Topological analysis of networks of linear features has recently gained popularity in structural geology, as it provides a robust system of fracture network characterisation with consistent terminology. This approach has mainly been applied by using discontinuous sample areas to characterise topology of a region, or geological feature (e.g. Procter and Sanderson, 2018). We apply network topology to investigate spatial variation of a natural fracture network in the damage zone of the Castle Cove Fault, Otway Basin, Victoria. The Castle Cove Fault's associated fracture network occurs in the hanging-wall Eumeralla Formation, a fine-to medium-grained volcanogenic sandstone or Early Cretaceous age. Topological characterisation of the Castle Cove Fault damage-zone identified an increase in the two-dimensional intensity of fracturing in the hanging-wall at a distance 70 m from the fault, reaching a maximum ~40 m from the fault, indicating the extent of the fault-damage zone is between 40 and 70 m from the main fault. Maximum fracture intensity values decay with a power law relationship with respect to distance from the fault plane, averaging ~0.06 adjacent to the fault, and ~0.02 within what is interpreted as the regional fracture network, 70 m + outboard of the fault. Fracture orientations in the damage zone are synthetic and antithetic with respect to the ~60° dip to the NW of the of the Castle Cove Fault, with these fault-related fractures overprinting an existing regional fracture network, creating high fracture network connectivity within the fault-damage zone. Our results show that network topology is a powerful tool for quantifying and visualising the properties of fracture networks associated with crustal-scale faults.

线性特征网络的拓扑分析最近在结构地质学中变得越来越流行，因为它提供了具有一致术语的强大的裂缝网络表征系统。这种方法主要是通过使用不连续的样本区域来表征区域拓扑或地质特征（例如，Procter and Sanderson，2018）。我们应用网络拓扑研究维多利亚州奥特韦盆地Castle Cove断层破坏区自然裂缝网络的空间变化。城堡湾断层的相关裂隙网络发生在上壁的Eumeralla组中，这是一种细到中粒的火山成因砂岩或早白垩纪。城堡湾断层破坏带的拓扑特征表明，距断层70 m处的悬壁二维断裂强度增加，距断层最大约40 m，表明了断层的程度。断层破坏带距主断层40至70 m。最大断裂强度值以幂律关系相对于距断层平面的距离衰减，平均为断层附近〜0.06，在断层外侧70 m +处被解释为区域性断裂网的内部为〜0.02。相对于Castle Cove断层的西北方向约60°的倾角，损伤区内的断裂方向是合成的和对立的，这些与断层有关的裂缝覆盖了现有的区域性裂缝网络，在断层破坏区域内建立较高的裂缝网络连通性。我们的结果表明，网络拓扑是量化和可视化与地壳尺度断层有关的裂缝网络特性的有力工具。