Article

Low-magnitude earthquakes in Rome: Structural interpretation and implications for the local stress field

July 1999
Geophysical Journal International 138(1):231 - 243

July 1999
138(1):231 - 243

DOI:10.1046/j.1365-246x.1999.00866.x

Authors:

National Institute of Geophysics and Volcanology

On 1995 June 12, a ML = 3.6 earthquake occurred in the Cecchignola area of southern Rome. A detailed structural investigation of this area and an analysis of macroseismic and instrumental data indicate a seismogenic area for the local low-magnitude seismicity that affects the city of Rome. A peripheral volcanic field in Cecchignola shows that the local seismicity could be related to the same volcanotectonics that affects the Colli Albani (Alban Hills) region. Fracture-field emission is proposed for the emplacement of about 2.5 km3 of lava, which developed a small plateau that was subsequently intruded by the feeder dyke of a large ignimbrite. The geometry of this dyke as well as the faults disrupting the lava field indicates NE–SW extension. Younger tectonic features show a NW-striking σ3 in the studied area, suggesting that dextral N–S strike-slip displacement generated structures that are not compatible with the local present-day stress field, characterized by a NE-striking σ3. An analysis of focal solutions and the spatial distribution of the 1995 June 12 microearthquake sequence suggests an E–W seismogenic structure whose trend is atypical of the structural setting of the area. The present study identifies surface faulting with the same trend as the focal mechanisms in the epicentral area and suggests that these faults represent an inactive surface expression of the deeper structures. It is also suggested that these structures originated during a different tectonic regime and are presently reactivated at depth by the NE–SW extension. The general NE orientation of the T axes from focal mechanisms for the Colli Albani earthquakes and for the 1995 June 12 Cecchignola event strongly supports a regional interpretation for the present-day stress field previously observed only in the Colli Albani area. It is likely that a combination of different tectonic styles during the last 600 kyr is necessary to explain the structural features of the Cecchignola area and of the Central Tyrrhenian Sea margin of Italy in general.

A morphotectonic approach to the study of earthquakes in Rome

Article

Full-text available

Jul 2022
NAT HAZARD EARTH SYS

Rome has the world's longest historical record of felt earthquakes, with more than 100 events during the last 2600 years. However, no destructive earthquake has been reported in the sources, and all of the greatest damage suffered in the past has been attributed to far-field events. While this fact suggests that a moderate seismotectonic regime characterizes the Roman area, no study has provided a comprehensive explanation for the lack of strong earthquakes in the region. Through the analysis of the focal mechanism and the morphostructural setting of the epicentral area of a “typical” moderate earthquake (Ml= 3.3) that recently occurred in the northern urban area of Rome, we demonstrate that this event reactivated a buried segment of an ancient fault generated under both a different and a stronger tectonic regime than that which is presently active. We also show that the evident structural control over the drainage network in this area reflects an extreme degree of fragmentation of a set of buried faults generated under two competing stress fields throughout the Pleistocene. Small faults and a present-day weaker tectonic regime with respect to that acting during the Pleistocene might explain the lack of strong seismicity in the long historical record, suggesting that a large earthquake is not likely to occur.

Historical faulting as the possible cause of earthquake damages in the ancient Roman port city of Ostia

Article

Full-text available

Aug 2020
J SEISMOL

This paper presents an original multidisciplinary (geological-structural-geomorphological and seismological) study aimed at investigating the origin of diffused seismic damages affecting several ancient buildings in the Roman port city of Ostia. We also evaluate the possibility to relate these damages to a previously hypothesized ENE-WSW trending fault, bordering the morphological height upon which the Ostia town was founded. Aimed at this scope, we performed seismic noise measures (by using 14 seismic stations) that show no significantly different response and lack of significant ground motion differential amplifications. The coexistence of (i) no local geological heterogeneities and (ii) low amplification of spectral ratios in the recorded seismic signals seems to exclude that the observed seismic damage may be the consequence of significant site effects. When also the large distance from the strongest Apennine’s seismogenic source areas is considered, the possibility that the observed damage may be the consequence of local events should be considered. We discuss the potentiality of the ENE-WSW trending fault as the source of the observed seismic damages, highlighting the supporting evidence as well as the uncertainties of such interpretation.

Coeval Uplift and Subsidence Reveal Magma Recharging Near Rome (Italy)

Article

Full-text available

Apr 2018
GEOCHEM GEOPHY GEOSY

Uplift and subsidence alternate throughout the life cycle of a volcano mirroring magma accumulation, migration and/or gas pressurization, and magma cooling or depressurization, respectively. The unusual occurrence of coeval inflation and deflation is difficult to reconcile with the recharging or cooling of a single magma chamber, or hydrological processes. Here, we show a persistent flank uplift and central subsidence at Colli Albani volcano near Rome (Italy), by mapping about twenty years of deformation by InSAR data. The magmatic helium signature increases in correspondence with N-S faults along the western slope of Colli Albani, which are therefore interpreted as deep-seated structures directly or indirectly connected with an underlying magma reservoir. Deformation modelling shows that these faults are pathways for fresh magma intrusion, whereas a residual magma is cooling below the deflating caldera. Therefore, magma recharge at depth is controlled by major faults along which the vents of the most recent activity (< 200 ka ago) concentrate in the western side of the volcano and not by the caldera structures. We demonstrate that the Colli Albani magmatic system is slowly rejuvenating, posing a volcanic threat for Rome.

Seismicity, seismogenic structures, and crustal stress fields in the greater Rome area (central Italy)

Article

Full-text available

Dec 2010

Instrumental seismicity of the greater Rome area is analyzed using the most recent seismological database. The aim of this study is to identify potential seismogenic structures responsible for the moderate seismicity that characterizes this sector, where no surface faulting is expected on the basis of the absence of strong local earthquakes, as evidenced by the 2000-year-long historical record. Nevertheless, in light of the great value and the high vulnerability of the architectural and monumental patrimony of Rome, even the occurrence of moderate events imposes a careful assessment of the hazard, linked to the presence of active faults that are undetectable by means of classic geological field investigation. Seismic data here analyzed belong to the period 1997-2008 and show local magnitude (ML) ranging from 1.5 to 4.7. To better constrain the hypocentral depths, we computed the Vp/Vs ratio using a modified Wadati method and the minimum 1-D velocity model that approximates the seismic structure of the study area. Moreover, we applied a double-difference hypocentral determination technique to improve earthquake locations. Most of the located seismicity appears to be concentrated within seven main clusters. Spatial distribution of the seismicity allowed us to identify several seismogenic structures, corresponding to previously undetected or only supposed active faults. The stress tensor obtained by inverting the focal mechanisms computed in this study is in agreement with the NE-SW extensional tectonic stress active in the inner chain of the Apennines, although there is evidence of some local stress field heterogeneities.

CO2 DRIVEN LARGE MAFIC EXPLOSIVE ERUPTIONS: A CASE STUDY FROM THE COLLI ALBANI VOLCANIC DISTRICT (ITALY)

Article

Full-text available

Nov 2013

Magma degassing is a critical process that play a major role in volcanic eruption style. Despite what generally thought not all volatiles emitted from volcanoes originate from a magmatic source, i.e. they exsolve from their host magma during ascent to the surface. Volcanoes rooted on thick sedimentary crust, indeed, have the potential to re-mobilise crustal volatiles. In particular, volcanoes emplaced in carbonate crust may re-mobilise a large amount of CO2 that significantly contributes towards the volcanic volatile budget and can play a critical role in enhancing the explosivity of the eruptions. Generally, the intensity and magnitude of explosive volcanic activity increase parallel to SiO2 content: i.e., relatively low-viscosity mafic magmas feed effusive or mildly explosive eruptions, whereas high-viscosity silicic magmas feed large explosive eruptions such as plinian and pyroclastic-flow forming ones. Pyroclastic-flow eruptions from the Colli Albani ultra-potassic volcanic district (Italy), one of the best examples of magmatic plumbing system emplaced within a thick carbonate sequence, however, represent a striking exception on a global scale. The juvenile fraction in pyroclastic flow deposits, which attain individual volumes in the order of tens of km3, is K-foiditic in composition, with SiO2 contents as low as 42 wt%, i.e. even much lower than those typical of basalts. We discuss the driving mechanisms for large mafic explosive eruptions based on the reconstruction of the pre-eruptive scenario and event dynamics of the most powerful Colli Albani eruption: the ~456 ka Pozzolane Rosse (PR) eruption. The PR eruptive succession begins with the effusion of a wide lava plateau from a peripheral vent, continues with a subplinian to moderate plinian eruption and ends with a single massive, poorly sorted pyroclastic flow body. We suggest that the addition of CO2 to the magma, due to carbonate assimilation from country rocks, is the major factor controlling explosivity. High CO2 activity in the volatile component, coupled with magma depressurisation, produced extensive leucite crystallisation, resulting into a dramatic increase of magma viscosity and volatile pressurisation and in turn into changing eruptive dynamics from early effusive to highly explosive at the PR eruption climax. The PR event may thus be regarded as the CO2-dominated end-member of a wide spectrum of volatile conditions controlling magma chamber processes, as well as eruptive and emplacement dynamics. The present case study provides evidence that the addition of free CO2 from entrained country rocks may drive mafic H2O-undersaturated magmas toward anomalously high-intensity explosive behaviour, as typical of silicic, H2O-dominated magmas.

