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1.
Variations in crustal thickness in the Zagros determined by joint inversion of P wave receiver functions (RFs) and Rayleigh wave group and phase velocity dispersion. The time domain iterative deconvolution procedure was employed to compute RFs from teleseismic recordings at seven broadband stations of INSN network. Rayleigh wave phase velocity dispersion curves were estimated employing two-station method. Fundamental mode Rayleigh wave group velocities for each station is taken from a regional scale surface wave tomographic imaging. The main variations in crustal thickness that we observe are between stations located in the Zagros fold and thrust belt with those located in the Sanandaj–Sirjan zone (SSZ) and Urumieh–Dokhtar magmatic assemblage (UDMA). Our results indicate that the average crustal thickness beneath the Zagros Mountain Range varies from ～46 km in Western and Central Zagros beneath SHGR and GHIR up to ～50 km beneath BNDS located in easternmost of the Zagros. Toward NE, we observe an increase in Moho depth where it reaches ～58 km beneath SNGE located in the SSZ. Average crustal thickness also varies beneath the UDMA from ～50 km in western parts below ASAO to ～58 in central parts below NASN. The observed variation along the SSZ and UDMA may be associated to ongoing slab steepening or break off in the NW Zagros, comparing under thrusting of the Arabian plate beneath Central Zagros. The results show that in Central Iran, the crustal thickness decrease again to ～47 km below KRBR. There is not a significant crustal thickness difference along the Zagros fold and thrust belt. We found the same crystalline crust of ～34 km thick beneath the different parts of the Zagros fold and thrust belt. The similarity of crustal structure suggests that the crust of the Zagros fold and thrust belt was uniform before subsidence and deposition of the sediments. Our results confirm that the shortening of the western and eastern parts of the Zagros basement is small and has only started recently.  相似文献   

2.
Iran is located in one of the seismically active regions of the world. Due to the high probability of earthquakes throughout the country and the potential for tsunami inundation along the coasts and offshore, comprehensive studies on the interaction of these natural phenomena are necessary. In this study, the most conservative scenarios are determined for possible earthquakes within the Khark zone (Persian Gulf) based on experimental relations between the fault length, magnitude and displacement, which are parameters for determining tsunamigenic sources. Subsequently, the maximum height of tsunami waves are calculated based on the specifications of the seismic source and its distance from the shore as well as the coastal slope. A zoning map of tsunami hazard is finally presented.  相似文献   

3.
Geological studies indicate that the southeastern Sanandaj–Sirjan Zone, located in the southeastern Zagros Orogenic Belt, is subdivided transversally into the Esfahan–Sirjan Block with typical Central Iranian stratigraphic features and the Shahrekord–Dehsard Terrane consisting of Paleozoic and Lower Mesozoic metamorphic rocks. The Main Deep Fault (Abadeh Fault) is a major lithospheric fault separating the two parts. The purpose of this paper is to clarify the role of the southeastern Sanandaj–Sirjan Zone in the tectonic evolution of the southeastern Zagros Orogenic Belt on the basis of geological evidence. The new model implies that Neo‐Tethys 1 came into being when the Central Iran Microcontinent split from the northeastern margin of Gondwana during the Late Carboniferous to Early Permian. During the Late Triassic a new spreading ridge, Neo‐Tethys 2, was created to separate the Shahrekord–Dehsard Terrane from Afro–Arabian Plate. The Zagros sedimentary basin was formed on a continental passive margin, southwest of Neo‐Tethys 2. The two ophiolitic belts of Naien–Shahrebabak–Baft and Neyriz were developed to the northeast of Neo‐Tethys 1 and southwest of Neo‐Tethys 2 respectively, related to the sinking of the lithosphere of the Neo‐Tethys 1 in the Late Cretaceous. It can be concluded that deposition of the Paleocene conglomerate on the Central Iran Microcontinent and Pliocene conglomerate in the Zagros Sedimentary Basin is directly linked to the uplift generated by collision.  相似文献   

