I'm a structural geologist mainly working on neotectonics and geothermal systems with associated vein structures, geofluids and active faulting. My research focuses on non-marine carbonates with special emphasys in Quaternary travertines. I worked in Italy, Turkey and North America. Since 2011 I teach science at Polo Liceale Spallanzani (Tivoli, Italy) where I created a geologically-environmentally focused high school project, with the partnership of Roma TRE University, INGV and EGU. Supervisors: Claudio Faccenna (Supervisor), Andrea Billi (Advisor), and Paola Tuccimei (Advisor)
Geological Society of America Bulletin, Nov 6, 2014
The main issue addressed in this work is the process leading to fluid subsurface entrapment and p... more The main issue addressed in this work is the process leading to fluid subsurface entrapment and pressure increase up to hydrofracturing and, possibly, to paroxysm in a hydrothermal setting, in order to envisage such processes and mitigate their effects in the volcanically active study area and elsewhere. A field and laboratory multidisciplinary approach is used in the fossil (late Pleistocene) portion of an active hydrothermal system (Colli Albani volcano, Rome, Italy). In this area, sulfate and sulfide mineralizations and strongly altered ignimbrites are exposed. The alteration acme occurs on top of a buried normal fault, where abundant degassing is still active, and fades away in 2–3 km. Based on pervasive versus discrete alteration styles, mineral assemblages, and further evidence, proximal and distal alteration domains are recognized. Both domains underwent steam-heated advanced argillic alteration with likely temperatures up to ~400 °C in the proximal domain and less than 150 °C in the distal domain. The process of hydrothermal alteration progressively and severely depleted many elements from the most permeable rock units, whereas the lowest-permeable unit (Tufo Lionato) underwent fracture and porosity healing accompanied by both mass and volume gain. In the proximal domain, the advanced argillic hydrothermal alteration eventually formed a substantial barrier to fluids. The hydrothermal fluids accumulated in and below this barrier, which was then suddenly hydrofractured when heat-driven hydraulic pressure overcame the effective stress, thus possibly leading to hydrothermal paroxysm. The decompression associated with hydrofracturing enhanced gas exsolution and mineral precipitation from the entrapped overpressured fluids. Mineral precipitation contributed, in turn, to fracture healing and to reinitiation of a new cycle of hydrothermal fluid entrapment. The key preconditions for the occurrence of the inferred processes are the contrasting compositions of K-alkaline host rocks and acidic alteration fluids, as also previously documented in other similar settings elsewhere.
Abstract Sinkholes and other karst structures in settled carbonate lands can be a significant sou... more Abstract Sinkholes and other karst structures in settled carbonate lands can be a significant source of hazard for humans and human works. Acque Albule, the study area of this work, is a Plio-Pleistocene basin near Rome, central Italy, superficially filled by a large and thick deposit of late Pleistocene thermogene travertine. Human activities blanket large portions of the flat territory covering most evidence from geological surface processes and potentially inducing scientists and public officials to underestimate some natural hazards including those connected with sinkholes. To contribute to the proper assessment of these hazards, a geomorphologic study of the basin was performed using digital elevation models (DEMs), recent aerial photographs, and field surveys. Historical material such as old aerial photographs and past geomorphologic studies both pre-dating the most part of quarrying and village building was also used together with memories of the elderly population. This preliminary study pointed out the presence of numerous potentially active sinkholes that are at present largely masked by either quarrying or overbuilding. Where this first study pointed out the apparent absence of sinkholes in areas characterized by high density of buildings, a detailed subsurface study was performed using properly-calibrated electrical resistivity tomography (ERT) and dynamic penetration measurements (DPSH), together with some borehole logs made available from the local municipality. This second study highlighted the presence of sinkholes and caves that are, this time, substantially hidden to the resolution of standard methods and materials such as aerial photographs, DEMs, and field surveys. Active sinkhole subsidence in the Acque Albule Basin may explain, at least in part, the frequent damages that affect numerous buildings in the area. The main conclusion from this study is that the mitigation of sinkhole hazard in highly populated areas has to pass through a thorough search of (hidden) sinkholes that can be masked by the Anthropocenic molding and blanketing of the territory. For these purposes, data from historical (pre-Anthropocene) documents as well as, where possible, subsurface investigations are fundamental.
