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1-Map showing structures in the Zagros fold-and-thrust belt, southwest Iran. Inset map shows location of the study area in the Middle East. Legend: A, Main Zagros thrust fault; B, Boundary of Imbricate Zone and Simply Folded zone; C, Kazerun Fault; D, Oman Line; E, Zagros Deformation Front; F, Axial trace of anticlines; G, Salt Domes.
Source publication
Initiation and formation of folds and the Kazerun high-angle fault zone, in the Zagros fold-and-thrust belt, were related to the continuing SW–NE oriented contraction that probably initiated in the Late Cretaceous, and intensified, starting in Miocene, when the Arabian and Eurasian plates collided. The contraction that led to folding and thrusting...
Contexts in source publication
Context 1
... the case of ASTER and ETM+ multi-spectral images, each single band is treated as a black and white image. Using the inversion option, subtle details in an image histogram become more visible (Figure 2-11). ...
Context 2
... shear continues, the third sets of fractures develop. These fractures were assigned to the P-shear set if they were synthetic, and made angles smaller than 20 o to the Kazerun fault trace (Figure 3-11). Yshear fractures were defined if they were synthetic and parallel (±3 o ) to the trace of the main Kazerun fault. ...
Context 3
... and thrusts are among the secondary structures that accompany strike-slip faults (Figure 3-11). Folds may form around shear zones in the early stages of the shear zone deformation perpendicular to the shortening direction, and in places where segments of the faults step or bend along the shear zone. ...
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Citations
... It is a highly deformed and fractured region Berberian (1995), Heydari (2008), and Shabafrooz et al. (2015), indicate the location of Bakhtegan-Tashk Lake (BTL), Kul, and Mond basins within the Zagros structural zones, as well as the distribution of water and wind gaps within them. ph1 to ph3 and pv1 to pv3 are the location topographic profiles across the Zagros Mountains shown in characterized by peaks over 3,000 m high and overthrusts exposing deep sedimentary formations (Mobasher & Babaie 2008). ...
Endorheic basins (ENBs) are inland drainage basins allowing no outflow to oceans. These basins in the active mountain chains of the convergence zones are under the influence of compressional tectonic activity and climate condition. The Zagros Mountains of Iran is one of the youngest convergence zones in which continental-continental collision has occurred. In this paper we hypothesize the formation of ENBs among the Zagros range after the epeirogenic stage in the Late Paleogene-Early Neogene. Due to tectonic activity and Quaternary climatic conditions, the ENBs pass the transition stage to exorheic, and still, some tectonic depressions are not linked to the evolutionary process of exorheic drainage of Zagros. The geometry of the drainage network of Kul and Mond basins in Fars arch shows that 67% of their water gaps are located along the thrusts and transverse basement faults in the east and west of the Fars arch. Geometrically, the Kul and Mond basins form triangles with their sides matching with the edges of the Arabian Plate where the major inherited faults of Arabian plate controls the shape of the Zagros basin and a low strain zone along the Razak fault with lower salt tectonic activity, where the wind gaps are created. The ENBs are located in the rainshadow slopes, but the Kul and Mond basins are located in the upwind slopes of rain waves. This factor and the heavy rains of the basin lead to increase of the erosion potential, destruction of depressions, and floods and consequently, the funnel-shaped gaps have a significant impact on the flood flow.
... subduction zones of the Pacific ring, Yamaoka et al., 1986;Fukao et al., 1987; the Alpine-Himalayan system, Sobel et al., 2013;Bosboom et al., 2014;Crespo-Blanc et al., 2016;Cifelli et al., 2016), long-lived crustal discontinuities at the orogen scale (e.g. Zagros, Mobasher and Babaie, 2008;Lacombe et al., 2011;Joudaki et al., 2016), inherited basement structures in intra-plate settings (e.g. the Iberian Chain, Casas et al., 1998;Merten et al., 2006), inherited salt-related structures (e.g. Vendeville and Nilsen, 1995;Rowan and Vendeville, 2006;Duffy et al., 2018;Santolaria et al., 2021a, b), vertical axis rotations (Pyrenees, Dinarès et al., 1992;Soto et al., 2006a;Mochales et al., 2012;Muñoz et al., 2013; Sevier thrust belt, Eldredge and Van der Voo, 1988;Yonkee and Weil, 2015), oblique convergence (e.g., Verkhoyansk and the Carpathians, Linzer, 1996;Linzer et al., 1998;Alps, Thöny et al., 2006;Konstantinovsky, 2007;Pueyo et al., 2007 and references therein) and complex evolutions including more than one of these variables have been invoked as responsible for their origin. ...
