Three-dimensional geometry and growth of a basement-involved fault network developed during multiphase extension, Enderby Terrace, North West Shelf of Australia
Three-dimensional geometry and growth of a basement-involved fault network developed during multiphase extension, Enderby Terrace, North West Shelf of Australia
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澳大利亚西北陆架恩德比台地多期伸展过程中发育的基底相关断层网络的三维几何结构和生长
DOI：
10.1130/b35779.1
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发表时间：
2021-01
期刊：
影响因子：
--
通讯作者：
Ken McClay
中科院分区：
文献类型：
--
作者：
Hongdan Deng;Ken McClay
基底断层的重新活动以及与新断层段的生长、相互作用和联系基本上是三维的，对于理解沉积盆地断层网络发育的演化至关重要。本文分析了澳大利亚西北陆架丹皮尔次盆地东缘恩德比台地复杂的、涉及基底的伸展断层网络的演化。高分辨率、深度转换的 3D 地震反射数据体用于表明基底相关断层的多相、倾斜伸展再活动控制了上覆地层中断层网络的发育。先前存在的断层的重新活动最初导致了上覆的、呈阶梯状的晚三叠世-中侏罗世断层段的形成，随着WNW方向的裂谷在边缘进行，这些断层段通过中继带的破裂而连接起来，形成两个相交的断层系统（F1和F2-F4）。最新侏罗纪-早白垩世（NNW-SSE延伸）的进一步重新激活在覆盖地层中产生了一组额外的阶梯状断层阵列。最终的断层网络由主要或主要断层和从属或分散断层以及连接各个组件的支线组成。我们的研究表明，中继坡道和/或垂直连接的破坏会产生垂直和水平分支线，从而产生复杂的最终断层几何形状。我们发现，基底相关断层的重复活动往往会形成连续的平面断层结构，有利于主要组成部分之间沿走向和深度的位移转移。
Basement fault reactivation, and the growth, interaction, and linkage with new fault segments are fundamentally three-dimensional and critical for understanding the evolution of fault network development in sedimentary basins. This paper analyzes the evolution of a complex, basement-involved extensional fault network on the Enderby Terrace on the eastern margin of the Dampier sub-basin, North West Shelf of Australia. A high-resolution, depth-converted, 3-D seismic reflection data volume is used to show that multiphase, oblique extensional reactivation of basement-involved faults controlled the development of the fault network in the overlying strata. Reactivation of the pre-existing faults initially led to the formation of overlying, en échelon Late Triassic−Middle Jurassic fault segments that, as WNW-directed rifting progressed on the margin, linked by breaching of relay zones to form two intersecting fault systems (F1 and F2−F4). Further reactivation in the latest Jurassic−Early Cretaceous (NNW-SSE extension) produced an additional set of en échelon fault arrays in the cover strata. The final fault network consists of main or principal faults and subordinate or splay faults, together with branch lines that link the various components. Our study shows that breaching of relay ramps and/or vertical linkages produces vertical and horizontal branch lines giving complex final fault geometries. We find that repeated activity of the basement-involved faults tends to form continuous and planar fault architectures that favor displacement transfer between the main constituent segments along strike and with depth.