GIS-based techniques are the best approach to the study of landslide susceptibility because they ... more GIS-based techniques are the best approach to the study of landslide susceptibility because they allow the management of several themes concerning instability factors. Besides, morphometric characteristics, playing an important role in landsliding processes, can be determined through the analysis of the digital terrain model. Here follows a list of the main phases of our analysis focusing on the mapping of earth flow susceptibility: - selection of the most useful instability factors (ie: lithology, slope, land use, hydrography, etc.); - multivariate statistic analysis of the ...
The depositional and erosional history of the Lapis Tiburtinus endogenic travertine located 30 km... more The depositional and erosional history of the Lapis Tiburtinus endogenic travertine located 30 km to the east of Rome, Central Italy, near the Colli Albani quiescent volcano, is interpreted through three-dimensional stratigraphy and uranium-series geochronology. Analyses of large exposures located in active quarries and of cores obtained from 114 industrial wells reveal that the travertine deposit is about 20 km2 wide and 60 m thick on average. The travertine thickness is over 85 m toward its western N-S-elongated side, where thermal springs and large sinkholes occur aligned over a seismically-active N-striking shallow fault. Results constrain the onset and conclusion of travertine deposition at about 115 and 30 ka, respectively. This deposit is characterized by a succession of depositional benches grown in an aggradational fashion and separated by five main erosional surfaces, which are associated with paleosols, conglomerates, and karstic features. This evidence shows that the tra...
This study is the first documentation of syn-diagenetic non-tectonic contractional deformations o... more This study is the first documentation of syn-diagenetic non-tectonic contractional deformations observed in two Pleistocene thermogene travertine deposits from the late Miocene-Pleistocene Tuscan extensional-hydrothermal province (Italy). The deposits consist of primary porous beds hosting secondary bed-parallel carbonate veins. The porous beds are generally flat-lying, particularly in the upper section of the deposits, whereas the veined beds frequently form undulated structures. These structures are up to a few meters in wavelength, are mostly confined within the lower-middle section of the deposits, and are here mostly interpreted as folds. Field observations, U-Th geochronology, and stable isotope analyses are used to characterize the origin of veins and folds. Radiometrically-determined age inversions, structure overprinting relationships, downward growth of vein crystals, deformation of primary sedimentary structures, and downward increasing frequency of veins and folds show that the undulated travertine beds can be mainly interpreted as the product of syn-diagenetic hydrothermal rejuvenation causing non-tectonic veining and folding. The non-tectonic hypothesis is also supported by the absence of contractional deformation in the travertine-hosting sediments. The folds were generated by complex mechanisms including bending and buckling caused by laterally-confined volume expansion during syn-diagenetic circulation of mineralizing fluids and related incremental veining. Modeling some folds with the Biot-Ramberg's buckling equation shows a vein-to-host travertine viscosity ratio between 1.5 and 4, confirming the syn-diagenetic origin of folds. Veining and folding changed some original properties of travertines including rheology, fabric, porosity, and chronological sequence. The identification of these structures and related changes of rock properties (e.g., age rejuvenation) is relevant for the proper interpretation of thermogene travertines as recorders of many geological processes including paleoclimate oscillations, earthquake occurrences, hydrothermal circulations, and uplift or incision rates. Synthesizing, the studied thermogene travertines appear more like sedimentary-hydrothermal-hybrid zoned deposits rather than pure sedimentary systems uniquely responding to the superposition law.