4.
Under the background of thrusting stress regime, a large number of strike-slip earthquakes occurred on the Miyaluo Fault during the Wenchuan earthquake sequence process, which is in the southern part of the Longmenshan Fault. In order to find the cause of their occurrence, stress tensors in subregions near the Miyaluo Fault are estimated. The result shows that in both north and south side of the Miyaluo Fault, the direction of principal compressive stress is nearly perpendicular to the Longmenshan Fault, and its dip is nearly horizontal, and the direction of tensile stress is nearly vertical. While in the Miyaluo fault zone, the direction of principal compressive stress is SWW-NEE, and its dip is nearly horizontal, the direction of principal tensile stress is NNW-SSE, also its dip is nearly horizontal. It is consistent with sinistral shear stress state in the Miyaluo fault zone. It was referred that the behavior of Miyaluo Fault during the Wenchuan earthquake sequence process was caused by tearing effect generated from unbalanced forces of two sides of the fault. To understand the rupture mode of the aftershocks in subregions as described above, the total seismic moment tensors are estimated by adding the corresponding component separately of the seismic moment tensor of aftershocks in each region. The result shows the similar trend of total seismic moment tensor components in the north and south side of the Miyaluo Fault(indicating the consistency of rupture mode in the north and south side of the Miyaluo Fault), and most seismic moment tensor components in the south side is higher than that in the north side, especially the compression component perpendicular to Longmenshan Fault and expansion component in the vertical direction. It indicates that thrusting component in the southeast direction in the south side is greater than that in the north side, and the thrusting difference causes the sinistral tearing effect of the Miyaluo Fault. We also find that the sinistral tearing component of the Miyaluo Fault is the same order of magnitude with the thrusting difference of its two sides, which indicates that the tearing effect of Miyaluo Fault can be completely explained by thrusting difference of its two sides. According to the analysis, we put forward the dynamic model of the Miyaluo Fault, which can explain the above phenomenon.  相似文献   

5.
The microseismicity of the southeastern-most Zagros is examined by high-resolution data recorded by a temporary dense local seismic network. The seismicity defines a diffuse pattern, mostly located beneath folds in the southern part of the High Zagros Fault (HZF). Seismicity dips gently northward in the depth range 6–25 km, implying slip on a major intracrustal thrust fault extending to the north of the Main Zagros Reverse Fault (MZRF) which seems to connect to the Mountain Frontal Fault (MFF). Furthermore, observed focal mechanisms suggest transpressive motion on the HZF located west of the Zendan-Minab-Palami (ZMP) fault system and striking obliquely to the convergent motion. These observations suggest that the transition zone between the Zagros continental collision zone and the Makran oceanic subduction zone is not confined to the east of the ZMP and some part of the this diffuse transition is accommodated north of the Hormuz Strait in the west by partitioning between strike-slip and shortening components. The Zagros reverse domain is terminated by a transpressive tectonic regime. Moho depth beneath the MZRF, deduced from receiver functions, is almost 45 km thinner than is observed in the central and northern parts of the Zagros. These observations support a model of active underthrusting of the Arabian plate beneath central Iran in the southeastern-most Zagros.  相似文献   

6.
The study of mantle lithosphere plays a key role to reveal predominant tectonic setting process of a region. The current geological and tectonic setting of Iran is due to the ongoing continental–continental collision of the Arabian and Eurasian plates. We applied a combined P and S receiver function analysis to the teleseismic data of nine permanent broadband seismic stations of the International Institute of Earthquake Engineering and Seismology located in different tectonic zones of Iranian plateau. More than 4 years of data were used to estimate the thickness of the crust and mantle lithosphere. According to our results, the crust is 50 km thick beneath the Zagros fold and thrust belt (ZFTB). We found the maximum Moho depth of approximately 70 km under the Sanandaj-Sirjan zone (SSZ) indicating the overthrusting of the crust of Central Iran onto the Zagros crust along the main Zagros thrust (MZT). Below the northeasternmost part of the Urumieh–Dokhtar Magmatic Arc (UDMA) and Central Iran, the Moho becomes shallower and lies at 40 km depth. Towards northeast, beneath the Alborz zone, the crust is 55 km thick. Based on S receiver functions, we provided new insights into the thickness of the Arabian and Eurasian lithospheres. The location of the boundary between these plates was estimated to be beneath the SSZ, which is slightly shifted northeastward relative to the surficial expression of the MZT. Furthermore, the Arabian plate is characterized by the relatively thick lithosphere of about 130 km beneath the ZFTB reaching 150 km beneath the SSZ, where the thickest crust was also observed. This may imply that the shortening across the Zagros is accommodated by lithospheric thickening. In contrast, UDMA and Central Iran are recognized by the thin lithosphere of about 80–85 km. This thin lithosphere may be associated with the asthenospheric upwelling caused by either lithospheric delamination or Neo-Tethys slab detachment beneath the Zagros collision zone.  相似文献   

