The Amatrice 2016 seismic sequence: a preliminary look at the mainshock and aftershocks distribution

We relocated the aftershocks of the MW 6.0 Amatrice 2016 mainshock by inverting with a non-linear probabilitstic method P- and S-arrival time readings produced and released in near realtime by the analyst seismologists of IGNV on duty in the seismic monitoring room. Earthquakes distribution shows the activation of a normal fault system with a main SW-dipping fault extending from Amatrice to NW of Accumoli village for a total length of 40 km. On the northern portion of the main fault hanging-wall volume, the structure become more complex activating an antithetic fault below the Norcia basin. It is worth nothing that below 8-9 km of depth, the whole fault system has an almost continuous sub-horizontal layer interested by an intense seismic activity, about 2 km thick.

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On the mechanical behaviour of a low-angle normal fault: the Alto Tiberina fault (Northern Apennines, Italy) system case study

Solid Earth ◽

10.5194/se-7-1537-2016 ◽

2016 ◽

Vol 7 (6) ◽

pp. 1537-1549 ◽

Cited By ~ 10

Author(s):

Luigi Vadacca ◽

Emanuele Casarotti ◽

Lauro Chiaraluce ◽

Massimo Cocco

Keyword(s):

Mechanical Behaviour ◽

Hanging Wall ◽

Normal Fault ◽

Active Role ◽

Northern Apennines ◽

Fault System ◽

Tectonically Active ◽

Main Fault ◽

Microseismic Activity ◽

High Degree

Abstract. Geological and seismological observations have been used to parameterize 2-D numerical elastic models to simulate the interseismic deformation of a complex extensional fault system located in the Northern Apennines (Italy). The geological system is dominated by the presence of the Alto Tiberina fault (ATF), a large (60 km along strike) low-angle normal fault dipping 20° in the brittle crust (0–15 km). The ATF is currently characterized by a high and constant rate of microseismic activity, and no moderate-to-large magnitude earthquakes have been associated with this fault in the past 1000 years. Modelling results have been compared with GPS data in order to understand the mechanical behaviour of this fault and a suite of minor syn- and antithetic normal fault segments located in the main fault hanging wall. The results of the simulations demonstrate the active role played by the Alto Tiberina fault in accommodating the ongoing tectonic extension in this sector of the chain. The GPS velocity profile constructed through the fault system cannot be explained without including the ATF's contribution to deformation, indicating that this fault, although misoriented, has to be considered tectonically active and with a creeping behaviour below 5 km depth. The low-angle normal fault also shows a high degree of tectonic coupling with its main antithetic fault (the Gubbio fault), suggesting that creeping along the ATF may control the observed strain localization and the pattern of microseismic activity.

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On the mechanical behaviour of a low angle normal fault: the Altotiberina fault (Northern Apennines, Italy) system case study

10.5194/se-2016-48 ◽

2016 ◽

Author(s):

Luigi Vadacca ◽

Emanuele Casarotti ◽

Lauro Chiaraluce ◽

Massimo Cocco

Keyword(s):

Mechanical Behaviour ◽

Numerical Models ◽

Hanging Wall ◽

Normal Fault ◽

Active Role ◽

Northern Apennines ◽

Fault System ◽

Tectonically Active ◽

Main Fault ◽

Microseismic Activity

Abstract. Geological and seismological observations have been used to parameterize 2D numerical models to simulate the interseismic deformation of a complex extensional fault system located in the Northern Apennines (Italy). The geological system is dominated by the presence of the Altotiberina fault (ATF), a large (60 km along strike) low-angle normal fault 20° dipping in the brittle crust (0–15 km). The ATF is currently interested by a high and constant rate of microseismic activity and no moderate-to-large magnitude earthquakes have been associated to it for the past 1000 years. Modelling results have been compared with GPS data in order to understand the mechanical behaviour of this fault and a suite of minor syn- and antithetic normal fault segments located in the main fault hanging-wall. The results of the simulations demonstrate the active role played by the Altotiberina fault in accommodating the on going tectonic extension in this sector of the chain. The GPS velocity profile constructed through the fault system cannot be explained without including the ATF's contribution to deformation, indicating that this fault although misoriented has to be considered tectonically active and with a creeping behaviour below 5 km of depth. The low angle normal fault also shows a high degree of tectonic coupling with its main antithetic fault (the Gubbio fault) suggesting that creeping along the ATF may control the observed strain localization and the pattern of microseismic activity.

