The Gubbio normal fault (Central Italy): geometry, displacement distribution and tectonic evolution

2004 ◽  
Vol 26 (12) ◽  
pp. 2233-2249 ◽  
Author(s):  
F. Mirabella ◽  
M.G. Ciaccio ◽  
M.R. Barchi ◽  
S. Merlini
Keyword(s):  
Tectonic Evolution ◽  
Central Italy ◽  
Normal Fault ◽  
Displacement Distribution

scholarly journals Seismogenesis in Central Apennines, Italy: an integrated analysis of minor earthquake sequences and structural data in the Amatrice-Campotosto area

2009 ◽  
Vol 47 (6) ◽  
Author(s):  
P. Boncio ◽  
G. Lavecchia ◽  
G. Milana ◽  
B. Rozzi
Keyword(s):  
Late Quaternary ◽  
Central Italy ◽  
Normal Fault ◽  
Structural Data ◽  
Integrated Analysis ◽  
Fault Plane Solutions ◽  
Small Magnitude ◽  
Fault Surface ◽  
Displacement Profile ◽  
Earthquake Sequences

We present a seismotectonic study of the Amatrice-Campotosto area (Central Italy) based on an integrated analysis of minor earthquake sequences, geological data and crustal rheology. The area has been affected by three small-magnitude seismic sequences: August 1992 (M=3.9), June 1994 (M=3.7) and October 1996 (M=4.0). The hypocentral locations and fault plane solutions of the 1996 sequence are based on original data; the seismological features of the 1992 and 1994 sequences are summarised from literature. The active WSWdipping Mt. Gorzano normal fault is interpreted as the common seismogenic structure for the three analysed sequences. The mean state of stress obtained by inversion of focal mechanisms (WSW-ENE-trending deviatoric tension) is comparable to that responsible for finite Quaternary displacement, showing that the stress field has not changed since the onset of extensional tectonics. Available morphotectonic data integrated with original structural data show that the Mt. Gorzano Fault extends for ~28 km along strike. The along-strike displacement profile is typical of an isolated fault, without significant internal segmentation. The strong evidence of late Quaternary activity in the southern part of the fault (with lower displacement gradient) is explained in this work in terms of displacement profile readjustment within a fault unable to grow further laterally. The depth distribution of seismicity and the crustal rheology yield a thickness of ~15 km for the brittle layer. An area of ~530 km2 is estimated for the entire Mt. Gorzano Fault surface. In historical times, the northern portion of the fault was probably activated during the 1639 Amatrice earthquake (I = X, M~ 6.3), but this is not the largest event we expect on the fault. We propose that a large earthquake might activate the entire 28 km long Mt. Gorzano Fault, with an expected Mmax up to 6.7.

scholarly journals Workflow of Digital Field Mapping and Drone-Aided Survey for the Identification and Characterization of Capable Faults: The Case of a Normal Fault System in the Monte Nerone Area (Northern Apennines, Italy)

2020 ◽  
Vol 9 (11) ◽  
pp. 616
Author(s):  
Mauro De Donatis ◽  
Mauro Alberti ◽  
Mattia Cipicchia ◽  
Nelson Muñoz Guerrero ◽  
Giulio F. Pappafico ◽  
...  
Keyword(s):  
Central Italy ◽  
Three Dimensional ◽  
Normal Fault ◽  
Field Work ◽  
Digital Data ◽  
Fault System ◽  
Seismic Profiles ◽  
Postgraduate Students ◽  
Recent Earthquakes

Field work on the search and characterization of ground effects of a historical earthquake (i.e., the Cagli earthquake in 1781) was carried out using terrestrial and aerial digital tools. The method of capturing, organizing, storing, and elaborating digital data is described herein, proposing a possible workflow starting from pre-field project organization, through reiteration of field and intermediate laboratory work, to final interpretation and synthesis. The case of one of the most important seismic events in the area of the northern Umbria–Marche Apennines provided the opportunity to test the method with both postgraduate students and researchers. The main result of this work was the mapping of a capable normal fault system with a great number of observations, as well as a large amount of data, from difficult outcrop areas. A GIS map and a three-dimensional (3D) model, with the integration of subsurface data (i.e., seismic profiles and recent earthquake distribution information), allowed for a new interpretation of an extensional tectonic regime of this Apennines sector, similar to one of the southernmost areas of central Italy where recent earthquakes occurred on 2016.

scholarly journals Surface Faulting Caused by the 2016 Central Italy Seismic Sequence: Field Mapping and LiDAR/UAV Imaging

