http://hdl.handle.net/2122/218 Thu, 23 May 2013 09:06:02 GMT 2013-05-23T09:06:02Z http://hdl.handle.net/2122/8658 Title: The Earth Expansion Evidence – A Challenge for Geology, Geophysics and Astronomy Authors: Scalera, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Boschi, E.; University of Bologna; Cwojdzinski, S.; Polish Geological Survey Editors: Scalera, Giancarlo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Boschi, Enzo; University of Bologna; Cwojdzinski, Stefan; Polish Geological Survey Fri, 30 Nov 2012 23:00:00 GMT http://hdl.handle.net/2122/8658 2012-11-30T23:00:00Z http://hdl.handle.net/2122/8478 Title: Integrating new and traditional approaches for the estimate of slip-rates of active faults: examples from the Mw 6.3, 2009 L’Aquila earthquake area, Central Italy Authors: Civico, Riccardo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia Abstract: This thesis developed a multidisciplinary and multi-scale investigation strategy based on the integration of traditional and innovative approaches aimed at improving the normal faults seismogenic identification and characterization, focusing mainly on slip-rate estimate as a measure of the fault activity. The L’Aquila Mw 6.3 April 6, 2009 earthquake causative fault was used as a test site for the application, testing, and refinement of traditional and/or innovative approaches, with the aim to 1) evaluate their strength or limitations 2) develop a reference approach useful for extending the investigation to other active faults in the area and 3) translate the results of the methodological approaches into new inputs to local seismic hazard. The April 6, 2009 L’Aquila earthquake occurred on a so far poorly known tectonic structure, considered having a limited seismic potential, the Paganica - San Demetrio fault system (PSDFS), and thus has highlighted the need for a detailed knowledge in terms of location, geometry, and characterization of the active faults that are the potential sources for future earthquakes. To fill the gap of knowledge enhanced by the occurrence of the 2009 L’Aquila earthquake, we developed a multidisciplinary and multiscale‐based strategy consisting of paleoseismological investigations, detailed geomorphological and geological field studies, as well as shallow geophysical imaging and an innovative methodology that uses, as an alternative paleoseismological tool, core sampling and laboratory analyses but also in situ measurements of physical properties. The integration of geomorphology, geology as well as shallow geophysics, was essential to produce a new detailed geomorphological and geological map of the PSDFS and to define its tectonic style, arrangement, kinematics, extent, geometry and internal complexities. Our investigations highlighted that the PSDFS is a 19 km-long tectonic structure characterized by a complex structural setting at the surface and that is arranged in two main sectors: the Paganica sector to the NW and the San Demetrio sector to SE. The Paganica sector is characterized by a narrow deformation zone, with a relatively small (but deep) Quaternary basin affected by few fault splays. The San Demetrio sector is characterized by a strain distribution at the surface that is accommodated by several tectonic structures, with the system opening into a set of parallel, km-spaced fault traces that exhume and dissect the Quaternary basin. The integration of all the fault displacement data and age constraints (radiocarbon dating, optically stimulated luminescence (OSL) and tephrochronology) resulting from paleoseismological, geomorphological, geophysical and geological investigations played a primary role in the estimate of the slip-rate of the PSDFS. Slip-rates were estimated for different time intervals in the Quaternary, from Early Pleistocene (1.8 Ma) to Late Holocene (last 5 ka), yielding values ranging between 0.09 and 0.58 mm/yr and providing an average Quaternary slip-rate representative for the PSDFS of 0.27 - 0.48 mm/yr. We contributed also to the understanding of the PSDFS seismic behavior and of the local seismic hazard by estimating the max expected magnitude for this fault on the basis of its length (ca. 20 km) and slip per event (up to 0.8 m), and identifying the two most active fault splays at present. Our multidisciplinary results converge toward the possibility of the occurrence of past surface faulting earthquakes characterized by a moment magnitude between 6.3 and 6.8, notably larger than the 2009 event, but compatible with the M range observed in historical earthquakes in the area. The slip-rate distribution over time and space and the tectonic style of the PSDFS suggested the occurrence of strain migration through time in the southern sector, from the easternmost basin-bounding fault splay toward the southwestern splays. This topic has a significant implication in terms of surface faulting hazard in the area, because it can contribute defining the fault splays that have a higher potential to slip during future earthquakes along the PSDFS. By a methodological point of view, the multidisciplinary and multiscale‐based investigation strategy emphasizes the advantages of the joint application of different approaches and methodologies for active faults identification and characterization. Our work suggests that each approach alone may provide sufficient information but only the application of a multidisciplinary strategy is effective in providing robust results and in defining a proper framework of active faults. Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/8478 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8296 Title: Stratigraphy, petrography and chronology of speleothem concretion at Tana Che Urla (Lucca, Italy): paleoclimatic implications Authors: Regattieri, E.; Department of Earth Sciences, University of Pisa, Pisa 56100, Italy; Isola, I.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Zanchetta, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Drysdale, R. N.; Department of Resource Management and Geography, University of Melbourne, Parkville 3010, Victoria, Australia; Hellstrom, J. C.; School of Earth Sciences, University of Melbourne, Parkville 3010, Victoria, Australia; Baneschi, I.; Istituto di Georisorse e Geoscienza-CNR, Pisa 56100, Italy Abstract: In this work we present the results of a stratigraphic and lithologic study of a flowstone from Tana che Urla Cave, Apuan Alps (central Italy) which grew intermittently between ca. 160 and 8 ka. The studied succession consists of an alternation of two different lithofacies (Lf-A, Lf-B): a brown, detrital-rich (Lf-A) and a white, inclusion-poor calcite (Lf-B). Using available growth rate data, the difference between the two lithofacies is thought to be the result of different amounts of meteoric precipitation, with Lf-A related to low growth rates at times of low precipitation during phases of climatic deterioration (stadial or glacial) and a higher flux of clastic material, and Lf-B related to high growth rates due to high infiltration under conditions of higher precipitation during wetter (interstadial/interglacial) periods, with lower clastic flux. Following this interpretation and the available chronology, the flowstone investigated shows a basal portion of Lf- A that was deposited during MIS6. The flowstone then passed from Lf-A to Lf B at the MIS6-5 transition, with Lf-B lasting for the full interglacial of MIS5e. A long growth interruption (hiatus H1) can be correlated with the MIS5d stadial, with resumption of lithofacies Lf-B occurring during the climatic amelioration of interstadial MIS5c. The age profile of the upper part of the flowstone is poorly constrained, and is characterised by several growth interruptions, suggesting that the last glacial was more severe compared to MIS6. Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/8296 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8257 Title: Precise microsampling of poorly laminated speleothems for U-series dating Authors: Drysdale, R. N.; Department of Resource Management and Geography, University of Melbourne, Parkville 3010, Victoria, Australia; Bence, T. P.; School of Earth Sciences, University of Melbourne, Parkville 3010, Victoria, Australia; Hellstrom, J. C.; School of Earth Sciences, University of Melbourne, Parkville 3010, Victoria, Australia; Couchoud, I.; Department of Resource Management and Geography, University of Melbourne, Parkville 3010, Victoria, Australia; Greig, A.; School of Earth Sciences, University of Melbourne, Parkville 3010, Victoria, Australia; Bajo, P.; Department of Resource Management and Geography, University of Melbourne, Parkville 3010, Victoria, Australia; Zanchetta, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Isola, I.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Spötl, C.; Institut für Geologie und Paläontologie, Universität Innsbruck, 6020 Innsbruck, Austria; Baneschi, I.; Istituto di Georisorse e Geoscienza-CNR, Pisa 56100, Italy; Regattieri, E.; Department of Earth Sciences, University of Pisa, Pisa 56100, Italy; Woodhead, J. D.; School of Earth Sciences, University of Melbourne, Parkville 3010, Victoria, Australia Abstract: One of the principal reasons why speleothems are recognised as important palaeoclimate archives is their suitability for accurate and precise uranium-series (U-series) age determination. Sampling speleothem sections for U-series dating is straightforward in most cases because visible growth layers are preserved. However, this is not always the case, and here we describe a sampling strategy whereby growth layers are resolved from trace-element images produced by laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). We apply this method to a section of an Italian