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Nilforoushan, FaramarzORCID iD iconorcid.org/0000-0003-1744-7004
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Publications (10 of 35) Show all publications
Carrillo, E., Koyi, H. A. & Nilforoushan, F. (2017). Structural significance of an evaporite formation with lateral stratigraphic heterogeneities (Southeastern Pyrenean Basin, NE Spain). Marine and Petroleum Geology, 86, 1310-1326
Open this publication in new window or tab >>Structural significance of an evaporite formation with lateral stratigraphic heterogeneities (Southeastern Pyrenean Basin, NE Spain)
2017 (English)In: Marine and Petroleum Geology, ISSN 0264-8172, E-ISSN 1873-4073, Vol. 86, p. 1310-1326Article in journal (Refereed) Published
Abstract [en]

We run a series of analogue models to study the effect of stratigraphic heterogeneities of an evaporite formation on thin-skinned deformation of the Southeastern Pyrenean Basin (SPB; NE Spain). This basin is characterized by the existence of evaporites, deposited during the Early-Middle Eocene with lateral variations in thickness and lithological composition. These evaporites are distributed in three lithostratigraphic units, known as Serrat Evaporites, Vallfogona and Beuda Gypsum formations and acted as decollement levels, during compressional deformation in the Lutetian. In addition to analogue modeling, we have used field data, detailed geological mapping and key cross-sections supported by seismic and well data to build a new structural interpretation for the SPB. In this interpretation, it is recognized that the basal and upper parts of the Serrat Evaporites acted as the main decollement levels of the so-called Cadi thrust sheet and Serrat unit. A balanced restoration of the basin indicates that thrust faults nucleated at the stratigraphic transition of the Serrat Evaporites (zone with lateral variations of thickness and lithological composition), characterized by a wedge of anhydrite and shale. The analogue models were setup based on information extracted from cross-sections, built in two sectors with different lithology and stratigraphy of the evaporites, and the restored section of the SPB. In these models, deformation preferentially concentrated in areas where thickness change, defined by wedges of the ductile materials, was inbuilt. Based on the structural interpretation and model results, a kinematic evolution of the SPB is proposed. The kinematic model is characterized by the generation of out-of-sequence structures developed due to lateral stratigraphic variations of the Serrat Evaporites. The present work shows a good example of the role of stratigraphic heterogeneities of an evaporite formation which acts as decollement level on structural deformation in a fold-thrust belt. The results of this work have implications for hydrocarbon exploration and are relevant for studying structural geometry and mechanics in shortened evaporite basins. (C) 2017 Elsevier Ltd. All rights reserved.

Place, publisher, year, edition, pages
Elsevier, 2017
Keyword
Evaporites, Stratigraphic heterogeneities, Structural deformation, Kinematic evolution, Pyrenees, Analogue modeling
National Category
Geology
Identifiers
urn:nbn:se:uu:diva-336494 (URN)10.1016/j.marpetgeo.2017.07.024 (DOI)000411296600077 ()
Available from: 2017-12-14 Created: 2017-12-14 Last updated: 2017-12-14Bibliographically approved
Joudaki, M., Farzipour-Saein, A. & Nilfouroushan, F. (2016). Kinematics and surface fracture pattern of the Anaran basement fault zone in NW of the Zagros Fold-Thrust Belt. International journal of earth sciences, 105(3), 869-883
Open this publication in new window or tab >>Kinematics and surface fracture pattern of the Anaran basement fault zone in NW of the Zagros Fold-Thrust Belt
2016 (English)In: International journal of earth sciences, ISSN 1437-3254, E-ISSN 1437-3262, Vol. 105, no 3, p. 869-883Article in journal (Refereed) Published
Abstract [en]

