Ridge jump reorientation of the South China Sea revealed by high‐resolution magnetic data

Abstract We establish a high‐resolution magnetic isochron pattern in the East Subbasin (ESB) of the South China Sea (SCS) based on recently collected magnetic data, which provides an updated age of seafloor spreading in the ESB and reveals a new type of ridge reorientation. Seafloor spreading in the ESB initiated at Chron 11n.1r (29.7 Ma) and ceased shortly after Chron 5Br (15.6 Ma). Successive ridge jumps occurred between Chrons 9r and 7n, which explains the substantial asymmetric geometry of the ESB. Furthermore, the ridge reorientation associated with ridge jumps highlights a new ridge reorientation model in which the ridge jumps off‐axis and reorients synchronously to adapt to the new direction of seafloor spreading. In the ESB, this type of reorientation responds more rapidly to changes in the direction of plate motion than gradual ridge rotation.