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(a) Geological section of the antithetic faults domain (AFD) (location on Fig. 2). The tectonic style is characterized by NE-dipping rotating normal faults bounding southward-tilted fault blocks. The NE-dipping antithetic faults cut the apexes of the alluvial fans of the Middle Aterno Valley deposits, suggesting that extensional faulting shifted from the Middle Aterno Valley toward the antithetic faults domain (AFD). (b) Domino model adopted to constrain the extension factor β in the AFD. A first-order estimate of the extension may be performed assuming steep initial (60º) fault dip and southwestward tilting of the fault blocks. The geometry of the fault blocks shows that, locally, the extension factor β could be as high as 1.75.
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Structural analysis and field mapping together with simple geometrical and flexural elastic models, document that two styles of Quaternary extensional tectonics characterized the Gran Sasso range (central Apennines, Italy). In the western part of the range, extension took place on 10–15-km-long range-front normal faults with associated 600–1000-m-h...
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... Butler & Mazzoli, 2006;Nemčok et al., 1995;Williams et al., 1989) and thrusts reactivated as normal faults (e.g. D'Agostino et al., 1998;Gamond, 1994) respectively, can produce buttressing onto or the reactivation of the entire inherited fault. Sometimes, fault reactivation can be recognized using field or subsurface data (e.g. ...
... Tavani et al., 2021;Tavarnelli, 1996;Tavarnelli et al., 2004) and thrust faults reused with normal kinematics (e.g. Curzi et al., 2020;D'Agostino et al., 1998;Faccenna et al., 1995). ...
The San Potito area in central Apennines (Italy), enclosed within the Latium‐Abruzzi carbonate platform, exposes anomalously pelagic carbonates filling an intraplatform basin formed during Jurassic rifting. Oriented obliquely to the regional NW‐SE trend of Cenozoic thrusts and extensional faults, the basin's eastern boundary fault system, striking N‐S, played a pivotal role in structuring orogenic and post‐orogenic features. Large tracts of the fault experienced double reactivation: positive inversion during Miocene shortening, and negative during post‐orogenic extension. Double reactivation is evidenced by older‐on‐younger extensional contacts, and by the change in orientation of thrusts and recent extensional faults from NW‐SE to NNW‐SSE, the latter being consistent with the trend of Jurassic rift‐related structures of the area. This structural interplay highlights the importance of Jurassic faults and their ability in forcing the structural trends, by surviving across multiple deformation stages, even controlling active extensional seismicity.
... The footwall ramp, that exhibits the highest dip along the thrust, is a preferential site for reactivation [e.g., Averbuch et al., 1992, Mohapatra and Johnson, 1998, Ouzgaït et al., 2010, Smith and Bruhn, 1984, Tari et al., 2023. These mechanical constraints lead to post-or late orogenic surface normal faults short-cutting the footwall flats and rooting down in the thrust ramps at depth [D'Agostino et al., 1998, Legrand et al., 1991, Mohapatra and Johnson, 1998, Roure et al., 1994, Stein and Blundell, 1990, Tari et al., 2023, Tavarnelli, 1999. Hence, exhumation of the deep geometry of the reactivating fault system (the initial thrust ramps) may lead to the observation of anomalously low angle normal faults [e.g., Ratcliffe et al., 1986, Morley, 2009 like in the Corinth Gulf region [Flotte et al., 2005, Jolivet et al., 2010a, Lecomte et al., 2012, Papanikolaou and Royden, 2007, Papanikolaou et al., 2009, Sorel, 2000. ...
... Due to the slab retreat of the Adriatic plate, the central Apennines have moved eastward to the European plate since Oligocene period [46,51,53,54]. During the Quaternary, the evolution of the Apennine was characterised by an extensional regime and influenced by thick sequence of continental deposits [55,56]. Moreover, in the Plio-Quaternary tectonics period, the clastic and alluvial deposits filled the intramontane plains [46,55,56]. ...
