Journal of Tethys: Vol. 4, No. 1, 069–087 ISSN: 2345–2471 ©2016 Offsets along the Doruneh fault; implications for dating sampling sites and slip rate determination Hamideh Amini1,*, Morteza Fattahi1, Mohammad Reza Ghassemi2 1- Physics of Earth Science Group, Institute of Geophysics, University of Tehran, Iran. 2- Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran. * Corresponding Author: [email protected]; [email protected] Received: 28 March, 2016 / Accepted: 05June 2016 / Published online: 07June 2016 Abstract The Doruneh fault is one of the longest and most prominent faults in Iran. However, only two recorded historical earthquakes with magnitudes more than 7 might be related to this fault. For getting more information on this fault more investigation in different fields are required. Fault displacement is one of the most important parameters needed to explore the fault activity. In this study, with the help of Landsat and Quickberd images of this region, several locations near Bardaskan, Khalil-Abad, Kashmar and Rezg-Abad are suggested for field measurement and OSL sampling to improve the information on this fault. Keywords: Displacement, Earthquake, Sampling, Doruneh Fault. 1- Introduction Most of the deformation in the Iranian Plateau is left-lateral slip over various scales. Most of the principally related or created by strike-slip information of the Doruneh Fault is provided by faults (e.g. Talebian and Jackson, 2002; Walker its morphotectonic features. These include and Jackson, 2004; Solaymani Azad et al. 2011; offset terrace rivers, alluvial fans and displaced Ritz et al. 2006; Regard et al. 2005; Le Dortz et river channels (e.g. Sieh and Jahus, 1984; Keller al. 2009; Shabanian et al. 2009b; Farbod et al. and Pinter, 2002; Talebian and Jackson, 2002; 2011). Shortening in Zagros and Alborz Walker and Jackson, 2002; Fattahi et al., 2006). mountains are recently localized with 5-9 According to the geometric arrangement and mm/yr (Hessami et al., 2006) and ~7 mm/yr trend of this fault it is possible to consider three (Djamour et al. 2010; Shabanian et al. 2012) western, central and eastern sections for this respectively. fault. These are extended in NE-SW, E-W and The left-lateral strike-slip fault Doruneh [called NW-SE orientations respectively. Kinematic by Wellman (1966)], also known as Great Kavir evidences of the Doruneh fault system indicates Fault [called by Stoclin and Nabavi (1973)], is a left-lateral slip rate of ~2.4±0.3 mm/yr located in the N-E of Iran (Figure 1). This is the (Fattahi et al., 2006; Tavakoli, 2007) in the second longest fault system of this region after central part of this fault on the Northern margin the Zagros Fault system. The length of this fault of the central Iran. is reported to be ~600 to 900 km, from the The oldest study on the Doruneh fault was done Afghanistan-Iran border to the Dasht-e-Kavir by Wellman (1966). He employed arial-photos desert of central Iran (e.g., Fattahi et al., 2006; and studied geomorphology of the region. He Javadi et al., 2013). presented 75m and 200m left-lateral The geomorphology of the Doruneh fault displacement of the rivers on this fault. In 1975 contains numerous indications of cumulative and 1977 Ambraseys and Moinfar who were concentrating on Kashmar earthquake 69 Amini et al., 2016 (1903.09.25) and Kaj-Drakht earthquake fault which is transmitting to the Dasht-e-Bayaz (1923.05.25) studied the seismotectonic and fault. Zare (2000) and Nabavi (1976) proposed geomorphology of the region. Walker and that this fault had right-lateral movements Jackson (2004) suggested the involvement of a before left-lateral movement. vertical axis clockwise rotation of the Doruneh Figure 1) Location of Doruneh fault in Iran region. Figure 2) Reported earthquakes around Doruneh fault; earthquakes are separated with different color of magnitude. Fattahi et al (2006), Tavakoli (2007), and Javadi regime. The eastern part of the Doruneh fault (2007) estimated the slip rate of the central part displays an imbricate reverse fault zone and is of this fault by using OSL dating, GPS and involved in a NNWtrending dextral shear zone applying tectonic and geological information between Central Iran and Eurasia. This implies respectively. that the eastern part forms a complex right- Recent geomorphological studies by Farbod et lateral trans-perssional relay zone between the al. (2011; 2012) proposed models for the Eastern and Northeastern Arabia-Eurasia Doruneh fault system defining three distinct convergence boundaries. The central part of segments (the western, central and eastern fault Doruneh fault shows exclusively a left-lateral zone) characterized by different kinematic strike-slip motion. The western part of the Journal of Tethys: Vol. 4, No. 1, 069–087 ISSN: 2345–2471 ©2016 Doruneh fault shows instead evidence of trans- displacements on the rivers and the geological pressional local tectonics in agreement with the layers by the Doruneh fault are investigated