Changes in direction of seafloor spreading revisited

Rotation and propagation have both been proposed as mechanisms by which spreading centers can reorient following changes in direction of seafloor spreading. The rotation hypothesis predicts a smooth asymmetric fanning of magnetic anomaly and abyssal hill orientations, whereas the propagation hypothesis predicts that the orientation changes will occur at abrupt discontinuities which are either failed rifts or pseudofaults. To test between these hypotheses, we conducted a detailed Sea Beam/magnetics/seismic reflection survey of the area where the direction of Pacific‐Farallon spreading changed between anomalies 24 and 22, just north of the major bend in the Surveyor fracture zone. The change in trend of seafloor fabric is abrupt, supporting the rift propagation hypothesis for spreading center reorientation.