A new compilation of magnetic anomaly identifications, recent side scan sonar data, and other data provide constraints on the mechanism of deformation of the area commonly known as the Gorda plate. A sharp boundary between the rigid Juan de Fuca plate and deformed material trends southeast from the northern part of the Gorda ridge. In material older than 2--3 Ma, the boundary is gradiational and trends more to the east. Previous observations that the anomalies east of the ridge are shorter than their counterparts on the Pacific plate are confirmed. There is no evidence for subduction or obduction along the Mendocino transform. Adjacent to the ridge, the deformation is interpreted to be distributed NW-SE right-lateral simple shear, possibly controlled by ductile deformation of the lower crust. Deformation of this sense is capable of producing the observed shortening the anomalies. Away from the ridge, apparently in crust of age 2--3 Ma, there must be a transition to deformation on observed NE-SW left-lateral faults parallel to the original spreading fabric. ¿ American Geophysical Union 1989