@article{OmraniMoazzenOberhaensli2018,
  author    = {Omrani, Hadi and Moazzen, Mohssen and Oberh{\"a}nsli, Roland},
  title     = {Geodynamic evolution of the Sabzevar zone, northern central Iranian micro-continent},
  series = {Mineralogy and petrology},
  volume    = {112},
  journal   = {Mineralogy and petrology},
  number    = {1},
  publisher = {Springer},
  address   = {Wien},
  issn      = {0930-0708},
  doi       = {10.1007/s00710-017-0505-3},
  pages     = {65 -- 83},
  year      = {2018},
  abstract  = {The Northern Central Iranian Micro-continent (CIM) represents Neotethys-related oceanic crust remnants, emplaced due to convergence between CIM and Eurasia plates during Eocene. Mafic and ultramafic units are exposed along the northern part of the CIM in the Sabzevar area. The geology and field relation of Sabzevar ophiolite indicate northward subduction of the Sabzevar basin. The average whole rock chemistry of mafic (gabbros) and ultramafic samples (lherzolite, harzburgite and dunite) is characterized by a range of MgO of 11.16-31.88, CaO 5.22-11.53 and Al2O3 2.77-14.57, respectively. Low LREE/HREE ratio of ultramafic samples is accompanied by enrichment of large ion lithophile elements (LILE) such as Sr, Pb and K. Mafic samples show two distinct groups with low and high LREE/HREE ratios. The spider diagram of mafic samples indicates enrichment in Sr, Pb and K and depletion in REE. Petrological and geochemical evidence and field relations show that the mafic rocks formed in a supra-subduction zone setting. Petrological studies reveal the role of fractional crystallization and assimilation effect by released fluids during subduction related generation of the Sabzevar mafic rocks. We suggest that the studied mafic rocks likely represent the basement of an initial island arc, which was generated in a supra-subduction zone setting within the Neotethys branch of the Sabzevar Ocean at the north of CIM. Copper, gold and chromite mineralizations are studied in relation to island arc setting and supra-subduction environment. Similarities in lithology, ophiolite age and mineralization between Sabzevar ophiolite and Bardaskan-Torbat Heydariyeh ophiolites testify for their separation due to rotation (or faulting) of the Central Iranian Micro-continent.},
  language  = {en}
}
@article{SalamatZoellerZareetal.2018,
  author    = {Salamat, Mona and Z{\"o}ller, Gert and Zare, Mehdi and Amini, Mortaza},
  title     = {The maximum expected earthquake magnitudes in different future time intervals of six seismotectonic zones of Iran and its surroundings},
  series = {Journal of seismology},
  volume    = {22},
  journal   = {Journal of seismology},
  number    = {6},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {1383-4649},
  doi       = {10.1007/s10950-018-9780-7},
  pages     = {1485 -- 1498},
  year      = {2018},
  abstract  = {One of the crucial components in seismic hazard analysis is the estimation of the maximum earthquake magnitude and associated uncertainty. In the present study, the uncertainty related to the maximum expected magnitude mu is determined in terms of confidence intervals for an imposed level of confidence. Previous work by Salamat et al. (Pure Appl Geophys 174:763-777, 2017) shows the divergence of the confidence interval of the maximum possible magnitude m(max) for high levels of confidence in six seismotectonic zones of Iran. In this work, the maximum expected earthquake magnitude mu is calculated in a predefined finite time interval and imposed level of confidence. For this, we use a conceptual model based on a doubly truncated Gutenberg-Richter law for magnitudes with constant b-value and calculate the posterior distribution of mu for the time interval T-f in future. We assume a stationary Poisson process in time and a Gutenberg-Richter relation for magnitudes. The upper bound of the magnitude confidence interval is calculated for different time intervals of 30, 50, and 100 years and imposed levels of confidence alpha = 0.5, 0.1, 0.05, and 0.01. The posterior distribution of waiting times T-f to the next earthquake with a given magnitude equal to 6.5, 7.0, and7.5 are calculated in each zone. In order to find the influence of declustering, we use the original and declustered version of the catalog. The earthquake catalog of the territory of Iran and surroundings are subdivided into six seismotectonic zones Alborz, Azerbaijan, Central Iran, Zagros, Kopet Dagh, and Makran. We assume the maximum possible magnitude m(max) = 8.5 and calculate the upper bound of the confidence interval of mu in each zone. The results indicate that for short time intervals equal to 30 and 50 years and imposed levels of confidence 1 - alpha = 0.95 and 0.90, the probability distribution of mu is around mu = 7.16-8.23 in all seismic zones.},