... During the Quaternary, the evolution of the Apennine was characterised by an extensional regime and influenced by thick sequence of continental deposits [55,56]. Moreover, in the Plio-Quaternary tectonics period, the clastic and alluvial deposits filled the intramontane plains [46,55,56]. It affected groundwater circulation within the karst aquifers, by hindering the evolution of the karst system. ...
Groundwater in karst aquifers is frequently tapped for drinking purposes, due to frequent huge volumes of resources. Unfortunately, vulnerability of these aquifers can be high, due to possible fast transfer of recharge water on springs by the karst network. On Gran Sasso Mountain regional aquifer, several springs are subjected to drinking withdrawal and an updated evaluation of their potential is now a fundamental issue to be considered, facing climate change effects, which reflect on variation of discharge regimen and values. To distinguish between different contribution of spring recharge, a tracer test has been carried out on the Vitella d’Oro spring, fed both by the regional aquifer and by a local system exposed to karst features developed in the Rigopiano Conglomerates formation. Thanks to hydrogeological, hydrogeochemical and isotopic data, a conceptual model of spring recharge has been proposed and subsequently validated by the tracer test results. All information confirms the superimposition on the regional base flow, by a relevant contribution of the karst network, influencing the spring discharge in recharge periods. In detail, a fast flow component is responsible for discharge peaks and frequently of turbidity events, having a mean velocity ranging from 30 to 70 m/h in the aquifer. Besides of this fast flow, an additional aliquot of the recharge is due to the same local aquifer, but slower flow clearly identifiable by hydrochemistry and isotopic data. Thanks to these findings, a renewed management of the spring has been suggested, considering the different degrees of aquifer vulnerability (turbidity occurrence) directly related to the discharge regimen.
... Its dip is markedly smaller than 60° as predicted by Anderson's theory of faulting for isotropic rocks under coaxial stresses. This further indicates that the crust under the rift is anisotropic and the stress axes rotate around the weak zones (Morley, 2010), which can readily lead to tectonic reactivation (e.g., Corti et al., 2011;D'Agostino et al., 1998;Faccenna et al., 1995). In addition, the normal LSF is developed in the hanging wall of the Lishi thrust fault (Figure 2). ...
The formation of magma‐poor continental rifts is an enigmatic process, as the weakening mechanism(s) for cratonic lithosphere remains uncertain in the absence of elevated lithospheric temperature. One view links weakening to melts hidden at depth, while another ascribes it to pre‐existing weaknesses. Long‐term extensional rates also influence lithospheric strength and rift evolution. We target the Linfen Basin (LB) in the magma‐poor Shanxi Rift System (SRS) in the North China Craton to understand these components. We apply cosmogenic ²⁶Al/¹⁰Be burial dating on 14 core samples at different depths from three deep boreholes in the basin and obtain six valid burial ages ranging from 2.37+1.18/−1.21 to 5.86+inf/−1.37 Ma. We further re‐interpret a seismic reflection profile and quantify the geometry and amount of extension by forward structural modeling with multiple constraints based on extensional fault‐bend folding theory. The timing of the basal sedimentation is estimated to be ∼6.1 and ∼4.2 Ma in the southern and northern portions, respectively, indicating diachronous, northward‐propagating rifting. The amount and mean rate of extension are ∼3.6 km and ∼0.9 km/Myr, respectively. The basin depths increasing northward indicates the clockwise rotation of the basin. We propose a basin‐scale non‐rigid transtensional bookshelf faulting model to explain the rotation patterns of the circum‐Ordos basins. We argue that the inherited structures weaken the cratonic lithosphere of the SRS, and the low extension rate contributes to its magma‐poor nature. We propose a lithospheric‐scale evolution model for the LB, invoking the inherited crustal weakness, low extension rate, and lower lithosphere counterflow.