The preexisting north-south trending basement faults and their reactivation played an important role during the evolution of the Zagros fold-thrust belt. The Anaran basement fault in the Lurestan region, NW of the Zagros, has been considered as a N-S trending basement lineament, although its surface structural expression is still debated. In this study, we use satellite images and field observations to identify and analyze the fractures in the sedimentary cover above the Anaran basement fault. Fracture analysis demonstrates that approaching the Anaran basement fault, the fracture pattern changes. The fractures association with reactivation of the deep-seated preexisting Anaran basement fault can be categorized in 4 sets based on their directions. The mean direction for maximum compressional stress is different between the fault- and fold-related fractures within and around the ABF shear zone. We estimated an orientation of N30±5° for the fault-related fractures and N45±5° for the fold-related fracture sets outside of the ABF shear zone. This difference suggests that the fold-related and fault-related fracture sets have been formed in different two stages of deformation throughout the area. The axial traces of some folds, especially the Anaran anticline, demonstrate a right-lateral offset along the ABF, such that, in central part of the Anaran anticline, the fold axis of this anticline is changed from its original NW–SE trend to approximately north-south trend of the ABF.

National Category
Geology
Research subject
Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
Identifiers
urn:nbn:se:uu:diva-253628 (URN)10.1007/s00531-015-1209-8 (DOI)000372612100009 ()
Funder
Swedish Research Council
Available from: 2015-05-29 Created: 2015-05-29 Last updated: 2017-12-04Bibliographically approved
Koyi, H., Nilfouroushan, F. & Hessami, K. (2016). Modelling role of basement block rotation and strike-slip faulting on structural pattern in cover units of fold-and-thrust belts. Geological Magazine, 153(5-6), 827-844
Open this publication in new window or tab >>Modelling role of basement block rotation and strike-slip faulting on structural pattern in cover units of fold-and-thrust belts
2016 (English)In: Geological Magazine, ISSN 0016-7568, E-ISSN 1469-5081, Vol. 153, no 5-6, p. 827-844Article in journal (Refereed) Published
Abstract [en]

A series of scaled analogue models are used to study (de)coupling between basement and cover deformation. Rigid basal blocks were rotated about a vertical axis in a bookshelf' fashion, which caused strike-slip faulting along the blocks and in the overlying cover units of loose sand. Three different combinations of cover-basement deformations are modelled: (i) cover shortening before basement fault movement; (ii) basement fault movement before cover shortening; and (iii) simultaneous cover shortening with basement fault movement. Results show that the effect of the basement faults depends on the timing of their reactivation. Pre- and syn-orogenic basement fault movements have a significant impact on the structural pattern of the cover units, whereas post-orogenic basement fault movement has less influence on the thickened hinterland of the overlying belt. The interaction of basement faulting and cover shortening results in the formation of rhombic structures. In models with pre- and syn-orogenic basement strike-slip faults, rhombic blocks develop as a result of shortening of the overlying cover during basement faulting. These rhombic blocks are similar in appearance to flower structures, but are different in kinematics, genesis and structural extent. We compare these model results to both the Zagros fold-and-thrust belt in southwestern Iran and the Alborz Mountains in northern Iran. Based on the model results, we conclude that the traces of basement faults in cover units rotate and migrate towards the foreland during regional shortening. As such, these traces do not necessarily indicate the actual location or orientation of the basement faults which created them.

National Category
Geology
Research subject
Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
Identifiers
urn:nbn:se:uu:diva-271070 (URN)10.1017/S0016756816000595 (DOI)000384436100005 ()
Funder
Swedish Research Council
Available from: 2016-01-05 Created: 2016-01-05 Last updated: 2017-12-01Bibliographically approved
Deng, H., Koyi, H. & Nilfouroushan, F. (2016). Superimposed folding and thrusting by two phases of mutually orthogonal or oblique shortening in analogue models. Journal of Structural Geology, 83, 28-45
Open this publication in new window or tab >>Superimposed folding and thrusting by two phases of mutually orthogonal or oblique shortening in analogue models
2016 (English)In: Journal of Structural Geology, ISSN 0191-8141, E-ISSN 1873-1201, Vol. 83, p. 28-45Article in journal (Refereed) Published
Abstract [en]