kinematics of the NEtrending branching Dahan- using the geological map (in different scales), Qaleh left-lateral strike-slip fault. aerial photos, Landsat 7, and Quickberd images. The kinematics of the fault is controlled by Finally, some locations with their displacements various interplaying factors. These include the are suggested for field study, sampling and present-day regional stress state structural dating to estimate the slip rate of the faults in complexities and geometries of the fault as well these regions. as the kinematic interactions between the fault and other intersecting fault zones (Farbod et al., 2- Geology and seismicity 2012). More investigations on this fault are 2.1- Geology published by Farbod et al. (2011), Pezzo et al. Most of displacements on the Doruneh fault are (2012), Shabanian et al. (2012), and Javadi et al. concentratedon the rivers which are in (2013; 2015). Quaternary deposits. If there are any There are several branches near each part of this displacements on the geological layers they are fault which can be considered as a fault system. observed on the Paleogene, Neogene and Remote sensing could help us to get more Quaternary layers (Amini et al., 2014). information on this fault. In this study the Figure 3) Three examples of Doruneh fault with their main traces. According to Farbod et al. (2011) the Doruneh Quaternary strike-slip movements affecting fault system is a structural assemblage with a post-Miocene geological structures and complex history of tectonic evolution along geomorphic landforms. which there is clear evidence in two distinct Along the western part the fault segments periods of faulting. The first period is the mostly show a left-stepping arrangement Cenozoic which is an initial vertical fault whereas to the east a parallel fault arrangement controlled by the northern margin of the is dominated. The central part of this fault is subsiding Neogen sedimentary basin located on more complex than the other two parts. the southern side of the fault. The second is the 71 Amini et al., 2016 Figure 4) Geology map of central part of Doruneh Fault with the geological layers in scale 1:250,000. Figure 5) Location of longitude between 57 02 and 57 10 ; a) without considering displacements, b) with considering 480, 139m left-lateral displacement, 131m right-lateral displacement, and 153m left-lateral displacement, respectively from top to down. The location explained in the text is shown with star. Journal of Tethys: Vol. 4, No. 1, 069–087 ISSN: 2345–2471 ©2016 Figure 6) Location of longitude between 57 59´ and 58 04´; a) without considering displacements, b) with considering maximum 322m left-lateral displacement. The location explained in the text is shown with star. Figure 7) Location of longitude between 57 24 and 57 27 ; a) without considering displacements, b) with considering 246, and 257m left-lateral displacement, 544m right-lateral displacement and 205m left-lateral displacement, respectively from top to down. Figure 8) Location of longitude between 58 23 and 58 27 ; a) without considering displacements, b) with considering maximum 164m left-lateral displacement. 73 Amini et al., 2016 2.1- Seismicity (Ambraseys and Melville, 1977). The low rate The active tectonics of Iran are moving of seismicity on the Doruneh fault is in contrast northwards with respect to Afghanistan at to the neighboring Dasht-e-Bayaz region.This ~15mm/yr (Vernant et al, 2004); accommodated region appears to play a similar role in the on right-lateral strike-slip fault systems on both regional tectonics (Walker et al., 2004) but has western (Gowk-Nayband fault system) and suffered from many earthquakes recorded both eastern (Neh and Zahedan fault systems) instrumentally and historically (Berberian and margins of the aseismic Dasht-e-Lut desert Yeats, 1999, 2001; Walker et al., 2004). Along (Walker and Jackson 2004; Regard et al., 2005). this fault and in nearby areas the historical (Ambraseys and Melville, 1982) and Despite the very clear expression of Doruneh instrumental (Jackson and McKenzie, 1984; fault in the geomorphology and its apparent Fattahi et al., 2006; Javadi, 2007) earthquakes major role in accommodating N-S right-lateral report indicate moderate seismicity for the shear across eastern Iran relatively few region. earthquakes have been recorded in this region Figure 9) Location of proposed situations for sampling on Doruneh Fault. The catalog of earthquakes with magnitude than 7 was occurred;the Khaf earthquake (in more than 5, collected from Engdahl, ISC, 1336.10.21 with 7.6) and Torbat-e-Jam Harvard, IRSC, IIEES centers, and Zare et al. earthquake (in year 765 with 7.5). Also, 7 (2014) are presented in Appendix (A). This historic earthquakes with magnitude between 6- catalog consists of historical and instrumental 6.5 recorded before 1940 (start of installation earthquakes with magnitude 5≤ Mw <7.6 and WWSSN around the world).They reported to be for period of 765 to 2015 (Figure 2).