  language  = {en}
}
@article{SalamatZoellerAmini2019,
  author    = {Salamat, Mona and Z{\"o}ller, Gert and Amini, Morteza},
  title     = {Prediction of the Maximum Expected Earthquake Magnitude in Iran:},
  series = {Pure and applied geophysics},
  volume    = {176},
  journal   = {Pure and applied geophysics},
  number    = {8},
  publisher = {Springer},
  address   = {Basel},
  issn      = {0033-4553},
  doi       = {10.1007/s00024-019-02141-3},
  pages     = {3425 -- 3438},
  year      = {2019},
  abstract  = {This paper concerns the problem of predicting the maximum expected earthquake magnitude μ in a future time interval Tf given a catalog covering a time period T in the past. Different studies show the divergence of the confidence interval of the maximum possible earthquake magnitude m_{ max } for high levels of confidence (Salamat et al. 2017). Therefore, m_{ max } should be better replaced by μ (Holschneider et al. 2011). In a previous study (Salamat et al. 2018), μ is estimated for an instrumental earthquake catalog of Iran from 1900 onwards with a constant level of completeness ( {m0 = 5.5} ). In the current study, the Bayesian methodology developed by Z{\"o}ller et al. (2014, 2015) is applied for the purpose of predicting μ based on the catalog consisting of both historical and instrumental parts. The catalog is first subdivided into six subcatalogs corresponding to six seismotectonic zones, and each of those zone catalogs is subsequently subdivided according to changes in completeness level and magnitude uncertainty. For this, broad and small error distributions are considered for historical and instrumental earthquakes, respectively. We assume that earthquakes follow a Poisson process in time and Gutenberg-Richter law in the magnitude domain with a priori unknown a and b values which are first estimated by Bayes' theorem and subsequently used to estimate μ. Imposing different values of m_{ max } for different seismotectonic zones namely Alborz, Azerbaijan, Central Iran, Zagros, Kopet Dagh and Makran, the results show considerable probabilities for the occurrence of earthquakes with Mw ≥ 7.5 in short Tf , whereas for long Tf, μ is almost equal to m_{ max }},
  language  = {en}
}
@article{OmraniMoazzenOberhaenslietal.2017,
  author    = {Omrani, Hadi and Moazzen, Mohssen and Oberh{\"a}nsli, Roland and Moslempour, Mohammad Elyas},
  title     = {Iranshahr blueschist: subduction of the inner Makran oceanic crust},
  series = {Journal of metamorphic geology},
  volume    = {35},
  journal   = {Journal of metamorphic geology},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0263-4929},
  doi       = {10.1111/jmg.12236},
  pages     = {373 -- 392},
  year      = {2017},
  abstract  = {The Makran accretionary prism in SE Iran and SW Pakistan is one of the most extensive subduction accretions on Earth. It is characterized by intense folding, thrust faulting and dislocation of the Cenozoic units that consist of sedimentary, igneous and metamorphic rocks. Rock units forming the northern Makran ophiolites are amalgamated as a melange. Metamorphic rocks, including greenschist, amphibolite and blueschist, resulted from metamorphism of mafic rocks and serpentinites. In spite of the geodynamic significance of blueschist in this area, it has been rarely studied. Peak metamorphic phases of the northern Makran mafic blueschist in the Iranshahr area are glaucophane, phengite, quartz +/- omphacite+epidote. Post peak minerals are chlorite, albite and calcic amphibole. Blueschist facies metasedimentary rocks contain garnet, phengite, albite and epidote in the matrix and as inclusions in glaucophane. The calculated P-T pseudosection for a representative metabasic glaucophane schist yields peak pressure and temperature of 11.5-15kbar at 400-510 degrees C. These rocks experienced retrograde metamorphism from blueschist to greenschist facies (350-450 degrees C and 7-8kbar) during exhumation. A back arc basin was formed due to northward subduction of Neotethys under Eurasia (Lut block). Exhumation of the high-pressure metamorphic rocks in northern Makran occurred contemporarily with subduction. Several reverse faults played an important role in exhumation of the ophiolitic and HP-LT rocks. The presence of serpentinite shows the possible role of a serpentinite diapir for exhumation of the blueschist. A tectonic model is proposed here for metamorphism and exhumation of oceanic crust and accretionary sedimentary rocks of the Makran area. Vast accretion of subducted materials caused southward migration of the shore.},