... The southern part of Mt Cesima consists of a carbonate succession, including Cretaceous shallow-water limestones passing upward to Maastrichtian-Paleocene recrystallized calcarenites and breccias (Calcari Cristallini Fm; Vitale & Ciarcia, 2022). The succession is folded, forming a south-verging anticline, and displaced by Lower-Pleistocene normal faults with associated syn-extensional continental deposits (D'Agostino et al., 1998;Demangeot, 1965). The pyroclastic products of the Roccamonfina volcano and the Campanian Ignimbrite eruption, as well as Volturno river deposits (Valente et al., 2019), contributed to the filling of the Garigliano Graben, formed starting from the Early Pleistocene (Giordano et al., 1995;Figure 1b). ...
The Roccamonfina volcano is located within the Garigliano Graben (southern Apennines, Italy) and has been active throughout the Middle‐Late Pleistocene. Along its polyphase volcanic history (630–55 ka), including several caldera‐forming eruptions (385–230 ka), several effusive/mildly explosive monogenetic events occurred along the volcano slopes, within the summit caldera, and along the graben‐bounding carbonate reliefs. In this paper, we present a multidisciplinary study of a mafic magmatic feeder dike intruded within the Meso‐Tertiary carbonates and overlying Lower Pleistocene breccias of Mt Cesima, northeast of the Roccamonfina volcano. We performed a stratigraphic and structural survey of the area and petrographic analyses on several samples of the dike. Results indicate that a ∼1 km long fissure fed an eruption that also emplaced a Strombolian pyroclastic sequence. Petrological data show that an open‐system mafic recharge fueled the tephritic magma that fed the eruption, whereas no evidence of significant pre/syn‐eruptive assimilation of carbonate has been identified. Stratigraphic and petrological data do not allow to firmly constrain the timing of the eruption, which could belong both to the pre‐Brown Leucitic Tuff (>354 ka) and to the post‐White Trachytic Tuffs (<230 ka) epochs of activity of the Roccamonfina volcano. Structural data show that the dike is broadly oriented E‐W and changes direction toward NE‐SW in correspondence with a pre‐existing fault damage zone. We suggest that magma was intruded during an N‐S trending extensional event in the Middle Pleistocene, whose prolonged activity resulted in regional uplift and exhumation of regional significance.
... Negative Plio-Pleistocene inversion (Carmignani et al., 1994;Lavecchia et al., 1994) produced new extensional structures that either truncated and/or partly reactivated pre-existing thrusts as low-angle normal faults Decandia and Tavarnelli, 1990;Ghisetti et al., 1993;D'Agostino et al., 1998;Corti et al., 2006;Bonini et al., 2010Bonini et al., , 2012, modifying the overall geometry of the stacked thrust pile. Note that only those hinterland-dipping normal faults which terminate downwards and detach onto pre-existing thrust surfaces represent cases for negative inversion as demonstrated by various studies (e.g. ...
The same sense movement on any given fault plane occurs much more frequently compared to the cases when the sense reverses. Therefore, positive or negative structural inversions are regarded as special cases within the much more general and typical process of fault reactivation. Extensional reactivation of former reverse faults or, specifically thrust planes in thrust fold belts, designated as “negative inversion”, received much less attention by both the petroleum industry and the academia than the opposite process. Based on the structural review of many case studies of positive and negative inversion they display contrasting kinematic patterns. One of the obvious structural differences is related to the geometry of short-cut structures developed during the more advanced stage of inversion. In the case of positive inversion, a short-cut thrust develops within the footwall of the major inverted fault to better accommodate the ongoing shortening. In contrast, a short-cut normal fault develops within the hanging wall of the partially inverted master fault during negative inversion. Based on a worldwide compilation there are examples of hydrocarbon fields with valid traps associated with negative inversion. Therefore, we suggest that even though negative inversion may not be as important for petroleum exploration as its positive counterpart, yet, it may produce more traps in the internal parts of thrust fold belt than currently perceived. At present, case studies of negative inversion defined by the extensional reactivation of pre-existing thrust planes are relatively rare, compared to the more frequent documentation of positive structural inversion in published literature. Whether this disparity between negative and positive inversion is a result of non-observation in the subsurface, at the expense of the former, or it is caused by a more fundamental structural difference between the two processes, it remains to be seen.
