Each frame is a reconstruction of a predicted isochron-pattern "snapshot" from our 16 mm computer graphic movie depicting plate tectonic and propagating rift evolution in the Juan de Fuca area. The reconstructions are at 1-million year intervals beginning at 29 million years before present with isochrons at 2-million year intervals. These images are from Hey and Wilson (1982). For a version with a soundtrack explaining the evolution of this system, click here.

Summary diagram of total-field magnetic anomalies southwest of Vancouver Island. Areas of positive anomalies (normal magnetization) are colored. These areas duplicate the reversal time scale, hence implying ages for the underlying crust as indicated. Central red anomalies coincide with ridge crests; Juan de Fuca to the north and Gorda to the south. Straight lines delineate faults (NB: the ones oblique to the transform fault connecting the Juan de Fuca and Gorda ridges are now known to be pseudofaults) offsetting the anomaly pattern. Figure from Vine (1968), with caption modified.