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

Earthquake Spectra ◽

10.1193/111417eqs236mr ◽

2018 ◽

Vol 34 (4) ◽

pp. 1585-1610 ◽

Cited By ~ 11

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.

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Localized extension in megathrust hanging wall following great earthquakes in western Nepal

Scientific Reports ◽

10.1038/s41598-021-00297-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Magali Riesner ◽

Laurent Bollinger ◽

Judith Hubbard ◽

Cyrielle Guérin ◽

Marthe Lefèvre ◽

...

Keyword(s):

High Resolution ◽

Hanging Wall ◽

Ground Surface ◽

Normal Fault ◽

Fault Scarp ◽

Fault System ◽

Digital Elevation ◽

Thrust Zone ◽

Elevation Model ◽

Short Time

AbstractThe largest (M8+) known earthquakes in the Himalaya have ruptured the upper locked section of the Main Himalayan Thrust zone, offsetting the ground surface along the Main Frontal Thrust at the range front. However, out-of-sequence active structures have received less attention. One of the most impressive examples of such faults is the active fault that generally follows the surface trace of the Main Boundary Thrust (MBT). This fault has generated a clear geomorphological signature of recent deformation in eastern and western Nepal, as well as further west in India. We focus on western Nepal, between the municipalities of Surkhet and Gorahi where this fault is well expressed. Although the fault system as a whole is accommodating contraction, across most of its length, this particular fault appears geomorphologically as a normal fault, indicating crustal extension in the hanging wall of the MHT. We focus this study on the reactivation of the MBT along the Surkhet-Gorahi segment of the surface trace of the newly named Reactivated Boundary Fault, which is ~ 120 km long. We first generate a high-resolution Digital Elevation Model from triplets of high-resolution Pleiades images and use this to map the fault scarp and its geomorphological lateral variation. For most of its length, normal motion slip is observed with a dip varying between 20° and 60° and a maximum cumulative vertical offset of 27 m. We then present evidence for recent normal faulting in a trench located in the village of Sukhetal. Radiocarbon dating of detrital charcoals sampled in the hanging wall of the fault, including the main colluvial wedge and overlying sedimentary layers, suggest that the last event occurred in the early sixteenth century. This period saw the devastating 1505 earthquake, which produced ~ 23 m of slip on the Main Frontal Thrust. Linked or not, the ruptures on the MFT and MBT happened within a short time period compared to the centuries of quiescence of the faults that followed. We suggest that episodic normal-sense activity of the MBT could be related to large earthquakes rupturing the MFT, given its proximity, the sense of motion, and the large distance that separates the MBT from the downdip end of the locked fault zone of the MHT fault system. We discuss these results and their implications for the frontal Himalayan thrust system.

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Structural complexities and tectonic barriers controlling recent seismic activity of the Pollino area (Calabria-Lucania, Southern Italy) – constraints from stress inversion and 3D fault model building

10.5194/se-2021-76 ◽

2021 ◽

Author(s):

Daniele Cirillo ◽

Cristina Totaro ◽

Giusy Lavecchia ◽

Barbara Orecchio ◽

Rita de Nardis ◽

...

Keyword(s):