subaqueous speleothem (CD3) that lacks persistent visible growth layering. Trace-element imaging revealed growth layers that are strongly non-planar in their geometry owing to the speleothem's pronounced euhedral crystal terminations. The most prominent trace-element layers were first digitized as x, y vector contours. We then interpolated these in the growth-axis direction to generate a series of contour lines at ∼250-μm increments. The coordinates of these contours were used to guide the sampling via a computerised micromilling lathe. This produced a total of 22 samples for U-series dating by multi-collector ICP-MS. The dating results returned ages in correct stratigraphic order within error. Close inspection of the U-series data and the derived depth–age model suggests that the main source of model-age uncertainty is unrelated to the contour sampling but instead more associated with how closely spaced the model ages are in time, i.e. the model age density. Comparisons between stable oxygen and carbon isotope profiles derived from aliquots of the dating samples and two other stable isotope profiles from CD3 spanning the same time period compare very favourably. Taken together, this suggests that our trace-element contouring method provides a reliable means for extracting samples for dating (and other geochemical analyses), and can be applied to similar speleothems lacking visible growth layering. Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/8257 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8248 Title: The Mt. Moio eruption (Etna): Stratigraphy, petrochemistry and 40Ar/39Ar age determination with inferences on the relationship between structural setting and magma intrusion Authors: Del Carlo, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Branca, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; De Beni, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Lo Castro, M. D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Wijbrans, J. R.; Faculteit Aard-en Levenswetenschappen, Vrije Universiteit, Amsterdam, The Netherlands Abstract: Mt. Moio is the most peripheral scoria cone of Etna volcano and rises above the Peloritani Mountains sedimentary basement, 18 km north of the volcano summit. Geological and tephrostratigraphic studies and 40Ar/39Ar age determinations were used to characterize the eruption and constrain its occurrence to ~ 29 ka ago, during the activity of the Ellittico volcano, the volcanic edifice active before the actual one, the Mongibello volcano. The Mt. Moio eruption formed a large scoria cone and a widespread tephra fallout deposit, indicating that vigorous explosive activity produced an eruptive plume; minor effusive activity produced a small lava flow at the end of the eruption. Geochemical data indicate that the composition of erupted magma became less evolved during the eruption (mugearite → basalt–hawaiite); thus Mt. Moio deposits have been divided into Lower and Upper Sequences characterized by similar depositional facies. Based on the classification of Etna flank eruptions available in the literature, Mt. Moio can be classed as an eccentric (sensu Rittmann) and Class B eruption. Historic flank eruptions (e.g. 1669, 1763, 2001, 2002–03) formed deposits that are petrochemically and stratigraphically similar to those of Mt. Moio. The general trend of the Mt. Moio eruptive fissure corresponds to that of extensional neotectonic lineaments in the Apenninic–Maghrebian Chain, indicating that the structure of the basement played a role in controlling the ascent of the volatile-rich magma during Ellittico volcano activity. Sun, 30 Sep 2012 22:00:00 GMT http://hdl.handle.net/2122/8248 2012-09-30T22:00:00Z http://hdl.handle.net/2122/8238 Title: A revision of the structure and stratigraphy of pre-Green Tuff ignimbrites at Pantelleria (Strait of Sicily) Authors: Rotolo, S. G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Scailet, S.; Institut des Sciences de la Terre d'Orléans (ISTO) – INSU-CNRS – Université d'Orléans; La Felice, S.; Univ. di PAlermo, Dip. Scienze della TErra e del MAre; Vita Scailet, G.; Institut des Sciences de la Terre d'Orléans (ISTO) – INSU-CNRS – Université d'Orléans Abstract: At Pantelleria, peralkaline silicic magmas were erupted across a range of eruptive typologies and magnitudes: pyroclastic flows, Plinian to strombolian pumice fallout and lava flows. In this paper we focus on the intermediate cycle of eruptive activity which is bracketed by ignimbrite units slightly older than the two caldera collapses which marked the volcanological activity of the island. This age interval (180 - 85 ka) was punctuated by six ignimbrite-forming eruptions (silicic and variably peralkaline) for a cumulative erupted magma volume of approximately 6 km3 dense rock equivalent. Based on new 40Ar/39Ar (Na,K)-feldspar ages and petrographic data, we propose an