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Highlights • Ongoing and active subduction in the western Makran. • Fracture zones divide Makran into two different subductions of two different dipp of sinking plates. • A mature Aleutian type for the eastern and a Kuril type of subduction for the western Makran. • Size of the plate boundary earthquakes are geometrically limited by different size of coupling areas in eastern and western Makran. • Makran plays important role in seismotectonic of triple junction between Eurasian, Indian and Arabian plates. Abstract The present study combined spatial distribution and mechanism of seismicity, seismicity parameters, geomorphology in satellite imagery and tectonic features in Makran inland to show that the Makran low angle thrust fault is divided into two separate segments. Depth dispersal of earthquakes, especially relocated events, shows that the sinking plate is steeper in the west than in the east of Makran. Significant facts were identified from the variation of Moho depth between west and east, slip rates of the inland faults and crustal shortenings in the north of Makran. The Sistan suture zone plays a significant role in dividing the overriding plate into a non-deforming Helmand block and a less deforming Lut block. These blocks have different resistances against the northward subduction. Large and great events, such as the 1989 Chabahar (M W 5.5) and 1945 Gwadur (M W 8.1), occurred in the south of subduction fronts of the western and eastern Makran, respectively. They occurred in shallow depth and were the pieces of evidence of weak and strong coupling between the oceanic and continental crusts on a low angle and a very low angle reverse faults, respectively. Spectral analysis and depth determination of the instrumental and pre instrumental earthquakes, respectively, helped to separate some plate boundary and intraplate events. This separation, geometry and non-characteristic behavior of the subduction zone, revealed from spatial and temporal distribution of the earthquakes, probably dedicate a mature Aleutian type for the subduction zone in the east. Missing great (M > 6.1) earthquakes, less slip rate of the continental faults and steeper dipping of the sinking plate in the west probably indicate a Kurile type for the Iranian part of subduction. Makran is a bimodal subduction, because geomorphological and seismic pieces of evidence indicate a NNW surficial and right lateral fracture zone in the continental crust and a NW deep and left lateral fracture zone in the oceanic crust, respectively. The fractures and geometry of subductions showed that the eastern Makran has seismotectonically a wider area for potential coupling of a larger earthquake than the western Makran. [ABSTRACT FROM AUTHOR]

In this work we present new AMS and structural results from the Ferdows active fold–thrust system (Lut block, Central Iran). AMS analyses show that the Miocene units of the Upper Red Formation have a well defined magnetic fabric of tectonic origin, with both magnetic lineation and magnetic foliation oriented parallel to the regional fold axes. In most of the cases the magnetic fabric, acquired when the bedding was still horizontal, is related to different degrees of LPS shortening. In some other cases, the magnetic foliation is vertical and oblique to the bedding, suggesting that in the Ferdows thrust–fold structure a cleavage system, not visible at the outcrop scale, has been developed as a consequence of later shortening related to the activity of the thrust system, responsible of the recent earthquakes in the area. Results from this study establish a relationships between the recent tectonics of the area and the evolution of the magnetic fabric and demonstrate that a well defined magnetic fabric of pure tectonic origin can also develop in poorly deformed rocks lacking field evidence of pervasive internal deformation. [ABSTRACT FROM AUTHOR]

The structure, age and petrogenesis of plutonic basement rocks from the Kuh-e-Sarhangi region, located in the Kashmar-Kerman tectonic zone of Central Iran are described. These intrusive rocks consist of a sub-alkaline, dominantly high-K calc-alkaline acidic suite, characterised by high SiO 2 (72.60–77.17 wt%), and alkalis (up to 8 wt%) and low Mg# (07-35). They are also enriched in Th, U and light rare earth elements, and depleted in Nb, Ta, and Ti, thus showing a geochemical fingerprint compatible with arc magmatism. The U–Pb zircon geochronology constrains magma crystallisation and emplacement during Ediacaran-Cambrian (ca. 575–535 Ma) times, under a tectonic regime dominated by transpressional tectonics as constrained by analysis of field structures. Combined inverse and forward modelling thermobarometry indicates pluton emplacement occurred in a thickened crustal environment, suggesting the Kuh-e-Sarhangi magmatic belt exposes the exhumed roots of a volcanic arc. This magmatism is interpreted as part of the Cadomian, subduction-related magmatism and framed within an oblique convergence scenario during formation of an Andean-type active margin all along the northern (proto-Tethyan) margin of the Gondwana Supercontinent. [ABSTRACT FROM AUTHOR]

Highlights: [•] AMS used to solve the ambiguity on the tectonic or sedimentary origin of magnetic lineation. [•] Comparison of magnetic fabric with available tectonic and sedimentary data. [•] The magnetic lineation in the Shemshak Group sandstones is tectonically originated. [•] AMS is a valuable tool to study deformation processes in sedimentary rocks. [Copyright &y& Elsevier]