Two Distinct Growth Styles of Riedel Shear Zones in Cratonic Strike‐Slip Fault System, Tarim Basin, NW China

The kinematics and progressive evolution of Riedel shear zones have been extensively studied, yet the factors controlling their distinct evolutionary styles in natural settings remain debated. Understanding such fracture network architecture has great implications, such as predicting subsurface fluid flow and assessing seismic hazards. In the northern Tarim Basin, NW China, three deeply buried Riedel shear zones with contrasting geometries provide an ideal opportunity to investigate their divergent evolution and formation mechanisms. By integrating borehole and high‐resolution 3D seismic reflection data sets, we characterized two geometric types: the F I 7 and F I 17 fault zones are dominated by right‐stepping synthetic (R) shears with partially developed secondary synthetic (P) shears, whereas the F I 5 fault zone is characterized by left‐stepping R shears and low‐angle (Y) shears, corresponding to R‐P and R‐Y shear fracture systems, respectively. Comparative tectonic analysis reveals two distinct evolutionary styles following the formation of en echelon R shears: Y‐dominated (F I 5) and P‐dominated (F I 17) shearing. Geomechanical analysis demonstrates that the overlap‐to‐separation ratio between adjacent R shears controls the magnitude of the local σ 1 rotation. A lower ratio (F I 5) results in limited stress rotation, favoring Y‐shear development, whereas a higher ratio (F I 17) promotes significant stress rotation and P‐shear formation. This study highlights that the overlap‐to‐separation ratio governs the subsequent kinematic evolution during progressive deformation, thereby controlling the final geometric architecture of Riedel shear zones.