7.
Receiver functions are widely employed to detect P-to-S converted waves and are especially useful to image seismic discontinuities in the crust. In this study we used the P receiver function technique to investigate the velocity structure of the crust beneath the Northwest Zagros and Central Iran and map out the lateral variation of the Moho boundary within this area. Our dataset includes teleseismic data (M b ≥ 5.5, epicentral distance from 30° to 95°) recorded at 12 three-component short-period stations of Kermanshah, Isfahan and Yazd telemetry seismic networks. Our results obtained from P receiver functions indicate clear Ps conversions at the Moho boundary. The Moho depths were firstly estimated from the delay time of the Moho converted phase relative to the direct P wave beneath each network. Then, we used the P receiver function inversion to find the properties of the Moho discontinuity such as depth and velocity contrast. Our results obtained from PRF are in good agreement with those obtained from the P receiver function modeling. We found an average Moho depth of about 42 km beneath the Northwest Zagros increasing toward the Sanandaj-Sirjan Metamorphic Zone and reaches 51 km, where two crusts (Zagros and Central Iran) are assumed to be superposed. The Moho depth decreases toward the Urmieh-Dokhtar Cenozoic volcanic belt and reaches 43 km beneath this area. We found a relatively flat Moho beneath the Central Iran where, the average crustal thickness is about 42 km. Our P receiver function modeling revealed a shear wave velocity of 3.6 km/s in the crust of Northwest Zagros and Central Iran increasing to 4.5 km/s beneath the Moho boundary. The average shear wave velocity in the crust of UDMA as SSZ is 3.6 km/s, which reaches to 4.0 km/s while in SSZ increases to 4.3 km/s beneath the Moho.  相似文献   

8.
Earthquakes in Iran and neighbouring regions are closely connected to their position within the geologically active Alpine-Himalayan belt. Modern tectonic activity is forced by the convergent movements between two plates: The Arabian plate, including Saudi Arabia, the Persian Gulf and the Zagros Ranges of Iran, and the Eurasian plate. The intensive seismic activity in this region is recorded with shallow focal depth and magnitude rising as high as Mw = 7.8. The study region can be attributed to a highly complex geodynamic process and therefore is well suited for multifractal seismicity analysis. Multifractal analysis of earthquakes (mb ≥ 3) occurring during 1973 – 2006 led to the detection of a clustering pattern in the narrow time span prior to all the large earthquakes: Mw = 7.8 on 16.9.1978; Mw = 6.8 on 26.12.2003; Mw = 7.7 on 10.5.97. Based on the spatio-temporal clustering pattern of events, the potential for future large events can be assessed. Spatio-temporal clustering of events apparently indicates a highly stressed region, an asperity or weak zone from which the rupture propagation eventually nucleates, causing large earthquakes. This clustering pattern analysis done on a well-constrained catalogue for most of the fault systems of known seismicity may eventually aid in the preparedness and earthquake disaster mitigation.  相似文献   

9.
The full moment tensor is a mathematical expression of six independent variables; however, on a routine basis, it is a common practice to reduce them to five assuming that the isotropic component is zero. This constraint is valid in most tectonic regimes where slip occurs entirely at the fault surface (e.g. subduction zones); however, we found that full moment tensors are best represented in transform fault systems. Here we present a method to analyze source complexity of earthquakes of different sizes using a simple formulation that relates the elastic constants obtained from independent studies with the angle between the slip and the fault normal vector, referred to as angle \( \theta \) ; this angle is obtained from the full moment tensors. The angle \( \theta \) , the proportion of volume change \( \left( k \right) \) and the constant volume (shear) component \( \left( T \right) \) are numerical indicators of complexity of the source; earthquakes are more complex as \( \theta \) deviates from \( \pi /2 \) or as T and k deviate from zero as well. These parameters are obtained from the eigensolution of the full moment tensor. We analyzed earthquakes in the Gulf of California that exhibit a clear isotropic component and we observed that the constant volume parameter T is independent of scalar moments, suggesting that big and small earthquakes are equally complex. In addition, simple models of one single fault are not sufficient to describe physically all the combinations of \( \theta \) in a source type plot. We also found that the principal direction of the strike of the Transform Fault System in the Gulf of California is following the first order approximation of the normal surface of the full moment tensor solution, whereas for deviatoric moment tensors the principal direction does not coincide with the strike of the Transform Fault System. Our observations that small and large earthquakes are equally complex are in agreement with recent studies of strike-slip earthquakes.  相似文献   