CO2-driven large mafic explosive eruptions: The Pozzolane Rosse case study from the Colli Albani Volcanic District (Italy)

Article

Full-text available

Apr 2010

Generally, the intensity and magnitude of explosive volcanic activity increase in parallel with SiO2 content. Pyroclastic-flow-forming eruptions in the Colli Albani ultrapotassic volcanic district (Italy) represent the most striking exception on a global scale, with volumes on the order of tens of cubic kilometres and K-foiditic compositions (SiO2 even <42wt.%). Here, we reconstruct the pre-eruptive scenario and event dynamics of the ~456ka Pozzolane Rosse (PR) eruption, the largest mafic explosive event of the Colli Albani district. In particular, we focus on the driving mechanisms for the unusually explosive eruption of a low-viscosity, mafic magma. Geologic, petrographic and geochemical data with mass balance calculations, supported by experimental data for Colli Albani magma compositions, provide evidence for significant ingestion of carbonate wall rocks by the Pozzolane Rosse K-foiditic magma. Moreover, the scattered occurrence of cored bombs in Pozzolane Rosse pyroclastic-flow deposits records carbonate entrainment even at the eruptive time scale, as also tested quantitatively by thermal modelling of magma–carbonate interaction and carbonate assimilation experiments. We suggest that the addition of free CO2 from decarbonation of country rocks was the major factor controlling magma explosivity. High CO2 activity in the volatile component, coupled with magma depressurisation, produced extensive leucite crystallisation at short time scales, resulting in a dramatic increase in magma viscosity and volatile pressurisation, which was manifested a change of eruptive dynamics from early effusion to the Pozzolane Rosse's highly explosive eruption climax. KeywordsMafic explosive eruptions–Eruption magnitude–Pyroclastic flow–Colli Albani–Potassic volcanism–Carbonate assimilation–CO2

Assessing the volcanic hazard for Rome: 40Ar/39Ar and In-SAR constraints on the most recent eruptive activity and present-day uplift at Colli Albani Volcanic District

Article

Full-text available

Jun 2016

We present new ⁴⁰Ar/³⁹Ar data which allow us to refine the recurrence time for the most recent eruptive activity occurred at Colli Albani Volcanic District (CAVD) and constrain its geographic area. Time elapsed since the last eruption (36 kyr) overruns the recurrence time (31 kyr) in the last 100 kyr. New interferometric synthetic aperture radar data, covering the years 1993–2010, reveal ongoing inflation with maximum uplift rates (>2 mm/yr) in the area hosting the most recent (<200 ka) vents, suggesting that the observed uplift might be caused by magma injection within the youngest plumbing system. Finally, we frame the present deformation within the structural pattern of the area of Rome, characterized by 50 m of regional uplift since 200 ka and by geologic evidence for a recent (<2000 years) switch of the local stress-field, highlighting that the precursors of a new phase of volcanic activity are likely occurring at the CAVD.

Independent 40Ar/39Ar and 14C age constraints on the last five glacial terminations from the aggradational successions of the Tiber River, Rome (Italy)

Article

Sep 2016
EARTH PLANET SC LETT

We use 13 new 40Ar/39Ar and 4 new 14C datings of volcanic deposits and organic material found within near-coastal aggradational successions deposited by the Tiber River near Rome, Italy, to integrate a larger dataset previously achieved in order to offer independent age constraints to the sea-level fluctuations associated with Late Quaternary glacial cycles during the last 450 ka. Results are compared with the chronologically independently constrained Red Sea relative sea-level curve, and with the astronomically tuned deep-sea benthic δ18O record. We find good agreements for the timings of change, and in several cases for both the amplitudes and timings of change during glacial terminations T-1, T-2, T-3, and T-5. There is one striking exception, namely for glacial termination T-4 that led into interglacial Marine Isotope Stage (MIS) 9. T-4 in our results is dated a full 18 ka earlier than in the Red Sea and deep-sea benthic δ18O records (which are in good agreement with each other in spite of their independent chronological constraints). The observed discrepancy is beyond the scale of the combined age uncertainties. One possible explanation is that the documented aggradation represents an early phase, triggered by a smaller event in the sea-level record, but the thickness of the aggradational sediment sequence then suggests that the amplitude of this earlier sea-level rise is underestimated in the Red Sea and benthic δ18O records. Also, this would imply that the aggradational succession of the main T-4 deglaciation has not yet been located in the study region, which is hard to reconcile with our extensive fieldwork and borehole coverage, unless unlikely non-deposition or complete erosion. Resolving this discrepancy will improve understanding of the timing of deglaciations relative to the orbitally modulated insolation forcing of climate and will require further focused research, both into the nature and chronology of the Tiber sequences of this period, and into the chronologies of the Red Sea and deep-sea benthic δ18O records.

The subsurface geology of Rome: Sedimentary processes, sea-level changes and astronomical forcing

Article

Full-text available

Sep 2014
EARTH-SCI REV

In this paper we present a reconstruction of the stratigraphic setting of the continental sedimentary sequences that were deposited by the Paleo-Tiber River within the greater area of Rome between 0.9 and 0.6 Ma, carried out through analyses of a large number of borehole data. Through palinspastic restoration of several cross sections we depict the original geometry of the sedimentary record that has been dislocated by intense tectonic activity linked to volcanism, and we reconstruct the geologic and paleogeographic evolution of this area. Moreover, we provide a complete review of the chronostratigraphic and magnetostratigraphic data reported in previous work, and we extend paleomagnetic analyses to three new clay sections. These geochronological constraints allow us to compare aggradation of the Paleo-Tiber sedimentary successions with the d18O record, evidencing a strict link between sedimentation and sea-level changes in the Rome area. By doing so, we provide a direct test on the timing of the sea-level rise for MIS 19 through MIS 15: a record of data for which no equivalent exists in the literature.

Looking into a volcanic area: An overview on the 350 m scientific drilling at Colli Albani (Rome, Italy)

Article

Apr 2008
J VOLCANOL GEOTH RES

A 350 m deep borehole was drilled in the Colli Albani volcanic district (Central Italy) in order to: understand the shallow crust structure beneath the volcanic complex; characterize the rock physical properties especially through in-situ measurements and, afterward, laboratory experiments; assess the local present-day stress field; install a broad-band seismometer at depth. The borehole is located adjacent to the western rim of the Tuscolano–Artemisio caldera, where several phenomena of unrest recently occurred. In 1989–90 a seismic swarm affected this area and a related uplift was recognized. In addition, high gas concentrations (mainly CO2 and H2S), in aquifers and soils, caused illnesses and casualties among inhabitants and animals in the past.

Natural Gas Hazard (CO2, 222Rn) within a Quiescent Volcanic Region and Its Relations with Tectonics: The Case of the Ciampino-Marino Area, Alban Hills Volcano, Italy

Article

Full-text available

Nov 2002

Groundwater surveys were performed by detailed(around 300 sites) grid-analysis of water temperature, pH, redox potential, electrical conductivity, 222Rn, alkalinity and by calculating the pCO2, throughout the Ciampino and Marino towns in the Alban Hills quiescent volcano (Central Italy). Following several episodes of dangerous CO2 exhalation from soils during the last 20 years and earlier ashistorically recorded, the work aimed at assessing the Natural Gas Hazard (NGH) including the indoor-Rn hazard. The NGH was defined as the probability of an area to become a site of poisonous peri-volcanic gas exhalations from soils to the lower atmosphere (comprising buildings). CO2 was found to be a ``carrier'' for the other poisonous minor and in trace components (HsS, CH4, 222Rn, etc.). This assessment was performed by extrapolating in the aquifer CO2 and 222Rn conditions, and discriminating sectors where future CO2 flux in soils as well as indoor-Rn measurements have to be noted. A preliminary indoor-Rn survey was performed at about 200 sites. The highest values were found in the highest pCO2 and high 222Rn values in groundwater. This indicates convection and enhanced permeability in certain sectors of the main aquifer, i.e., along the bordering faults and inside the gas-trap of the Ciampino Horst., where ``continuous gas-phase micro-macro seepage mechanism'' is invoked to explain the high peri-volcanic gases flux.

Monti Sabatini and Colli Albani: the dormant twin volcanoes at the gates of Rome

Article

Full-text available

May 2020

This multi-disciplinary work provides an updated assessment of possible future eruptive scenarios for the city of Rome. Seven new ⁴⁰Ar/³⁹Ar ages from selected products of the Monti Sabatini and Vulsini volcanic districts, along with a compilation of all the literature ages on the Colli Albani and Vico products, are used to reconstruct and compare the eruptive histories of the Monti Sabatini and Colli Albani over the last 900 ka, in order to define their present state of activity. Petrographic analyses of the dated units characterize the crystal cargo, and Advanced-InSAR analysis highlights active deformation in the MS. We also review the historical and instrumental seismicity affecting this region. Based on the chronology of the most recent phases and the time elapsed between the last eruptions, we conclude that the waning/extinguishment of eruptive activity shifted progressively from NW to SE, from northern Latium toward the Neapolitan area, crossing the city of Rome. Although Monti Sabatini is unaffected by the unrest indicators presently occurring at the Colli Albani, it should be regarded as a dormant volcanic district, as the time of 70 kyr elapsed since the last eruption is of the same order of the longest dormancies occurred in the past.

A review of the Villafranchian fossiliferous sites of Latium in the framework of the geodynamic setting and paleogeographic evolution of the Tyrrhenian Sea margin of central Italy

Article

Full-text available

Jul 2018
QUATERNARY SCI REV

In the present study we provide a paleontological and chronostratigraphic review of the Villafranchian fossiliferous sites of Latium, revising the biochronologic attribution based on their framing within the geodynamic and paleogeographic evolutionary picture for this region. Aimed at this scope, we reconstruct the sedimentary and structural history of the Early Pleistocene marine basins through the review and the regional correlation of published stratigraphic sections and borehole data. Moreover, we combine the chronostratigraphic constraints provided in this study to the near-coast deposits of Gelasian-Santernian age (2.58–1.5 Ma) with the results of a recent geomorphologic study of this area, allowing us to reconstruct a suite of terraced paleo-surfaces correlated with marine isotopic stages 21 through 5. By doing so, we provide further age constraints to the sedimentary and tectonic processes acting on the Tyrrhenian Sea margin in Quaternary times, highlighting a possible different paleogeographic evolution of the southern coastal area where the Middle-Villafranchian type-section of Coste San Giacomo site is located, with respect to the northern sector.

