The Main Recent Fault (MRF) is a major active strike-slip fault system at the NE border of the Arabian platform and Central Iran. Both geometry and kinematics of the fault system is rather well known along its central part and at its SE termination, while its possible continuation to the northwest is ambiguous. Moreover, less regard has been paid to possible relationships between this major intracontinental fault system and other strike-slip faults in NW Iran – SE Anatolia. This paper investigates both the structural pattern and kinematics of deformation in the region to the north of latitude 37°N, between the North Tabriz Fault and the MRF. We followed this goal through detailed fault mapping, structural field measurements, and fault-slip analyses, complemented by the reconstruction of cumulative geomorphic offsets along the main fault segments. The collected data sets have led us to propose a new tectonic model for the northwest corner of the Arabia – Central Iran collision zone. Our results reveal that the intracontinental dextral shear between Arabia-Central Iran, which is mainly localized along the MRF, continues to the north of latitude 37°N along a branch of the Neotethyan suture penetrating into SE Anatolia. The dextral fault system abruptly dies out at latitude 37.5° N joining two NNW-striking normal fault zones, which accommodate the dextral translation of Central Iran relative to Arabia through ESE-trending extension. The region in NW Iran and SE Anatolia is affected by a heterogeneous active stress field due to different tectonic processes such as tectonic escape, block translation, and localized extension. The dynamics of these processes is either directly governed by the Arabia – Eurasia oblique convergence or indirectly controlled by frontal collision and pure shear deformation in central Anatolia.

主要近期断层（MRF）是位于阿拉伯平台和伊朗中部东北边界的主要活动走滑断层系统。断层系统的几何形状和运动学沿其中央部分和东南端都广为人知，而其向西北的可能延续是模棱两可的。此外，很少有人关注这一主要的洲际断层系统与伊朗西北部安纳托利亚东南部其他走滑断层之间的可能关系。本文研究了北大不里士断层和MRF之间北纬37°N以北地区的结构模式和变形运动学。我们通过详细的断层测绘，结构现场测量和断层滑动分析，以及沿着主要断层段的累积地貌偏移的重建，实现了这一目标。收集的数据集使我们为阿拉伯-伊朗中部碰撞区的西北角提出了一个新的构造模型。我们的研究结果表明，阿拉伯半岛-伊朗中部之间的大陆内部右旋剪切主要分布在MRF上，沿着新特提斯缝合线的一个分支一直延伸到北纬37°N，并贯穿东南安那托利亚。右旋断层系统在北纬37.5°处突然消亡，连接两个NNW撞击的正常断层带，这些区域通过ESE趋势扩展适应了伊朗中部相对于阿拉伯的右旋平移。伊朗西北部和安纳托利亚东南部地区由于构造逃逸，块体平移和局部扩展等不同的构造过程而受到非均质活动应力场的影响。