ABSTRACT The high school Liceo Scientifico "Lazzaro Spallanzani" at Tivoli (Rom... more ABSTRACT The high school Liceo Scientifico "Lazzaro Spallanzani" at Tivoli (Rome) has been fully involved in the study of geological and geophysical features of the town of Tivoli and the surrounding area in the last twelve years. Objective of this activity is to promote the knowledge of the local territory from the geological point of view. Main activities: • School year 2001-2002: Setting up inside the school building of a Geological Museum focusing on "Geological Evolution of Latium, Central Italy" (in collaboration with colleagues M. Mancini, and A. Pierangeli). • March, 15, 2001: Conference of Environmental Geology. Lecturer: Prof. Raniero Massoli Novelli, L'Aquila University and Società Italiana di Geologia Ambientale. • School years 2001-2002 and 2002-2003: Earth Sciences course for students "Brittle deformation and tectonic stress in Tivoli area". • November, 2003: Conference of Geology, GIS and Remote Sensing. Lecturers: Prof. Maurizio Parotto and Dr Alessandro Cecili (Roma Tre University, Rome), and Dr Stefano Pignotti (Istituto Nazionale per la Ricerca sulla Montagna, Rome). • November, 2003, 2004 and 2005: GIS DAY, organized in collaboration with ESRI Italia. • School year 2006-2007: Earth Sciences course for students "Acque Albule basin and the Travertine of Tivoli, Latium, Central Italy" (focus on travertine formation). • School year 2010-2011: Earth Sciences course for students "Acque Albule basin and the Travertine of Tivoli. Geology, Hydrogeology and Microbiology of the basin, Latium, Central Italy" (focus on thermal springs and spa). In the period 2009-2010 a seismic station with three channels, currently working, was designed and built in our school by the science teachers Felice De Angelis and Tomaso Favale. Our seismic station (code name LTTV) is part of Italian Experimental Seismic Network (IESN) with identification code IZ (international database IRIS-ISC). The three drums are online in real time on websites http://www.spallanzanitivoli.it/stazionesismica/ and http://www.iesn.it. Furthermore, until the end of January 2012 a semi-professional seismograph will work with educational aims. These activities allowed the school to receive the first prize in the 2002 contest held by the italian scientific magazine Quark "Giornalisti Scientifici si diventa" (How to become a scientific journalist), with an article co-authored with three students titled "Una TAC per il Vesuvio" (CT scan for Vesuvius). The article was published in the n. 15 issue of Quark magazine, May 2002. The school also runs a Science and Chemistry Laboratory, equipped with: (a) 1 mobile seismograph with six geophones for seismic invesitgation (rifraction, reflection, REMI, MASW, and HVSR), (b) 1 polarized microscope for mineralogy and petrography, (c) various geochemical instruments for water analysis (pH, Eh, T, etc.), (d) 1 Geiger counter to detect β- particles and γ rays, and (e) 2 calcimeters to calculate the percentage of calcium carbonate in calcareous rocks. Two meteorological stations managed by Physics Laboratory, both online with data processing in real time, are hosted inside school building. Finally, we are planning a new scientific project for the next school year, involving students and science teachers, probably named "Gas hazard in volcanic and geothermal areas of the eastern Rome province".
Geological Society of America Bulletin, Nov 6, 2014
The main issue addressed in this work is the process leading to fluid subsurface entrapment and p... more The main issue addressed in this work is the process leading to fluid subsurface entrapment and pressure increase up to hydrofracturing and, possibly, to paroxysm in a hydrothermal setting, in order to envisage such processes and mitigate their effects in the volcanically active study area and elsewhere. A field and laboratory multidisciplinary approach is used in the fossil (late Pleistocene) portion of an active hydrothermal system (Colli Albani volcano, Rome, Italy). In this area, sulfate and sulfide mineralizations and strongly altered ignimbrites are exposed. The alteration acme occurs on top of a buried normal fault, where abundant degassing is still active, and fades away in 2–3 km. Based on pervasive versus discrete alteration styles, mineral assemblages, and further evidence, proximal and distal alteration domains are recognized. Both domains underwent steam-heated advanced argillic alteration with likely temperatures up to ~400 °C in the proximal domain and less than 150 °C in the distal domain. The process of hydrothermal alteration progressively and severely depleted many elements from the most permeable rock units, whereas the lowest-permeable unit (Tufo Lionato) underwent fracture and porosity healing accompanied by both mass and volume gain. In the proximal domain, the advanced argillic hydrothermal alteration eventually formed a substantial barrier to fluids. The hydrothermal fluids accumulated in and below this barrier, which was then suddenly hydrofractured when heat-driven hydraulic pressure overcame the effective stress, thus possibly leading to hydrothermal paroxysm. The decompression associated with hydrofracturing enhanced gas exsolution and mineral precipitation from the entrapped overpressured fluids. Mineral precipitation contributed, in turn, to fracture healing and to reinitiation of a new cycle of hydrothermal fluid entrapment. The key preconditions for the occurrence of the inferred processes are the contrasting compositions of K-alkaline host rocks and acidic alteration fluids, as also previously documented in other similar settings elsewhere.