Orogens may suffer more than one phase shortening resulting in superposition of structures of different generations. Superimposition of orthogonal or oblique shortening is studied using sandbox and centrifuge modelling. Results of sand models show that in orthogonal superimposition, the two resulting structural trends are approximately orthogonal to each other. In oblique superimposition, structures trend obliquely to each other in the relatively thin areas of the model (foreland), and mutually orthogonal in areas where the model is thickened during the first phase of shortening (i.e. the hinterland). Thrusts formed during the first shortening phase may be reactivated during the later shortening phase. Spacing of the later phase structures is not as wide as expected, considering they across the pre-existing thickened wedge. Superposition of structures results in formation of type 1 fold interference pattern. Bedding is curved outwards both in the dome and basin structures. Folded layers are dipping and plunging outwards in a dome, while they are dipping and plunging inwards in a basin. In the areas between two adjacent domes or basins (i.e. where an anticline is superimposed by a syncline or a syncline is superimposed by an anticline), bedding is curved inwards, and the anticlines plunge inwards and the synclines outwards. The latter feature could be helpful to determine the age relationship for type 2 fold interference pattern. In tectonic regions where multiple phases of shortening have occurred, the orogenic-scale dome-and-basin and arrowhead-shaped interference patterns are commonly formed, as in the models. However, in some areas, the fold interference pattern might be modified by a later phase of thrusting. Similar to models results, superimposition of two and/or even more deformation phases may not be recorded by structures all over the tectonic area.

Keyword
multiple orthogonal/oblique shortening; superimposed deformation; structure spacing; fold interference patterns
National Category
Geology
Research subject
Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
Identifiers
urn:nbn:se:uu:diva-242960 (URN)10.1016/j.jsg.2015.08.005 (DOI)000371842600003 ()
Available from: 2015-02-03 Created: 2015-02-03 Last updated: 2017-12-05Bibliographically approved
Vajedian, S., Motagh, M. & Nilfouroushan, F. (2015). Response to Sowter, A.; Cigna, F. On the Use of the ISBAS Acronym in InSAR Applications. Comment on Vajedian, S.; Motagh, M.; Nilfouroushan, F. StaMPS Improvement for Deformation Analysis in Mountainous Regions: Implications for the Damavand Volcano and Mosha Fault in Alborz. Remote Sens. 2015, 7, 8323–8347 [Letter to the editor]. Remote Sensing, 7(9), 11324-11325
Open this publication in new window or tab >>Response to Sowter, A.; Cigna, F. On the Use of the ISBAS Acronym in InSAR Applications. Comment on Vajedian, S.; Motagh, M.; Nilfouroushan, F. StaMPS Improvement for Deformation Analysis in Mountainous Regions: Implications for the Damavand Volcano and Mosha Fault in Alborz. Remote Sens. 2015, 7, 8323–8347
2015 (English)In: Remote Sensing, Vol. 7, no 9, p. 11324-11325Article in journal, Letter (Refereed) Published
National Category
Geology
Research subject
Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
Identifiers
urn:nbn:se:uu:diva-271073 (URN)10.3390/rs70911324 (DOI)000362511400016 ()
Available from: 2016-01-05 Created: 2016-01-05 Last updated: 2016-01-26Bibliographically approved
Vajedian, S., Motagh, M. & Nilfouroushan, F. (2015). STaMPS improvement for deformation analysis in mountainous regions: Implications for Damavand volcano and Mosha fault in Alborz. Remote Sensing, 7(7), 8323-8347
Open this publication in new window or tab >>STaMPS improvement for deformation analysis in mountainous regions: Implications for Damavand volcano and Mosha fault in Alborz
2015 (English)In: Remote Sensing, ISSN 2072-4292, E-ISSN 2072-4292, Vol. 7, no 7, p. 8323-8347Article in journal (Refereed) Published
Abstract [en]

