Layer-parallel Shortening Templates Associated with Double-edge Fault-propagation Folding
Pressure-solution cleavage is frequently among the most abundant mesostructures in carbonate thrust wedges. It can exert a primary function in fluid migration, and consequently, understanding its time-space evolution can significantly impact the reservoir modeling and performance. The evidence that pressure-solution cleavage is commonly at a high angle to bedding and, in many cases, displays a frequency distribution relating to the host-fold geometry indicates a partial synfolding development driven by fault-fold kinematics. Double-edge fault-propagation folding assumes layer-parallel shortening during fold evolution. Accordingly, this model can provide a tool for inferring the distribution of pressure-solution cleavage within thrust-related folds that, under appropriate stress conditions, can significantly improve secondary porosity and permeability in reservoirs.
We summarize the pressure-solution cleavage pattern in three anticlines that have possibly developed by double-edge fault-propagation folding, and then we analyze the deformation patterns associated with double-edge fault-propagation folding, investigating the influence of different model parameters (i.e., ramp propagation history, shape, and initial length) onto the cross-sectional deformation pattern in fault-propagation anticlines. Modeling results indicate that, in carbonate thrust wedges, forelimb panels and footwall sectors close to the thrust ramp can provide promising targets for hydrocarbon exploration.