Andronico, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia <br/> <br/>Editors: Calvari, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Inguaggiato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Puglisi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Ripepe, M; Università degli Studi di Firenze, Firenze, Italia; Rosi, M.; Università degli Studi di Pisa, Pisa, Italia <br/> <br/>Abstract: The 5 April 2003 eruption of Stromboli volcano (Italy) was the most violent in the past 50 years. It was also the best documented due to the accurate geophysical monitoring of the ongoing effusive eruption. Detailed field studies carried out a few hours to a few months after the event provided further information that were coupled with visual documentation to reconstruct the explosive dynamics. The eruption consisted of an 8-min-long explosive event preceded by a short-lived precursory activity that evolved into the impulsive ejection of gas and pyroclasts. Meter-sized ballistic blocks were launched to altitudes of up to 1400 m above the craters falling on the volcano flanks and on the village of Ginostra, about 2 km far from the vent. The vertical jet of gas and pyroclasts above the craters fed a convective plume that reached a height of 4 km. The calculated erupted mass yielded values of 1.1–1.4 × 108 kg. Later explosions generated a scoria flow deposit, with an estimated mass of 1.0–1.3 × 107 kg. Final, waning ash explosions closet the event. The juvenile fraction consisted of an almost aphyric, highly vesicular pumice mingled with a shallow-derived, crystal-rich, moderately vesicular scoria. Resuming of the lava emission a few hours after the paroxysm indicate that the shallow magmatic system was not significantly modified during the explosions. Combination of volume data with duration of eruptive phases allowed us to estimate the eruptive intensity: during the climactic explosive event, the mass discharge rate was between 106 and 107 kg/s, whereas during the pyroclastic flow activity, it was 2.8–3.6 × 105 kg/s. Strong similarities with other historical paroxysms at Stromboli suggest similar explosion dynamics. http://hdl.handle.net/2122/4532 Title: New insights into Late Pleistocene explosive volcanic activity and caldera formation on Ischia (southern Italy) <br/> <br/>Authors: Brown, R.; Department of Earth Sciences, University of Bristol,; Orsi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; de Vita, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia <br/> <br/>Abstract: A new pyroclastic stratigraphy is presented for the island of Ischia, Italy, for the period ∼75–50 ka BP. The data indicate that this period bore witness to the largest eruptions recorded on the island and that it was considerably more volcanically active than previously thought. Numerous vents were probably active during this period. The deposits of at least 10 explosive phonolite to basaltictrachyandesite eruptions are described and interpreted. They record a diverse range of explosive volcanic activity including voluminous fountain-fed ignimbrite eruptions, fallout from sustained eruption columns, block-and-ash flows, and phreatomagmatic eruptions. Previously unknown eruptions have been recognised for the first time on the island. Several of the eruptions produced pyroclastic density currents that covered the whole island as well as the neighbouring island of Procida and parts of the mainland. The morphology of Ischia was significantly different to that seen today, with edifices to the south and west and a submerged depression in the centre. The largest volcanic event, the Monte Epomeo Green Tuff (MEGT) resulted in caldera collapse across all or part of the island. It is shown to comprise at least two thick intracaldera ignimbrite flowunits, separated by volcaniclastic sediments that were deposited during a pause in the eruption. Extracaldera deposits of the MEGT include a pumice fall deposit emplaced during the opening phases of the eruption, a widespread lithic lag breccia outcropping across much of Ischia and Procida, and a distal ignimbrite in south-west Campi Flegrei. During this period the style and magnitude of volcanism was dictated by the dynamics of a large differentiated magma chamber, which was partially destroyed during the MEGT eruption. This contrasts with the small-volume Holocene and historical effusive and explosive activity on Ischia, the timing and distribution of which has been controlled by the resurgence of the Monte Epomeo block. The new data contribute to a clearer understanding of the long-term volcanic and magmatic evolution of Ischia.