An analysis of sea-surface magnetic profiles and an aeromagnetic contour chart west of Bermuda yields a new tectonic framework for the Keathley (M-series) seafloor spreading magnetic anomaly sequence. Changes in spreading direction derived from the western Keathley sequence occur at times corresponding to M24, M21 and M11, of which M11 is a time of continental breakup. The models facilitate new identifications of the anomalies between M16 and M4, obviating the need for anomalously slow spreading between M11 and M4, previously suggested by other workers and by us, and placing the location of the well-defined rough-smooth basement boundary at M11. The models show that spreading rates contemporaneously vary among profiles collected between flowlines as determined by a recently presented kinematic history. This strongly suggests that individual ridge axis segments act independently of another in detail. Our reconstruction technique records in map form where the ridge crest has made significant departures from perfect symmetry and a predictable spreading rate during its evolutionary history. Among eight profiles collected parallel to seafloor spreading flowlines in the western North Atlantic encompassing only 2700 km of “normal” oceanic crust we can identify more than fourteen ridge-jump events. There is evidence for a small (≈ 30 km) ridge jump to the east of many ridge axis segments at M24. This is supported in the eastern North Atlantic conjugate crust of the Canary basin where M25 and M24 are poorly represented. A series of four ridge jumps to the east along one paleoridge axis segment now located at 36°N, 65°W is related to the passage of the Mesozoic Mid-Atlantic Ridge crest over the Verde hotspot at ≈ 137 m.y. B.P. The Project Magnet magnetic anomaly contour chart for the area between 29° N and 40° N has been used to determine stage poles of motion for processes occurring at the ridge crest related to its segmentation, which have a component oblique to spreading between chrons M21 and M11. These trends may relate to the motion of the ridge crest over the mantle.