Seismic Activity ◽

Model Building ◽

Fault Model ◽

P Wave ◽

Fault System ◽

Double Difference ◽

Seismic Sequence ◽

High Angle ◽

Time Space ◽

Seismological Data

Abstract. The integration of field geology and high-resolution seismological data allowed us to reconstruct the 3D Fault Model of the sources which gave rise to the 2010–2014 Pollino seismic sequence. The model is constrained at the surface by structural geological data which provide the true attitude of the single faults and their cross-cut relationships. At depth, the fault geometry was obtained using the distributions of selected high-quality relocated hypocenters. Relocations were carried out through a non-linear Bayloc algorithm, followed by the double-difference relative location method HypoDD, applied to a 3D P-wave velocity model. Geological and seismological data converge in describing an asymmetric active extensional fault system characterized by an E to NNE-dipping low-angle detachment, with its high-angle synthetic splays, and SW- to WSW-dipping, high-angle antithetic faults. The cluster of hypocenters and the peculiar time-space evolution of the seismic activity highlight that two sub-parallel WSW-dipping seismogenic sources, namely the Rotonda-Campotenese and Morano-Piano di Ruggio faults activated during the seismic crisis. By applying to the activated structures the appropriate earthquake-scaling relationships, based on fault length and fault area, we infer that the maximum expected magnitudes calculated using the fault area are the more reliable. We estimated Mw = 6.4 for the Rotonda-Campotenese and Mw = 6.2 for the Morano-Piano di Ruggio deducing that both the faults did not release their seismic potential during the 2010–2014 seismic sequence. The size of the activated patches, reconstructed by projecting on the 3D seismogenic fault planes the early aftershocks of the seismicity clusters, are consistent with the observed magnitude of the associate strongest events. Finally, we point out that the western segment of the Pollino Fault, despite not being presently active, acts as a barrier to the southern propagation of the Rotonda-Campotenese and Morano-Piano di Ruggio faults, limiting their dimensions and seismogenic potential.

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Using 2D long-streamer seismic waveform tomography to decipher sedimentary processes surrounding a forearc fault offshore Alaska

10.5194/egusphere-egu21-13056 ◽

2021 ◽

Author(s):

Amin Kahrizi ◽

Matthias Delescluse ◽

Mathieu Rodriguez ◽

Pierre-Henri Roche ◽

Anne Bécel ◽

...

Keyword(s):

Mass Transport ◽

Hanging Wall ◽

Plate Boundary ◽

Normal Fault ◽

P Wave ◽

Fault System ◽

Fault Activity ◽

Seismic Waveform ◽

Waveform Tomography ◽

Mass Transport Deposits

Acoustic full-waveform inversion (FWI), or waveform tomography, involves use of both phase and amplitude of the recorded compressional waves to obtain a high-resolution P-wave velocity model of the propagation medium. Recent theoretical and computing advances now allow the application of this highly non-linear technique to field data. This led to common use of the FWI for industrial purposes related to reservoir imaging, physical properties of rocks, and fluid flow. Application of FWI in the academic domain has, so far, been limited, mostly because of the lack of adequate seismic data. Modern multichannel seismic (MCS) reflection data acquisition now&#160; have long offsets which, in some cases, enable constraining FWI-derived subsurface velocities at a significant enough depth to be useful for structural or tectonic purposes.In this study, we show how FWI can help decipher the record of a fault activity through time at the Shumagin Gap in Alaska. The MCS data were acquired on R/V Marcus G. Langseth during the 2011 ALEUT cruise using two 8-km-long seismic streamers and a 6600 cu. in. tuned airgun array. One of the most noticeable reflection features imaged on two profiles is a large, landward-dipping normal fault in the overriding plate; a structural configuration making the area prone to generating both transoceanic and local tsunamis, including from landslides. This fault dips ~40&#176;- 45&#176;, cuts the entire crust and connects to the plate boundary fault at ~35 km depth, near the intersection of the megathrust with the forearc mantle wedge. The fault system reaches the surface at the shelf edge 75 km from the trench and forms the ~6-km deep Sanak basin. However, the record of the recent fault activity remains unclear as contouritic currents tend to be trapped by the topography created by faults, even after they are no longer active.&#160; Erosion surfaces and onlaps from contouritic processes as well as gravity collapses and mass transport deposits result in a complex sedimentary record that make it challenging to evaluate the fault activity using conventional MCS imaging alone. The long streamers used facilitated recording of refraction arrivals in the targeted continental slope area, which permitted running streamer traveltime tomography followed by FWI to produce coincident detailed velocity profiles to complement the reflection sections. We performed FWI imaging on two 40-km-long sections of the ALEUT lines crossing the Sanak basin. The images reveal low velocities of mass transport deposits as well as velocity inversions that may indicate mechanically weak layers linking some faults to gravity sliding on a d&#233;collement. One section also shows a velocity inversion in continuity to a bottom simulating reflector (BSR) only partially visible in the reflection image. The BSR velocity anomaly abruptly disappears across the main normal fault suggesting either an impermeable barrier or a lack of trapped fluids/gas in the hanging wall.

