Fault-propagation folding in extensional settings: Examples of structural style and synrift sedimentary response from the Suez rift, Sinai, Egypt (vol 112, pg 1877, 2000)
Fault-propagation folding in extensional settings: Examples of structural style and synrift sedimentary response from the Suez rift, Sinai, Egypt (vol 112, pg 1877, 2000)
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伸展环境中的断层传播褶皱：埃及西奈苏伊士裂谷的结构样式和同裂谷沉积响应示例（第 112 卷，第 1877 页，2000 年）
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
Sanjeev K. Gupta
中科院分区：
文献类型：
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作者：
I. Sharp;R. Gawthorpe;J. Underhill;Sanjeev K. Gupta
苏伊士裂谷渐新世-中新世的野外资料表明，同时期的生长断裂、褶皱和转移带对共裂谷层序的发育起着主要的控制作用。苏伊士裂谷的生长褶皱与急倾正断层向上扩展有关，导致上覆地层形成宽的、向上加宽的单斜。断层扩展过程中的褶皱由泥岩层的层平行滑动和剥离以及从主断层向外扩展的正常和罕见的反向次级断层调节。主断层最终向地表延伸，在上盘留下了单斜的陡翼和大部分次级断层。这种演化的构造样式对同世辐合沉积的几何形态和堆积模式具有明显的控制作用。同裂谷沉积物向生长单斜和隐伏断裂方向表现为上覆不整合和层内不整合，而向远离生长单斜的宽向斜扩展段发散。通过隐伏断层的持续运动导致单斜分支和相关的辐合带沉积物的递进旋转，每一个较年轻的层序都以较浅的角度向盆地内倾斜。由此产生的剪切带几何形状与通常预期的靠近正断层的地层几何形状有很大不同。相堆积模式的沿走向变化也通常与断层和相关褶皱向低起伏转移带的位移减少有关。来自其他裂谷盆地的资料表明，断层传播褶皱并非苏伊西湾所独有。
Field data from the Oligocene–Miocene Gulf of Suez rift demonstrate that coeval growth faults, folds, and transfer zones exerted a major control on synrift stratigraphic sequence development. Growth folds in the Suez rift are related to steeply dipping normal faults that propagated upward, resulting in broad, upward-widening monoclines in overlying strata. Folding during fault propagation was accommodated by layer-parallel slip and detachment along mudstone horizons as well as by normal and rare reverse secondary faults that propagated away from the master fault. The eventual propagation of the master fault through to the surface left the steep limb of the monocline and most of the secondary faults in the hanging wall. This evolving structural style exerted a marked control on the geometry and stacking patterns of coeval synrift sediments. Synrift sediments display onlap and intraformational unconformities toward the growth monoclines and buried faults, whereas they diverge into broadly synclinal expanded sections away from the growth monocline. Continued movement across buried faults resulted in the progressive rotation of the monoclinal limb and associated synrift sediments, each successively younger sequence dipping basinward at a shallower angle than the previous one. The resulting synrift geometries differ significantly from stratal geometries normally anticipated adjacent to normal faults. Along-strike variations in facies stacking patterns are also commonly associated with decreasing displacement across faults and associated folds toward low-relief transfer zones. Data from other rift basins indicate that fault-propagation folds are not unique to the Gulf of Suez.