10.
Ooid grainstone/packstone carbonate facies of the Dalan, Kangan, and Arab formations are the main hydrocarbon reservoirs in the Persian Gulf. Based on detailed petrographic and petrophysical analyses,sedimentological and mineralogical features of the Permian to Late Cretaceous carbonate and iron-rich coated grains from Zagros and the Persian Gulf were investigated. Frequent ooids in these formations indicate a high-energy environment and a wave-dominated shallow carbonate platform. Because of wi...  相似文献   

11.
The goal of this paper is to study the velocity field and deformation parameters in Southern Spain and surrounding areas (Ibero-Maghrebian region) using GPS episodic measurements. Results are compared to those previously published as well as deformation parameters derived from seismic data. For this purpose, a geodetic GPS network of 12 stations was observed during eight field campaigns from 1998 to 2005 by the San Fernando Naval Observatory (ROA), Spain. Relative GPS velocities in the Gulf of Cadiz with respect to the stable part of Eurasia are ～4.1 mm/yr in a NW–SE to NNW–SSE direction. In the Betics, Alboran Sea and North of Morocco, velocities are ～4.4 mm/yr in a NW–SE direction, and they are ～2.3 mm/yr in a N–S direction in the eastern part of the Iberian Peninsula. These results are in agreement with the anticlockwise rotation of the African plate. GPS strain tensors are determined from the velocity model, to obtain a more realistic crustal deformation model. The Gulf of Cadiz is subjected to uniform horizontal compression in a NNW–SSE direction, with a rotation to N–S in the Alboran Sea and Northern Morocco. An extensional regime in a NW–SE direction, which rotates to W–E, is present in the Internal Betics area. In the Betic, Alboran Sea and North of Morocco regions we compare seismic deformation rates from shallow earthquakes with the determined GPS deformation rates. The comparison indicates a seismic coupling of 27%, while the remaining 73% might be generated in aseismic processes. Deformations measured in the Ibero-Maghrebian region with GPS could be interpreted in terms of either elastic loading or ductile deformation.  相似文献   

12.
《Journal of Geodynamics》1999,27(4-5):451-468
The seismic activity of the Sinai subplate region on the basis of both historical (2200B.C.–1900 A.D.) and recent (1900–1995) earthquake catalogs have been evaluated.Moderateand large earthquakes occurred mainly at the subplate boundaries, Dead Sea Fault (DSF) systemin the east, Cyprean arc in the north, and Suez rift in the southwest.Along the Dead Sea Fault system the activity concentrated at the southern andcentralsegments. The earthquake distribution appears to have a tendency to cluster in time andspace.The swarms (February, 1983; April, 1990; August, 1993 and November, 1995) in the GulfofAqaba indicate that the southern segment of the Dead Sea Fault system is the mostseismogenicthrough the last two decades. North of the Dead Sea depression the seismic activitytends to haveoccurred with NW trend to extend under the Levantine Sea. Although the northernsegment ofthe Dead Sea Fault system is well defined from geological, geophysical and historicalearthquakeactivity recent seismic activity is practically absent especially north of Latitude 34°N.In the eastern Mediterranean the seismicity is much higher in the area of the Hellenicarcthan in the Cyprean arc. Moreover, the activity occurs in a wide belt suggesting that theplateboundary is a deformation zone instead of a single line.The seismic activity in the Gulf of Suez is scattered and does not have any distincttrend.However, three active zones are delineated. At the mouth of the gulf most of activityisconcentrated where the Sinai triple junction (Africa, Arabia, Sinai) is situated. The centralpartand the northern part of the gulf include the adjacent area as far as the river Nile. Actually,theactivity is markedly decreased from south to north.Although there is no seismological evidence that the Suez rift continues into theeasternMediterranean, the activity in the Gulf of Suez region cannot be ignored.The parameters of magnitude-frequency relation (a, b) indicate thatthelevel of earthquake activity in the Sinai subplate region is generally moderate. Moreover,theenergy release curve shows a regular trend and reflects occasional high activity. © 1999ElsevierScience Ltd. All rights reserved.  相似文献   