Abstract Sinkholes and other karst structures in settled carbonate lands can be a significant sou... more Abstract Sinkholes and other karst structures in settled carbonate lands can be a significant source of hazard for humans and human works. Acque Albule, the study area of this work, is a Plio-Pleistocene basin near Rome, central Italy, superficially filled by a large and thick deposit of late Pleistocene thermogene travertine. Human activities blanket large portions of the flat territory covering most evidence from geological surface processes and potentially inducing scientists and public officials to underestimate some natural hazards including those connected with sinkholes. To contribute to the proper assessment of these hazards, a geomorphologic study of the basin was performed using digital elevation models (DEMs), recent aerial photographs, and field surveys. Historical material such as old aerial photographs and past geomorphologic studies both pre-dating the most part of quarrying and village building was also used together with memories of the elderly population. This preliminary study pointed out the presence of numerous potentially active sinkholes that are at present largely masked by either quarrying or overbuilding. Where this first study pointed out the apparent absence of sinkholes in areas characterized by high density of buildings, a detailed subsurface study was performed using properly-calibrated electrical resistivity tomography (ERT) and dynamic penetration measurements (DPSH), together with some borehole logs made available from the local municipality. This second study highlighted the presence of sinkholes and caves that are, this time, substantially hidden to the resolution of standard methods and materials such as aerial photographs, DEMs, and field surveys. Active sinkhole subsidence in the Acque Albule Basin may explain, at least in part, the frequent damages that affect numerous buildings in the area. The main conclusion from this study is that the mitigation of sinkhole hazard in highly populated areas has to pass through a thorough search of (hidden) sinkholes that can be masked by the Anthropocenic molding and blanketing of the territory. For these purposes, data from historical (pre-Anthropocene) documents as well as, where possible, subsurface investigations are fundamental.
GIS-based techniques are the best approach to the study of landslide susceptibility because they ... more GIS-based techniques are the best approach to the study of landslide susceptibility because they allow the management of several themes concerning instability factors. Besides, morphometric characteristics, playing an important role in landsliding processes, can be determined through the analysis of the digital terrain model. Here follows a list of the main phases of our analysis focusing on the mapping of earth flow susceptibility: - selection of the most useful instability factors (ie: lithology, slope, land use, hydrography, etc.); - multivariate statistic analysis of the ...
The depositional and erosional history of the Lapis Tiburtinus endogenic travertine located 30 km... more The depositional and erosional history of the Lapis Tiburtinus endogenic travertine located 30 km to the east of Rome, Central Italy, near the Colli Albani quiescent volcano, is interpreted through three-dimensional stratigraphy and uranium-series geochronology. Analyses of large exposures located in active quarries and of cores obtained from 114 industrial wells reveal that the travertine deposit is about 20 km2 wide and 60 m thick on average. The travertine thickness is over 85 m toward its western N-S-elongated side, where thermal springs and large sinkholes occur aligned over a seismically-active N-striking shallow fault. Results constrain the onset and conclusion of travertine deposition at about 115 and 30 ka, respectively. This deposit is characterized by a succession of depositional benches grown in an aggradational fashion and separated by five main erosional surfaces, which are associated with paleosols, conglomerates, and karstic features. This evidence shows that the tra...
