Two-dimensional, plane-strain finite element numerical models produce small normal faults similar to those formed during the Oligocene to Miocene of the salt-cored St. Malo anticline in the deepwater Gulf of Mexico. The mechanical stratigraphy used in the models was derived from well data and a rate-independent, elastic-plastic constitutive model with a non-associated flow rule was used to represent the behavior of weak, over-consolidated rocks. Motion of salt is modeled by displacing the base of the overburden from an initially flat configuration to the observed present-day geometry. Model results using dominantly vertical displacement with minor extension (2%) are consistent with observed faulting at St. Malo. Small amounts of contraction (2–5%) in the numerical model suppress normal faulting whereas 2% extension best reproduces the observed structural style. The normal faults develop during elastic-plastic bending and evolve from sub-vertical, plastic mode-I failure zones to dominantly inclined normal faults. Throws of normal faults produced by the numerical models range from 11 m to 123 m. By comparison, the throws observed in the crest of the St. Malo anticline range from 30 m to 300 m. Models only using vertical displacement develop normal faults with ≤50 m throws due to bending; these are below seismic resolution. Only models with ≥2% extension develop normal faults that would be detectible (i.e., throws ≥50 m). A constraint of all the models is that the top of the salt is not faulted. The maximum depth of normal faulting in the models is ca. 900 m below the top of the reservoir. The maximum throws at the top of the reservoir in the models are ca. 30–65 m. Initiation of the normal faults as plastic mode-I failure zones in the numerical models suggests a mechanism that could facilitate early seal breach, even without juxtaposition of stratal leak points.

二维平面应变有限元数值模型产生的小正断层类似于墨西哥深水湾盐芯圣马洛背斜渐新世至中新世期间形成的小断层。模型中使用的机械地层学来自井数据，并且使用具有非关联流动规则的与速率无关的弹塑性本构模型来表示弱、过度固结岩石的行为。盐的运动是通过将覆盖层的底部从最初的平坦配置移动到现在观察到的几何形状来模拟的。使用主要垂直位移和少量延伸 (2%) 的模型结果与在圣马洛观察到的断层一致。数值模型中的少量收缩（2-5%）抑制了正常断层，而 2% 的伸展最好地再现了观察到的结构样式。正断层在弹塑性弯曲过程中发育，并从亚垂直的塑性Ⅰ型破坏区演变为以倾斜为主的正断层。数值模型产生的正断层抛距范围从 11 m 到 123 m。相比之下，在 St. Malo 背斜顶部观察到的抛掷范围从 30 m 到 300 m。仅使用垂直位移的模型由于弯曲而发展出小于 50 m 的正断层；这些都低于地震分辨率。只有具有 ≥2% 延伸的模型会产生可检测的正常故障（即，投掷 ≥50 m）。所有模型的一个约束是盐的顶部没有故障。模型中正常断层的最大深度约为。水库顶部以下 900 m。模型中水库顶部的最大投掷量约为。30-65 米。在数值模型中将正断层作为塑性模式 I 破坏区的起始表明了一种可以促进早期密封破坏的机制，即使没有并列地层泄漏点也是如此。