  language  = {en}
}
@article{SakiMoazzenOberhaensli2011,
  author    = {Saki, A. and Moazzen, Mohssen and Oberh{\"a}nsli, Roland},
  title     = {P-T evolution of the precambrian metamorphic complex, NW Iran a study of metapelitic rocks},
  series = {Geological journal},
  volume    = {46},
  journal   = {Geological journal},
  number    = {1},
  publisher = {Wiley-Blackwell},
  address   = {Malden},
  issn      = {0072-1050},
  doi       = {10.1002/gj.1236},
  pages     = {10 -- 25},
  year      = {2011},
  abstract  = {The Mahneshan Metamorphic Complex (MMC) is one of the Precambrian terrains exposed in the northwest of Iran. The MMC underwent two main phases of deformation (D-1 and D-2) and at least two metamorphic events (M-1 and M-2). Critical metamorphic mineral assemblages in the metapelitic rocks testify to regional metamorphism under amphibolite-facies conditions. The dominant metamorphic mineral assemblage in metapelitic rocks (M-1) is muscovite, biotite I, Garnet I, staurolite, Andalusite I and sillimanite. Peak metamorphism took place at 600-620 degrees C and similar to 7 kbar, corresponding to a depth of ca. 24 km. This was followed by decompression during exhumation of the crustal rocks up to the surface. The decrease of temperature and pressure during exhumation produced retrograde metamorphic assemblages (M-2). Secondary phases such as garnet II biotite It. Andalusite II constrain the temperature and pressure of M, retrograde metamorphism to 520-560 degrees C and 2.5-3.5 kbar, respectively. The geothermal gradient obtained for the peak of metamorphism is 33 degrees C km(-1), which indicates that peak metamorphism was of Barrovian type and occurred under medium-pressure conditions. The MMC followed a 'clockwise' P T path during metamorphism, consistent with thermal relaxation following tectonic thickening. The bulk chemistry of the MMC metapelites shows that their protoliths were deposited at an active continental margin. Together with the presence of palaeo-suture zones and ophiolitic rocks around the high-grade metamorphic rocks of the MMC, these features suggest that the Iranian Precambrian basement formed by an island-arc type cratonization.},
  language  = {en}
}
@article{DonnerRoesslerKruegeretal.2013,
  author    = {Donner, Stefanie and R{\"o}ßler, Dirk and Kr{\"u}ger, Frank and Ghods, Abdolreza and Strecker, Manfred},
  title     = {Segmented seismicity of the M (w) 6.2 Baladeh earthquake sequence (Alborz Mountains, Iran) revealed from regional moment tensors},
  series = {Journal of seismology},
  volume    = {17},
  journal   = {Journal of seismology},
  number    = {3},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {1383-4649},
  doi       = {10.1007/s10950-013-9362-7},
  pages     = {925 -- 959},
  year      = {2013},
  abstract  = {The M (w) 6.2 Baladeh earthquake occurred on 28 May 2004 in the Alborz Mountains, northern Iran. This earthquake was the first strong shock in this intracontinental orogen for which digital regional broadband data are available. The Baladeh event provides a rare opportunity to study fault geometry and ongoing deformation processes using modern seismological methods. A joint inversion for hypocentres and a velocity model plus a surface-wave group dispersion curve analysis were used to obtain an adapted velocity model, customised for mid- and long-period waveform modelling. Based on the new velocity model, regional waveform data of the mainshock and larger aftershocks (M (w) a parts per thousand yen3.3) were inverted for moment tensors. For the Baladeh mainshock, this included inversion for kinematic parameters. All analysed earthquakes show dominant thrust mechanisms at depths between 14 and 26 km, with NW-SE striking fault planes. The mainshock ruptured a 28A degrees south-dipping area of 24 x 21 km along a north-easterly direction. The rupture plane of the mainshock does not coincide with the aftershock distribution, neither in map view nor with respect to depth. The considered aftershocks form two main clusters. The eastern cluster is associated with the mainshock. The western cluster does not appear to be connected with the rupture plane of the mainshock but, instead, indicates a second activated fault plane dipping at 85A degrees towards the north.},
  language  = {en}