2018 ◽  
Vol 34 (4) ◽  
pp. 1585-1610 ◽  
Author(s):  
Stefano Gori ◽  
Emanuela Falcucci ◽  
Fabrizio Galadini ◽  
Paolo Zimmaro ◽  
Alberto Pizzi ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Central Italy ◽  
Normal Fault ◽  
Fault System ◽  
Surface Rupture ◽  
Field Mapping ◽  
Central Italy Earthquake ◽  
Levels Of Detail ◽  
Main Fault ◽  
Surface Ruptures

The three mainshock events (M6.1 24 August, M5.9 26 October, and M6.5 30 October 2016) in the Central Italy earthquake sequence produced surface ruptures on known segments of the Mt. Vettore–Mt. Bove normal fault system. As a result, teams from Italian national research institutions and universities, working collaboratively with the U.S. Geotechnical Extreme Events Reconnaissance Association (GEER), were mobilized to collect perishable data. Our reconnaissance approach included field mapping and advanced imaging techniques, both directed towards documenting the location and extent of surface rupture on the main fault exposure and secondary features. Mapping activity occurred after each mainshock (with different levels of detail at different times), which provides data on the progression of locations and amounts of slip between events. Along the full length of the Mt. Vettore–Mt. Bove fault system, vertical offsets ranged from 0–35 cm and 70–200 cm for the 24 August and 30 October events, respectively. Comparisons between observed surface rupture displacements and available empirical models show that the three events fit within expected ranges.

Disproving the Presence of Paleozoic‐Triassic Metamorphic Rocks on the Island of Zannone (Central Italy): Implications for the Early Stages of the Tyrrhenian‐Apennines Tectonic Evolution

Tectonics ◽  
2020 ◽  
Vol 39 (12) ◽  
Author(s):  
Manuel Curzi ◽  
Andrea Billi ◽  
Eugenio Carminati ◽  
Federico Rossetti ◽  
Richard Albert ◽  
...  
Keyword(s):  
Tectonic Evolution ◽  
Central Italy ◽  
Metamorphic Rocks ◽  
Early Stages

Sequential modelling of the 2016 Central Italy earthquake cluster using multisource satellite observations and quantitative assessment of Coulomb stress change

2020 ◽  
Vol 221 (1) ◽  
pp. 451-466 ◽  
Author(s):  
Qian Xu ◽  
Qiang Chen ◽  
Jingjing Zhao ◽  
Xianwen Liu ◽  
Yinghui Yang ◽  
...  
Keyword(s):  
Surface Deformation ◽  
Central Italy ◽  
Normal Fault ◽  
Satellite Observations ◽  
Fault System ◽  
Potential Zone ◽  
Seismic Zone ◽  
Seismogenic Fault ◽  
Positive Effects ◽  
Sequence Of Events

SUMMARY A sequence of earthquake events consisting of three large shocks occurred in Central Italy from August to October in 2016 with the duration of almost 2 months. The preliminary study on the seismic mechanism suggests that the sequence of events is the result from the activity of the SW dipping Mt Bove–Mt Vettore–Mt Gorzano normal fault system. For investigation and understanding of the coseismic faulting of the seismogenic fault alignment, we collect a set of comprehensive satellite observations including the Sentinel-1A, ALOS-2/PALSAR-2 and GPS data to map the coseismic surface deformation and estimate the source models in this study. The derived faulting model for the first Amatrice event is characterized by two distinct slip asperities suggesting that it is a predominantly normal dip-slip motion with slight strike-slip component. The second event, Visso earthquake is almost a purely normal rupture. The third Norcia event is dominated by the normal dip-slip rupture of the seismogenic fault, and has propagated up to the ground with significant slip. The three faulting models are then utilized to quantify the Coulomb failure stress (CFS) change over the seismic zone. First, the CFS change on the subsequent two seismogenic faults of the earthquake sequence is estimated, and the derived positive CFS change induced by the preceding earthquakes suggests that the early events have positive effects on triggering the subsequent seismicity. We then explore the response relation of the aftershocks including 961 events with magnitudes larger than M 3.0 to the CFS change over the seismic zone. It suggests that the rupture pattern of the aftershocks is similar to the major shocks with predominantly normal dip-slip. To assess the risk of the future seismic hazard, we analyse quantitatively the spatial distribution of aftershock occurrence and CFS transfer at the seismogenic depth, indicating that the ruptures of the three major shocks do partly release the accumulated strain on the associated fault alignment as well as the dense aftershock, but the CFS increase zone with few aftershocks in the southwest of the eastern Quaternary fault alignment of Central Italy poses the potential of further rupture. In particular, the distribution of aftershock migration also suggests that the north extension of the Mt Bove fault is the potential zone with rupture risk.