... Under the combined influence of internal geodynamic forces, such as diastrophism, magmatic activity and earthquakes, the properties of tectonic fractures (mainly fracture intensity and density) in rock masses usually exhibit spatial variability and a high degree of inhomogeneity [4]. Fracture abundance, as a comprehensive indicator describing the degree of fracturing in rock masses, also exhibits spatial variability and inhomogeneous properties [5]. Quantitative characterization and analysis of these spatial variabilities and other features have broad practical applications because fractures reduce the structural integrality of subsurface rock masses and create fluid pathways. ...
This study examines fractures in the Gaosong ore field to determine the main factors affecting the spatial variability in the fracture structure. The attributes of fractures, including the fracture orientation, intensity and intersection density, in the Wuzishan anticline and near the Lotus mountain fault in the Gaosong ore field in the GeJiu ore district were extracted by using a modified circular scanning line method. The fracture intensity and intersection density were analyzed based on the semivariance geostatistics function by using the volume of variation and the amount of relative variability. These parameters quantitatively describe the spatial variability in the fracture structure. The mean and standard variance of fracture intensity and intersection density in the ore field decrease with distance from the Lotus mountain fault, while the coefficient of variation increases. The spatial anisotropy is closely related to the axial direction of the Wuzishan anticline and the orientation of the Lotus mountain fault. The main factors affecting the spatial variability in the fault structure can be determined with the semivariance geostatistics function, and the results are useful for studying the geology of the mining area and can help to construct an accurate structural model to serve the needs of mine production.
... Aside from major faults, there are numerous fractures with different trends formed on the fold. Although precise information about the kinematics between the folds and faults are not available for the study area anticline, findings from some studies from different parts of the Zagros have shown that minor faults and fracture systems are related to either folds, or major basement faults (such as Sarvestan, Bala Rud, Kazerun, Izeh, and Anaran Faults) with strike-slip deformation (Mobasher and Babaie, 2008;Tavani et al., 2014;Joudaki et al., 2016). Fold-related fractures are those of the axial (FA), cross-axial (FC), and two oblique (FO1 and FO2) fracture sets (Mobasher and Babaie, 2008;Joudaki et al., 2016). ...
... Although precise information about the kinematics between the folds and faults are not available for the study area anticline, findings from some studies from different parts of the Zagros have shown that minor faults and fracture systems are related to either folds, or major basement faults (such as Sarvestan, Bala Rud, Kazerun, Izeh, and Anaran Faults) with strike-slip deformation (Mobasher and Babaie, 2008;Tavani et al., 2014;Joudaki et al., 2016). Fold-related fractures are those of the axial (FA), cross-axial (FC), and two oblique (FO1 and FO2) fracture sets (Mobasher and Babaie, 2008;Joudaki et al., 2016). ...
... Fractures associated with major basement faults correspond to five sets (including: synthetic Riedel shear fractures (R); antithetic Riedel shear fractures (R ′ ); synthetic P-shear fractures; Yshear fractures, parallel to the main strike-slip fault; and extensional T-set fractures, parallel to the principal shortening direction (Z)) (Mobasher and Babaie, 2008). Amongst these fractures, oblique fractures as well as extensional fractures oriented parallel to the anticline axes exert a major control in the increase of drainage basin orientation. ...
