Deep controls on foreland basin system evolution along the Sicilian fold and thrust belt

2015 ◽  
Vol 186 (4-5) ◽  
pp. 273-290 ◽  
Author(s):  
Maurizio Gasparo Morticelli ◽  
Vera Valenti ◽  
Raimondo Catalano ◽  
Attilio Sulli ◽  
Mauro Agate ◽  
...  

Abstract Neogene-Quaternary wedge-top-basins arose during the Sicilian fold and thrust belt (FTB) build-up. The infilling sedimentary successions are: i) middle-upper Miocene silicoclastics succession, accommodated on top of the accreted Sicilide and Numidian flysch nappes; ii) upper Miocene-lower Pliocene deepening-upwards sediments unconformably overlying the inner Meso-Cenozoic deep-water, Imerese and Sicanian thrust units; iii) Upper Pliocene-Quaternary coastal-open shelf deposits unconformably covering (in the outer sector of the FTB) a tectonic stack (Gela thrust system). These successions are characterized by a basal unconformity on the deformed substrate believed to be the depositional interface common both to the coeval wedge-top and foredeep basins. The tectono-sedimentary evolution of the syn-tectonic basins was controlled by the progressive deepening of the structural levels, which were active during the growing of the FTB. The palinspastic restoration of a crustal geological transect in central Sicily points to: i) the occurrence of two subsequent, basal main thrusts (MT1 and MT2) active during the Neogene-middle Pleistocene tectonic evolution, as well as ii) a decrease in slip- and shortening-rate, estimated for the later MT2 as compared to earlier MT1 basal main thrust. The foreland-basin system evolution recorded during these two steps suggests: – the regional lithofacies distribution, during late Tortonian-early Pliocene, accounted for a wide depozone including the Iblean plateau and its offshore;– a crucial change was recorded by the late Pliocene-Pleistocene wedge-top depozone, when the deeper basal main thrust (MT2) involved and thickened (in the inner sector of the FTB) the crystalline basement (thin- to thick-skinned thrust tectonics); this change influenced the depozones, progressively narrowing up to the present-day setting. As regards this general evolutionary framework, thin-skinned and thick-skinned thrust tectonics can be recognized in the Sicilian FTB evolution. The late Tortonian-early Pliocene, thin-skinned thrust tectonics include two main tectonic events, a “shallow-seated” Event 1 and a “deep-seated” Event 2, with the Pliocene-Pleistocene thick-skinned thrust tectonics representing a third tectonic event (Event 3).

2020 ◽  
Author(s):  
Manuel Díaz-Azpiroz ◽  
Inmaculada Expósito ◽  
Alejandro Jiménez-Bonilla ◽  
Juan Carlos Balanyá

<p>Displacement between tectonic plates is normally partitioned into different tectonic domains accommodating specific components of the bulk strain, such that no single domain can possibly be regarded as representative of the overall kinematics. Eventually, this partitioning can be produced at different scales. Therefore, plate kinematic motion estimations based on the surface geological record should ideally rely on detailed multiscale, structural analyses of all different tectonic domains involved.</p><p>The Betic-Rif orogen was formed during the Cenozoic by the convergence and subsequent collision of the Alboran domain and the South Iberian and Maghrebian paleomargins. After the main Miocene event, oblique convergence has been still active up to present times in both branches of the resulting Gibraltar Arc. In this work we analyze how dextral oblique convergence in the northern Betic branch is partitioned into different tectonic domains of the orogen external zones and foreland, where contrasting strain fields are deduced. These domains present distinctive rheologies, thus showing also specific structural styles. As such, we present data of upper Miocene-Present structures from four different tectonic domains along a complete transect of the western Betics (southern Spain), from the internal-external zones boundary outwards. In the inner fold and thrust belt, the detached South Iberian paleomargin and Flysch trough units (mostly limestones and other carbonatic rocks) are deformed mainly by upright and double-verging folds as well as reverse faults, both registering mostly orthogonal shortening. The outer fold and thrust belt progressed toward the foreland incorporating block-in-matrix formations, with evaporite-rich marly matrix, formed ahead the mountain front; its main deformation is resolved at a strike-slip dominated, dextral transpressional zone. The upper Miocene deposits of the foreland basin (calcarenites and marls) are affected by weak deformation combining some shortening and an unconstrained strike-slip component, as deduced from seismic profiles. Finally, Paleozoic structures of the foreland, formerly developed at non- to medium-grade metamorphic conditions, were likely reactivated under a dextral transpressional strain field, which acts in combination with forebulge bending.</p><p>The strongly arcuate shape of the Gibraltar Arc likely imposes contrasting kinematics along strike within the same tectonic domain. Indeed, the inner fold and thrust belt shows nearly orthogonal shortening to the west, in a more frontal position, and a strike-slip dominated high-strain zone (the so-called Torcal shear zone) to the east. By contrast, preliminary studies show no significant differences in the kinematics of the foreland eastward from the analyzed transect.</p><p>All of our kinematic results from the studied domains are compatible with an overall dextral oblique convergence. However, more accurate strain estimations are needed to constrain the plate displacements responsible for the upper Miocene-Recent deformation in the Gibraltar Arc northern branch. Moreover, detailed analyses of strain partitioning modes will shed light into the relationships between these plate displacements and the resulting strain patterns.</p>


2021 ◽  
Author(s):  
Salvatore Critelli ◽  
Sara Criniti

The sandstone composition of foreland basin has a wide range of provenance signatures, reflecting the interplay between flexed underplate region and abrupt growth of the accreted upper plate region. The combination of contrasting detrital signatures reflects these dual plate interactions; indeed, several cases figure out that the earliest history of older foreland basin infilling is marked by quartz-rich sandstones, with cratonal or continental-block provenance of the flexed underplate flanks. As upper plate margin grows over the underplate, the nascent fold-and-thrust belt starts to be the main producer of grain particles, reflecting the space/time dependent progressive unroofing of the subjacent orogenic source terranes. The latter geodynamic processes are mainly reflected in the nature of sandstone compositions that become more lithic fragment-rich and feldspar-rich as the fold-thrust belt involves the progressive deepest portions of upper plate crustal terranes. In this context sandstone signatures reflect quartzolithic to quartzofeldspathic compositions.