Rome in its setting. Post-glacial aggradation history of the Tiber River alluvial deposits and tectonic origin of the Tiber Island

Article

Full-text available

Mar 2018
PLOS ONE

The Tiber valley is a prominent feature in the landscape of ancient Rome and an important element for understanding its urban development. However, little is known about the city’s original setting. Our research provides new data on the Holocene sedimentary history and human-environment interactions in the Forum Boarium, the location of the earliest harbor of the city. Since the Last Glacial Maximum, when the fluvial valley was incised to a depth of tens of meters below the present sea level, ¹⁴C and ceramic ages coupled with paleomagnetic analysis show the occurrence of three distinct aggradational phases until the establishment of a relatively stable alluvial plain at 6–8 m a.s.l. during the late 3rd century BCE. Moreover, we report evidence of a sudden and anomalous increase in sedimentation rate around 2600 yr BP, leading to the deposition of a 4-6m thick package of alluvial deposits in approximately one century. We discuss this datum in the light of possible tectonic activity along a morpho-structural lineament, revealed by the digital elevation model of this area, crossing the Forum Boarium and aligned with the Tiber Island. We formulate the hypothesis that fault displacement along this structural lineament may be responsible for the sudden collapse of the investigated area, which provided new space for the observed unusually large accumulation of sediments. We also posit that, as a consequence of the diversion of the Tiber course and the loss in capacity of transport by the river, this faulting activity triggered the origin of the Tiber Island.

Seismic response of the geologically complex alluvial valley at the "Europarco Business Park" (Rome - Italy) through instrumental records and numerical modelling

Article

Full-text available

Jan 2016

The analysis of the local seismic response in the "Europarco Business Park", a recently urbanized district of Rome (Italy) developed over the alluvial valley of the "Fosso di Vallerano" stream, is here presented. A high-resolution geological model, reconstructed over 250 borehole log-stratigraphies, shows a complex and heterogeneous setting of both the local Plio- Pleistocene substratum and the Holocene alluvia. The local seismo-stratigraphy is derived by a calibration process performed through 1D numerical modelling, accounting for: i) 55 noise measurements, ii) 10 weak motion records obtained through a temporary velocimetric array during the August 2009 L'Aquila- Gran Sasso seismic sequence and iii) one cross-hole test available from technical report. Based on the reconstructed seismostratigraphy, the local seismic bedrock is placed at the top of a gravel layer that is part of the Pleistocene deposits and it does not correspond to the local geological bedrock represented by Plio-Pleistocene marine deposits. 1D amplifcation functions were derived via numerical modelling along three representative sections that show how in the Fosso di Vallerano area two valleys converge into a single one moving from SE toward NW. The obtained results reveal a main resonance at low frequency (about 0.8 Hz) and several higher resonance modes, related to the local geological setting. Nonlinear effects are also modelled by using strong motion inputs from the offcial regional dataset and pointed out a general down-shift (up to 0.5 Hz) of the principal modes of resonance as well as an amplitude reduction of the amplifcation function at frequencies higher than 7 Hz.

The Pliocene and Quaternary of the Mid Tiber Valley (Central Apennines)

Article

Full-text available

Jan 2003

New data on Pliocene-Quaternary stratigraphy and on the geological evolution of the Middle Valley of the Tiber River (M.V.T.) are here presented. It is also presented the Geological Map of the Middle Valley of the Tiber River (two sheets), at scale 1:40,000. Two main tectono-se dimentary phases are recognised: the first one, Middle Pliocene-Early Pleistocene in age, was dominated by subsidence; the second, spanning from Early Pleistocene to Holocene, was dominated by the Apennine Chain's uplift and volcanism. Two 3rd order sedimentary cycles characterise the first phase. The 1st cycle corresponds to the Tenaglie-Fosso San Martino Unit (Piacentian-early Gelasian) and is composed of coastal and marine shelf deposits. The 2nd cycle is composed of: the shallow marine and transitional Chiani-Tevere Formation (Late Gelasian-Santernian); the laterally continuous Poggio Mirteto Formation, of the fluvial-deltaic environment; the regressive, fluvial-lacustrine Giove in Teverina Formation. Fourth order progradational-transgressive cycles are recorded within the Chiani-Tevere Formation. The second phase comprises the prod ucts of the Mt Cimino Volcanic Complex (late Early Pleistocene) and the terraced fluvial deposits of the Civita Castellana Unit (late Early Pleistocene-Middle Pleistocene), Graffignano Unit (Middle Pleistocene), Rio Fratta Unit (late Middle Pleistocene), Sipicciano Unit (Late Pleistocene) and of the modern Tiber River plain. The fluvial units are covered by volcanics from the Vulsini Mts, Vico and Sabatini Mts Districts (Middle-Late Pleistocene), by the travertines of the Grotte Santo Stefano Unit (Middle Pleistocene), Fiano Unit (Late Pleistocene) and "Travertini recenti" (Holocene). The pala eogeography during the first phase was characterised by the transverse drainage of prograding fluvial-deltaic systems, which flowed from ENE to the centre of the M.V.T. basin. During the second phase the modern Tiber river developed with axial drainage. Type sections for the Chiani-Tevere and Poggio Mirteto Formations and for the Civita Castellana, Graffignano, Grotte Santo Stefano, Rio Fratta and Sipicciano Units are proposed.

4 Vinciguerra Tectonophysics 09

Data

Full-text available

Jun 2013

Late Pleistocene depositional cycles of the Lapis Tiburtinus travertine (Tivoli, Central Italy): Possible influence of climate and fault activity

Article

Jul 2008
GLOBAL PLANET CHANGE

The depositional and erosional history of the Lapis Tiburtinus endogenic travertine located circa 25 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 km 2 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 fault. The travertine age was calculated using the U/Th isochron method. Results constrain the onset and conclusion of travertine deposition at about 115 and 30 ka, respectively. The three-dimensional study of the travertine shows that this deposit is characterized by a succession of depositional benches grown in an aggradational fashion. The benches are separated by five main erosional surfaces, which are associated with paleosols, conglomerates, and karstic features. This evidence shows that the travertine evolution was mostly controlled by water table fluctuations. Chronological correlations between travertine evolution and paleoclimate indicators suggest that the travertine deposition was partly modulated by climate conditions. Other influencing factors may have been fault-related deformation and volcanic events.

Gas geochemistry of natural analogues for the studies of geological CO 2 sequestration

Article

Jul 2009
APPL GEOCHEM

Editorial handling by R. Fuge a b s t r a c t Geological sequestration of anthropogenic CO 2 appears to be a promising method for reducing the amount of greenhouse gases released to the atmosphere. Geochemical modelling of the storage capacity for CO 2 in saline aquifers, sandstones and/or carbonates should be based on natural analogues both in situ and in the laboratory. The main focus of this paper has been to study natural gas emissions representing extremely attractive surrogates for the study and prediction of the possible consequences of leakage from geological sequestration sites of anthropogenic CO 2 (i.e., the return to surface, potentially causing local-ised environmental problems). These include a comparison among three different Italian case histories: (i) the Solfatara crater (Phlegraean Fields caldera, southern Italy) is an ancient Roman spa. The area is characterised by intense and diffuse hydrothermal activity, testified by hot acidic mud pools, thermal springs and a large fumarolic field. Soil gas flux measurements show that the entire area discharges between 1200 and 1500 tons of CO 2 per day; (ii) the Panarea Island (Aeolian Islands, southern Italy) where a huge submarine volcanic-hydrothermal gas burst occurred in November, 2002. The submarine gas emissions chemically modified seawater causing a strong modification of the marine ecosystem. All of the collected gases are CO 2 -dominant (maximum value: 98.43 vol.%); (iii) the Tor Caldara area (Cen-tral Italy), located in a peripheral sector of the quiescent Alban Hills volcano, along the faults of the Ardea Basin transfer structure. The area is characterised by huge CO 2 degassing both from water and soil. Although the above mentioned areas do not represent a storage scenario, these sites do provide many opportunities to study near-surface processes and to test monitoring methodologies.

Post-caldera activity in the Alban Hills Volcanic District (Italy): 40Ar/39Ar geochronology and insights into magma evolution

Article

Full-text available

May 2003

We present 24 40Ar/39Ar ages for the youngest volcanic products from the Alban Hills volcanic district (Rome). Combined with petrological data on these products, we have attempted to define the chronology of the most recent phase of activity and to investigate the magma evolution of this volcanic district. The early, mainly explosive activity of the Alban Hills spanned the interval from 561±1 to 351±3 ka. After approximately 50-kyr of dormancy, a mainly effusive phase of activity took place, accompanied by the strombolian activity of a small central edifice (Monte delle Faete). This second phase of activity spanned the interval 308±2 to 250±1 ka. After another dormancy period of approximately 50-kyr, a new, hydromagmatic phase of activity started at 200 ka at several centers located to the southwest of the Monte delle Faete edifice. After an initial recurrence period of approximately 50-kyr, which also characterized this new phase of activity, the longest dormancy period (approximately 80-kyr) in the history of the volcanic district preceded the start of the activity of the Albano and Giuturna centers at 70±1 ka. Results of our study suggest a quasi-continuous magmatic activity feeding hydromagmatic centers with a new acme of volcanism since around 70 ka. Based on data presented in this paper, we argue that the Alban Hills should not be considered an extinct volcanic district and a detailed re-assessment of the volcanic hazard for the area of Rome is in order.