Salt diapirs in southern Iran provide excellent exposures of the host rock sedimentary sequences that record salt diapiric growth in compressional settings. This study addresses the reactivation of one particular diapir in the core of an anticline of the Zagros Fold and Thrust Belt (ZFTB) using the classical concept of halokinetic sequences. These sequences reflect the relative rise of the salt diapirs with respect to the depositional rate of the sediments in their surroundings. The resulting reconstruction indicates irregular deposition of the total eight sets of host rock sedimentary packages around the diapir during the Oligocene-Miocene that developed in response to the progressive rise of the host anticline. Folding of host rocks was associated with vertical movement of blocks bounded by cross-faults radiating from the boundary of the diapir, specifically around the triangular indenter on the north, deflecting the anticline to a southward advancing salient. The halokinetic sequences record an early stage of diapiric rise in the rhythmic alternation of gypsum and fossiliferous carbonate with siliciclastic material followed by fossiliferous limestone typical for lagoonal to slope environment in a limestone reef setting. The last stage is associated with thin-skinned tectonics of the uppermost halokinetic sequences thrust towards the diapir. Rapid thickness change of the halokinetic strata along the periphery of the diapir in the southern sector that includes also the crestal region of the anticline indicates compressional reactivation of the structure as early as 11 Ma (Gachsaran Formation), likely associated with salt overflow in the anticline crestal region, where the adjacent halokinetic sequences are completely overturned.
... Folds are segmented into separate domes, and their fold axes are bent at the intersections with transversal faults. Folds are doubly plunging in an en-echelon pattern and often fault-cored, with dominating foreland and hinterland verging thrusts (Farzipour-Saein & Koyi, 2014;Jassim & Goff, 2006;Koyi et al., 2004;Mobasher, 2007). ...
... The large-scale curved lineament L13 almost coincides with the HZRF (Figure 7) which has been reported previously in the tectonic maps of Iraq by Al-Kadhimi et al. (1996) and Jassim and Goff (2006). The HZRF is regarded as an active deep basement fault (Bahroudi & Talbot, 2003;Mobasher, 2007) (Figure 7) which is reported in previous studies (Al-Hakari, 2011;Stevanovic & Markovic, 2004). The BBTF is reported to be an SW-dipping basement fault which is displayed on the surface as Baranan Homocline verging to the hinterland (Al-Hakari, 2011). ...
... The ZMMF is suggested to be a deep, active blind reverse fault with an NW-SE trend that separates the ZHFZ (hanging wall) from the Zagros Low Folded Zone (footwall) (Al-Qayim et al., 2012). Stratigraphic, seismic and drilling investigations have shown more than 6 km of vertical displacement along the ZMFF (Mobasher, 2007). The Darbandi Bazian-Qaradagh-Sagrma anticline represents the surface expression of the fault in the study area (Al-Qayim et al., 2012) (Figure 8). ...
This study reports results of gravity and magnetic surveys conducted for the first time in the western segment of the Zagros Fold-and-Thrust Belt in the Kurdistan Region. This study attempts to delineate deep structures in an area, which has not been surveyed before. CG-5 Autograv gravimeter and G-857 portable proton-precession magnetometer were used to acquire gravity and magnetic data from 750 stations along over eleven traverses across and parallel to the Zagros trend (NW–SE). Six of these traverses are parallel to the Zagros trend, whereas the others are perpendicular to the trend of the other traverses and can be tied where they intersect. The total length of the traverses is about 1000 km. Tilt Angle of horizontal gradient method is used to detect regional gravity and magnetic lineaments. The mapped lineaments from regional gravity and magnetic surveys are divided into two categories: the NE–SW lineaments, which represent transversal faults in the study area, and the NW–SE lineaments, which represent the Zagros Thrust Faults, some of which may be linked to the inverted basement normal faults of Arabian passive margin (the NW–SE Najd Fault system). The results show that there is a relationship between the regional gravity and magnetic lineaments outlining the same deep geological features. The data presented here confirm the presence of regional longitudinal and transversal lineaments documented in other studies (e.g. Anah-Qalat Dizeh Fault, Surdash-Tikrit Fault, Sirwan Fault, Khanaqin Fault, Zagros Mountain Front Fault, Baranan Back Thrust Fault and High Zagros Reverse Fault) and outlines new lineaments not mapped before. Most of the detected regional lineaments in the current study coincide with the previously confirmed lineaments, which have played a significant role in the tectonic evolution of the Zagros Fold-and-Thrust Belt. As such, this study contributes to a better understanding of the subsurface structure of the Kurdistan segment of the Zagros Fold-and-Thrust Belt and probably the rest of the belt.