updated volcanostratigraphic scheme for these welded and rheomorphic ignimbrites that can be summarised as follows: (i) the age of the old (‘La Vecchia’) caldera collapse is now tightly constrained between 139-146 ka and the caldera-forming eruption can be traced to a lithic-rich welded tuff breccia that outcrops in two opposite sectors of the island (south-west and north-east); (ii) four ignimbrite units previously considered unrelated are now merged in two distinct eruptive paroxysmal events at 107 and 85 ka. In particular, the 85 ka eruptive event is comparable in magnitude to the younger (caldera forming) Green Tuff Plinian eruption; (iii) the recurrence patterns of the 107 and 85 ka eruptions, compared to the Green Tuff, allow us to qualitatively assess that the climax in production of low-temperature silicic and peralkaline melt was focused in the age interval 85-45 ka. Mon, 31 Dec 2012 23:00:00 GMT http://hdl.handle.net/2122/8238 2012-12-31T23:00:00Z http://hdl.handle.net/2122/8237 Title: Deformed Pleistocene marine terraces along the Ionian sea margin of southern Italy: Unveiling blind fault-related folds contribution to coastal uplift Authors: Santoro, Enrico; Dipartimento di Scienze della Terra, Università degli Studi di Napoli Federico II, Napoli; Ferranti, Luigi; Dipartimento di Scienze della Terra, Università degli Studi di Napoli Federico II, Napoli; Burrato, Pierfrancesco; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Mazzella, Maria Enrica; Dipartimento di Scienze della Terra, Università degli Studi di Napoli Federico II, Napoli; Monaco, Carmelo; Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Sezione di Scienze della Terra, Università di Catania Editors: Critelli, Salvatore; Muto, Francesco; Perri, Francesco; Petti, Fabio Massimo; Sonnino, Maurizio; Zuccari, Alessandro Abstract: Morphotectonic analysis and fault numeric modeling of uplifted marine terraces along the southern half of the Taranto Gulf , between the Sibari and San Nicola plains (Fig. 1), allow us to place quantitative constraints on Middle Pleistocene-Holocene deformation in the Southern Apennines. Mon, 17 Sep 2012 22:00:00 GMT http://hdl.handle.net/2122/8237 2012-09-17T22:00:00Z http://hdl.handle.net/2122/8095 Title: Late Holocene landscape change history related to the Alpine Fault determined from drowned forests in Lake Poerua, Westland, New Zealand Authors: Langridge, R. M.; GNS Science; Basili, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Basher, L.; Landcare Research NZ Ltd; Wells, A. P.; McLennan Rd, R D Hawea, Luggate, New Zealand Abstract: Lake Poerua is a small, shallow lake that abuts the scarp of the Alpine Fault on the West Coast of New Zealand’s South Island. Radiocarbon dates from drowned podocarp trees on the lake floor, a sediment core from a rangefront alluvial fan, and living tree ring ages have been used to deduce the late Holocene history of the lake. Remnant drowned stumps of kahikatea (Dacrycarpus dacrydioides) at 1.7–1.9m water depth yield a preferred time-ofdeath age at 1766–1807 AD, while a dryland podocarp and kahikatea stumps at 2.4–2.6m yield preferred time-of-death ages of ca. 1459–1626 AD. These age ranges are matched to, but offset from, the timings of Alpine Fault rupture events at ca. 1717 AD, and either ca. 1615 or 1430 AD. Alluvial fan detritus dated from a core into the toe of a rangefront alluvial fan, at an equivalent depth to the maximum depth of the modern lake (6.7 m), yields a calibrated age of AD 1223–1413. This age is similar to the timing of an earlier Alpine Fault rupture event at ca. 1230AD±50 yr. Kahikatea trees growing on rangefront fans give ages of up to 270 yr, which is consistent with alluvial fan aggradation following the 1717AD earthquake. The elevation levels of the lake and fan imply a causal and chronological link between lake-level rise and Alpine Fault rupture. The results of this study suggest that the growth of large, coalescing alluvial fans (Dry and Evans Creek fans) originating from landslides within the rangefront of the Alpine Fault and the rise in the level of Lake Poerua may occur within a decade or so of large Alpine Fault earthquakes that rupture adjacent to this area. These rises have in turn drowned lowland forests that fringed the lake. Radiocarbon chronologies built using OxCal show that a series of massive landscape changes beginning with fault rupture, followed by landsliding, fan sedimentation and lake expansion. However, drowned Kahikatea trees may be poor candidates for intimately dating these events, as they may be able to tolerate water for several decades after metre-scale lake level rises have occurred. Mon, 25 Jun 2012 22:00:00 GMT http://hdl.handle.net/2122/8095 2012-06-25T22:00:00Z http://hdl.handle.net/2122/7589 Title: In search of Tsunami deposits along the eastern coast of Sicily (Italy): state of the art Authors: