When extension events are greatly separated in time, older faults may be buried and stratigraphically separated from newly developing faults at shallower depths. During rifting, the buried structures may reactivate and propagate upwards to be expressed within the shallow system. The degree of linkage between structural levels determines the influence that the deeper structures can exert over the geometry and evolution of the incipient fault system. In this study we use 3D seismic reflection data to examine how a deep fault population across the Laminaria High, NW shelf of Australia influences the development of a younger fault system at shallow depths. These fault populations are non-parallel and decoupled across a mechanically weak interval. The majority of shallow faults are not linked to those at depth. However, the reactivation and upward propagation of some of the deeper faults produce anomalously oriented structures at shallow depths, hard-linked to the deeper structures. One fault in particular shows along-strike variability, with the deep segment reactivated and present at shallow depths in the west. To the east, the shallow and deep fault segments become decoupled across the mechanically weak interval, although some soft-linkage and strain transfer still occurs. We suggest that this switch in the degree of coupling along the fault is due to the geometry of the deeper structure, with the transition corresponding to a prominent relay ramp. We show how the geometry of a deeper fault may affect its propensity to reactivate during subsequent extensional events, ultimately affecting the degree of structural inheritance that is expressed within younger, shallower fault populations.

中文翻译：

---

垂直分离的断层种群之间变量解耦对结构遗传的影响——澳大利亚西北大陆架海带高地

当伸展事件在时间上大大分开时，较老的断层可能被埋藏并在地层上与较浅深度的新发育断层分开。在裂谷过程中，埋藏结构可能会重新激活并向上传播以在浅层系统内表现出来。构造层级之间的联系程度决定了深层构造对初始断层系统的几何形状和演化的影响。在这项研究中，我们使用 3D 地震反射数据来研究澳大利亚西北海陆架的深层断层群如何影响浅层较年轻断层系统的发展。这些断层群是不平行的，并且在机械薄弱的区间内解耦。大多数浅层断层与深层断层无关。然而，一些较深断层的重新激活和向上扩展在浅层产生了异常定向的结构，与较深的结构紧密相连。一个断层特别显示了沿走向的变化，深段重新激活并出现在西部的浅层深处。在东部，浅层和深层断层段在机械薄弱层段上变得分离，尽管仍然发生一些软连接和应变传递。我们认为这种沿断层耦合程度的转换是由于较深结构的几何形状，过渡对应于一个突出的继电器斜坡。我们展示了更深断层的几何形状如何影响其在随后的伸展事件中重新激活的倾向，最终影响在年轻人中表达的结构继承程度，