... Aside from major faults, there are numerous fractures with different trends formed on the fold. Although precise information about the kinematics between the folds and faults are not available for the study area anticline, findings from some studies from different parts of the Zagros have shown that minor faults and fracture systems are related to either folds, or major basement faults (such as Sarvestan, Bala Rud, Kazerun, Izeh, and Anaran Faults) with strike-slip deformation (Mobasher and Babaie, 2008;Tavani et al., 2014;Joudaki et al., 2016). Fold-related fractures are those of the axial (FA), cross-axial (FC), and two oblique (FO1 and FO2) fracture sets (Mobasher and Babaie, 2008;Joudaki et al., 2016). ...
... Although precise information about the kinematics between the folds and faults are not available for the study area anticline, findings from some studies from different parts of the Zagros have shown that minor faults and fracture systems are related to either folds, or major basement faults (such as Sarvestan, Bala Rud, Kazerun, Izeh, and Anaran Faults) with strike-slip deformation (Mobasher and Babaie, 2008;Tavani et al., 2014;Joudaki et al., 2016). Fold-related fractures are those of the axial (FA), cross-axial (FC), and two oblique (FO1 and FO2) fracture sets (Mobasher and Babaie, 2008;Joudaki et al., 2016). ...
... Fractures associated with major basement faults correspond to five sets (including: synthetic Riedel shear fractures (R); antithetic Riedel shear fractures (R ′ ); synthetic P-shear fractures; Yshear fractures, parallel to the main strike-slip fault; and extensional T-set fractures, parallel to the principal shortening direction (Z)) (Mobasher and Babaie, 2008). Amongst these fractures, oblique fractures as well as extensional fractures oriented parallel to the anticline axes exert a major control in the increase of drainage basin orientation. ...
... Zagros Foredeep Fault (ZFF) is an NW-SE fault located to the northeast of the Arabian plate and represents a discontinuous line that almost parallels the Mountain Front Fault (MFF) (Fig. 1) (Berberian 1995;Jassim and Göff 2006;Mobasher 2007;Abdulnaby et al. 2016a). The Zagros Foredeep Fault extends from southern Iran, through Iraqi territories to northeastern Syria, where the fault takes the E-W trend in Sinjar and Syria (Abdul-Wahe and Asfahani 2018; Abdulnaby 2019; Abdulnaby et al. 2016aAbdulnaby et al. , 2020. ...
... It represents the frontal edge of the Zagros Fold-Thrust Belt and separates it from the Mesopotamia Foredeep and Persian Gulf (Abdulnaby et al. 2020). Zagros Foredeep Fault is displaced almost 150 km right laterally by Kazerun strike-slip fault (Berberian 1995;Mobasher 2007). ...
... There is a lot of confusion and complexity about the Zagros Foredeep Fault. Many authors (e.g., Berberian 1995;Mobasher 2007) believe that Zagros Foredeep Fault represents a reverse fault that was formed during the collision between the Arabian and Eurasian plates. Others (e.g., Abdulnaby 2019; Abdulnaby et al. 2016aAbdulnaby et al. , 2020Darweesh et al. 2017) think that it has a reverse movement, but it began as a normal fault during the Late Triassic period. ...
