Structural Architecture and Fault Kinematics of the Jifn Basin, Arabian Shield: Evidence for a Sinistral Pull‐Apart Basin Along the Najd Fault System During the Late Stages of Gondwanan Collisional Orogeny
Mustafa Al‐Zahrani, Amara Masrouhi, Abdulaziz Samkari, Hamzah Shujoon, Nawaaf AlMuntshry, Mohammed Al‐Subhi, Haitham Baggazi, Murad Abdulfarraj, Khaled Rahimi, Ahmad Redaa, Olivier BellierABSTRACT
The Arabian Shield records one of the world's largest Neoproterozoic intracontinental strike‐slip systems, the ~1300 km‐long NW‐trending Najd Fault System, developed during the late stages of Gondwana amalgamation. The Jifn Basin represents a tectonically controlled pull‐apart basin formed within this sinistral shear regime under dominantly brittle transtensional conditions. Integrated field structural analysis, fault‐slip kinematics, paleostress inversion, satellite imagery, and aeromagnetic interpretation reveal that the basin is bounded by NW–SE‐trending sinistral strike‐slip faults defining a left‐stepping releasing stepover geometry characteristic of pull‐apart basin development. Paleostress inversions from dozens of fault‐slip datasets indicate a dominant ENE–WSW to E–W subhorizontal compressional stress field consistent with regional Najd shear kinematics. Structural observations document syn‐sedimentary normal faulting, growth structures, slumps, and tectonically induced paleoslopes, confirming active basin subsidence during sedimentation. Fold axial‐plane analysis within slump deposits indicates dominant N‐ to NW‐directed sediment transport towards the basin depocenter. Aeromagnetic data reveal continuous NW‐trending deep‐seated structural lineaments spatially correlated with the Jifn–Zarghat fault corridor, indicating that the mapped brittle faults represent the shallow crustal expression of major Najd shear zones. Localised transpressional structures, including pop‐up geometries and reverse fault reactivation, reflect strain partitioning along the evolving strike‐slip corridor. Basin development between ~590 and 560 Ma was contemporaneous with the terminal stages of East and West Gondwana collision within the East African Orogen, supporting interpretation of the Jifn Basin as part of a broader network of late Ediacaran Najd‐controlled Jibalah pull‐apart basins.