Deformation of a Roman Aqueduct (II-III Century AD) near Rome, Italy

Conference Paper

Full-text available

Jan 2002

Along the modern trace of the Tiburtina road, approximately 20 km north-east of the city of Rome, recent archaeological diggings have brought to light a system of aqueduct galleries constructed by roman engineers (II-III century A.D). Two narrow water channels (A and B) of this aqueduct system were strongly deformed by tectonic movement that occurred subsequent to their construction. The archaeological site falls inside the Acque Albule basin (AAB): a travertine plateau, upper Pleistocene in age with a medium thickness of approximately 60 m. The AAB has been interpreted as a rhomb-shaped pull-apart basin (7 km long, 4 km wide) created by strike-slip faulting within a N-S shear zone that crosses the Rome area. Its evolution is attributed to Middle-Upper Pleistocene times. The principal N-S water channel (A) evidences both brittle (extensive) and ductile (compressive) deformations, whereas the shorter channel (B) to the south-west reveals predominantly ductile deformations associated with compression. A detailed survey of the A channel indicates a segmented course along the length of the entire structure, with orientations ranging between N10°E and N10°W, and with one section oriented at N35°W. The smaller B channel situated to the south-west of the principal excavation indicates that deformation can be linked to transverse compression resulting in a restriction and rotation of the structure. The geometry of the deformation pattern and the brittle structures affecting the surrounding rock, the presence of sections deformed in a ductile manner, the segmentation of the two channels into tracts rotated in different directions, the narrowing of an internal section of the B channel orientated N15°W, are all elements compatible with strike-slip tectonics. To provide additional quantitative support for these observations, 3 sites (35 samples) were drilled, for paleomagnetic and anisotropy of magnetic susceptibility analyses, in the "Pozzolane Rosse" Formation (457+/-4 kyr). With respect to a few years ago, when the Roman volcanoes were considered extinct and with no signs of active tectonic activity present in the area, it seems today that the Eternal City is not still destined - geologically speaking - to eternal rest!

Chronostratigraphic study of the Grottaperfetta alluvial valley in the city of Rome (Italy): Investigating possible interaction between sedimentary and tectonic processes

Article

Full-text available

Dec 2009

We carried out geomorphologic and geological investigations in a south-eastern tributary valley of the Tiber River in Rome, the Grottaperfetta valley, aimed to reconstruct its buried geometry. Since results of the geomorphologic study evidenced anomalies of the stream beds, we performed geoelectric and boreholes prospecting to check whether recent faulting, rather than an inherited structural control, possibly contributed to the evolution of the alluvial valley. Vertical offsets of the stratigraphic horizons across adjacent boreholes were evidenced within the Late Pleistocene-Holocene alluvium and its substratum. In order to rule out the effects of irregular geometry of the alluvial deposits, we focussed on sectors where vertical offsets affected all the stratigraphic horizons (alluvium and pre-Holocene substratum), showing an increasing displacement with depth. We identified a site where repeated displacements occur coupled with a lateral variation of soil resistivity, and we drilled an oblique borehole aimed to cross and sample the possible fault zone affecting the terrain. A 7 cm thick granular layer, inclined 50°÷70° on the horizontal, was recovered 5 m b.g., and it was interpreted as the filling material of a fracture. The convergence of the reported features with independent evidence from geoelectric and geomorphologic investigations leads to hypothesize the presence of a faulting zone within the Holocene alluvial terrains and to propose the excavation of a trench to verify this hypothesis.

Palaeomagnetic results from an archaeological site near Rome (Italy): new insights for tectonic rotation during the last 0.5 Myr

Article

Approximately 20 km north-east of Rome, along the modern trace of the Tiburtina road, recent archaeological diggings have brought to light a system of aqueduct galleries constructed by Roman engineers. This site falls inside the Acque Albule Basin, a travertine plateau Upper Pleistocene in age, that has been interpreted as a rhombshaped pull-apart basin created by strike-slip faulting within a N-S shear zone. This study provides evidence that two narrow water channels of this aqueduct system were significantly deformed by tectonic movement that occurred subsequent to their construction (II-III century A.D.). The geometry of the deformation pattern is compatible with that expected for a shear zone bounded by N-S oriented, right-lateral faults. The palaeomagnetic study of the volcanic formation («Pozzolane Rosse» Formation, 457± 4 kyr) containing the Roman aqueduct system evidences significant clockwise rotation around sub-vertical axis, consistent with the above-mentioned tectonic style. published

"Ricostruzione della morfologia del Vulcano Tuscolano-Artemisio nei Colli Albani" Nisio S. (Eds) (2023) - Giornate di Geologia & Storia. Memorie Descrittive della Carta Geologica d’Italia, Dipartimento per il Servizio Geologico d’Italia, ISPRA, 110: pp. 508

Article

Full-text available

May 2023

This monograph attempts to reconstruct the morphology of the Tuscolano-Artemisio Volcano, active in the first phase of the volcanic apparatus of the Alban Hills, from about 600,000 to about 350,000 years ago. In fact, about 350,000 years ago there was probably the collapse of the Tuscolano-Artemisio building with the formation of the homonymous Tuscolano-Artemisia caldera of about 10 km in diameter, still largely present and recognizable on the ground. For the reconstruction of the morphology of the Tuscolano-Artemisio volcano, a comparison was made with the Vicano north of Rome and Roccamonfina south of Rome volcanoes, both with an ultrapotassic chemistry like the volcano of the Alban Hills. Both the Vicano volcano and the Roccamonfina volcano currently have a circular summit caldera at a high altitude with a diameter of about 6 km. It was therefore hypothesized that a caldera of the same size could also be in the Tuscolano-Artemisio volcano until 350,000 years ago. The reconstruction took place starting from the study of the slope from the remains of the slopes of the Tuscolano-Artemisio enclosure, extending them upward to meet the hypothesized caldera. Thus, an altitude of the Tuscolano-Artemisio Volcano of about 1,530 m a.s.l. was found, therefore more than 500 m higher than the current maximum altitude of the Alban Hills which is just over 1,000 m a.s.l. Finally, it was investigated which human species could have witnessed the eruptions of the volcano of the Alban Hills, starting with the archaeological findings in the same area of the Alban Hills and in the neighboring areas in central-southern Lazio. It is believed that all human species present in Europe in that period of time have witnessed in the overall period of activity of the Alban Hills (from 600,000 to 36,000 years ago), which from the oldest to the most recent and current are: Homo Heidelbergensis, Homo Neanderthal and Homo Sapiens.

Holocene aggradation history of the Murcia alluvial valley: Insights into early Rome's paleoenvironmental evolution

Article

May 2022
QUATERN INT

Through the analysis of seven 15–30 m deep boreholes drilled in the western sector of the Circus Maximus we reconstruct the aggradational history of one main tributary valleys of the Tiber River in Rome, the Murcia Valley (Vallis Murcia). Consistent with recent acquisitions in the Tiber Valley, we identify a Bronze Age (4500-3000 yr BP) paleogeographic setting characterized by the lowering of the drainage network base level. This would have created a dry alluvial plain, suitable for human settlement. We also find evidence for dramatic overflooding which occurred during the 6th century BCE and was responsible for the rapid rise from 2 to 6 m a.s.l. of the valley floors within the Tiber catchment basin in Rome. We suggest that these paleogeographic features can be identified in mythical and ethno-historical accounts of early Rome. Besides providing insights into the paleolandscape and anthropogenic interventions in the Murcia Valley, these previously unrecognized hydrological dynamics may attest to paleoclimatic fluctuation that have occurred since 5000 yr BP. Contrary to the dry and cold conditions prevalent during the Bronze through the Iron Age, the exceptional flooding events of the archaic period suggest a shift in climatic trends. However, tectonic and anthropogenic factors could have also had a combined and cumulative effect, requiring detailed paleoenvironmental and palaeolandscape studies.

A morpho-tectonic approach to the study of earthquakes in Rome

Preprint

Full-text available

Jan 2022

Rome has the world’s longest historical record of felt earthquakes, with more than 100 events during the last 2,600 years. However, no destructive earthquake has been reported in the sources and all of the greatest damage suffered in the past has been attributed to far-field events. While this fact suggests that a moderate seismotectonic regime characterizes the Rome area, no study has provided a comprehensive explanation for the lack of strong earthquakes in the region. Through the analysis of the focal mechanism and the morphostructural setting of the epicentral area of a "typical" moderate earthquake (ML = 3.3) that recently occurred in the northern urban area of Rome, we demonstrate that this event reactivated a buried segment of an ancient fault generated under both a different and a stronger tectonic regime than that which is presently active. We also show that the evident structural control over the drainage network in this area reflects an extreme degree of fragmentation of a set of buried faults generated under two competing stress fields throughout the Pleistocene. Small faults and a present-day weaker tectonic regime with respect to that acting during the Pleistocene explain the lack of strong seismicity and imply that a large earthquake could not reasonably occur.

A review of the stratigraphy of Rome (Italy) according to geochronologically and paleomagnetically constrained aggradational successions, glacio-eustatic forcing and volcano-tectonic processes

Article

Full-text available

Mar 2017
QUATERN INT

In this paper we provide a critical review of the studies conducted on the geology of Rome since the first half of the 20th century, aimed at presenting an updated state of the art on the stratigraphy of this area. Following this introductory summary, we present a complete reconstruction of the geological evolution and the resulting chrono-litho-stratigraphic setting of the greater area of Rome, according to a series of works that in the last 20 years have adopted an innovative methodological approach based on the conceptual model of aggradational successions deposited in response to sea-level rise during the glacial terminations, and on the strict geochronologic constraints to the sedimentary record achieved by paleomagnetic investigation of clay sections and 40Ar/39Ar dating of interbedded volcanic materials. We also present a complete overview on the chronostratigraphy of the two volcanic districts of Colli Albani and Monti Sabatini, located SE and NWof Rome respectively, that has been achieved integrating the field work with the large number of radiometric ages provided in these years on their eruptive products. Moreover, we propose a revised stratigraphic column to compare the most recent official 1:50,000 and 1:10,000 geologic mapping of Rome, which is intended as a tool of correlation for an international audience of Quaternary scientists to approach the study of this area. A detailed discussion of the proposed revisions is also provided as supplementary information to this paper.

