DISTINCT ELEMENT MODELING OF STRUCTURES FORMED IN SEDIMENTARY OVERBURDEN BY EXTENSIONAL REACTIVATION OF BASEMENT NORMAL FAULTS

Fault and fold patterns in sedimentary rocks have been modeled using a computer code based on the distinct element method (DEM). This numerical method considers the relative motion of disconnected classic elements governed by Newton's laws and frictional sliding criteria. Forces are transmitted between elements at contact points. By changing element size ratios, assemblages of elements can simulate different kinematic behavior from localized faulting to distributed flow. As an application of the method, we investigate folding and faulting patterns that develop in the sedimentary overburden above basement normal faults. The number, position, orientation, and sense of slip on faults as well as the fold geometry depend on the basement fault dip and basement rotation. The DEM model results have practical implications for predicting the evolving characteristics of structural traps and their petroleum potential.