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Structural characterization of fault damage zones in carbonates (Central Apennines, Italy)

10.5194/egusphere-egu21-1525 ◽

2021 ◽

Author(s):

Miriana Chinello ◽

Michele Fondriest ◽

Giulio Di Toro

Keyword(s):

Fault Zone ◽

Hanging Wall ◽

Damage Zone ◽

Normal Fault ◽

Vertical Displacement ◽

Fault System ◽

Normal Faults ◽

Central Apennines ◽

Fault Surface ◽

Fracture Intensity

The Italian Central Apennines are one of the most seismically active areas in the Mediterranean (e.g., L&#8217;Aquila 2009, Mw 6.3 earthquake). The mainshocks and the aftershocks of these earthquake sequences propagate and often nucleate in fault zones cutting km-thick limestones and dolostones formations. An impressive feature of these faults is the presence, at their footwall, of few meters to hundreds of meters thick damage zones. However, the mechanism of formation of these damage zones and their role during (1) individual seismic ruptures (e.g., rupture arrest), (2) seismic sequences (e.g., aftershock evolution) and (3) seismic cycle (e.g., long term fault zone healing) are unknown. This limitation is also due to the lack of knowledge regarding the distribution, along strike and with depth, of damage with wall rock lithology, geometrical characteristics (fault length, inherited structures, etc.) and kinematic properties (cumulative displacement, strain rate, etc.) of the associated main faults.Previous high-resolution field structural surveys were performed on the Vado di Corno Fault Zone, a segment of the ca. 20 km long Campo Imperatore normal fault system, which accommodated ~ 1500 m of vertical displacement (Fondriest et al., 2020). The damage zone was up to 400 m thick and dominated by intensely fractured (1-2 cm spaced joints) dolomitized limestones with the thickest volumes at fault oversteps and where the fault cuts through an older thrust zone. Here we describe two minor faults located in the same area (Central Apennines), but with shorter length along strike. They both strike NNW-SSE and accommodated a vertical displacement of ~300 m.The Subequana Valley Fault is about 9 km long and consists of multiple segments disposed in an en-echelon array. The fault juxtaposes pelagic limestones at the footwall and quaternary deposits at the hanging wall. The damage zone is < 25 m &#160;thick &#160;and comprises fractured (1-2 cm spaced joints) limestones beds with decreasing fracture intensity moving away from the master fault. However, the damage zone thickness increases up to &#8764;100 m in proximity of subsidiary faults striking NNE-SSW. The latter could be reactivated inherited structures.The Monte Capo di Serre Fault is about 8 km long and characterized by a sharp ultra-polished master fault surface which cuts locally dolomitized Jurassic platform limestones. The damage zone is up to 120 m thick and cut by 10-20 cm spaced joints, but it reaches an higher fracture intensity where is cut by subsidiary, possibly inherited, faults striking NNE-SSW.Based on these preliminary observations, faults with similar displacement show comparable damage zone thicknesses. The most relevant damage zone thickness variations are related to geometrical complexities rather than changes in lithology (platform vs pelagic carbonates). &#160;In particular, the largest values of damage zone thickness and fracture intensity occur at fault overstep or are associated to inherited structures. The latter, by acting as strong or weak barriers (sensu Das and Aki, 1977) during the propagation of seismic ruptures, have a key role in the formation of damage zones and the growth of normal faults.

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Heterogeneous Behavior of the Campotosto Normal Fault (Central Italy) Imaged by InSAR GPS and Strong-Motion Data: Insights from the 18 January 2017 Events

Remote Sensing ◽

10.3390/rs11121482 ◽

2019 ◽

Vol 11 (12) ◽

pp. 1482 ◽

Cited By ~ 5

Author(s):

Daniele Cheloni ◽

Nicola D’Agostino ◽

Laura Scognamiglio ◽

Elisa Tinti ◽

Christian Bignami ◽

...