Zagros Foredeep Fault (ZFF) is located to the northeast of the Arabian plate and represents a discontinuous line that extends from southern Iran, through Iraqi territories to northeastern Syria. This research aims to study the seismotectonics of the Zagros Foredeep Fault at the collision zone between the Arabian and Eurasian plates. The results show that fifteen earthquake sequences have occurred on the Zagros Foredeep Fault. One of these sequences consists of more than 200 earthquakes in one month (April 2021). The study of the stress regime and the focal mechanism solutions in the Zagros Foredeep Fault shows that the fault has a reverse movement in most parts of it and a strike-slip at the northwestern part of it. Zagros Foredeep Fault was displaced by two strike-slip faults in Khuzestan that are extended from Basrah transversal basement faults. The mechanism of the Abdul-Aziz fault in Syria is a strike-slip with normal movement, which reveals that this fault is not a part of the Zagros Foredeep Fault. The authors believe that the Zagros fault formed in the Late Triassic period as a normal fault and reactivated with reverse movement in the Tertiary period during the collision between the Arabian-Eurasian plates.
... The rose diagrams ( Figure 6) of the extracted lineaments were plotted and compared with the general trend of the CTFB. The total fractures obtained from the remote sensing technique were divided into different sets on the rose diagrams according to their angle and direction relative to the fold axis [54][55][56]. If a fracture set has a trend parallel with the fold axial trend (i.e., within 0-15°of the fold axial trace), it is defined as the "axial fracture set." ...
... Conditions. In a fold-thrust belt, two major fracture systems are generally developed, which are fold-related and faultrelated fractures [55,56,95]. Fractures with different orientations can be attributed to changes in the stress field during folding [95]. ...
... Fractures with different orientations can be attributed to changes in the stress field during folding [95]. Fold-related fractures may be axial, cross-axial, and oblique fractures [55,56]. In the CTFB area, a good relation prevails between fold-related fractures and the fold axes ( Figure 6). ...
The tectonic deformation of the outer Indo-Burman Ranges (i.e., Chittagong Tripura Fold Belt, CTFB) is associated with the oblique convergence of Indo-Burmese plates since the latest Miocene. This article presents detailed field evidence of deformation structures and their kinematics in the exposed Tertiary successions in the CTFB. We combine observations made in this study with the published structural, geodetic, and seismic data sets to present an overview of the active tectonic framework of the region and its strain partitioning. To determine the kinematic evolution, décollement depth, and amount of strain, we combined geologic field mapping, structural analysis of fifteen anticlines, fracture/lineament analysis, and paleostress analysis of faults that define the ∼100 km wide CTFB. Structural data and kinematic analyses suggest subhorizontal plane strain with approximately 10% east-west shortening (oriented ~65°) that is perpendicular to the axial plane (oriented ~155°) of the CTFB anticlines. No evidence of significant transpression or strike-slip faulting has been observed in the CTFB and, therefore, suggests that full slip-partitioning is normal to the outer belt and parallel to the inner belt of the IBR. Paleostress analysis results are in good agreement with the present-day stress regime, and this implies that past and present deformation is dynamically related with the normal component of India-Burma oblique vector velocity motion.
... Unfortunately, information about kinematics between folds and faults are not available in the study area. Nevertheless, results of some studies in the western Zagros (Lurestan), the central Zagros (Izeh zone and Dezful Embayment), and the southeastern Zagros (western Fars) have shown that minor faults and fracture systems in the ZSFB are related to either folds or major basement faults (i.e., Kazerun, Izeh, Sarvestan, Bala Rud and Anaran faults) with strike-slip kinematics (Mobasher and Babaie, 2008;Casini et al., 2011;Tavani et al., 2014;Joudaki et al., 2016). The activities of basement faults with strike-slip movements have resulted in the deformation of several large-scale fold structures and hence the formation of numerous subsidiary faults and fractures (Mobasher and Babaie, 2008). ...
