Differential Fault-Related Early Miocene Sedimentation, Bayou Hebert Area, Southwestern Louisiana
Differential Fault-Related Early Miocene Sedimentation, Bayou Hebert Area, Southwestern Louisiana
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路易斯安那州西南部河口赫伯特地区与差异断层相关的早中新世沉积
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发表时间：
1988
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通讯作者：
R. P. McCulloh
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作者：
R. P. McCulloh
路易斯安那州西南部Bayou Hebert地区的测井资料表明，与同一断层带有关的大部分差异沉积不能归因于简单的扩张。相反，断层带下倾一侧的下中新统层序主要是通过沉积单元的幕式沉积而生长的，而在上覆一侧没有相关的对应单元。这些单元在断层附近厚达2000英尺(600米)，大多数在几公里的距离内横向不连续。孤立的下伏段位于层序中沿断裂带走向不同位置的不同位置，反映了下伏地块的沉降速率在横向和时间上的变化。这些间隔可能代表了断层上倾的侵蚀或沉积绕过的次数。断块上厚层段的隔离增加了意外储集单元的可能性，并可能促进与同期断裂和生长断层的沉积特征有关的组合圈闭的发育。多个横向相邻间隔的锥形边缘的重叠也可能在重叠区域产生小的弯曲结构。
Well logs from the Bayou Hebert area in southwestern Louisiana show that most of the differential sedimentation associated with one zone of contemporaneous faults cannot be attributed to simple expansion. Rather, the lower Miocene sequence on the downthrown side of the fault zone has grown principally by the episodic deposition of sedimentary units that have no correlative counterparts on the upthrown side. Such units range up to about 2,000 ft (600 m) thick near faults, and most are laterally discontinuous over distances of several kilometers. The isolated downthrown intervals lie in different parts of the sequence at various places along the strike of the fault zone, indicating lateral and temporal variation in subsidence rates in the downthrown block. The intervals may represent times of erosion or sediment bypass updip of faults. Isolation of thick intervals on the downthrown block adds potential for unexpected reservoir units and may enhance the development of combination traps associated with contemporaneous faulting and deposition characteristic of growth faults. Overlapping of the tapered edges of multiple laterally adjacent intervals may also create potential for small flexural structures in the areas of overlap.