One of the many factors affecting the petroleum potential of thin-skinned thrust belts and their foreland plates is late orogenic normal, reverse, and strike-slip faulting, which occurs in the foreland plates and occasionally extends into the overlying thin-skinned thrust belts. This tectonism is typically active during the late stages of convergent orogeny, when subduction-driven thin-skinned thrusting ceases and the remaining convergence and geometric adjustment occur mainly within the foreland plate. The distribution, character, and orientation of particular structures generated during this collisional event, however, is to a great extent determined by the geometries of crustal blocks and orientations of preexisting faults and other weak zones within the foreland plates. As a result, despite the similar orogenic stress field, the dominant geometric expressions in various parts of the orogenic system may be different.
Because massive petroleum generation and migration in both the thrust belt and in the foreland plate commonly occur later in the orogenic phase, late orogenic faulting can critically affect the whole petroleum system, including the generation, migration, and preservation of hydrocarbons. The potential existence of late orogenic tectonics should then be examined thoroughly, especially when exploring for petroleum at deeper structural levels of thrust belts and the underlying foreland plates.
This is demonstrated by three examples from the Vienna Basin, Eastern Carpathians, and Dinarides-Hellenides, all parts of the European Alpine system. Several other examples, including the Rocky Mountain Laramide uplifts, the Eastern Cordillera in Colombia, and Timan-Pechora inverted structures in Russia, are mentioned to document the common occurrence of late orogenic faulting in orogenic systems.