2020 ◽  
Author(s):  
Alexander Razmadze

<p>Gare Kakheti foothills are located between Lesser Caucasus and Kakheti Ridge and are mainly represented by the series of NEN dipping thrust faults, most of which are associated with fault‐related folds. Gare Kakheti foothills as a part of the Kura foreland fold-and-thrust belt developed formerly as a foreland basin (Oligocene-Lower Miocene) (e.g. Alania et al., 2017). Neogene shallow marine and continental sediments in the Gare Kakheti foothills keep the record on the stratigraphy and structural evolution of the study area during the compressive deformation. Interpreted seismic profiles and structural cross-sections across the Udabno, Tsitsmatiani, and Berebisseri synclines show that they are thrust-top basins. Seismic reflection data reveal the presence of growth fault-propagation folds and some structural wedges (or duplex). The evolution of the Udabno, Tsitsmatiani, and Berebisseri basins is compared with simple models of thrust-top basins whose development is controlled by the kinematics of competing for growth anticlines. Growth anticlines are mainly represented by fault-propagation folds. The geometry of growth strata in associated footwall synclines and the sedimentary infill of thrust-top basins provide information on the thrusting activity in terms of location, geometry, and age.<br>This work was supported by Shota Rustaveli National Science Foundation (SRNSF - #PHDF-19-268).</p><p> </p>


2015 ◽  
Vol 186 (4-5) ◽  
pp. 243-256 ◽  
Author(s):  
Francesco Cavalcante ◽  
Giacomo Prosser ◽  
Fabrizio Agosta ◽  
Claudia Belviso ◽  
Giuseppe Corrado

Abstract The Gorgoglione Formation represents the infill of a thrust-top basin, which records the tectonic evolution of the southern Apennines (Italy) since Upper Miocene times. The Upper Miocene basin was divided into two main sub-basins, showing both about NNW-SSW elongation. During ongoing contractional deformation, the Gorgoglione basin was incorporated into the allochthonous units of the Apennine fold-and-thrust belt, as outlined by the emplacement of thrust sheets of internal provenance (Sicilide Unit) and by the development of two main generations of tight to open folds. In this work, the modalities of deformation associated to the incorporation of the Gorgoglione Formation into the fold-and-thrust belt has been documented by means of mineralogical and structural analyses. Mineralogical data show that, in the northeastern sub-basin of the Gorgoglione Formation, the illite content and the order of illite/smectite mixed layer increase near the contact with the overlaying Sicilide Unit. These data are hence used to estimate the relative tectonic load produced by thrusting of the aforementioned tectonic unit. Structural data are consistent with tight, NNW-trending, meso-scale folds particularly frequent in the upper pelitic/arenaceous portion of the Gorgoglione Formation. Within these folded pelitic levels, a well-developed axial-plane foliation, and an ordered I/S (R1 and R3) with higher illite content, is documented. Instead, other folds developed far away from the Sicilide klippen show an incipient axial-plane foliation and a random I/S (R0) with lower illite amount is found in pelites. The data suggest that the eastern sub-basin of the Gorgoglione Formation underwent variable tectonic load, increasing from E to W, as well as deformation produced by thrusting of Sicilide sheet. The mineralogical data also indicate that illitization process is favoured for the high availability of potassium due to the dissolution of k-feldspar. High potassium availability affects the samples subjected to the highest diagenetic degree, characterized by kaolinite illitization process.


Tectonics ◽  
2014 ◽  
Vol 33 (9) ◽  
pp. 1659-1680 ◽  
Author(s):  
Mariya Levina ◽  
Brian K. Horton ◽  
Facundo Fuentes ◽  
Daniel F. Stockli

2017 ◽  
Vol 47 (2) ◽  
pp. 540
Author(s):  
E. Kamberis ◽  
S. Sotiropoulos ◽  
F. Marnelis ◽  
N. Rigakis

Thrust faulting plays an important role in the structural deformation of Gavrovo and Ionian zones in the central part of the ‘External Hellenides’ fold-and-thrust belt. The Skolis mountain in NW Peloponnese as well as the Varassova and Klokova mountains in Etoloakarnania are representative cases of ramp anticlines associated with the Gavrovo thrust. Surface geology, stratigraphic data and interpretation of seismic profiles indicate that it is a crustal-scale thrust acted throughout the Oligocene time. It is characterized by a ramp-flat geometry and significant displacement (greater than 10 km). Out of sequence thrust segmentation is inferred in south Etoloakarnania area. Down flexure and extensional faulting in the Ionian zone facilitated the thrust propagation to the west. The thrust emplacement triggered halokenetic movement of the Triassic evaporites in the Ionian zone as well as diapirisms that were developed in a later stage in the vicinity of the Skolis mountain.


Sign in / Sign up

Export Citation Format

Share Document