This study is the first documentation of syn-diagenetic non-tectonic contractional deformations o... more This study is the first documentation of syn-diagenetic non-tectonic contractional deformations observed in two Pleistocene thermogene travertine deposits from the late Miocene-Pleistocene Tuscan extensional-hydrothermal province (Italy). The deposits consist of primary porous beds hosting secondary bed-parallel carbonate veins. The porous beds are generally flat-lying, particularly in the upper section of the deposits, whereas the veined beds frequently form undulated structures. These structures are up to a few meters in wavelength, are mostly confined within the lower-middle section of the deposits, and are here mostly interpreted as folds. Field observations, U-Th geochronology, and stable isotope analyses are used to characterize the origin of veins and folds. Radiometrically-determined age inversions, structure overprinting relationships, downward growth of vein crystals, deformation of primary sedimentary structures, and downward increasing frequency of veins and folds show that the undulated travertine beds can be mainly interpreted as the product of syn-diagenetic hydrothermal rejuvenation causing non-tectonic veining and folding. The non-tectonic hypothesis is also supported by the absence of contractional deformation in the travertine-hosting sediments. The folds were generated by complex mechanisms including bending and buckling caused by laterally-confined volume expansion during syn-diagenetic circulation of mineralizing fluids and related incremental veining. Modeling some folds with the Biot-Ramberg's buckling equation shows a vein-to-host travertine viscosity ratio between 1.5 and 4, confirming the syn-diagenetic origin of folds. Veining and folding changed some original properties of travertines including rheology, fabric, porosity, and chronological sequence. The identification of these structures and related changes of rock properties (e.g., age rejuvenation) is relevant for the proper interpretation of thermogene travertines as recorders of many geological processes including paleoclimate oscillations, earthquake occurrences, hydrothermal circulations, and uplift or incision rates. Synthesizing, the studied thermogene travertines appear more like sedimentary-hydrothermal-hybrid zoned deposits rather than pure sedimentary systems uniquely responding to the superposition law.
ABSTRACT The high school Liceo Scientifico "Lazzaro Spallanzani" at Tivoli (Rom... more ABSTRACT The high school Liceo Scientifico "Lazzaro Spallanzani" at Tivoli (Rome) has been fully involved in the study of geological and geophysical features of the town of Tivoli and the surrounding area in the last twelve years. Objective of this activity is to promote the knowledge of the local territory from the geological point of view. Main activities: • School year 2001-2002: Setting up inside the school building of a Geological Museum focusing on "Geological Evolution of Latium, Central Italy" (in collaboration with colleagues M. Mancini, and A. Pierangeli). • March, 15, 2001: Conference of Environmental Geology. Lecturer: Prof. Raniero Massoli Novelli, L'Aquila University and Società Italiana di Geologia Ambientale. • School years 2001-2002 and 2002-2003: Earth Sciences course for students "Brittle deformation and tectonic stress in Tivoli area". • November, 2003: Conference of Geology, GIS and Remote Sensing. Lecturers: Prof. Maurizio Parotto and Dr Alessandro Cecili (Roma Tre University, Rome), and Dr Stefano Pignotti (Istituto Nazionale per la Ricerca sulla Montagna, Rome). • November, 2003, 2004 and 2005: GIS DAY, organized in collaboration with ESRI Italia. • School year 2006-2007: Earth Sciences course for students "Acque Albule basin and the Travertine of Tivoli, Latium, Central Italy" (focus on travertine formation). • School year 2010-2011: Earth Sciences course for students "Acque Albule basin and the Travertine of Tivoli. Geology, Hydrogeology and Microbiology of the basin, Latium, Central Italy" (focus on thermal springs and spa). In the period 2009-2010 a seismic station with three channels, currently working, was designed and built in our school by the science teachers Felice De Angelis and Tomaso Favale. Our seismic station (code name LTTV) is part of Italian Experimental Seismic Network (IESN) with identification code IZ (international database IRIS-ISC). The three drums are online in real time on websites http://www.spallanzanitivoli.it/stazionesismica/ and http://www.iesn.it. Furthermore, until the end of January 2012 a semi-professional seismograph will work with educational aims. These activities allowed the school to receive the first prize in the 2002 contest held by the italian scientific magazine Quark "Giornalisti Scientifici si diventa" (How to become a scientific journalist), with an article co-authored with three students titled "Una TAC per il Vesuvio" (CT scan for Vesuvius). The article was published in the n. 15 issue of Quark magazine, May 2002. The school also runs a Science and Chemistry Laboratory, equipped with: (a) 1 mobile seismograph with six geophones for seismic invesitgation (rifraction, reflection, REMI, MASW, and HVSR), (b) 1 polarized microscope for mineralogy and petrography, (c) various geochemical instruments for water analysis (pH, Eh, T, etc.), (d) 1 Geiger counter to detect β- particles and γ rays, and (e) 2 calcimeters to calculate the percentage of calcium carbonate in calcareous rocks. Two meteorological stations managed by Physics Laboratory, both online with data processing in real time, are hosted inside school building. Finally, we are planning a new scientific project for the next school year, involving students and science teachers, probably named "Gas hazard in volcanic and geothermal areas of the eastern Rome province".