... Basins positioned at higher altitudes, in turn, typically are underfilled, and the amplitude of topographic relief created by fault horsts positively correlates with fault throw (Pizzi, 2003). The flanks of the faultbounded basins are onlapped by scree slopes and/or alluvial fans (Giraudi, 1995;D'Agostino et al., 1998;D'Alessandro et al., 2003;Galadini et al., 2003;Sanders et al., 2018a). ...
... Of these, in the present context, only the Campo Imperatore fault system is of interest that delimits an intramontane basin individuated during the Early Pleistocene (Figs 1 and 2). Aside from a few antithetic faults of comparatively small throw, the basin essentially is a halfgraben with a range front in the North (Figs 1B and 2) (D'Agostino et al., 1998;Ghisetti & Vezzani, 1986;Calamita et al., 2010). Whereas the eastern and central segment of the Campo Imperatore fault system are dormant, the segment west of Monte Brancastello (see Fig. 2) shows clear-cut evidence for recent activity (Demurtas et al., 2016;Ortner et al., 2018;Galli et al., 2022). ...
Whereas deposits of extremely‐rapid, 'catastrophic' mass wastings >105 m3 in volume (for example, the Marocche di Dro rock avalanche in the Southern Alps and the Flims rockslide in the Western Alps) are easily recognized by their sheer mass and blocky surface, the identification of fossil catastrophic mass wastings partly removed by erosion must be based on deposit characteristics. Herein, a 'fossil' (pre‐last glacial) rock avalanche, previously interpreted as either a till or debris flow, is described. The deposit, informally called ‘Rubble Breccia’, is located in the intramontane Campo Imperatore halfgraben that is bounded by a master fault with up to ca 900 m topographic throw. Based on documentation from field to thin section, and by comparative analysis with post‐glacial rock avalanches, tills and debris flows, the Rubble Breccia is reinterpreted as a rock avalanche. The Rubble Breccia consists of an extremely‐poorly sorted, disordered mixture of angular clasts from sand to block size. Many clasts show fitted subclast boundaries in crackle, jigsaw and mosaic fabrics, as diagnostic of catastrophic mass wasting deposits. Intercalated layers of angular to well‐rounded clasts of coarse sand to fine pebble size, and deformed into open to recumbent folds, may represent shear belts folded during terminal avalanche propagation. The clast spectrum of the Rubble Breccia – mainly shallow‐water bioclastic limestones, Saccocoma wackestones and other deep‐water limestones and dolostones – is derived from the front range along the northern margin of the basin. Calcite cement found within the Rubble Breccia was dated with the U/Th disequilibrium method to 124.25 ± 2.76 ka BP, providing an ante‐quam age constraint to the rock avalanche event. Because catastrophic mass wasting is a common erosional process, fossil deposits thereof should be more widespread than have been identified to date, though this may be a consequence of misidentification. The criteria outlined here provide a template to identify fossil catastrophic mass wasting deposits of any age.
... It has been demonstrated that the development of these fault systems can be associated with the reactivation of pre-existing, inherited faults that developed in a previous phase of the Wilson cycle. For example, it has been shown that inherited reverse faults can reactivate and be re-used as normal faults if subjected to extension (D'Agostino et al., 1998;Morley et al., 2004;Corti et al., 2006;Wilson et al., 2010;Salazar-Mora et al., 2018;Collanega et al., 2019;Ye et al., 2020;Wu et al., 2020). Similarly, it has been shown that pre-existing extensional faults developed during rifting can undergo reactivation and be re-used as reverse faults if subjected to shortening (Jackson, 1980;Coward et al., 1991Coward et al., , 1999Butler et al., 1997;Pérez-Estaún et al., 1997;Brown et al., 1999;De Paola et al., 2006;Camanni et al., 2014 a;Reilly et al., 2017;Tavani et al., 2020Tavani et al., , 2021Martín-González et al., 2021), in some cases undergoing inversion and giving rise to basement uplifts (Rodgers, 1987;Sibson, 1995;Bonini et al., 2012;Camanni et al., 2014 b;Di Domenica et al., 2014). ...