... Nevertheless, results of some studies in the western Zagros (Lurestan), the central Zagros (Izeh zone and Dezful Embayment), and the southeastern Zagros (western Fars) have shown that minor faults and fracture systems in the ZSFB are related to either folds or major basement faults (i.e., Kazerun, Izeh, Sarvestan, Bala Rud and Anaran faults) with strike-slip kinematics (Mobasher and Babaie, 2008;Casini et al., 2011;Tavani et al., 2014;Joudaki et al., 2016). The activities of basement faults with strike-slip movements have resulted in the deformation of several large-scale fold structures and hence the formation of numerous subsidiary faults and fractures (Mobasher and Babaie, 2008). The angular relationship between a major right-lateral fault and fracture sets are given in Fig. 14. ...
... synthetic Riedel shear fractures (R); antithetic Riedel shear fractures (R ′); synthetic P-shear fractures; Y-shear fractures, parallel to the main strike-slip fault; and extensional T-set fractures, parallel to the principal shortening direction (Z). The second group of fractures that are related to the structural elements of folds are known as fold-related fractures (Fig. 14b), including the axial (FA), cross-axial (FC), and two oblique (FO1 and FO2) fracture sets (Stephenson et al., 2007;Mobasher and Babaie, 2008;Joudaki et al., 2016). The axial and cross-axial sets are extensional, whereas two oblique sets are shear fractures. ...
Quantitative analysis of drainage network properties plays an important role in the identification of active tectonics and their spatial variations. The purpose of this study is to analyze the drainage's confluence angle (α) in relation to tectonic activity and morphometric characteristics of drainage basins. A total of 23 drainage basins in the Zagros Simply Folded Belt were selected and then the values of α were calculated for 7829 drainage junctions. The relationship between α and other morphometric indexes such as basin area, perimeter, slope, asymmetry factor, shape, circularity, drainage density, ratio of the 1st-order streams to the total number of streams of all orders, and density of drainage's hierarchical anomaly were analyzed. Results show that mean of α increases as the order of stream junctions increases. Basins with higher values of elongation, the ratio of the 1st-order streams to the total number of streams of all orders, and density of drainage's hierarchical anomaly have higher α values. Results also show that the lateral and vertical growth of anticlines, axes of anticlines, trends of faults and drainage patterns influenced by folds growth strongly control the confluence angles of drainage channels in the studied basins.
... Moreover, previous works (e.g., Khadivi, 2010;Mobasher, 2006;Sepehr et al., 2002) have confirmed the presence of several fault zones in the southern Iran. Within the study area, the folded and faulted zone is comprised of box folds, which are oriented similar to the main NW-SE Zagros trend. ...
A total of 64 samples were collected from the Kazhdumi Formation (Albian) of south Zagros Basin (Coastal Fars Zone) in order to study the biostratigraphy and analyse the lithofacies. Stratigraphic distribution of identified larger benthic and planktonic foraminifers has confirmed the presence of three successive biozones: Mesorbitolina subconcava‐Orbitolina discoidea Zone, Favusella washitensis Zone followed by an upper Conicorbitolina conica‐Mesorbitolina parva Zone. Generally, orbitolinids are well developed in the Albian succession in the studied section, whereas the stratigraphic distribution of planktonic foraminifers is more restricted, dominating the Favusella washitensis Zone. Nevertheless, microscopic investigation recognizes five microfacies consisting of extraclast‐foraminifer packstone, peloid‐intraclast Orbitolina wackestone, foraminiferal plankton wackestone, intraclast‐Orbitolina grainstone, and coral‐rudist wackestone, which indicated a shallow water carbonates palaeoenvironment (intertidal, lagoon, bar) and open marine. The alternation of both planktic and benthic foraminifera through the Kazhdumi Formation confirms a rapid transgression and regression in the studied section during Albian time, which is attributed to Kazerun basement fault behaviour in the mentioned time interval. The Orbitolinids are well expand in Albian strata (Kazhdumi Formation) which are co‐existed with other agglutinated larger Foraminifera and calcareous algae. The basement faults of the Coastal Fars area affected the studied strata during Albian time. Rapid transgression caused the occurrence of plankton and reappearance of Orbitolinids was function of rapid regression during Late Albian age. Discoidal test of Orbitolinids are well expand in lower portion of the Albian sequence, whereas the conical type are distributed in the upper part of Kazhdumi Formation.