New data on the Tuscolano-Artemisio phase of the Alban Hills: Some insights on climatic conditions

Article

Jan 2011

A pyroclastic flow 14 m thick embedding well-preserved wood remains has been retrieved at a depth of 120 m from a borehole drilled near the village of Lanuvio, about 9 km south of the Lake of Albano. 40Ar/39Ar analyses on a leucititic lava flow immediately overlying the drilled ignimbrite, gave an age of 485 ± 1ka. Facies and age constraints are consistent with pyroclastic products of the first Tuscolano-Artemisio phase. The new findings presented here contribute toward reconstructing the early eruptive history of the Alban Hills. New chronological data further define the time interval and spatial distribution of the extrusive phase, coinciding with the transition from the first to the second Tuscolano-Artemisio phases. It is also suggested that the pyroclastic products of the Latium region (Rome) with their embedded wood remains, represent an important "archive" of arboreal expansion, allowing better definition of the climatic conditions characterizing interglacial stages 13-15 of the Oxygen Isotope Curve.

Morphostructural characteristics of the drainage channel of the Tevere River in the Rome urban area

Article

Jan 2000

Cited By :1, Export Date: 22 January 2015

Pulsed uplift estimated from terrace elevations in the coast of Rome: Evidence for a new phase of volcanic activity?

Article

May 2001
EARTH PLANET SC LETT

The most recent phase of activity from the Roman volcanoes, since 45 ka, has been interpreted to be the waning stage of the older explosive activity that peaked between 550 and 250 ka. Yet substantial regional uplift from approximately 250 ka suggests that magma chambers beneath the area are growing rather than shrinking. We have estimated the uplift history of the region using radioisotopically and paleomagnetically constrained coastal terrace elevation data that allow us to correlate these terraces with marine oxygen isotopic stages 1-22. Elevations have been corrected for glacio-eustatic sea-level change. Our study shows that over the last million years, regional uplift of coastal terraces occurred in pulses that preceded volcanic activity at roughly 800 ka (in the Monti Sabatini) and 600 ka (in the Alban Hills). The recent pulse of uplift since 250 ka occurred primarily during a period of relative volcanic dormancy that lasted from 250 to 45 ka. We hypothesize that the most recent volcanic activity since 45 ka may reflect the completion of magma chamber recharge, suggesting the start of a new volcanic epoch. It is also possible that the local tectonic stress field changed recently from one dominated by transpression to one dominated by extension, allowing magma to more easily reach the surface via normal faults.

Climate-controlled fault-valve cycles revealed by 3D stratigraphy and U-series geochronology of the Lapis Tiburtinus travertine, Tivoli, Central Italy

Conference Paper

Full-text available

Oct 2007

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.

F-phlogopites in the Alban Hills Volcanic District (Central Italy): Indications regarding the role of volatiles in magmatic crystallisation

Article

Jun 2000
J VOLCANOL GEOTH RES

A systematic analysis of micas contained in effusive, pyroclastic and hypabyssal rocks of the Alban Hills Volcanic District (AHVD) (Central Italy) was made in order to characterise minerals of pyroclastic units for tephrostratigraphy and to obtain as much information as possible on the activity of volatiles in this magmatic system. The phlogopite shows a large range of F contents (between 0.50 and 7.50 wt%) that make it possible to discriminate different AHVD lithologies; in particular, micas of lava groundmass are characterised by extremely high F (up to 7.50 wt%) and Ba (up to 9.70 wt%) contents, seldom or never found in other magmatic ultrapotassic rocks. Moreover, the micas of pyroclastics, ultramafic cumulates and holocrystalline inclusions made up of leucite, clinopyroxene and phlogopite (hereafter italites) show Mg/(Mg+Fe) values between 0.65 and 0.90 that are not correlated with F contents. The variations in F contents observed in the AHVD micas do not appear to be due to a “temperature” effect or pressure changes, but they may be due to variations in the H2O and CO2 activities in the magma chamber. They make it possible to differentiate three crystallisation environments in the AHVD magmatic system. The first one had elevated CO2 activity and formed the italites near the carbonate contact; these rocks represent, at least those enriched in clinopyroxene without skarn-minerals, the hypabyssal crystallisation of the AHVD magmas at the periphery of magma chamber. The second one, characterised by a higher water activity, is represented by the micas of the ultramafic cumulates and pyroclastic scorias, and is located in the inner part of magma chamber. The third environment, the groundmass of the lavas, it is not related with the previous ones and is characterised by the absence of water and by a high F activity. In general, our results suggest that the compositional variations observed in the micas (Al, Si, Ti, Ba) reflect different H2O activities (inversely correlated with F activity) in the magma chamber.

Large mafic eruptions at Alban Hills Volcanic District (Central Italy): Chronostratigraphy, petrography and eruptive behavior

Article

Jan 2009
J VOLCANOL GEOTH RES

Despite its ultra-potassic, basic geochemistry (40 ≤ SiO2 ≤ 50 wt.%), the Alban Hills Volcanic District was characterized by a highly explosive phase of activity, the Tuscolano–Artemisio phase, which emplaced very large volumes (several tens of km3 each cycle) of pyroclastic-flow deposits, mafic in composition (SiO2 ≤ 45 wt.%) in the time span 600–350 ka. In contrast to the abundance of pyroclastic-flow deposits, very scarce basal Plinian deposits and, more in general, fallout deposits are associated to these products. While some of the pyroclastic-flow deposits have been described in previous literature, no specific work on the Tuscolano–Artemisio phase of activity has been published so far. In particular, very little is known on the products of the early stages, as well as of the final, post-caldera activity of each eruptive cycle. Here we present a comprehensive stratigraphic and geochronologic study of the Tuscolano–Artemisio phase of activity, along with new textural and petrographic data. We describe the detailed stratigraphy and petrography of five reference sections, where the most complete suites of products of the eruptive cycles, comprising the initial through the final stages, are exposed. We assess the geochronology of these sections by means of 18 new 40Ar/39Ar age determinations, integrating them with 16 previously performed, aimed to describe the eruptive behavior of the Alban Hills Volcanic District during this phase of activity, and to assess the recurrence time and the duration of the dormancies.

The history of the Monti Sabatini and Alban Hills volcanoes: Ground for assessing volcanic-tectonic hazards for Rome

Article

Jun 2001
J VOLCANOL GEOTH RES

The volcanic rocks of Rome provide chronostratigraphic constraint that is of use to geologists, archaeologists, and paleontologists. Identifying the areal distribution of these rocks, their mode of emplacement and a detailed chronology of the eruptive events also, is crucial for assessing local natural hazards in a volcanic-tectonic context, and for recognizing whether the volcanoes may erupt again in the future. We have identified and dated many of the volumetrically significant eruptive units from the Monti Sabatini and Alban Hills (Colli Albani) and propose a formalized volcanic stratigraphy for Rome. It is probable that seismic events triggered some eruptions, as several ignimbrites from the two volcanoes have statistically indistinguishable ages. Following a 200+ kyr period of dormancy that was coincident with a pulse of regional uplift, the Alban Hills appears to have begun recently (circa 45 ka), a new eruptive cycle. Therefore, accurate assessment of volcanic-tectonic hazards, and estimation of possible future volcanic activity, is necessary for the safety of the five million people living near these volcanoes.

Evidence of active tectonics on a Roman aqueduct system (II-III century AD) near Rome, Italy

Article

Apr 2004
J STRUCT GEOL

In this paper we describe evidence of strong tectonic deformation affecting two aqueducts of Roman age (II–III century A.D.). The channels are located approximately 20 km northeast of Rome along the ancient Via Tiburtina. Brittle and ductile deformation affects these two structures, including extensional joint systems, NE-oriented faults, and horizontal distortion. This deformation is consistent with right-lateral movement on major N-striking faults, and represents the first evidence that tectonic deformation took place in historical times in the vicinity of Rome, with local strike–slip movement superimposed on a regional extensional fault system.

Strike-slip faulting and block rotation: A possible trigger mechanism for lava flows in the Alban Hills?

Article

Jan 2001
J STRUCT GEOL

Fabrizio Marra

It is suggested in this paper that two distinct tectonic triggers, tapping different depths of a magma reservoir, may be the cause of nearly contemporaneous eruptions of lava flows and ignimbrites in the Alban Hills. The area between the Alban Hills and Rome underwent alternating regional extensional and strike-slip faulting during the Middle Pleistocene. The geometries of the main structural dislocations in Quaternary strata, combined with a statistical analysis of drainage network trends, show a structural pattern that is consistent with local strain partitioning in transpressive zones at strike-slip fault bends, superimposed on regional extension. Based on this analysis, it is suggested that local clockwise block rotation between parallel N–S strike-slip faults might have generated local crustal decompression, allowing relatively volatile-free magma to rise from deep reservoirs beneath the Alban Hills, triggering peripheral fissure lava flows. In contrast, the main ignimbrite eruptions appear to tap shallow, volatile-rich magma reservoirs and are controlled by extensional processes.