Fault reactivation is a process that has long been described in nature and modelled in the laboratory. Although many plate boundaries worldwide have undergone successive deformation events during one or more Wilson cycles, most often the influence of fault reactivation on mainly the last deformation event can be comprehensively estimated. The northern South China Sea area has undergone, in the last 60 Myr, an entire Wilson cycle associated with the opening and the ongoing closure of the South China Sea oceanic basin. The continental basement that underwent extension during the opening of the South China Sea was associated with at least two, well-defined, systems of faults inherited from the Cretaceous tectonic evolution of the area. Also, the ongoing closure of the northern South China Sea is partial as convergence is highly oblique and collision is very localized and confined to the Taiwan mountain belt, while in most of the Eurasian rifted margin the extensional structures related to the opening of the South China Sea are not yet overprinted. Both these conditions make the northern South China Sea area an ideal one for investigating the significance of fault reactivation throughout the Wilson cycle. In this article, we first review the tectonic history of the northern South China Sea area in the last 60 Myr focusing on how it is reflected on the northern South China Sea rifted margin and the Taiwan mountain belt. We then review the influence that fault reactivation has exerted in these two areas. We found that fault reactivation had a crucial role in accommodating deformation during both the divergence and convergence episodes of the Wilson cycle, and that the degree to which faults are reactivated as well as the style of fault reactivation can be shown to be associated with the angle that inherited faults form with the extension and shortening directions, respectively. Reactivation of faults involving significant remobilisation of basement rocks seems to have been promoted for faults that were forming a high angle with the extension and shortening directions. These results highlight not only the continuous significance that fault reactivation can have during the Wilson cycle undergone at a plate boundary, but also how the first-order, underlying, geometric controls on fault reactivation can display consistency throughout the cycle itself.
... This can be illustrated by the distribution of focal mechanisms of earthquakes (Fig. 3) showing mostly reverse fault-type earthquakes along the northern coast of Africa and north of Sicily (Meghraoui et al., 1996;Deverchère et al., 2003;Medaouri et al., 2014). Extension, however, is still active within the Apennines, especially in the regions of highest elevation (Lavecchia, 1988;D'Agostino et al., 1998;Collettini and Barchi, 2002;Ghisetti and Vezzani, 2002;Collettini and Barchi, 2004) and also in the internal zones of the internal part of the Southern French-Italian Alps (not show on Fig. 3 because magnitudes are too small, only symbolized by a double-headed arrow) Calais et al., 2002;Delacou et al., 2004;Walpersdorf et al., 2018). The present-day stress pattern is quite simple, as shown by several types of indicators (focal mechanisms, in-situ measurements, boreholes) in the World Stress Map (Zoback, 1992;Heidbach et al., 2018) with s hmax trending NNE-SSW in most regions whatever the local tectonic regime, extensional, compressional or strike-slip (Fig. 4). ...
... Shortening is radial in the frontal zones of the Apennines. Extension remains active with frequent earthquakes in the internal Apennines all the way to the crestline (Amato et al., 1993;D'Agostino et al., 1998) and it is also active in the internal parts of the southern Alps Delacou et al., 2004;Walpersdorf et al., 2018;Sternai et al., 2019). It is also active in the southeast Tyrrhenian Sea with fast slab retreat until the end of the Pliocene (Sartori et al., 2004;Prada et al., 2014, Prada et al., 2018. ...
