Detachment fault system associated with a mature metamorphic core complex (MCC) is still not well understood. Using high‐resolution 3D seismic data, we analyse the geometries and kinematic development of detachment fault system associated with a mature and exhumated MCC in the northern South China Sea rifted margin, with an emphasis on the MCC‐associated faults within the supra‐detachment basin. Faults within the supra‐detachment basin can be classified into three stages, the pre‐MCC, syn‐MCC and post‐MCC faults, based on their formation time relative to the MCC. The NE to NEE‐striking pre‐MCC faults developed in the early syn‐rift 1 stage, and the NW to WNW‐striking post‐MCC faults were both dominated by the regional tectonics and are perpendicular to the extension directions. While the syn‐MCC faults, synchronous with the MCC development in the late syn‐rift 1 stage, show overall EW‐striking, consistent with the long axis of the KP MCC. These syn‐MCC faults were well developed and are significant in shaping the basin architecture. Besides, the syn‐MCC faults are regularly distributed in the four zones overlying the convex‐upward master detachment fault surface, and are defined in this study as a synthetic fault zone, an upper collapse synformal‐graben fault zone, a lower collapse antiformal‐graben fault zone and an antithetic fault zone respectively. These four fault zones show distinct features and evolutionary patterns, and have a closed relationship with the rolling‐hinge process of the KP MCC. An evolutionary model is established for the development of MCC‐associated detachment fault system which should have global implications.

中文翻译：

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与成熟变质岩心杂岩体相关的分离断裂系统发育——来自南海北部开平凹陷裂谷缘的洞察


与成熟变质岩心杂岩体 （MCC） 相关的分离断层系统仍不十分了解。使用高分辨率 3D 地震数据，我们分析了与南海北部裂谷边缘成熟和挖掘的 MCC 相关的分离断层系统的几何形状和运动学发展，重点是上分离盆地内的 MCC 相关断层。上脱离盆地内的断层可根据它们相对于 MCC 的形成时间分为三个阶段，即 MCC 前、syn-MCC 和 MCC 后断层。NE 至 NEE 走向的 MCC 前断层发育于早期 syn-rift 1 阶段，NW 至 WNW 走向的 MCC 后断层均受区域构造主导，并垂直于延伸方向。而 syn-MCC 断层与 syn-rift 1 晚期的 MCC 发展同步，总体上呈现 EW 走向，与 KP MCC 的长轴一致。这些 syn-MCC 断层发育良好，对塑造盆地结构具有重要意义。此外，syn-MCC 断层规则分布在凸向上的主分离断面上方的 4 个带中，本研究分别定义为合成断裂带、上部塌陷同形地堑断裂带、下部塌状反地堑断裂带和对立断裂带。这四个断层带表现出不同的特征和演化模式，并与 KP MCC 的滚动铰链过程有着密切的关系。为 MCC 相关分离断层系统的发展建立了一个进化模型，该模型应该具有全球意义。