Intratransform Origins of Mid-ocean Ridge Microplates

We present evidence that the Easter and Juan Fernandez microplates originated by rift propagation from within transform fault zones at locations far from ridge-transform intersections. An intratransform spreading center may have served as the focal point for each new propagation. Both events appear coincident with a circum-Pacific plate reorganization dated at 5.6 Ma, which may have been related to a change in Pacific absolute plate motion and a counterclockwise rotation of Pacific-Nazca relative plate motion. This intratransform model may be applicable to the generation of other microplates and may thus serve as a general model for microplate origins.