13.
Makran is one of the largest accretionary prisms on Earth, formed by the closure of the Neotethys ocean which is now represented by its remnant, the Gulf of Oman. Tectonic evolution of the Makran island‐arc system is explored within the context of a north dipping subduction zone, with temporal variations in slab dip arrangement. In a Middle Jurassic–Early Paleocene steep slab dip arrangement, the Mesozoic magmatic arc and the Proto‐Jaz Murian depression, which was an intra‐arc extensional basin, were developed. This was associated with development of outer‐arc ophiolitic mélange and oceanward migration of the Bajgan–Durkan continental sliver, which is the continuation of the Sanandaj–Sirjan zone of the Zagros orogenic belt into the Makran region. In a Late Paleocene to Late Pliocene moderate to shallow slab dip arrangement, compression and tectonic inversion of the Proto‐Jaz Murian extensional basin into the Jaz Murian compressive basin was associated with the uplift of the southern part of the Jaz Murian Depression along the South Jaz Murian Fault, and emplacement of the Paleogene–Neogene magmatic arc, behind the Jaz Murian compressive basin. A shallow slab dip arrangement in the Quaternary led to the emplacement of a third magmatic arc inland, over the southern part of the Yazd–Tabas–Lut micro‐continental block. It is envisioned that the Makran island‐arc system will pass through similar tectonic events in the future, as the Zagros island‐arc system did in the past. However, a future remnant and/or residual basin similar to the present Gulf of Oman will continue to survive to the east.  相似文献   

14.
The Alborz is one of the most important seismotectonic provinces in Iran. Furthermore, emplacement of Tehran as a mega city in southern part of the Alborz intensifies the seismic vulnerability in this area. In this study, the focal mechanism data from teleseismic and local seismic networks are used for stress tensor inversion. The earthquake focal mechanisms in the Central Alborz are divided into several groups with respect to their location. Two different stress tensor inversions, linear and nonlinear, are used for obtaining the principal stress orientations. The results show spatial variations in tectonic stress field, consistent with fault orientations and faulting mechanisms. The maximum compressional stress directions obtained in this study are confirmed by fast S-wave polarization axes reported by a previous shear wave splitting study. The maximum horizontal stress directions are also compared with GPS strain rates. The results indicate a partitioning of deformation in the area due to regional stresses along preexisting faults.  相似文献   

15.
Arias intensity is considered as a shaking parameter suitable for characterizing earthquake impact on ground stability. Within the framework of a study aimed at providing tools for the assessment of hazards related to earthquake-induced slope failures, Arias intensity attenuation relations were determined for the Zagros Mountains region, an active tectonic belt elongated NW–SE in the western and south-western part of Iran. The calculation of relation coefficients was based on strong-motion data of earthquakes located in the Zagros area and recorded by Iranian stations managed by the Building and Housing Research Center of Iran (BHRC). Five models of attenuation relation were considered and their coefficients were estimated through a least-square regression analysis. The relations obtained were then applied to a data sample different from that used for regression and the root mean square (RMS) of residuals was examined in order to compare effectiveness of different relations in probabilistic estimates. Furthermore a comparison made with attenuation relations obtained for Alborz and the central part of Iran showed significant differences possibly related to structural differences.  相似文献   

16.
Non-linear teleseismic S-phase tomography across the Zagros collision zone in southwestern Iran is used to determine a high-resolution image of the upper-mantle structure. The inversion was done using 41 high-quality earthquakes recorded by 19 broad-band and medium-band stations along a 620 km long profile across the collision zone. Smearing from strong crustal velocity anomalies into the upper-mantle is suppressed by travel-time corrections calculated based on a 3-D crustal model for the study area. Our results show that the relatively old and cold Arabian shield has a higher velocity (up to 6% faster, at depths between 70 and 300 km) than the younger lithosphere farther north in Central Iran. These two upper-mantle domains are separated by a sharp near-vertical transition whose surface expression coinciding with the Main Zagros Thrust.  相似文献   