Interferometric Synthetic Aperture Radar (InSAR) capability to detect slow deformation over terrain areas is limited by temporal decorrelation, geometric decorrelation and atmospheric artefacts. Multitemporal InSAR methods such as Persistent Scatterer (PS-InSAR) and Small Baseline Subset (SBAS) have been developed to deal with various aspects of decorrelation and atmospheric problems affecting InSAR observations. Nevertheless, the applicability of both PS-InSAR and SBAS in mountainous regions is still challenging. Correct phase unwrapping in both methods is hampered due to geometric decorrelation in particular when using C-band SAR data for deformation analysis. In this paper, we build upon the SBAS method implemented in StaMPS software and improved the technique, here called ISBAS, to assess tectonic and volcanic deformation in the center of the Alborz Mountains in Iran using both Envisat and ALOS SAR data. We modify several aspects within the chain of the processing including: filtering prior to phase unwrapping, topographic correction within three-dimensional phase unwrapping, reducing the atmospheric noise with the help of additional GPS data, and removing the ramp caused by ionosphere turbulence and/or orbit errors to better estimate crustal deformation in this tectonically active region. Topographic correction is done within the three-dimensional unwrapping in order to improve the phase unwrapping process, which is in contrast to previous methods in which DEM error is estimated before/after phase unwrapping. Our experiments show that our improved SBAS approach is able to better characterize the tectonic and volcanic deformation in the center of the Alborz region than the classical SBAS. In particular, Damavand volcano shows an average uplift rate of about 3 mm/year in the year 2003–2010. The Mosha fault illustrates left-lateral motion that could be explained with a fault that is locked up to 17–18 km depths and slips with 2–4 mm/year below that depth.

Keyword
InSAR, atmospheric correction, topographic correction, modified 3D unwrapping, Damavand volcano, Mosha Fault
National Category
Geology
Research subject
Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
Identifiers
urn:nbn:se:uu:diva-253632 (URN)10.3390/rs70708323 (DOI)000360919900004 ()
Available from: 2015-05-29 Created: 2015-05-29 Last updated: 2017-12-04Bibliographically approved
Zarifi, Z., Nilfouroushan, F. & Raeesi, M. (2014). Crustal stress Map of Iran: Insight from seismic and geodetic computations. Pure and Applied Geophysics, 171(17), 1219-1236
Open this publication in new window or tab >>Crustal stress Map of Iran: Insight from seismic and geodetic computations
2014 (English)In: Pure and Applied Geophysics, ISSN 0033-4553, E-ISSN 1420-9136, Vol. 171, no 17, p. 1219-1236Article in journal (Refereed) Published
Abstract [en]

We used the focal mechanisms of crustal earthquakes (depth <40 km) in the period 1909-2012 and the available GPS velocities, estimated from the data collected between 1999 to 2011, to estimate the magnitude and directions of maximum principal stress and strain rates in Iran. The Pearson product moment correlation was used to find the correlation between the stress field obtained from the focal mechanism stress inversion and that obtained using the seismic and geodetic strain rates. Our assumption is that stresses in a continuum are produced by tectonic forces and the consequent deformation on the crustal scale. Therefore, the direction of the stress and strain (or strain rate) are ideally be the same. Our results show a strong correlation between the directions of the principal components of stress and strain (rate) obtained using the different data/methods.  Using  weighted average analysis, we present a new stress map for Iran.

Keyword
Geodetic strain rate, Seismic strain rate, Stress inversion, Iran, Stress map
National Category
Earth and Related Environmental Sciences
Research subject
Geophysics with specialization in Seismology; Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
Identifiers
urn:nbn:se:uu:diva-205582 (URN)10.1007/s00024-013-0711-9 (DOI)000340480700008 ()
Funder
Swedish Research Council
Available from: 2013-08-20 Created: 2013-08-20 Last updated: 2017-12-06Bibliographically approved
Vajedian, S., Motagh, M. & Nilfouroushan, F. (2014). Improved multi-temporal InSAR technique for monitoring volcano and tectonic deformation in the center of Alborz, Iran. Remote Sensing
Open this publication in new window or tab >>Improved multi-temporal InSAR technique for monitoring volcano and tectonic deformation in the center of Alborz, Iran
2014 (English)In: Remote Sensing, ISSN 2072-4292, E-ISSN 2072-4292Article in journal (Other academic) Submitted
National Category
Geology
Research subject
Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
Identifiers
urn:nbn:se:uu:diva-241049 (URN)
Available from: 2015-01-08 Created: 2015-01-08 Last updated: 2017-12-05
Mousavi, Z., Walpersdorf, A., Walker, R., Tavakoli, F., Pathier, E., Nankali, H., . . . Djamour, Y. (2013). Global Positioning System constraints on the active tectonics of NE Iran and the South Caspian region. Earth and Planetary Science Letters, 377-378, 287-298
Open this publication in new window or tab >>Global Positioning System constraints on the active tectonics of NE Iran and the South Caspian region
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2013 (English)In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 377-378, p. 287-298Article in journal (Refereed) Published
Abstract [en]

