Changing the motion of Ladar fault during Quaternary, Khur area, Central Iran

Iran's tectonic movements have always been influenced by the convergence of the Arabia–Eurasia plates.The Arabian plate has caused extensive and complex changes in the Iranian plateau by applying pressureforces on the Eurasian plate, which is even more complicated by knowing that the direction of these forceshas not been the same over time (Allen et al., ۲۰۰۴). This convergence, in addition to causing the closure ofthe Neo-Tethys Ocean in the south and west of Iran, has also led to the formation of important strike-slipfault systems in Central Iran, where the major structures formed in Central Iran are affected by this system.The study area is located in the Central Iran, north of Yazd Block and west of Khur town (Fig. ۱). The majorfractures in the study area are affected by the Doruneh (Great Kavir) fault system. Ladar fault with NE-SWdirection is an oblique reverse fault that stretched parallel to the Doruneh fault. Considering the latestconvergence direction obtained based on GPS data (Vernant et al., ۲۰۰۴), it seems that Ladar fault, likeDoruneh fault in the north and Ordib fault in the south, has a sinistral component of movement. In thisstudy, evidences have been presented that show Ladar fault from late Cenozoic to Quaternary, in additionto the dip-slip component, also has dextral and sinistral strike-slip components of movements. The authorstry to examine the mechanism and chronological orders of these movements by providing variousevidences. In this research, the movements of the Ladar fault system during Quaternary have been studiedand processed by using remote sensing data (Landsat ۷ (ETM+)) digital elevation model (Alos Palsar witha resolution of ۱۲ meters (DEM)), Google Earth images, and airborne magnetic data as well as field studies.Characteristics of drainages and shape and different generations of alluvial fans are the best ways toidentify subsurface and hidden structures, including hidden faults, and are also one of the most importantneotectonics evidences. Deviation of two or more parallel streams in one direction can be evidence of ahidden fault or a plunging anticline. Sometimes the movement of the fault causes the stream to separatefrom its main bed and the activity of new currents in the displaced streams causes the creation of a newbed in the downstream path (Keller and Pinter, ۱۹۹۶). Vertical erosion of canals that can occur in responseto uplift in the area is among the evidence that can help identify faults and neotectonics movements. Alluvial fans are among the sedimentary structures that are formed conically from the exit of the mountainto the plain (Bull, ۱۹۷۷). The state of expansion and the different generations of the structures indicate theperformance of different tectonic regimes during the Quaternary. In the Khur area, central Iran, a set ofthese sedimentary evidences has been used to assess the new tectonic status of the Khur area and the Ladarfault movements.