Keyword(s):

Central Italy ◽

Sampling Rate ◽

Strong Motion ◽

Normal Fault ◽

Slip Distribution ◽

Fault System ◽

Time Interval ◽

Seismic Sequence ◽

Main Shocks ◽

Heterogeneous Behavior

On 18 January 2017, the 2016–2017 central Italy seismic sequence reached the Campotosto area with four events with magnitude larger than 5 in three hours (major event MW 5.5). To study the slip behavior on the causative fault/faults we followed two different methodologies: (1) we use Interferometric Synthetic Aperture Radar (InSAR) interferograms (Sentinel-1 satellites) and Global Positioning System (GPS) coseismic displacements to constrain the fault geometry and the cumulative slip distribution; (2) we invert near-source strong-motion, high-sampling-rate GPS waveforms, and high-rate GPS-derived static offsets to retrieve the rupture history of the two largest events. The geodetic inversion shows that the earthquake sequence occurred along the southern segment of the SW-dipping Mts. Laga normal fault system with an average slip of about 40 cm and an estimated cumulative geodetic moment of 9.29 × 1017 Nm (equivalent to a MW~6). This latter estimate is larger than the cumulative seismic moment of all the events, with MW > 4 which occurred in the corresponding time interval, suggesting that a fraction (~35%) of the overall deformation imaged by InSAR and GPS may have been released aseismically. Geodetic and seismological data agree with the geological information pointing out the Campotosto fault segment as the causative structure of the main shocks. The position of the hypocenters supports the evidence of an up-dip and northwestward rupture directivity during the major shocks of the sequence for both static and kinematic inferred slip models. The activated two main slip patches are characterized by rise time and peak slip velocity in the ranges 0.7–1.1 s and 2.3–3.2 km/s, respectively, and by ~35–50 cm of slip mainly concentrated in the shallower northern part of causative fault. Our results show that shallow slip (depth < 5 km) is required by the geodetic and seismological observations and that the inferred slip distribution is complementary with respect to the previous April 2009 seismic sequence affecting the southern half of the Campotosto fault. The recent moderate strain-release episodes (multiple M~5–5.5 earthquakes) and the paleoseismological evidence of surface-rupturing events (M~6.5) suggests therefore a heterogeneous behavior of the Campotosto fault.

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Seismic reflection imaging of the low-angle Panamint Valley normal fault system, eastern California, USA

10.5194/egusphere-egu2020-5625 ◽

2020 ◽

Author(s):

Ryan Gold ◽

William Stephenson ◽

Richard Briggs ◽

Christopher DuRoss ◽

Eric Kirby ◽

...

Keyword(s):

Seismic Reflection ◽

Late Quaternary ◽

Hazard Analysis ◽

Hanging Wall ◽

Normal Fault ◽

Alluvial Fan ◽

P Wave ◽

Fault System ◽

Normal Faults ◽

High Angle

A fundamental question in seismic hazard analysis is whether <30&#186;-dipping low-angle normal faults (LANFs) slip seismogenically. In comparison to more steeply dipping (45-60&#186;) normal faults, LANFs have the potential to produce stronger shaking given increased potential rupture area in the seismogenic crust and increased proximity to manmade structures built on the hanging wall. While inactive LANFs have been documented globally, examples of seismogenically active LANFs are limited. The western margin of the Panamint Range in eastern California is defined by an archetype LANF that dips west beneath Panamint Valley and has evidence of Quaternary motion. In addition, high-angle dextral-oblique normal faults displace mid-to-late Quaternary alluvial fans near the range front. To image shallow (<1 km depth), crosscutting relationships between the low- and high-angle faults along the range front, we acquired two high-resolution P-wave seismic reflection profiles. The northern ~4.7-km profile crosses the 2-km-wide Wildrose Graben and the southern ~1.1-km profile extends onto the Panamint Valley playa, ~7.5 km S of Ballarat, CA. The profile across the Wildrose Graben reveals a robust, low-angle reflector that likely represents the LANF separating Plio-Pleistocene alluvial fanglomerate and pre-Cambrian meta-sedimentary deposits. High-angle faults interpreted in the seismic profile correspond to fault scarps on Quaternary alluvial fan surfaces. Interpretation of the reflection data suggests that the high-angle faults vertically displace the LANF up to 70 m within the Wildrose Graben. Similarly, the profile south of Ballarat reveals a low-angle reflector, which appears both rotated and displaced up to 260 m by high-angle faults. These results suggest that near the Panamint range front, the high-angle faults are the dominant late Quaternary structures. We conclude that, at least at shallow (<1 km) depths, the LANF we imaged is not seismogenically active today.