17.
We determine the stress field of Guangdong and its adjacent area by using focal mechanism solutions of 137 earthquakes and obtain tectonic stress tensors in 12 zones. The result shows that the azimuth of maximum principal stress σ1 is approximately WNW in southwestern Fujian, southern Jiangxi, Guangdong’s Heyuan and the Pearl River Delta, NW in Guangdong’s Yangjiang, and nearly NNW in the two zones of eastern Guangxi and Beibuwan Gulf (the Northern Gulf), varying clockwise in WNW-NW-NNW from east to west. The azimuth of minimum principal stress σ3 varies from NNE to ENE. The relative magnitude of medium principal stress σ2 (R value), is the smallest in Beibuwan and largest in Longyan of Fujian. Strike-slip faulting is dominated in the study area.  相似文献   

18.
通过对2008年5月12日发生的汶川8.0级地震的发震构造——中央断裂映秀—南坝段地震地表破裂、地表形变及断裂上余震迁移等特征的详细调查和分析,结果表明：（1）自映秀至南坝,断层活动方式表现为由逆冲逐渐过渡为逆冲-右旋走滑、再到走滑分量与逆冲分量大致相当,同时断层两盘滑动伴有相对弱旋转活动;（2）在断层总体走向NE向、逆冲为主兼右旋走滑活动方式下,局部表现为走向NW向、逆冲为主兼左旋走滑活动方式;（3）地震裂缝与单侧破裂面关系,以及地表重叠缩短形变特征表明,断层活动、应变能释放是在近EW向区域构造应力及NE向局部构造应力综合作用下的结果.依据断层沿线地表裂缝产状的变化,粗略推出映秀至南坝段主应力方向由SEE向NEE方向变化,与前人使用CAP（Cut and Pasate）方法求出的主余震源机制方向基本一致.  相似文献   

19.
利用Snoke方法求解和收集得到的77次中小地震的震源机制解资料, 采用Gephart应力张量反演方法, 获得了郯庐断裂带鲁苏皖段构造应力场, 最大主压应力方位角为80°, 最小主压应力方位角为172°, 最大、 中等和最小主压应力倾角分别为15°、 65°和19°, 反映了研究区处于近EW向水平作用和近NS向的水平拉张作用环境下。 根据地震活动、 地质构造及震源机制解差异, 我们将郯庐断裂带鲁苏皖段分5个区段开展研究, 结果显示: 5个分区应力场存在局部差异, 最大主压应力方位角处于63°～88°之间, 从北往南总体方向成顺时针偏转的趋势。 跨郯庐断裂带两侧的应力场研究结果显示, 从西到东最大主压应力方向有一个逆时针偏转的趋势, 西侧最大主压应力方向更接近EW向, 东侧更接近NE向, 郯庐断裂带内处于两侧的过渡地段。  相似文献   

20.
The collision zone between the Arabian and Eurasian plates is one of the most seismically active regions. Northern Iraq represents the northeastern part of the Arabian plate that has a suture zone with the Turkish and Iranian plates called the Bitlis–Zagros suture zone. The orientations of the principal stress axes can be estimated by the formal stress inversion of focal mechanism solutions. The waveform moment tensor inversion method was used to derive a focal mechanism solution of 65 earthquakes with magnitudes range from 3.5 to 5.66 in the study area. From focal mechanism solutions, the direction of slip and the orientations of the moment stress axes (P, N, and T) on the causative fault surface during an earthquake were determined. The dataset of the moment stress axes have been used to infer the regional principal stress axes (σ 1, σ 2, and σ 3) by the formal stress inversion method. Two inversion methods, which are the new right dihedron and the rotational optimization methods, were used. The results show that six stress regime categories exist in the study area. However, the most common tectonic regimes are the strike-slip faulting (43.94 %), unspecified oblique faulting (27.27 %), and thrust faulting (13.64 %) regimes. In most cases, the strike-slip movement on the fault surfaces consists of left-lateral (sinistral) movement. The normal faulting is located in one small area and is due to a local tensional stress regime that develops in areas of strike-slip displacements as pull-apart basins. The directions of the horizontal stress axes show that the compressional stress regime at the Bitlis–Zagros suture zone has two directions. One is perpendicular to the suture zone near the Iraq–Iran border and the second is parallel in places as well as perpendicular in others to the suture zone near the Iraq–Turkey border. In addition, the principal stress axes in the Sinjar area near the Iraq–Syria border have a E–W direction. These results are compatible with the tectonic setting of the Arabian–Eurasian continental collision zone and the anticlockwise rotation of the Arabian plate that is evidently responsible for the strike-slip displacements on fault surfaces.  相似文献   

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