Evolution of the south-central segment of the Archean Abitibi Belt, Quebec. Part II: Tectonic evolution and geomechanical model

1983 ◽  
Vol 20 (9) ◽  
pp. 1355-1373 ◽  
Author(s):  
Erich Dimroth ◽  
Lazlo Imreh ◽  
Normand Goulet ◽  
Michel Rocheleau
Keyword(s):  
Tectonic Evolution ◽  
Anisotropic Plate ◽  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Normal Fault ◽  
Geomechanical Model ◽  
Southwestern Part ◽  
South Central ◽  
Central Segment ◽  
Volcanic Terrain

In this paper, we describe the relations between the paleogeographic and tectonic evolution of the southwestern part of the Archean Abitibi and Bellecombe belts. Volcanism in the Abitibi Belt created a very thick, anisotropic plate composed of competent volcanic rocks and broken by the Duparquet–Destor break. The depocenters of the upper division of diverse volcanic rocks subsided about 10 km relative to their surroundings, and some central volcanic complexes within this division were consolidated by synvolcanic plutons and their thermal metamorphic aureole. The Cadillac break, a normal fault, separated the Abitibi and Bellecombe belts. The latter consisted of comparatively incompetent sedimentary rocks on top of a basement composed of ultramafic–mafic flows.North–south compression of the volcanic terrain during the Kenoran Orogeny produced a set of flexure folds, F1, that curve around the consolidated cores of central volcanic complexes generally in an easterly direction. Synclinoria nucleated at the deeply subsident depocenters of the upper diverse division. Further north–south flattening and subvertical stretching produced the east-trending F2 folds, their axial-plane schistosity S2, and local superposed schistosities S3 and S4. Southward verging recumbent folds suggest that the Bellecombe Belt simultaneously was pulled northward below the Abitibi Belt. During the orogeny, the Duparquet–Destor and Cadillac breaks were transformed to thrust faults; the Duparquet–Destor break also shows minor (< 3 km) right-lateral strike slip. Diapiric rise of late- to post-kinematic plutons locally distorted earlier schistosities.

scholarly journals Geophysical characterisation of two segments of the Møre-Trøndelag Fault Complex, Mid-Norway

2011 ◽  
Vol 3 (1) ◽  
pp. 159-186
Author(s):  
A. Nasuti ◽  
C. Pascal ◽  
J. Ebbing ◽  
J. F. Tønnesen
Keyword(s):  
Tectonic Evolution ◽  
Deep Structure ◽  
Normal Fault ◽  
Geophysical Data ◽  
Data Sets ◽  
Normal Faulting ◽  
The South ◽  
The Past ◽  
Magnetic Resistivity ◽  
Wide Zone

Abstract. The Møre-Trøndelag Fault Complex (MTFC) has controlled the tectonic evolution of Mid-Norway and its shelf for the past 400 Myr through repeated reactivations during Paleozoic, Mesozoic and perhaps Cenozoic times, the very last phase of reactivation involving normal to oblique slip faulting. Despite its pronounced signature in the landscape, its deep structure has remained unresolved until now. We focused on two specific segments of the MTFC (i.e. the so-called "Tjellefonna" and "Bæverdalen" faults) and acquired multiple geophysical data sets (i.e. gravity, magnetic, resistivity and shallow refraction profiles). A 100–200 m wide zone of gouge and/or brecciated bedrock dipping steeply to the south is interpreted as being the "Tjellefonna Fault" stricto sensu. The fault appears to be flanked by two additional but minor damage zones. A secondary normal fault also steeply dipping to the south but involving indurated breccias was detected ~1 km farther north. The "Bæverdalen Fault" is interpreted as a ~700 m wide and highly deformed zone involving fault gouge, breccias and lenses of intact bedrock, as such it is probably the most important fault segment in the studied area and accommodated most of the strain during presumably late Jurassic normal faulting. Our geophysical data are indicative of a "Bæverdalen Fault" dipping steeply towards the south, in agreement with the average orientation of the local tectonic grain. Our findings suggest that the influence of Mesozoic normal faulting along the MTFC on landscape development is more complex than previously anticipated.

Sign in / Sign up

Export Citation Format

Share Document