Physical properties of tuffs from a scientific borehole at Alban hills volcanic district (central Italy)

Article

Jun 2009
TECTONOPHYSICS

Recent seismic swarms and hydrothermal activity suggest that the Quaternary volcanic complex of the Alban Hills may pose a threat to the city of Rome. A 350 m scientific borehole was therefore drilled into this volcanic area to elucidate its inner structure for the first time. Wire-line logs were run in the borehole in order to characterize the physical properties of the rocks and their variations with depth. In particular, a detailed sonic log was run to measure the P-wave velocity from the well-head down to 110 m. To further investigate velocity changes, we carried out laboratory measurements of P and S elastic wave velocities and fluid permeability at effective pressures up to 70 MPa during both increasing and decreasing pressure cycles on selected core samples representative of the main volcanic units. Specifically, we studied samples from two pyroclastic units representative of two classes of volcanic deposits that are representative of the whole succession: (i) a coarse-grained, well-lithified facies (Pozzolane Rosse unit), containing abundant mm-to-cm lava clasts and crystals; and (ii) a fine-grained, matrix-supported pyroclastic deposit (Tufo Pisolitico di Trigoria unit), with rare lithic lava clasts and sparse pumice. Elastic wave velocities reveal significant differences between units and indicate how, within the same lithology, the different degree of lithification and presence of clasts can affect significantly physical property values. The mean laboratory value of the P-wave velocity for Pozzolane Rosse and Tufo Pisolitico di Trigoria units is respectively of 3.75 and 3.2 km/s at an effective pressure equivalent to that at the depth at which the sonic velocity was measured.

Palaeomagnetic results from an archaeological site near Rome (Italy): New insights for tectonic rotation during the last 0.5 Myr

Article

Full-text available

Dec 2009

Evolution of a transfer related basin: the Ardea basin (Latium, Central Italy)

Article

Full-text available

Jan 1994

Extension in the Tyrrhenian Sea and Shortening in the Apennines as Result of Arc Migration Driven by Sinking of the Lithosphere

Article

Full-text available

Apr 1986

Previously proposed models for the evolution of the Tyrrhenian basin-Apenninic arc system do not seem to satisfactorily explain the dynamic relationship between extension in the Tyrrhenian and compression in the Apennines. The most important regional plate kinematic constraints that any model has to satisfy in this case are: (1) the timing of extension in the Tyrrhenian and compression in the Apennines, (2) the amount of shortening in the Apennines, (3) the amount of extension in the Tyrrhenian, and (4) Africa-Europe relative motion. The estimated contemporaneous (post-middle Miocene) amounts of extension in the Tyrrhenian and of shortening in the Apennines appear to be very similar. The extension in the Tyrrhenian Sea is mostly accomplished in an E-W direction, and cannot be straightforwardly related to the calculated N-S Africa-Europe convergence. A model of outward arc migration fits all these constraints. In a subducting system, the subduction zone is expected to migrate outward due to the sinking of the underthrusting plate into the mantle. The formation of a back-arc or internal basin, i.e. of a basin internal to the surrounding belt of compression, (in this case the Tyrrhenian Sea) is then expected to take place if the motion of the overriding plate does not compensate for the retreat of the subduction zone. The sediment cover will be stripped from the underthrusting plate by the outward migrating arc of the overriding plate, and will accumulate to form an accretionary wedge. This accretionary body will grow outward in time, and will eventually become an orogenic belt, (in this case the present Apennines) when the migrating arc collides with the stable continental foreland on the subducting plate. An arc migration model satisfactorily accounts for the basic features of the Tyrrhenian-Apennine system and for its evolution from 17 Ma to the present, and appears to be analogous to the tectonic evolution of other back-arc settings both inside and outside the Mediterranean region. An interesting implication of the proposed accretionary origin of the Apennines is that the problematic “Argille Scagliose” (scaly clays) melange units might have been emplaced as overpressured mud diapirs, as observed in other accretionary prisms, and not by gravity slides from the internal zones.

Re-evaluation of minor events: The examples of the 1895 and 1909 Rome earthquakes

Article

Full-text available

May 1993

The city of Rome is subjected to moderate seismic risk due to both local and external seismicity. Up to now, the maximum intensity felt has never exceeded VIII MCS. The 1 November 1895 (I o = VII) and 31 August 1909 (I o = VI) earthquakes demonstrate that small local events can also cause damage in a large old city. In the present work, we have re-evaluated the intensity values of those two events by means of automatic processing. A comparison between the present results with geological evidence and previous studies is shown, especially for the historical centre of Rome. For the first time, the 1909 earthquake instrumental magnitudeM L = 3.6 has been calculated from original recordings.

Tectonic setting and Sinkhole Features: case histories from western Central Italy

Article

Full-text available

Jan 1993

The aim of this study is to clarify the possible relationships between tectonics and sinkholes in western central Italy. This area is characterized by a Mesozoic-Cainozoic carbonate platform bordered on the west by Plio-Quarternary sedimentary deposits and volcanic deposits. Natural sinkholes are mostly localized in the marginal zone, where shallow groundwaters mingle with thermally and chemically amonalous deep groundwaters. Detailed geological and structural analysis in two representative sites ("Fosso di San Martino' and "Piana di San Vittorino'), coupled with 4He and 222Rn and other chemicophysical measurements, show that groundwaters cause the dissolution of the bedrock beneath cohesionless deposits and the development of karst features along master fractures. The collapse of these caves, and the subsequent development of sinkholes, are often related to earthquake shocks. -Authors

Fault mechanisms from near source data: Joint inversion of S polarizations and P polarities

Article

Full-text available

Mar 1991

We propose a non-linear inversion method for studying the earthquake mechanism by combining the information carried by both S-wave polarizations and P-wave polarities from near-source records. The posterior probability of parameters (strike, dip and slip fault angles) for the given observational data sets is computed by using a Bayesian approach. The conditional probability density function of S polarizations given a model parameter set is defined assuming a Gaussian distribution for the expected errors. The P polarity information is taken into account in the form of a prior probability density function, which has been defined according to Brillinger, Udias & Bolt (1980). The method is based on the estimate by an exhaustive search of the posterior probability of model parameters. This probability is then represented by its projection on plane sections in the model space. This enables one to locate the maximum likelihood solutions, and to get a reliable estimate of the parameter correlation and resolution. Numerical examples and data analysis show that the addition of a few S polarizations to a P polarity data set greatly improves the resolution on the fault parameters. The proposed method is suitable to study the low-magnitude seismicity in active tectonic and volcanic areas which are monitored by local networks as the use of three-component sensors becomes more systematic.

Local seismicity in Rome (Italy): Recent results from macroseismic evidences

Article

Full-text available

Jun 1996

This paper presents the results obtained from the study of the macroseismic effects of the June 12, 1995 Rome earthquake. The event, MD = 3.8, provoked VI degree MCS effects in neighbourhoods of Southern Rome. This earthquake is important within the framework of seismicity in the Rome area, as it is the first noteworthy one ever to be recorded in the instrumental age, and provides a good comparison with historical earthquakes which have occurred in the same area. The filtering procedure performed on the macroseismic field reveals out the anomalies of the attenuation pattern and the site effect. The results reconfirm what has only recently emerged from the analysis of historical earthquakes, i.e. Rome is affected by local seismicity, that can cause damage in the southern neighbourhoods and the downtown area, especially where the site contributes to the amplification of the effects.

The June 12, 1995 microearthquake sequence in the city of Rome

Article

Full-text available

Dec 1996

The earthquake of June 12, 1995 has been located using local and regional data (41°48.8'N, 12°30.8°6E at a depth of about 11.5 km) a few kilometers inside the city limit of Rome, in its southernmost part. This is the first event that occurred in Rome for which instrumental data are available. The local magnitude estimated from digital recordings is ML 3.6 and it was largely felt reaching intensity VI MCS. We constrained the focal mechanism by analyzing the S-wave polarization and it agrees well with the distribution of P-wave polarities. The fault plane solution shows a dominant strike slip mechanism (strike 275°, dip 70°, rake - 140°). Seismic moment, M0 = 2.3 ± 0.6 1021dyne × , was computed from S-wave displacement spectra of horizontal components of ground motion digital waveforms. The corresponding source radius ranges between 200 and 500 m, depending on the assumed stress drop (100 bars or 10 bars, respectively). The earthquake was preceded by a ML 2.6 foreshock. The seismic sequence lasted a few days during which 38 aftershocks were recorded. The seismicity pattern shows the characteristics of a mainshock-aftershock sequence, rather than swarm behavior which seems to characterize the activity of the neighboring seismogenic areas of the Alban Hills. We used a master event algorithm to locate some of the aftershocks. Results show that the relocated aftershocks are clustered in a small volume in proximity of the mainshock hypocenter.

Earthquakes in Rome during the past one hundred years

Article

Full-text available

Jun 1995

We have studied the seismic response of the city of Rome using the available macroseismic data of local earthquakes which occurred during the past one hundred years. These earthquakes were generated by three dislinct seismogenic sources falling within the present extent of Rome. The comparison with the effect produced in Rome by a large Apennine earthquake (January 13. 1915) suggests that the damage patterns are similar and that they are mainly controlled by the local geology and morphology. The analysis shows that most of the damage was concentrated in buildings located on alluvial deposits of the Tiber River rather than in buildings underlain by different lithologies. In addition, the largest concentration of heavy darnage occurred in buildings located on the alluvial deposits of the right-hand side of the Tiber River valley, and particularly where the buried interface between Holocene and Pliocene deposits is steepest. This close relationship between damage pattern on the one hand, and geology and geometry of the shallowest deposits on the other hand, supports the results of ground motion modeling studies of the same area and similar observations collected in different regions of the world during large earthquakes.