We present a velocity field compiled from a network of 27 permanent and 20 campaign GPS stations  across NE Iran. This new GPS velocity field helps to investigate how Arabia-Eurasia collision deformation is accommodated at the northern boundary of the deforming zone. The present-day northward motion decreases eastward from 11 mm/yr at Tehran (~52°E) to 1.5 mm/yr at Mashhad  (~60°E). N-S shortening across the Kopeh Dagh, Binalud and Kuh-e-Surkh ranges sums to 4.5±0.5 mm/yr at longitude 59°E. The available GPS velocities allow us to describe the rigid-body rotation of the South Caspian about an Euler pole that is located further away than previously thought. We suggest that two new stations (MAVT and MAR2), which are sited far from the block boundaries, are most  likely to indicate the full motion of the South Caspian basin. These stations suggest that NW motion is accommodated by right-lateral slip on the Ashkabad fault (at a rate of up to 7 mm/yr) and by up to 4-6 mm/yr of summed left-lateral slip across the Shahroud left-lateral strike-slip system. Our new GPS results are important for assessing seismic hazard in NE Iran, which contains numerous large population centers and possesses an abundant historical earthquake record. Our results suggest that the fault zones along the eastern Alborz and western Kopeh Dagh may accommodate slip at much faster rates than previously thought. Fully assessing the role of these faults, and the hazard that they represent, requires independent verification of their slip-rates through additional GPS measurements and geological fieldwork.

Place, publisher, year, edition, pages
Elsevier, 2013
Keyword
Iran, GPS, active deformation, Kopeh Dagh, Alborz, Binalud
National Category
Geology
Research subject
Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
Identifiers
urn:nbn:se:uu:diva-188510 (URN)10.1016/j.epsl.2013.07.007 (DOI)000325192100027 ()
Available from: 2012-12-17 Created: 2012-12-17 Last updated: 2017-12-06Bibliographically approved
Liu, Z., Koyi, H., Swantesson, J., Nilfouroushan, F. & Reshetyuk, Y. (2013). Kinematics and 3-D internal deformation of granular slopes: analogue models and natural landslides. Journal of Structural Geology, 53, 27-42
Open this publication in new window or tab >>Kinematics and 3-D internal deformation of granular slopes: analogue models and natural landslides
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2013 (English)In: Journal of Structural Geology, ISSN 0191-8141, E-ISSN 1873-1201, Vol. 53, p. 27-42Article in journal (Refereed) Published
Abstract [en]

This study uses results from a series of analogue models, and field observations, scanned data and sections of natural landslides to investigate the kinematics and internal deformation during the failure of an unstable slope. The models simulate collapse of granular slopes and focus on the spatial and temporal distribution of their internal structures. Using a series of systematically designed models, we have studied the effect of friction and deformability of the runout base on internal deformation within a granular slope. The results of these different models show that the collapse of granular slopes resulted in different-generation extensional faults at the back of the slope, and contractional structures (overturned folds, sheath folds and thrusts) at the toe of the slope. The failure surfaces and the volume of the failure mass changed both spatially and temporally. Younger failure surfaces formed in the back of the older ones by incorporating additional new material from the head of the slope. Our model results also show that the nature of the runout base has a significant influence on the runout distance, topography and internal deformation of a granular slope. Model results are compared with natural landslides where local profiles were dug in order to decipher the internal structures of the failure mass. The natural cases show similar structural distribution at the head and toe of the failure mass. As in model results, our field observations indicate the presence of at least two generations of failure surfaces where the older ones are steeper.

Keyword
Granular slopes, Analogue models, Landslides, Internal deformation, Runout base
National Category
Geology Earth and Related Environmental Sciences
Research subject
Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
Identifiers
urn:nbn:se:uu:diva-188231 (URN)10.1016/j.jsg.2013.05.010 (DOI)000322805600003 ()
Available from: 2012-12-14 Created: 2012-12-14 Last updated: 2017-12-06Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0003-1744-7004

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