Shear fracture surfaces are commonly rough on varied scales, and understanding the roughness properties is crucial to predict their slip behaviour. Using natural rock samples from the Singhbhum Shear Zone, eastern India, this study develops an approach to heterogeneous surface roughness analysis of shear fractures, forming two distinct domains: striated, anisotropic zone and non-striated, isotropic zone. Analogue experiments run on brittle-ductile models under a pure shear condition produce similar heterogeneous roughness characteristics of shear fractures. Using a laser profilometer, we constructed 3D topologies of both natural and experimental shear surfaces, which are presented to show the distinctive roughness characteristics of the striated and non-striated zones in terms of their fractal properties. ΔD, which stands for the difference between across- (D_⊥) and along- (D_∥) the slip direction, is calculated to evaluate the degree of their roughness anisotropy. This fractal parameter indicates strong anisotropy with ΔD = 0.0787–0.2118 in striated zones, which is significantly weak, where ΔD = 0.0024–0.0603 in non-striated zones. Finally, the article presents an in-depth discussion of this roughness study from the perspective of slip-stuck kinematics on shear surfaces from laboratory experiments and their geophysical implications, e.g., interpretation of earthquake event patterns on seismic faults and permeability of fractured rocks.

剪切断口表面通常在不同尺度上都很粗糙，理解粗糙度特性对于预测它们的滑动行为至关重要。本研究使用来自印度东部 Singhbhum 剪切带的天然岩石样本，开发了一种对剪切裂缝进行异质表面粗糙度分析的方法，形成了两个不同的区域：条纹各向异性区域和非条纹各向同性区域。在纯剪切条件下对脆性-延性模型进行的模拟实验产生了类似的剪切断裂的不均匀粗糙度特征。使用激光轮廓仪，我们构建了自然和实验剪切面的 3D 拓扑结构，这些拓扑结构用于显示条纹和非条纹区域在分形特性方面的独特粗糙度特征。ΔD代表横跨（D⊥ ）和沿（D∥ _{）滑移方向的}差值，计算其粗糙度各向异性的程度。 该分形参数表明条纹区具有ΔD = 0.0787–0.2118的强各向异性，明显较弱，其中ΔD  = 0.0024–0.0603 在非条纹区。最后，本文从实验室实验的剪切面上的滑移粘附运动学及其地球物理意义（例如，地震断层上地震事件模式的解释和裂隙岩石的渗透性）的角度深入讨论了这种粗糙度研究。