OCEANIC TRANSVERSE RIDGES - A FLEXURAL RESPONSE TO FRACTURE-ZONE-NORMAL EXTENSION

One of the most puzzling characteristics of sea-floor morphology is th e occurrence of anomalously shallow, fracture-zone-parallel, oceanic t ransverse ridges. A model is proposed for the formation of transverse ridges near lat 21 degrees and 24 degrees N on the Mid-Atlantic Ridge in which the differential responses of large-offset and small-offset f racture zones to recent changes in spreading direction result in the g eneration of normal faults that coincide with the off-axis traces of f racture zones, Numerical models of the flexural response of the lithos phere to normal faulting suggest that modest amounts of extension (<5 km) along low-angle faults (<45 degrees) are responsible for the trans verse ridges.