Active and remnant subducted slabs beneath Italy: evidence From seismic tomography and seismicity

Article

Full-text available

Jun 1993

Recent seismic activity and earthquake occurrence along the Apennines

Article

Jan 1993

The paper analyzes the seismicity along the Apennines in order to relate the seismicity pattern to the seismogenic environment and to the active tectonic processes. The analysis of crustal and subcrustal seismicity shows that the northern and southern Apennines are characterized by two distinct patterns of seismicity. These two domains are separated by two important lithological discontinuities. The seismicity along the Apennines is mainly concentrated in a narrow belt running along the chain, with an evident geometrical offset which corresponds to the Ancona-Anzio line. The main features of some recent seismic sequences are analysed in order to discuss the seismicity patterns in terms of the hypothesis of segmentation of the southern Apennine seismogenic belt. -from Authors

Aspetti della sismicità storica di Roma

Article

Jan 1986

Definizione delle relazioni stratigrafiche e della geocronologia di alcune effusioni laviche neli area dei Colli Albani

Article

Jan 1990

Ar-40/Ar-39 geochronology of Roman volcanic province tephra in the Tiber River valley: Age calibration of middle Pleistocene sea-level changes

Article

Jun 1998
GEOL SOC AM BULL, GSA Bulletin

The close proximity of the Roman volcanic province to the Tyrrhenian Sea coastline provides a unique opportunity to combine clastic stratigraphy with 40Ar/39Ar geochronology to constrain the timing of Pleistocene sea-level oscillations. The main eruptions from the Monti Sabatini volcanic distribution occurred during the interval 560-280 ka, and the Alban Hills volcanic district main eruptions span 560-350 ka. The interfingering of volcanics from these two centers with fluvial and shallow-marine sediments of the Tiber River and delta provides a datable relative sea-level record for this portion of middle Pleistocene time. We calculate the timing of glacial terminations using analytical errors only, then assess age uncertainties that include analytical plus systematic errors; the latter is required to compare 40Ar/39Ar ages with those from other dating methods. Terminations III, V, and VI occur at 278 (261, 285) ka (95% confidence interval), 430 (422, 442) ka, and 534 (520, 541) ka, respectively, when only analytical uncertainties are used to calculate the ages of bracketing volcanic horizons. The confidence interval expands significantly when full external errors are considered, with predicted ages of 276 (258, 289) ka, 430 (416, 448) ka, and 533 (512, 548) ka for the terminations. The resultant 40Ar/39Ar chronology is generally consistent with the deep-sea δ34O record of sea-level change tuned to Earth's obliquity cycle for glacial terminations VI, V, and III. In addition, the 40Ar/39Ar constrained Tiber River delta sea-level record has the added benefit of identifying when coastal sections respond to complex (multistep) terminations.

Il substrato plio-pleistocenico nell'area romana

Article

Jan 1995

Datability of Quaternary volcanic rocks: an 40Ar/39Ar perspective on age conflicts in lavas from the Alban Hills, Italy

Article

Jan 1992
EUR J MINERAL

Igor Maria Villa

High-resolution 40Ar/39Ar dating experiments on four leucites from lavas and scoriae of the Alban Hills, recently reported to have 230Th/238U ages between 7 and 25 ka, fail to confirm these young age assignments. Plateau and isochron ages are concordant and consistent with the previously knbown history of the volcano: 355, 283, 250, and 30-40 ka. Major amounts of magma were not produced during the Holocene in the Alban Hills; the city of Rome is not exposed to an increased volcanic risk. -from Author

Gravimetry and deep structure of the Sabatinian and Alban volcanic areas (Latium)

Article

Jan 1976

B. Toro

Tettonica pleistocenica tra il M. Soratte ed i Monti Cornicolani (Lazio)

Article

Jan 1993

Strain partitioning in transpression zones

Article

Jun 1995
J STRUCT GEOL

Transpressional strain acting upon structurally anisotropic rocks can be partitioned into separate deformational domains of pure shear and simple shear. This contrasts with homogeneous transpression in which both the pure shear and the simple shear strain components are uniformly distributed across the zone of deformation. Structural weaknesses capable of partially or fully accommodating one component of deformation include lithological contacts, rheological heterogeneities, and faults or shear zones situated within the deformation zone or lying along its boundaries. Partitioning of transprcssional strain can occur when stress is applied oblique to pre-existing structural weaknesses, or can occur during later stages of progressive strain, when the early deformation of isotropic rocks imparts sufficient anisotropy to allow subsequent strain to be partitioned. Partitioning of transpressional strain into domains lying parallel to the deformation zone boundaries can be distinguished from ‘fault-stepped’ transpression, in which strain is partitioned along the length of a segmented fault zone.

Stress and the direction of slip on fault planes

Article

Aug 1990

John W. Gephart

The shear stress direction on a fault plane depends only on four of the six components of the stress tensor. Assuming only that the slip direction marks the shear stress direction on any fault plane (and that stress is homogeneous), it is possible to estimate these four stress parameters from populations of fault planes with known slip directions, as several workers have observed. Different formulations of the problem may yield varying best-fitting stresses and estimates of uncertainty. In the simplest case, no assumptions are made regarding the orientations of fault planes relative to the stress tensor; thus the technique allows for the possibility that the fault planes may be very weak. Here we present simple analytical and graphical descriptions of the field of admissible fault geometries relative to any four-parameter stress model, which can be used to illustrate the significance of various inverse strategies. In particular, this paper explores the effects of using two alternative measures of misfit between an observed fault datum and stress model: (1) the pole rotation (the angle between the observed and predicted slip direction on the observed fault plane), and (2) the minimum rotation (the smallest angle between the observed fault geometry and any fault geometry which is consistent with the model). By allowing for variation of the fault plane as well as the slip vector, the minimum rotation procedure generally achieves a more stable and (presumably) realistic estimate of the actual discrepancy between a fault observation and stress model than the pole rotation procedure. In a test case using 17 earthquake focal mechanisms from the YuIi region of eastern Taiwan, separate inversions based on the two misfit criteria yield different optimum stress models and uncertainty estimates. Additional constraints on the stress tensor, such as the effect of friction, can be superimposed on the ones used here.

The 1989–1990 seismic swarm in the Alban Hills volcanic area, Central Italy

Article

Jul 1994
J VOLCANOL GEOTH RES

A long seismic swarm has been recorded by a digital microseismic network that the Istituto Nazionale di Geofisica (ING) deployed from April 1989 to March 1990 in the Alban Hills Quaternary volcanic region, about 20 km southeast of Rome. The network consisted of thirteen digital stations equipped with four six-component (weak motion and strong motion sensors), three three-component and six vertical weak motion seismometers, including both broad-band and short-period sensors. More than 3000 earthquakes were detected during about one year of operation. The data recorded during the sequence provided an unprecedented opportunity to resolve details of the seismogenic features of this area that has experienced earthquakes since the Roman age. Although the temporal distribution of seismicity reveals a volcanic-type swarm activity, the recorded seismic signals show medium-high frequency waveforms and clear S-wave arrivals typical of `'tectonic" earthquakes. About 1100 earthquakes in a magnitude range between M(D) approximately 1.5 and M(D) approximately 4.0 have been located. The seismicity delineates a approximately 6x12km2NW-SE-elongated region that corresponds to the area where the most recent (0.027 Ma) phreato-magmatic activity took place. Almost no earthquakes occurred beneath the central cone and the eastern side of the caldera. The seismicity is shallow and is mostly concentrated in two clusters that are offset laterally and are at slightly different depths (3-5 and 4-6 km). The fault plane solutions of the strongest earthquakes reveal a approximately NE-SW extension, consistent with the regional orientation of the stress field along the Apenninic chain as obtained by other seismological data.

Evidence of active extension in Quaternary volcanoes of Central Italy from breakout analysis and seismicity

Article

Jul 1995

We present active stress directions obtained from borehole breakout analysis performed on 15 geothermal wells located in the western coastal regions of Central Italy. The study area (a 200 km by 50 km NW-elongated area bordering the Apennines) includes several Quaternary high-K alkaline volcanoes active mainly after 0.6 Ma. We analyzed both paper logs and digital data to detect breakout directions, the two techniques yielding similar results. The breakout results show a predominant ENE direction of SHmin, with local deviations in one region (Sabatini volcano) where no seismicity is observed. The comparison of breakout data with stress directions inferred from inversion of microearthquake (M<4) focal mechanisms computed in three of the four volcanoes suggests that the whole area is presently undergoing NE to ENE extension.

Recent uplift of the Alban Hills Volcano (Italy): Evidence for magmatic inflation?

Article

Aug 1995

First-order leveling surveyed in 1951 and 1994 along a line across the Alban Hills volcano reveals maximum vertical uplift of 30 cm (average of 7 mm/yr) in the region of geologically recent (0.020-0.030 Ma) explosive activity. The uplifted region corresponds to an area where seismic activity is concentrated, at depths of 3-6 km. Uplift exceeding 10 cm is observed over a 14-km wide zone in the center of a 40-km long line, with the deformation tapering to zero at both ends of the line. Data from a few sparse, older benchmarks measured in 1891 and 1927 suggest that the deformation in the first half of this century was very small compared to the period 1951-1994. The observed uplift, together with increased seismic activity, suggest that recent magma injection has occurred in the upper crust beneath the Alban Hills volcano.

The opening of the Tyrrhenian Sea: an experimental approach

Article

Sep 1996
GEOPHYS J INT

The E-W-opening Tyrrhenian Sea developed after the Cretaceous-Palaeogene Alpine collision, nearly perpendicular to the motion of the African plate, as a back-arc of the Adria-Ionian westward subduction. Three driving mechanisms have been proposed to explain the dynamic evolution of the Tyrrhenian-Apennine system: (1) the northward indentation of the African plate; (2) the retreating subduction of the Adria-Ionian lithosphere; and (3) the gravitational collapse of the Alpine post-collisional wedge. In order to define the relative contribution of each of these mechanisms in the Neogene dynamic of the Tyrrhenian-Apennine system, we performed 3-D laboratory experiments, in which we simulated a retreating subduction process in a compressional regime oriented perpendicularly to the direction of subduction; in this framework we also tested the influence of the gravitational collapse of the overriding plate. Experiments were constructed using dry sand and silicone putties to simulate brittle upper crust and ductile lower crust/upper mantle, respectively; these layers floated on a high-density, low-viscosity glucose syrup which simulated the asthenosphere. The main conclusion of our experiments is that large-scale continental extension, similar to that observed in the Tyrrhenian area, could be reproduced perpendicular to the shortening direction induced by the indentation of the African plate; in this framework, extensional processes are indeed possible if the trench retreat velocity is higher than the rate of shortening induced by the advancing African plate. Our experimental results indicate that this high trench retreat velocity could be explained by the coexistence of the gravitational collapse of the post-Alpine wedge with a slab-pull process, linked to the retreating subduction of the Adria-Ionian plate. While the first mechanism is predominant in the Northern Tyrrhenian area, the second one seems to be important in the latest stage of extension and oceanic accretion of the Southern Tyrrhenian area.

