Abstract - Interaction and displacement transfer between active intersecting strike-slip (or transform) and extensional fault systems are examined. Outcrop data from a well preserved strike-slip fault and rift intersection in New Zealand are compared to a global dataset of 13 such intersections in both continental and oceanic crust. Displacement transfer between strike-slip and normal faults is typically accomplished by gradual changes of fault orientations and slip vectors close to the intersection zone. For two and three plate configurations these changes result in sub-parallelism of the slip vectors of the component faults with their line of intersection. The dimensions of the area over which fault-strike and slip vectors change is principally controlled by the extent to which displacements on the dominant of the two intersecting fault systems are confined to a single slip surface or distributed across a zone. Where slip is spatially distributed, the region in which the two displacement fields are superimposed produces transtension and associated oblique slip. This distributed off-fault deformation facilitates the development of a quasi-stable configuration of the fault intersection region, maintaining both the regional geometry and kinematics of the intersection zone which, in many cases, would not be possible for rigid-block translations. The dimensions of the transition zone are larger for continental crust than for oceanic crust because oceanic crust is thinner, fault geometries in oceanic crust are simpler two-plate configurations and the slip vectors of the component intersecting fault systems are sub-parallel.
Journal of Structural Geology, 29, 100-116, 2007.