The present-day tectonic setting of the Western Mediterranean region, from the Pyrénées to the Betics and from the Alps to the Atlas, results from a complex 3-D geodynamic evolution involving the interactions between the Africa, Eurasia and Iberia plates and asthenospheric mantle dynamics underneath. In this paper, we review the main tectonic events recorded in this region since the Early Cretaceous and discuss the respective effects of far-field and near-field contributions, in order to unravel the origin of forces controlling crustal deformation. The respective contributions of mantle-scale, plate-scale and local processes in the succession of tectonic stages are discussed. Three periods can be distinguished: (1) the first period ( Tethyan Tectonics ), from 110 to 35 Ma, spans the main evolution of the Pyrenean orogen and the early evolution of the Betics, from rifting to maximum shortening. The rifting between Iberia and Europe and the subsequent progressive formation of new compressional plate boundaries in the Pyrénées and the Betics, as well as the compression recorded all the way to the North Sea, are placed in the large-scale framework of the African and Eurasian plates carried by large-scale mantle convection; (2) the second period ( Mediterranean Tectonics ), from 32 to 8 Ma, corresponds to a first-order change in subduction dynamics. It is most typically Mediterranean with a dominant contribution of slab retreat and associated mantle flow in crustal deformation. Mountain building and back-arc basin opening are controlled by retreating and tearing slabs and associated mantle flow at depth. The 3-D interactions between the different pieces of retreating slabs are complex and the crust accommodates the mantle flow underneath in various ways, including the formation of metamorphic core complexes and transfer fault zones; (3) the third period ( Late-Mediterranean Tectonics ) runs from 8 Ma to the Present. It corresponds to a new drastic change in the tectonic regime characterized by the resumption of N-S compression along the southern plate boundary and a propagation of compression toward the north. The respective effects of stress transmission through the lithospheric stress-guide and lithosphere-asthenosphere interactions are discussed throughout this period.
... This "Basin and Range" like area consists on NE dipping (dip angles of 25°-40°) antithetic normal faults bounding southward the tilted blocks that likely detach onto a splay of the Gran Sasso thrust at relatively shallow depth (∼2 km). The presence of a shallow-seated detachment fault is supported by the very limited dimensions of the blocks tilted by the fault (D'Agostino et al., 1998;Falcucci et al., 2015). Valle Force fault is located just north-east of Barisciano village (Figure 2e). ...
... Indeed, the fault/fracture network associated with these DGSDs is similar to the one of Valle Force small normal fault (Figures 7a and 13), that should flatten at 2-3 km of depth on a preexisting low angle fault (D'Agostino et al., 1998;Falcucci et al., 2015;Figure 14), and of the damage zones of large and seismogenic normal faults exhumed from 1 to 3 km depth (e.g., San Benedetto-Gioia dei Marsi and Vado di Corno fault zones: Agosta & Aydin, 2006;Agosta & Kirschner, 2003;Demurtas et al., 2016;Fondriest et al., 2020;Figures 13 and 14). However, in the latter cases, most of the minor faults and fractures strike NW-SE, consistently with the NE-SW oriented Middle Pleistocene to Holocene stretching of the central Apennines (D'Agostino et al., 2011). ...
Active faulting and deep‐seated gravitational slope deformation (DGSD) are common geological hazards in mountain belts worldwide. In the Italian central Apennines, kilometer‐thick carbonate sedimentary sequences are cut by major active normal faults that shape the landscape, generating intermontane basins. Geomorphological observations suggest that the DGSDs are commonly located in fault footwalls. We selected five mountain slopes affected by DGSD and exposing the footwall of active seismogenic normal faults exhumed from 2 to 0.5 km depth. Field structural analysis of the slopes shows that DGSDs exploit preexisting surfaces formed both at depth and near the ground surface by tectonic faulting and, locally, by gravitational collapse. Furthermore, the exposure of sharp scarps along mountain slopes in the central Apennines can be enhanced either by surface seismic rupturing or gravitational movements (e.g., DGSD) or by a combination of the two. At the microscale, DGSDs accommodate deformation mechanisms similar to those associated with tectonic faulting. The widespread compaction of micro‐grains (e.g., clast indentation), observed in the matrix of both normal faults and DGSD slip zones, is consistent with clast fragmentation, fluid‐infiltration, and congruent pressure‐solution active at low ambient temperatures (<60°C) and lithostatic pressures (<80 MPa). Although clast comminution is more intense in the slip zones of normal faults because of the larger displacement accommodated, we are not able to find microstructural markers that allow us to uniquely distinguish faults from DGSDs.