Stratigraphic and tectonic features of the Middle Pleistocene sedimentary and volcanic deposits in the area of Rome (Italy)

Article

Mar 1998
QUATERN INT

The analysis of a large number of stratigraphic logs from boreholes, as well as an extensive field survey, suggests that the Middle Pleistocene sedimentary deposits in the area of Rome can be subdivided into two groups, each one characterised by a different stratigraphy and tectonic setting: a north-eastern sector, corresponding to the eastern urban area of Rome, and a south-western sector, corresponding to the Ponte Galeria area.In the north-eastern sector, the distribution of sediments is influenced by vertical block faulting showing a predominantly north-south trend, superimposed on a Middle Pleistocene NE–SW extensional tectonic domain. In the south-western sector, we suggest that the “Ponte Galeria Formation” auct. can be subdivided into two depositional sequences that can be linked to isotope stages 19 and 21. In addition, a sedimentary hiatus is proposed at the top of the Ponte Galeria sequence. It corresponds to the deposition of a continental succession in the north-eastern sector before the emplacement of pyroclastic deposits from the Colli Albani and Sabatini volcanic Districts. The correlation between these two depositional sequences, that have been identified, and the oxygen isotope time scale allowed us to extend our investigation across to the urban area of Rome, where we have recognised six sedimentary cycles, all of Pleistocene age, which have been tentatively related to particular isotopes stages.

Acquacetosa e Lava di Vallerano, Roma), Rend. The general consistency of T-axis orientations from focal Soc

143-146

Albani

Albani, (Lava dell'Acquacetosa e Lava di Vallerano, Roma), Rend. The general consistency of T-axis orientations from focal Soc. Geol. It., 13, 143–146.

fundamental discussions and suggestions, to Alessandro Amato 1994b. An example of late Pleistocene strike-slip tectonics: the Acque Albule basin

C Faccenna
R Funiciello
P Montone
M Parotto
M Voltaggio

to write this paper. I am also grateful to Francesco Salvini for Faccenna, C., Funiciello, R., Montone, P., Parotto, M. & Voltaggio, M., fundamental discussions and suggestions, to Alessandro Amato 1994b. An example of late Pleistocene strike-slip tectonics: the Acque Albule basin (Tivoli, Latium), Mem. Descr. Carta Geol. d'It., 49, for a critical review of the manuscript, and to Daniel B. Karner 37–50.

Geological summary of the Central Apennines, in Structural Model of Italy, eds Ogniben, L., Parotto, M. volcanic province tephra in the Tiber River valley: age calibration of Middle Pleistocene sea-level changes

Jan 1975
257-311

D B Karner
P R Renne
Roman Geochronology
M Parotto
A Praturlon

Karner, D.B. & Renne, P.R., 1998. 40Ar/39Ar Geochronology of Roman Parotto, M. & Praturlon, A., 1975. Geological summary of the Central Apennines, in Structural Model of Italy, eds Ogniben, L., Parotto, M. volcanic province tephra in the Tiber River valley: age calibration of Middle Pleistocene sea-level changes, Bull. seism. Soc. Am., & Praturlon, A., Quad. Ric. Scient., 90, 257–311, CNR, Rome. Patacca, E., Sartori, R. & Scandone, P., 1991. Tyrrhenian Basin and 110, 740–747.

Fault mechanisms from near-source Fiordelisi, A., 1995. Evidence of active extension in Quaternary volcanoes of Central Italy from breakout analysis and seismicity, data: joint inversion of P polarities and S polarization

Jan 1991
441-451

A Zollo
P Bernard

Zollo, A. & Bernard, P., 1991. Fault mechanisms from near-source Fiordelisi, A., 1995. Evidence of active extension in Quaternary volcanoes of Central Italy from breakout analysis and seismicity, data: joint inversion of P polarities and S polarization, Geophys. J. Int., 104, 441–451.

Stratigrafia e assetto geologico dell'area tirrenico del settore dell'Appennino centrale in base a dati strutturali: implicazioni per l'evoluzione del Mar Tirreno

Jan 1995
49-118

F Marra
C Rosa

Marra, F. & Rosa, C., 1995. Stratigrafia e assetto geologico dell'area tirrenico del settore dell'Appennino centrale in base a dati strutturali: implicazioni per l'evoluzione del Mar Tirreno, Mem. Soc. Geol. It., romana, L a Geologia di Roma, Il Centro Storico, Mem. Descr. Della Carta Geol. d'It., 50, 49–118.

Earthquake occurrence and crustal an experimental approach to the opening of the Tyrrhenian Sea, structure, in T he

Jan 1995
193-211

A Amato
C Chiarabba

Amato, A. & Chiarabba, C., 1995. Earthquake occurrence and crustal an experimental approach to the opening of the Tyrrhenian Sea, structure, in T he Volcano of the Alban Hills, pp. 193–211, ed. Geophys. J. Int., 126, 781–795.

Re-evaluation of minor events: the examples of the 1895 and 1909 Rome earthquakes, Natural Hazards Extension in the Tyrrhenian sea and shortening in the Apennines as results of arc migration

Jan 1986
219-235

F Riguzzi
A Tertulliani

Riguzzi, F. & Tertulliani, A., 1993. Re-evaluation of minor events: the examples of the 1895 and 1909 Rome earthquakes, Natural Hazards, Malinverno, A. & Ryan, W.B.F., 1986. Extension in the Tyrrhenian sea and shortening in the Apennines as results of arc migration 7, 219–235.

Evoluzione tettonica recente del margine driven by sinking of the lithosphere

Jan 1986
227-245

F Salvini
M Tozzi

Salvini, F. & Tozzi, M., 1986. Evoluzione tettonica recente del margine driven by sinking of the lithosphere, T ectonics, 5, 227–245.

Effetto fonti Petrology, in T he del Mille in Italia e nell'Area Mediterranea

Jan 1989
194-223

D Molin
E Guidoboni
R Trigila
E Agosta
C Currado
De Benedetti
A A Freda
C Gaeta
M Palladino
D M Rosa
C Guidoboni
E Sga
Bologna

Molin, D. & Guidoboni, E., 1989. Effetto fonti, effetto monumenti a Roma: i terremoti dell'antichità a oggi, in I T erremoti prima Trigila, R., Agosta, E., Currado, C., De Benedetti, A.A., Freda, C., Gaeta, M., Palladino, D.M. & Rosa, C., 1995. Petrology, in T he del Mille in Italia e nell'Area Mediterranea, pp. 194–223, ed. Guidoboni, E., SGA, Bologna. Volcano of the Alban Hills, pp. 95–165, ed. Trigila, R., Università degli Studi di Roma 'La Sapienza', Rome.

The Apenninic arcs: kinematic relations since late Tortonian times

Jan 1977
425-451

E Locardi
G Lombardi
R Funiciello
M Parotto

Locardi, E., Lombardi, G., Funiciello, R. & Parotto, M., 1977. The Apenninic arcs: kinematic relations since late Tortonian times, Mem. Soc. Geol. It., 45, 425–451.

Three-dimensional Albani seismogenic area (Montone et al. 1995) In the area velocity structure and earthquake relocation in the Alban Hills near San Vittorino, another low-magnitude event was recorded Volcano

Jan 1994
295-306

Colli Chiarabba
C Malagnini
L Amato

orientations determined from instrumental data from the Colli Chiarabba, C., Malagnini, L. & Amato, A., 1994. Three-dimensional Albani seismogenic area (Montone et al. 1995). In the area velocity structure and earthquake relocation in the Alban Hills near San Vittorino, another low-magnitude event was recorded Volcano, Central Italy, Bull. seism. Soc. Am., 84, 295–306.

Stratigraphy Rome area suggests that the present-day regional stress field and volcano-tectonics, in T he The potassium-argon dating of Montone et al. (1995), showing a NE-oriented s3. The surface Late Cenozoic rocks in East Africa and Italy

Jan 1965
33-71

D Rita
C Faccenna
R Funiciello
C Rosa
R Trigila
Università
Studi Di Roma 'la
Sapienza
Rome

mechanisms with different hypocentral depths throughout the De Rita, D., Faccenna, C., Funiciello, R. & Rosa, C., 1995. Stratigraphy Rome area suggests that the present-day regional stress field and volcano-tectonics, in T he Volcano of the Alban Hills, pp. 33–71, ed. Trigila, R., Università degli Studi di Roma 'La Sapienza', Rome. follows the stress field evaluated in the Colli Albani area by Everden, J.F. & Curtis, G.H., 1965. The potassium-argon dating of Montone et al. (1995), showing a NE-oriented s3. The surface Late Cenozoic rocks in East Africa and Italy, Current Anthropol., deformation pattern linked with right-lateral strike-slip

Stratigraphy and volcano-tectonics

D De
C Rita
R Faccenna
C Funiciello
Rosa

Jan 1992
369

Villa I.M.

Low-magnitude earthquakes in Rome: Structural interpretation and implications for the local stress field

Abstract

No full-text available

Recommended publications

Geodynamic and seismotectonic model of a long-lived transverse structure: The Schio-Vicenza Fault Sy...

Tectonics and Seismicity in the periAdriatic Zones: Implications for Seismic Hazard in Italy

Seismicity, seismotectonics and crustal velocity structure of the Messina Strait (Italy)

New Insight into the Recent Earthquake Activity in North Cambay Basin, Western India: Seismological...