Oblique slip and the geometry of normal-fault linkage: mechanics and a case study from the Basin and Range in Oregon

Evolution of vertical faults at an extensional plate boundary, southwest Iceland

“…Left-stepping, échelon fracture segments are common at Vogar, and are indicative of localized stress perturbations associated with right-lateral oblique slip along the upper tip line of a subsurface normal fault (Pollard et al, 1982;Schlische et al, 2002). Furthermore, the prevalent pattern of segment linkages, forming upper ramp breaches across relay zones, is consistent with right-lateral oblique slip along a left-stepping échelon fracture zone (Crider, 2001). Considering that normal faults form with strike orientations perpendicular to the least compressive principal stress direction, the right-lateral oblique slip motion suggested by the pattern of surface fracturing implies a clockwise rotation of the stress field between the time of initial normal fault growth at depth and the development of the surface fracture zones.…”

“…The program has been used in several previous studies of geological problems involving faulting (Willemse et al, 1996;Willemse, 1997;Crider and Pollard, 1998;Pollard, 1999, 2001;Kattenhorn et al, 2000;Maerten, 2000;Maerten et al, 2000Maerten et al, , 2002Crider, 2001). The program is based on the governing equations of linear elastic fracture mechanics for homogeneous and isotropic solids.…”

“…Overlapping fault segments are typically hard-linked by joints that propagated from the tip of the segment on the footwall side of the overlap zone to intersect the segment on the hanging wall side. This is an upper ramp breach, using the terminology of Crider (2001), and resulted in a throughgoing normal fault.…”

Structural style in a young flexure-induced oblique extensional system, north-western Bonaparte Basin, Australia

“…In addition, the upper ramp breach of left-stepping en echelon faults (Figs. 12 and 13) that requires right-lateral oblique slip (Crider, 2001), is opposite to what was proposed for Timor Sea region. Nevertheless, southwest of the BrowseeBonaparte Transition (O'Brien, 1993;Elliott, 1994), wrench-dominated stresses may potentially explain the Neogene-Recent deformation (Keep et al, 2002;Harrowfield et al, 2003;Keep et al, 2007).…”

Sampling the uncertainty associated with segmented normal fault interpretation using a stochastic downscaling method

“…Moreover, many studies highlight relationships between overlap zone dimension and linkage maturity (Crider, 2001;Crider and Pollard, 1998;Soliva and Benedicto, 2004). The geometry and displacement of 39 centimeter-to-meter-scale relay ramps are studied by Soliva and Benedicto (2004) and grouped in three categories:…”