Flexural-slip folding in buckling phases of orogenic belts: Insight into the tectonic evolution of fault splays in the East Iran orogen

Introduction: The East Iran orogen has experienced multiple buckling phases resulting in the formation of strike-slip fault splays. geometric and kinematic characteristics these splays are influenced by folding mechanisms. This study focuses on investigating structural tectonic evolution model Khousf splay, located northern terminus Nehbandan right-lateral system. Methods: Field visits geometrical properties from map views were used to analyze features splay. splay was found consist a multi-plunging anticline syncline, referred as respectively. Flexural slip identified significant mechanism for structures. Structural evidence, including parasitic folds, active duplexes, suggested that flexural occurred discrete movement horizons among rock units. Results: Analysis folds cores limbs syncline revealed M, W, Z, S shapes, with complex slicken-line patterns observed faults parallel beds at limbs. analysis results indicated strain partitioning inclined left- transpressional zones. Shortening estimates obtained profiles Shekarab zone approximately 33%, 65%, 68% NE-SW, N-S, NW-SE profiles, In Arc area, which is core anticline, shortening NE-SW N-S ranged 14% 10%. this area broad, close, semi-elliptical, parabolic suggesting secondary axis directions have been superimposed first-generation E-W refolded Discussion: findings highlight suggest played crucial role presence indicate complexity deformation processes. zones history area. superimposition different adds further Overall, provides new insights into orogen.