Abstract In the Brachina–Bunyeroo area of the Flinders Ranges, South Australia, the lower Cambrian Hawker Group and the overlying Billy Creek Formation, are affected by two clearly defined fault systems. The southern, the Manga Fault System, was initially a synsedimentary fault-flexure. Movement commenced in post-lower Wilkawillina Limestone time and produced a fault-flexure zone separating a depocentre to the south and relative uplift to the north, causing thickness and facies changes in the Wilkawillina Limestone on the down-dropped southern side. Mernmerna Formation deep-water limestones were deposited south of the fault, but not to the north. Oraparinna Shale, up to 400 m thick, was deposited south of the fault, thinning northwards to <200 m across the fault and onlapping the flexure zone north of the fault. The stable archaeocyath reef-tract of the Wilkawillina Limestone north of the fault is covered only by a few metres of Oraparinna Shale. Later movements on the Manga Fault System produced thrust-style displacements, repeating the overlying Billy Creek Formation and Wirrealpa Limestone. In contrast, the Brachina Fault System to the north was only active in the uppermost Hawker Group time and no thickness or facies changes occur across it within the Hawker Group. Uplift of the southern shoulder of the Brachina Fault System, however, allowed erosion of the uppermost part of the Hawker Group, so that Billy Creek Formation disconformably overlies Wilkawillina Limestone; major movement along the Brachina Fault System occurred during Billy Creek Formation deposition. Fault activity had ceased prior to deposition of the Wirrealpa Limestone as this is not displaced by the Brachina Fault System.

中文翻译：

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南澳大利亚弗林德斯山脉中西部 Brachina-Bunyeroo 地区下寒武纪霍克群内沉积的构造控制

摘要 在南澳大利亚弗林德斯山脉的 Brachina-Bunyeroo 地区，下寒武纪霍克群和上覆的比利溪组受到两个明确界定的断层系统的影响。南部的 Manga 断层系统最初是一个同沉积断层弯曲。运动开始于后下威尔卡维利纳石灰岩时代，并产生了一个断层弯曲带，将南部的沉积中心与北部的相对隆起分开，导致下降的南侧威尔卡威利纳石灰岩的厚度和相变化。Mermmerna 组深水石灰岩沉积在断层以南，但未沉积到北。高达 400 m 厚的 Oraparinna 页岩沉积在断层以南，向北变薄至 <200 m 穿过断层并与断层以北的弯曲带重叠。断层以北的 Wilkawillina 石灰岩稳定的古生物礁带仅被几米的 Oraparinna 页岩覆盖。Manga 断层系统的后期运动产生了推力式位移，重复了上覆的比利溪组和 Wirrealpa 石灰岩。相比之下，北部的 Brachina 断层系统仅在最上层的霍克群时间活跃，在霍克群内没有发生厚度或相变化。然而，Brachina 断层系统南肩部的隆升使 Hawker Group 的最上部受到侵蚀，因此 Billy Creek 组不整合地覆盖在 Wilkawillina 石灰岩上；沿 Brachina 断层系统的主要运动发生在 Billy Creek 地层沉积期间。