New scenario for structural segmentation and subduction modeling in Makran (Iran and Pakistan)

The Makran subduction zone is located in southeastern Iran and southern Pakistan. It was formed by the subduction of part of the oceanic crust of the Arabian Plate beneath the Eurasian Plate. In the eastern part of this zone, the convergence rate, coastal uplift and seismicity are higher than in the western part of this zone. In addition, there are a larger number of Quaternary volcanoes in the western part due to a subduction arc of the oceanic lithosphere. The study of the velocity vectors shows that the asymmetric pressure impressed the Makran and in addition a number of tectonic evidences were attributed to different dip angles of subduction. The results indicate that the segmentation of the Makran is influenced by two key factors: asymmetric pressure, resulting in varying convergence rates, and different subduction dip angles. These factors are identified as the origin parameters that contribute to the formation of two distinct blocks with contrasting structures. Based on the considerations made in this study, subduction in the Makran was modeled. And a new structural segmentation was presented in this zone. The results indicate a propagation of the eastern boundary of the Lut block in Makran. The model presented in this paper was able to show the tectonic problems of the Makran and furthermore demonstrate the discrepancy between the tectonic features of the western and eastern blocks of the Makran.