Barbano, M. S.; Dipartimento di Scienze Geologiche, Università di Catania, Catania, Italy; De Martini, P. M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Pantosti, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Smedile, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Del Carlo, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Gerardi, F.; Dipartimento di Scienze Geologiche, Università di Catania, Catania, Italy; Guarnieri, P.; Dipartimento di Scienze Geologiche, Università di Catania, Catania, Italy; Pirrotta, C.; Dipartimento di Scienze Geologiche, Università di Catania, Catania, Italy Abstract: Eastern Sicily has been affected in historical times by large earthquakes followed by devastating tsunamis, such as the 1169, 1693 and 1908 events. In order to provide a long-term assessment for tsunami recurrence and related hazards, we developed a multi-disciplinary study, with a paleoseismo-logical approach, aimed to recognize and date historical and paleotsunami deposits. Starting from information on the effects of known tsunamis (hit localities, inundation areas, run-up heights) and with a geomorphological approach, we selected several sites—such as coastal lakes, marshes and lagoons—potentially suitable for preserving tsunami deposits. In these sites, 64 test gouge cores have been dug by hand and engine coring. In order to reconstruct paleoenvironments and to identify potential paleotsunami deposits, sedimentological and paleontological analyses were carried out. Magnetic and X-ray analyses were used to highlight susceptibility variations and peculiar small-scale sedimentary structures not detectable through the standard stratigraphic investigation. Moreover, radiocarbon dating and tephra identification provide age ranges of the tsunami deposits and constraints for sedimentation rates allowing the correlation with historical events. At Capo Peloro in northeastern Sicily, combining archaeological, historical, and C14 data, we associated two tsunami deposits with the earthquakes occurred in 1783 and 17 A.D. We also collected evidence for the occurrence of multiple inundations at sites in the eastern flank of Mt. Etna: three events in the past 580 yrs at the Anguillara site and four events in the past 4000 yrs at the Gurna site. In southeastern Sicily, in the Augusta bay, combining historical, tephrostratigraphical and C14 dating, we reconstructed a tsunami inundation history composed of six events in the past 4000 yrs; the two most recent ones are related to the 1693 and 1169 earthquakes. Fri, 31 Dec 2010 23:00:00 GMT http://hdl.handle.net/2122/7589 2010-12-31T23:00:00Z http://hdl.handle.net/2122/7586 Title: Tephrostratigraphy, chronology and climatic events of the Mediterranean basin during the Holocene: An overview Authors: Zanchetta, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Sulpizio, R.; University of Bari, Italy; Roberts, N.; University of Plymouth, UK; Cioni, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Eastwood, W. J.; University of Birmingham, UK; Siani, G.; CNRS - Université Paris-Sud XI, France; Caron, B.; University of Pisa, Italy and CNRS-Université Paris-Sud XI, France; Paterne, M.; Laboratoire des Sciences du Climat et de l'Environment, France; Santacroce, R.; University of Pisa, Italy Abstract: The identification and characterisation of high-frequency climatic changes during the Holocene requires natural archives with precise and accurate chronological control, which is usually difficult to achieve using only 14C chronologies. The presence of time-spaced tephra beds in Quaternary Mediterranean successions represents an additional, independent tool for dating and correlating different sedimentary archives. These tephra layers are potentially useful for resolving long-standing issues in paleoclimatology and can help towards correlating terrestrial and marine paleoclimate archives. Known major tephras of regional extent derive from central and southern Italy, the Hellenic Arc, and from Anatolia. A striking feature of major Holocene tephra deposition events in the Mediterranean is that they are clustered rather than randomly distributed in time. Several tephra layers occurred at the time of the S1 sapropel formation between c. 8.4 and 9.0 ka BP (Mercato, Gabellotto-Fiumebianco/E1, Cappadocia) and other important tephra layers (Avellino, Agnano Monte Spina, ‘Khabur’ and Santorini/Thera) occurred during the second and third millennia BC, marking an important and complex phase of environmental changes during the mid- to late-Holocene climatic transition. There is great potential in using cryptotephra to overlap geographically Italian volcanic ashes with those originating from the Aegean and Anatolia, in order to connect regional tephrochronologies between the central and eastern Mediterranean. Mon, 31 Jan 2011 23:00:00 GMT http://hdl.handle.net/2122/7586 2011-01-31T23:00:00Z