The long-term evolution of endogenic travertines may provide important insights into paleoclimate... more The long-term evolution of endogenic travertines may provide important insights into paleoclimate, tectonic activity, geothermal resources, and, more in general, subsurface fluid circulation. Fissure ridge travertines grown from geothermal springs of Denizli basin, southwestern Turkey, are investigated through stratigraphic, structural, geochemical, and geochronological methods, with the aim of understanding the growth of these elongate mound- shaped structures. Two main types of travertine deposits are recognized: (1) bedded travertines, which form the bulk of fissure ridges, and (2) banded travertines, which grew as veins within the bedded travertine chiefly along its central feeding conduit. Stratigraphic and structural observations shed light on the bedded-banded travertine relationships, where the banded one grew through successive accretion phases, intruding the bedded travertine across its strata or along them forming sill-like structures. The bedded and banded travertines alternated their growth as demonstrated by complicated geometrical relationships and by the upward suture, in places, of banded travertine by bedded travertine that was, in turn, injected by younger banded travertine. The bedded travertine is often tilted away from the central axis of the fissure ridge, thus leaving more room for the central banded travertine to form. Travertine bed unconformities are, in places, the effect of bed tilting. U-series data confirm the bedded-banded travertine temporal relationships and show that the growth of the studied fissure ridges lasted several tens of thousands of years during Quaternary time. C and O stable isotope data together with previously published rare Earth element analyses indicate a shallow feeding circuit for the studied structures, where banded and bedded travertines are characterized by similar isotope signature and, therefore, by the same feeding fluid, but slightly different precipitation conditions. A crack-and-seal mechanism of fissure ridge growth is proposed, where the progressive tilting of bedded travertine limbs over a soft substratum creates the necessary space for the central veins to grow. This implies that active tectonics may have played a subordinate role in the growth of the studied fissure ridges. The role of paleoclimate and fluid pressure remains to be ascertained.
Geological Society of America Abstracts with Programs, Vol. 39, No. 6, p. 240, Oct 2007
The depositional and erosional history of the upper Pleistocene Lapis Tiburtinus travertine locat... more The depositional and erosional history of the upper Pleistocene Lapis Tiburtinus travertine located 25 km in the east of Rome, Italy, near the Colli Albani quiescent volcano is analyzed by three-dimensional stratigraphy and uranium-series geochronology. Analyses of large exposures within active quarries and of 114 drilled cores from industrial databases (kindly provided by Centro Valorizzazione Travertino Romano, www.centrotravertinoromano.it) reveal that the travertine body is approximately 20 km2 wide and averagely 60 m thick. The travertine thickens to about 90 m toward its western, N-S-elongated side, where thermal springs occur aligned over a seismically-active, N-striking, shallow fault. The travertine age was calculated using the U/Th isochron method. Results constrain the onset and conclusion of travertine deposition at about 120 and 30 ka, respectively. The travertine succession is interrupted by five main erosional surfaces associated with paleosoils, conglomerates, and karstic features. Ages of erosional events match cold and dry climate periods occurred during late Pleistocene time. We interpret the aggradational growth of the travertine body as connected with warm and humid climate periods. The increase of the water table height in the travertine basin and in the surrounding carbonate massifs increased fluid pressures and discharge, and forced fault slip and related dilational deformations, thus keeping open the fluid pathways along the fault underlying the travertine. A hypothetical correlation is hence established between climate cycles and fault-valve activity. Results may be tested in sites where recent travertines and seismically-active faults occur (e.g. California, Greece, Nevada, and Turkey) to assess fault slip recurrence intervals and improve seismic hazard estimates.
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