Differential deformation and its main controls on strike-slip structures: Evidence from sandbox experiments

Strike-slip faults and associated structures have major influences on hydrocarbon accumulation and exploration. Pre-existing structures and the competence of sedimentary strata lead to differential deformation features and spatial distribution of strike-slip fault systems. The differential deformation of basement-involved strike-slip faults and the influence of incompetent layers on overlying layers were investigated using physical sandbox experiments. The displacement of basement-involved strike-slip faults controlled the deformation style and intensity of overlying layers. Lithology and cap rock thickness controlled strike-slip range and deformation intensity in shallow formations. The width of a strike-slip zone increased with incompetent layer thickness. Physical sandbox experiments showed that with contraction of strike-slip displacement, which kind of structural styles were formed, fold or fault block, was determined by the thickness of incompetent layer. The change of strike on basement fault caused extension or contraction stress fields. It is an important factor to control the segmentation of strike-slip faults and the differential deformation of vertical tectonics.