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Faulting, doming and basin formation during orogenic arcuation – the case of the Shkoder-Peja Normal Fault System (northern Albania and Kosovo)

10.5194/egusphere-egu21-14816 ◽

2021 ◽

Author(s):

Marc U. Grund ◽

Mark R. Handy ◽

Jörg Giese ◽

Jan Pleuger ◽

Lorenzo Gemignani ◽

...

Keyword(s):

Hanging Wall ◽

Normal Fault ◽

Sedimentary Basins ◽

Vertical Displacement ◽

Ductile Deformation ◽

Fault System ◽

Normal Faulting ◽

Two Phase ◽

Brittle Faulting ◽

Topographic Constraints

The junction between the Dinarides and the Hellenides coincides with an orogenic bend characterized by a complex system of faults, domes and sedimentary basins. The major structure at this junction is the Shkoder-Peja Normal Fault (SPNF) system, which trends oblique to the orogen and is segmented along strike, with ductile-to-brittle branches in its southwestern and central parts that border two domes in its footwall: (1) the Cukali Dome (RSCM peak-T 190-280&#176;C), a doubly-plunging upright antiform deforming Dinaric nappes, including the Krasta-Cukali nappe with its Middle Triassic to Early Eocene sediments; (2) the newly discovered Decani Dome (RSCM peak-T 320-460&#176;C) delimited to the E by the ~1500 m wide Decani Shear Zone (DSZ) that exposes Paleozoic to Mesozoic strata of the East Bosnian Durmitor nappe (EBD). In the northeasternmost segment, the strike of the SPNF system changes from roughly orogen-perpendicular to orogen-parallel. There, the SPNF system has brittle branches- most notably the Dukagjini Fault (DF) that forms the northwestern limit of the Western Kosovo Basin (WKB).The westernmost ductile-brittle SPNF segment strikes along the southern limb of the Cukali Dome with an increasing vertical offset from 0 m near Shkoder eastwards to >1000 m at the eastern extent of the dome (near Fierza) where normal faulting cuts the nappe contact between the High Karst and Krasta-Cukali unit. The central segment north of the Tropoja Basin, with several smaller branches changing in strike, has a vertical throw of at least 1500 meters based on topographic constraints. Even further to the northeast, the SPNF system includes the moderately E-dipping DSZ juxtaposing the EBD in its footwall against m&#232;lange of the West Vardar unit in its hanging wall, where offset is difficult to determine. 3 km eastwards, in the hanging wall to the DSZ, the brittle DF accommodates another 1000 m of vertical displacement as constrained by maximum depth of sediments of the WKB.Ductile deformation along the Cukali and Decani Domes occurred sometime between the end of Dinaric thrusting and the formation of the WKB. Brittle faulting partly reactivates ductile segments, but also creates new branches (DF) within the hanging wall of the ductile DSZ. These were active during mid-Miocene to Pliocene times as constrained by syn-tectonic sediments in the WKB. We interpret the SPNF system as a two-phase composite extensional structure with normal faulting that migrated from its older trace along the ductile DSZ to the brittle DF as indicated by cross-cutting relations. The Decani Dome, with higher metamorphic temperature conditions than the Cukali Dome, may reflect the south-westernmost extent of late Paleogene extension in the Dinarides. It may be related to other core complexes and possibly to limited subduction rollback beneath the Dinarides (Matenco and Radivojevi, 2012). Extension from mid-Miocene time onwards was probably related to Hellenic CW rotation during Neogene orogenic arcuation, possibly triggered by enhanced rollback beneath the Hellenides (Handy et al., 2019).Handy, M.R.,et al. 2019: Tectonics, v. 38, p. 2803&#8211;2828, doi:10.1029/2019TC005524.Matenco, L.,& Radivojevi, D. 2012: Tectonics, v. 31, p. 1&#8211;31, doi:10.1029/2012TC003206.

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