}
@article{OmraniMoazzenOberhaenslietal.2013,
  author    = {Omrani, Hadi and Moazzen, Mohssen and Oberh{\"a}nsli, Roland and Altenberger, Uwe and Lange, Manuela},
  title     = {The Sabzevar blueschists of the North-Central Iranian micro-continent as remnants of the Neotethys-related oceanic crust subduction},
  series = {International journal of earth sciences},
  volume    = {102},
  journal   = {International journal of earth sciences},
  number    = {5},
  publisher = {Springer},
  address   = {New York},
  issn      = {1437-3254},
  doi       = {10.1007/s00531-013-0881-9},
  pages     = {1491 -- 1512},
  year      = {2013},
  abstract  = {The Sabzevar ophiolites mark the Neotethys suture in east-north-central Iran. The Sabzevar metamorphic rocks, as part of the Cretaceous Sabzevar ophiolitic complex, consist of blueschist, amphibolite and greenschist. The Sabzevar blueschists contain sodic amphibole, epidote, phengite, calcite +/- A omphacite +/- A quartz. The epidote amphibolite is composed of sodic-calcic amphibole, epidote, albite, phengite, quartz +/- A omphacite, ilmenite and titanite. The greenschist contains chlorite, plagioclase and pyrite, as main minerals. Thermobarometry of a blueschist yields a pressure of 13-15.5 kbar at temperatures of 420-500 A degrees C. Peak metamorphic temperature/depth ratios were low (similar to 12 A degrees C/km), consistent with metamorphism in a subduction zone. The presence of epidote in the blueschist shows that the rocks were metamorphosed entirely within the epidote stability field. Amphibole schist samples experienced pressures of 5-7 kbar and temperatures between 450 and 550 A degrees C. The presence of chlorite, actinolite, biotite and titanite indicate greenschist facies metamorphism. Chlorite, albite and biotite replacing garnet or glaucophane suggests temperatures of > 300 A degrees C for greenschist facies. The formation of high-pressure metamorphic rocks is related to north-east-dipping subduction of the Neotethys oceanic crust and subsequent closure during lower Eocene between the Central Iranian Micro-continent and Eurasia (North Iran).},
  language  = {en}
}
@article{LandgrafZielkeArrowsmithetal.2013,
  author    = {Landgraf, Angela and Zielke, Olaf and Arrowsmith, J. Ram{\´o}n and Ballato, Paolo and Strecker, Manfred and Schildgen, Taylor F. and Friedrich, Anke M. and Tabatabaei, Sayyed-Hassan},
  title     = {Differentiating simple and composite tectonic landscapes using numerical fault slip modeling with an example from the south central Alborz Mountains, Iran},
  series = {Journal of geophysical research : Earth surface},
  volume    = {118},
  journal   = {Journal of geophysical research : Earth surface},
  number    = {3},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {2169-9003},
  doi       = {10.1002/jgrf.20109},
  pages     = {1792 -- 1805},
  year      = {2013},
  abstract  = {The tectonically driven growth of mountains reflects the characteristics of the underlying fault systems and the applied tectonic forces. Over time, fault networks might be relatively static, but stress conditions could change and result in variations in fault slip orientation. Such a tectonic landscape would transition from a simple to a composite state: the topography of simple landscapes is correlated with a single set of tectonic boundary conditions, while composite landscapes contain inherited topography due to earlier deformation under different boundary conditions. We use fault interaction modeling to compare vertical displacement fields with topographic metrics to differentiate the two types of landscapes. By successively rotating the axis of maximum horizontal stress, we produce a suite of vertical displacement fields for comparison with real landscapes. We apply this model to a transpressional duplex in the south central Alborz Mountains of Iran, where NW oriented compression was superseded by neotectonic NE compression. The consistency between the modeled displacement field and real landforms indicates that the duplex topography is mostly compatible with the modern boundary conditions, but might include a small remnant from the earlier deformation phase. Our approach is applicable for various tectonic settings and represents an approach to identify the changing boundary conditions that produce composite landscapes. It may be particularly useful for identifying changes that occurred in regions where river profiles may no longer record a signal of the change or where the spatial pattern of uplift is complex.},
  language  = {en}
}